A road map that misses some turns

A review of No Miracles Needed

Also published on Resilience

Mark Jacobson’s new book, greeted with hosannas by some leading environmentalists, is full of good ideas – but the whole is less than the sum of its parts.

No Miracles Needed, by Mark Z. Jacobson, published by Cambridge University Press, Feb 2023. 437 pages.

The book is No Miracles Needed: How Today’s Technology Can Save Our Climate and Clean Our Air (Cambridge University Press, Feb 2023).

Jacobson’s argument is both simple and sweeping: We can transition our entire global economy to renewable energy sources, using existing technologies, fast enough to reduce annual carbon dioxide emissions at least 80% by 2030, and 100% by 2050. Furthermore, we can do all this while avoiding any major economic disruption such as a drop in annual GDP growth, a rise in unemployment, or any drop in creature comforts. But wait – there’s more! In so doing, we will also completely eliminate pollution.

Just don’t tell Jacobson that this future sounds miraculous.

The energy transition technologies we need – based on Wind, Water and Solar power, abbreviated to WWS – are already commercially available, Jacobson insists. He contrasts the technologies he favors with “miracle technologies” such as geoengineering, Carbon Capture Storage and Utilization (CCUS), or Direct Air Capture of carbon dioxide (DAC). These latter technologies, he argues, are unneeded, unproven, expensive, and will take far too long to implement at scale; we shouldn’t waste our time on such schemes.  

The final chapter helps to understand both the hits and misses of the previous chapters. In “My Journey”, a teenage Jacobson visits the smog-cloaked cities of southern California and quickly becomes aware of the damaging health effects of air pollution:

“I decided then and there, that when I grew up, I wanted to understand and try to solve this avoidable air pollution problem, which affects so many people. I knew what I wanted to do for my career.” (No Miracles Needed, page 342)

His early academic work focused on the damages of air pollution to human health. Over time, he realized that the problem of global warming emissions was closely related. The increasingly sophisticated computer models he developed were designed to elucidate the interplay between greenhouse gas emissions, and the particulate emissions from combustion that cause so much sickness and death.

These modeling efforts won increasing recognition and attracted a range of expert collaborators. Over the past 20 years, Jacobson’s work moved beyond academia into political advocacy. “My Journey” describes the growth of an organization capable of developing detailed energy transition plans for presentation to US governors, senators, and CEOs of major tech companies. Eventually that led to Jacobson’s publication of transition road maps for states, countries, and the globe – road maps that have been widely praised and widely criticized.

In my reading, Jacobson’s personal journey casts light on key features of No Miracles Needed in two ways. First, there is a singular focus on air pollution, to the omission or dismissal of other types of pollution. Second, it’s not likely Jacobson would have received repeat audiences with leading politicians and business people if he challenged the mainstream orthodox view that GDP can and must continue to grow.

Jacobson’s road map, then, is based on the assumption that all consumer products and services will continue to be produced in steadily growing quantities – but they’ll all be WWS based.

Does he prove that a rapid transition is a realistic scenario? Not in this book.

Hits and misses

Jacobson gives us brief but marvelously lucid descriptions of many WWS generating technologies, plus storage technologies that will smooth the intermittent supply of wind- and sun-based energy. He also goes into considerable detail about the chemistry of solar panels, the physics of electricity generation, and the amount of energy loss associated with each type of storage and transmission.

These sections are aimed at a lay readership and they succeed admirably. There is more background detail, however, than is needed to explain the book’s central thesis.

The transition road map, on the other hand, is not explained in much detail. There are many references to scientific papers in which he outlines his road maps. A reader of No Miracles Needed can take Jacobson’s word that the model is a suitable representation, or you can find and read Jacobson’s articles in academic journals – but you don’t get the needed details in this book.

Jacobson explains why, at the level of a device such as a car or a heat pump, electric energy is far more efficient in producing motion or heat than is an internal combustion engine or a gas furnace. Less convincingly, he argues that electric technologies are far more energy-efficient than combustion for the production of industrial heat – while nevertheless conceding that some WWS technologies needed for industrial heat are, at best, in prototype stages.

Yet Jacobson expresses serene confidence that hard-to-electrify technologies, including some industrial processes and long-haul aviation, will be successfully transitioning to WWS processes – perhaps including green hydrogen fuel cells, but not hydrogen combustion – by 2035.

The confidence in complex global projections is often jarring. For example, Jacobson tells us repeatedly that the fully WWS energy system of 2050 “reduces end-use energy requirements by 56.4 percent” (page 271, 275).1 The expressed precision notwithstanding, nobody yet knows the precise mix of storage types, generation types, and transmission types, which have various degrees of energy efficiency, that will constitute a future WWS global system. What we should take from Jacobson’s statements is that, based on the subset of factors and assumptions – from an almost infinitely complex global energy ecosystem – which Jacobson has included in his model, the calculated outcome is a 56% end-use energy reduction.

Canada’s Premiers visit Muskrat Falls dam construction site, 2015. Photo courtesy of Government of Newfoundland and Labrador; CC BY-NC-ND 2.0 license, via Flickr.

Also jarring is the almost total disregard of any type of pollution other than that which comes from fossil fuel combustion. Jacobson does briefly mention the particles that grind off the tires of all vehicles, including typically heavier EVs. But rather than concede that these particles are toxic and can harm human and ecosystem health, he merely notes that the relatively large particles “do not penetrate so deep into people’s lungs as combustion particles do.” (page 49)

He claims, without elaboration, that “Environmental damage due to lithium mining can be averted almost entirely.” (page 64) Near the end of the book, he states that “In a 2050 100 percent WWS world, WWS energy private costs equal WWS energy social costs because WWS eliminates all health and climate costs associated with energy.” (page 311; emphasis mine)

In a culture which holds continual economic growth to be sacred, it would be convenient to believe that business-as-usual can continue through 2050, with the only change required being a switch to WWS energy.

Imagine, then, that climate-changing emissions were the only critical flaw in the global economic system. Given that assumption, is Jacobson’s timetable for transition plausible?

No. First, Jacobson proposes that “by 2022”, no new power plants be built that use coal, methane, oil or biomass combustion; and that all new appliances for heating, drying and cooking in the residential and commercial sectors “should be powered by electricity, direct heat, and/or district heating.” (page 319) That deadline has passed, and products that rely on combustion continue to be made and sold. It is a mystery why Jacobson or his editors would retain a 2022 transition deadline in a book slated for publication in 2023.

Other sections of the timeline also strain credulity. “By 2023”, the timeline says, all new vehicles in the following categories should be either electric or hydrogen fuel-cell: rail locomotives, buses, nonroad vehicles for construction and agriculture, and light-duty on-road vehicles. This is now possible only in a purely theoretical sense. Batteries adequate for powering heavy-duty locomotives and tractors are not yet in production. Even if they were in production, and that production could be scaled up within a year, the charging infrastructure needed to quickly recharge massive tractor batteries could not be installed, almost overnight, at large farms or remote construction sites around the world.

While electric cars, pick-ups and vans now roll off assembly lines, the global auto industry is not even close to being ready to switch the entire product lineup to EV only. Unless, of course, they were to cut back auto production by 75% or more until production of EV motors, batteries, and charging equipment can scale up. Whether you think that’s a frightening prospect or a great idea, a drastic shrinkage in the auto industry would be a dramatic departure from a business-as-usual scenario.

What’s the harm, though, if Jacobson’s ambitious timeline is merely pushed back by two or three years?

If we were having this discussion in 2000 or 2010, pushing back the timeline by a few years would not be as consequential. But as Jacobson explains effectively in his outline of the climate crisis, we now need both drastic and immediate actions to keep cumulative carbon emissions low enough to avoid global climate catastrophe. His timeline is constructed with the goal of reducing carbon emissions by 80% by 2030, not because those are nice round figures, but because he (and many others) calculate that reductions of that scale and rapidity are truly needed. Even one or two more years of emissions at current rates may make the 1.5°C warming limit an impossible dream.

The picture is further complicated by a factor Jacobson mentions only in passing. He writes,

“During the transition, fossil fuels, bioenergy, and existing WWS technologies are needed to produce the new WWS infrastructure. … [A]s the fraction of WWS energy increases, conventional energy generation used to produce WWS infrastructure decreases, ultimately to zero. … In sum, the time-dependent transition to WWS infrastructure may result in a temporary increase in emissions before such emissions are eliminated.” (page 321; emphasis mine)

Others have explained this “temporary increase in emissions” at greater length. Assuming, as Jacobson does, that a “business-as-usual” economy keeps growing, the vast majority of goods and services will continue, in the short term, to be produced and/or operated using fossil fuels. If we embark on an intensive, global-scale, rapid build-out of WWS infrastructures at the same time, a substantial increment in fossil fuels will be needed to power all the additional mines, smelters, factories, container ships, trucks and cranes which build and install the myriad elements of a new energy infrastructure. If all goes well, that new energy infrastructure will eventually be large enough to power its own further growth, as well as to power production of all other goods and services that now rely on fossil energy.

Unless we accept a substantial decrease in non-transition-related industrial activity, however, the road that takes us to a full WWS destination must route us through a period of increased fossil fuel use and increased greenhouse gas emissions.

It would be great if Jacobson modeled this increase to give us some guidance how big this emissions bump might be, how long it might last, and therefore how important it might be to cumulative atmospheric carbon concentrations. There is no suggestion in this book that he has done that modeling. What should be clear, however, is that any bump in emissions at this late date increases the danger of moving past a climate tipping point – and this danger increases dramatically with every passing year.

1In a tl;dr version of No Miracles Needed published recently in The Guardian, Jacobson says “Worldwide, in fact, the energy that people use goes down by over 56% with a WWS system.” (“‘No miracles needed’: Prof Mark Jacobson on how wind, sun and water can power the world”, 23 January 2023)

 

Photo at top of page by Romain Guy, 2009; public domain, CC0 1.0 license, via Flickr.

Dreaming of clean green flying machines

Also published on Resilience

In common with many other corporate lobby groups, the International Air Transport Association publicly proclaims their commitment to achieving net-zero carbon emissions by 2050.1

Yet the evidence that such an achievement is likely, or even possible, is thin … to put it charitably. Unless, that is, major airlines simply shut down.

As a 2021 Nova documentary put it, aviation “is the high-hanging fruit – one of the hardest climate challenges of all.”2 That difficulty is due to the very essence of the airline business.

What has made aviation so attractive to the relatively affluent people who buy most tickets is that commercial flights maintain great speed over long distances. Aviation would have little appeal if airplanes were no faster than other means of transportation, or if they could be used only for relatively short distances. These characteristics come with rigorous energy demands.

A basic challenge for high-speed transportation – whether that’s pedaling a bike fast, powering a car fast, or propelling an airplane fast – is that the resistance from the air goes up with speed, not linearly but exponentially. As speed doubles, air resistance quadruples; as speed triples, air resistance increases by a factor of nine; and so forth.

That is one fundamental reason why no high-speed means of transportation came into use until the fossil fuel era. The physics of wind resistance become particularly important when a vehicle accelerates up to several hundred kilometers per hour or more.

Contemporary long-haul aircraft accommodate the physics in part by flying at “cruising altitude” – typically about 10,000 meters above sea level. At that elevation the atmosphere is thin enough to cause significantly less friction, while still rich enough in oxygen for combustion of the fuel. Climbing to that altitude, of course, means first fighting gravity to lift a huge machine and its passengers a very long way off the ground.

A long-haul aircraft, then, needs a high-powered engine for climbing, plus a large store of energy-dense fuel to last through all the hours of the flight. That represents a tremendous challenge for inventors hoping to design aircraft that are not powered by fossil fuels.

In Nova’s “The Great Electric Airplane Race”, the inherent problem is illustrated with this graphic:

graphic from Nova, “The Great Electric Airplane Race,” 26 May 2021

A Boeing 737 can carry up to 40,000 pounds of jet fuel. For the same energy content, the airliner would require 1.2 million pounds of batteries (at least several times the maximum take-off weight of any 737 model3). Getting that weight off the ground, and propelling it thousands of miles through the air, is obviously not going to work.

A wide variety of approaches are being tried to get around the drastic energy discrepancy between fossil fuels and batteries. We will consider several such strategies later in this article. First, though, we’ll take a brief look at the strategies touted by major airlines as important short-term possibilities.

“Sustainable fuel” and offsets

The International Air Transport Association gives the following roadmap for its commitment to net-zero by 2050. Anticipated emissions reductions will come in four categories:
3% – Infrastructure and operational efficiencies
13% – New technology, electric and hydrogen
19% – Offsets and carbon capture
65% – Sustainable Aviation Fuel

The tiny improvement predicted for “Infrastructure and operational efficiencies” reflects the fact that airlines have already spent more than half a century trying to wring the most efficiency out of their most costly input – fuel.

The modest emission reductions predicted to come from battery power and hydrogen reflects a recognition that these technologies, for all their possible strengths, still appear to be a poor fit for long-haul aviation.

That leaves two categories of emission reductions, “Offsets and carbon capture”, and “Sustainable Aviation Fuel”.

So-called Sustainable Aviation Fuel (SAF) is compatible with current jet engines and can provide the same lift-off power and long-distance range as fossil-derived aviation fuel. SAF is typically made from biofuel feedstocks such as vegetable oils and used cooking oils. SAF is already on the market, which might give rise to the idea that a new age of clean flight is just around the corner. (No further away, say, than 2050.)

Yet as a Comment piece in Nature* notes, only .05% of fuel currently used meets the definition of SAF.4 Trying to scale that up to meet most of the industry’s need for fuel would clearly result in competition for agricultural land. Since growing enough food to feed all the people on the ground is an increasingly difficult challenge, devoting a big share of agricultural production to flying a privileged minority of people through the skies is a terrible idea.5

In addition, it’s important to note that the burning of SAF still produces carbon emissions and climate-impacting contrails. The use of SAF is only termed “carbon neutral” because of the assumption that the biofuels are renewable, plant-based products that would decay and emit carbon anyway. That’s a dubious assumption, when there’s tremendous pressure to clear more forests, plant more hectares into monocultures, and mine soils in a rush to produce not only more food for people, but also more fuel for wood-fired electric generating stations, more ethanol to blend with gasoline, more biofuel diesel, and now biofuel SAF too. When SAF is scaled up, there’s nothing “sustainable” about it.

What about offsets? My take on carbon offsets is this: Somebody does a good thing by planting some trees. And then, on the off chance that these trees will survive to maturity and will someday sequester significant amounts of carbon, somebody offsets those trees preemptively by emitting an equivalent amount of carbon today.

Kallbekken and Victor’s more diplomatic judgement on offsets is this:

“The vast majority of offsets today and in the expected future come from forest-protection and regrowth projects. The track record of reliable accounting in these industries is poor …. These problems are essentially unfixable. Evidence is mounting that offsetting as a strategy for reaching net zero is a dead end.”6 (emphasis mine)

Summarizing the heavy reliance on offsetting and SAF in the aviation lobby’s net-zero plan, Kallbekken and Victor write “It is no coincidence that these ideas are also the least disruptive to how the industry operates today.” The IATA “commitment to net-zero”, basically, amounts to hoping to get to net-zero by carrying on with Business As Usual.

Contestants, start your batteries!

Articles appear in newspapers, magazines and websites on an almost daily basis, discussing new efforts to operate aircraft on battery power. Is this a realistic prospect? A particularly enthusiastic answer comes in an article from the Aeronautical Business School: “Electric aviation, with its promise of zero-emission flights, is right around the corner with many commercial projects already launched. …”7

Yet the electric aircraft now on the market or in prototyping are aimed at very short-haul trips. That reflects the reality that, in spite of intensive research and development in battery technology through recent decades, batteries are not remotely capable of meeting the energy and power requirements of large, long-haul aircraft.

The International Council on Clean Transportation (ICCT) recently published a paper on electric aircraft which shows why most flights are not in line to be electrified any time soon. Jayant Mukhopadhaya, one of the report’s co-authors, discusses the energy requirements of aircraft for four segments of the market. The following chart presents these findings: 

Table from Jayant Mukhopadhaya, “What to expect when expecting electric airplanes”, ICCT, July 14, 2022.

The chart shows the specific energy (“eb”, in Watt-hours per kilogram) and energy density (“vb”, in Watt-hours per liter) available in batteries today, plus the corresponding values that would be required to power aircraft in the four major market segments. Even powering a commuter aircraft, carrying 19 passengers up to 450 km, would require a 3-time improvement in specific energy of batteries.

Larger aircraft on longer flights won’t be powered by batteries alone unless there is a completely new, far more effective type of battery invented and commercialized:

“Replacing regional, narrowbody, and widebody aircraft would require roughly 6x, 9x, and 20x improvements in the specific energy of the battery pack. In the 25 years from 1991 to 2015, the specific energy and energy density of lithium-ion batteries improved by a factor of 3.”8

If the current rate of battery improvement were to continue for another 25 years, then, commuter aircraft carrying up to 19 passengers could be powered by batteries alone. That would constitute one very small step toward net-zero aviation – by the year 2047.

This perspective helps explain why most start-ups hoping to bring electric aircraft to market are targeting very short flights – from several hundred kilometers down to as little as 30 kilometers – and very small payloads – from one to five passengers, or freight loads of no more than a few hundred kilograms.

The Nova documentary “The Great Electric Airplane Race” took an upbeat tone, but most of the companies profiled, even if successful, would have no major impact on aviation’s carbon emissions.

Joby Aviation is touted as “the current leader in the race to fill the world with electric air taxis.” Their vehicles, which they were aiming to have certified by 2023, would carry a pilot and 4 passengers. A company called KittyHawk wanted to build an Electrical Vertical Take-Off and Landing (EVTOL) which they said could put an end to traffic congestion. The Chinese company Ehang was already offering unpiloted tourism flights, for two people and lasting no more than 10 minutes.

Electric air taxis, if they became a reality after 50 years of speculation, would result in no reductions in the emissions from the current aviation industry. They would simply be an additional form of energy-intensive mobility coming onto the market.

Other companies discussed in the Nova program were working on hybrid configurations. Elroy’s cargo delivery vehicle, for example, would have batteries plus a combustion engine, allowing it to carry a few hundred kilograms up to 500 km.

H2Fly, based in Stuttgart, was working on a battery/hydrogen hybrid. H2Fly spokesperson Joseph Kallo explained that “The energy can’t flow out of the [hydrogen fuel] cell as fast as it can from a fossil fuel engine or a battery. So there’s less power available for take-off. But it offers much more range.”

By using batteries for take-off, and hydrogen fuel cells at cruising altitude, Kallo said this technology could eventually work for an aircraft carrying up to 100 passengers with a range of 3500 km – though as of November 2020 they were working on “validating a range of nearly 500 miles”.

To summarize: electric and hybrid aviation technologies could soon power a few segments of the industry. As long as the new aircraft are replacing internal combustion engine aircraft, and not merely adding new vehicles on new routes for new markets, they could result in a small reduction in overall aviation emissions.

Yet this is a small part of the aviation picture. As Jayant Mukhopadhaya told treehugger.com in September,

“2.8% of departures in 2019 were for [flights with] less than 30 passengers going less than 200 km. This increases to 3.8% if you increase the range to 400 km. The third number they quote is 800 km for 25 passengers, which would then cover 4.1% of global departures.”9

This is roughly 3–4% of departures – but it’s important to recognize this does not represent 3–4% of global passenger km or global aviation emissions. When you consider that the other 96% of departures are made by much bigger planes, carrying perhaps 10 times as many passengers and traveling up to 10 times as far, it is clear that small-plane, short-hop aviation represents just a small sliver of both the revenue base and the carbon footprint of the airline industry.

Short-haul flights are exactly the kind of flights that can and should be replaced in many cases by good rail or bus options. (True, there are niche cases where a short flight over a fjord or other impassable landscape can save many hours of travel – but that represents a very small share of air passenger km.)

If we are really serious about a drastic reduction in aviation emissions, by 2030 or even by 2050, there is just one currently realistic route to that goal: we need a drastic reduction in flights.

* * *

Postscript: At the beginning of October a Washington Post article asked “If a Google billionaire can’t make flying cars happen, can anyone?” The article reported that KittyHawk, the EVTOL air taxi startup highlighted by Nova in 2021 and funded by Google co-founder Larry Page, is shutting down. The article quoted Peter Rez, from Arizona State University, explaining that lithium-ion batteries “output energy at a 50 times less efficient rate than their gasoline counterparts, requiring more to be on board, adding to cost and flying car and plane weight.” This story underscores, said the Post, “how difficult it will be to get electric-powered flying cars and planes.”

*Correction: The original version of this article attributed quotes from the Nature Comment article simply to “Nature”. Authors’ names have been added to indicate this is a signed opinion article and does not reflect an official editorial position of Nature.

Footnotes

1 IATA, “Our Commitment to Fly Net Zero by 2050”.

2 Nova, “The Great Electric Airplane Race” – 26 May 2021.

3 “The Difference In Weight Between The Boeing 737 Family’s Many Variants”, by Mark Finlay, April 24, 2022.

4  Steffen Kallbekken and David G. Victor, Nature, “A cleaner future for flight — aviation needs a radical redesign”, 16 September 2022.

5 Dan Rutherford writes, “US soy production contributes to global vegetable oil markets, and prices have spiked in recent years in part due to biofuel mandates. Diverting soy oil to jet fuel would put airlines directly in competition with food at a time when consumers are being hammered by historically high food prices.” In “Zero cheers for the supersoynic renaissance”, July 11, 2022.

6 Kallbekken and Victor, Nature, “A cleaner future for flight — aviation needs a radical redesign”, 16 September 2022.

7 “The path towards an environmentally sustainable aviation”, by Óscar Castro, March 23, 2022.

8 Jayant Mukhopadhaya, “What to expect when expecting electric airplanes”, ICCT, July 14, 2022.

9 “Air Canada Electrifies Its Lineup With Hybrid Planes”, by Lloyd Alter, September 20, 2022.


Photo at top of page: “Nice line up at Tom Bradley International Terminal, Los Angeles, November 10, 2013,” photo by wilco737, Creative Commons 2.0 license, on flickr.

Right-sizing delivery vehicles

Cargo bikes can replace far heavier vehicles for a substantial share of urban deliveries. But should you buy a cargo bike for personal use? Probably not.

ALSO PUBLISHED ON RESILIENCE.ORG

In North America we think in extreme terms when it comes to last-mile freight delivery. Whether the cargo is a couple of bags of groceries, a small parcel, a large-screen TV or a small load of lumber, we routinely dispatch vehicles with hundreds-of-horsepower engines.

This practice has never made sense, and there have always been niche markets where some products and parcels have been delivered by bicycle couriers instead of truck drivers. Historically, cargo bikes were in wide use in many cities in the decades before cars and trucks cemented their death grip on most urban traffic lanes.1

Today the cargo bike industry is growing rapidly due to several factors. Many cities are establishing zero-emissions zones. The cost of gasoline and diesel fuel has risen rapidly. Congested traffic means powerful expensive vehicles typically travel at bicycle-speed or slower in downtown areas. Last but not least, the development of low-cost, lightweight electric motors for small vehicles dramatically boosts the freight delivery capacity of e-assist bikes even in hilly cities.

Thousands of companies, from sole-proprietor outfits to multinational corporations, are now integrating cargo bikes into their operations. At the same time there is an explosion of new micro-powered vehicle designs on the market.2

Where a diesel-powered urban delivery van will have an engine with hundreds of horsepower, an electric-assist bike in the EU is limited to a motor of 250 W, or about one-third of one horsepower.3 Yet that small electric motor is enough to help a cyclist make typical parcel deliveries in many urban areas at a faster rate than the diesel van can manage.

A great many other deliveries are made, not by companies, but simply by individuals bringing their own purchases home from stores. In this category, too, North Americans tend to believe an SUV or pick-up truck is the obvious tool for the job. But in many car-clogged cities and suburbs a bicycle, whether electric-assist or not, is a much more appropriate tool for carrying purchases home from the store.

Image from pxhere.com, licensed via CC0 Public Domain.

This is an example of a change that can be made at the device level, rapidly, without waiting for system-level changes that will take a good bit longer. When it comes to reducing carbon emissions and reducing overall energy use, the rapid introduction and promotion of cargo bikes as delivery vehicles is an obvious place to make quick progress.

At the same time, the adoption of more appropriate delivery devices will become much more widespread if we simultaneously work on system-level changes. These changes can include establishing more and larger urban zero-emission zones; lowering speed limits for heavy vehicles (cars and trucks) on city streets; and rapid establishment of safe travel lanes for bikes throughout urban areas.

The environmental impact of deliveries

The exponential growth in online shopping over the past twenty years has also led to “the constant rise in the use of light commercial vehicles, despite every effort by cities and regulators to reduce congestion and transport emissions.”4

Last-mile urban delivery, notes the New York Times, “is the most expensive, least efficient and most impactful part of the supply chain.”5

Typical urban parcel delivery trucks have an outsize impact:

“Claudia Adriazola-Steil, acting director of the Urban Mobility Program at the World Resources Institute’s Ross Center for Sustainable Cities, said freight represented 15 percent of the vehicles on the roads in urban areas, but occupied 40 percent of the space. ‘They also emit 50 percent of greenhouse gas emissions and account for 25 percent of fatalities ….’”6

Since vehicle speeds in downtown areas are typically slow, most parcels are not very heavy, and the ability to travel in lanes narrower than a typical truck is a great advantage, a substantial portion of this last-mile delivery can be done by cargo bikes.

Both Fed-Ex and UPS are now building out electric-assist cargo bike fleets in many Western European cities. UPS has also announced plans to test electric-assist cycles in Manhattan.7

How much of the last-mile delivery business can be filled by cargo bikes? A report by the Rapid Transition Alliance says that “In London, it’s estimated that up to 14% of small van journeys in the most congested parts of the city could be made with cargo bikes.”8 City Changer Cargo Bike estimates that in Europe “up to 50% of urban delivery and service trips could be replaced by cargo bikes….”9

It’s important to note that big corporations aren’t the only, or even the major, players in this movement. Small businesses of every sort – ice-cream vendors, bakeries, self-employed carpenters and plumbers, corner grocery stores – are also turning to cargo bikes. The City Changer Cargo Bike report says that “It is important to highlight that the jobs created by cargo bikes are mainly created by Small and Medium-size Enterprises.”10

For small companies or large, the low cost of cargo bikes compared to delivery vans is a compelling factor. The New York Times cites estimates that “financial benefits to businesses range from 70-90% cost savings compared to reliance on delivery vans.”11

The cost savings come not only from the low initial purchase price and low operating costs of cargo bikes, but also from the fact that “electric cargo bikes delivered goods 60 percent faster than vans did in urban centers, and that an electric cargo bike dropped off 10 parcels an hour compared with a van’s six.”12

It’s no wonder the cargo bike industry is experiencing rapid growth. Kevin Mayne of Cycling Industries Europe says sales are growing at 60% per year across the European Union and could reach 2 million cargo bike sales per year by 2030.

Delivery vans in European cities are typically powered by diesel. Replacing a few hundred thousand diesel delivery vans with e-cargo bikes will obviously have a significant positive impact on both urban air quality and carbon emissions.

But what if diesel delivery vans are switched instead to similar-sized electric delivery vans? Does that make the urban delivery business environmentally benign?

Far from it. Electric delivery vans are just as heavy as their diesel counterparts. That means they cause just as much wear and tear on city streets, they pose just as much collision danger to cyclists, pedestrians, and people in smaller vehicles, and they produce just as much toxic tire and brake dust.

Finally, there is the significant impact of mining and manufacturing all that vehicle weight, in terms of upfront carbon emissions and many other environmental ills. There are environmental costs in manufacturing cargo bikes too, of course. But whereas a delivery van represents a large amount of weight for a much smaller delivery payload, a cargo bike is a small amount of weight for a relatively large payload.

In a listing by Merchants Fleet of the “5 Best Electric Cargo Vans for Professionals”, all the vehicles have an empty-weight a good bit higher than the maximum weight of cargo they can carry. (The ratios of empty vehicle weight to maximum cargo weight range from about 1.5 to 3.5.)13

By contrast, a recent list of recommended electric-assist cargo bikes shows that the ratios are flipped: all of these vehicles can carry a lot more cargo than the vehicles themselves weigh, with most in the 4 – 5 times cargo-weight-to-empty-vehicle-weight range.14

One other factor is particularly worthy of note. The lithium which is a key ingredient of current electric-vehicle batteries is difficult, perhaps impossible, to mine and refine in an environmentally benign way. Lithium batteries will be in extremely high demand if we are to “electrify everything” while also ramping up storage of renewably, intermittently generated electricity. Given these constraints, shouldn’t we take care to use lithium batteries in the most efficient ways?

Let’s look at two contrasting examples. An Urban Arrow Cargo bike has a load capacity of 249 kg (550 lbs), and a battery weight of 2.6 kg (5.7 lbs)15 – a payload-to-battery-weight ratio of about 44.

The Arrival H3L3 electric van has a load capacity of 1484 kg (3272 lbs) and its battery is rated at 111 kWh.16 If we assume, generously, that the Arrival’s battery weighs roughly the same as Tesla’s 100 kWh battery, then the battery weight is 625 kg (1377 lbs).17 The Arrival then has a payload-to-battery-weight ratio of about 2.4.

In this set of examples, the e-cargo bike has a payload-to-battery-weight ratio almost 20 times as high as the ratio for the e-cargo van.

Clearly, this ratio is just one of many factors to consider. The typical e-cargo van can carry far heavier loads, at much higher speeds, and with a longer range between charges, than e-cargo bike can manage. But for millions of urban last-mile deliveries, these theoretical advantages of e-cargo vans are of little or no practical value. In congested urban areas where travel speeds are low, daily routes are short, and for deliveries in the 1 – 200 kg weight range, the e-cargo bike can be a perfectly adequate device with a small fraction of the financial and environmental costs of e-cargo vans.

On Dundas Street, Toronto, 2018.

Cargo bikes, or just bikes that carry cargo?

A rapid rollout of cargo bikes in relatively dense urban areas is an obvious step towards sustainability. But should you buy a cargo bike for personal use?

Probably not, in my opinion – though there will be many exceptions. Here is why I think cargo bikes are overkill for an average person.

Most importantly, the bikes most of us have been familiar with for decades are already a very good device for carrying small amounts of cargo, particularly with simple add-ons such as a rack and/or front baskets.

A speed fetish was long promoted by many bike retailers, according to which a “real bike” was as light as possible and was ridden by a MAMIL – Middle-Aged Male In Lycra – who carried nothing heavier than a credit car. Cargo bikes can represent a chance for retailers to swing the pendulum to the opposite extreme, promoting the new category as a necessity for anyone who might want to carry more than a loaf of bread.

In spite of bike-industry biases, countless people have always used their bikes – any bikes – in routine shopping tasks. And with the addition of a sturdy cargo rack and a set of saddlebags, aka panniers, a standard-form bike can easily carry 25 kg or more of groceries. Or hardware, or gardening supplies, or a laptop computer and set of office clothes, or a stack of university textbooks.

The bikes now designed and marketed as cargo bikes can typically carry several times as much weight, to be sure. But how often do you need that capability, and is it worth the considerable downside that comes with cargo bikes?

Cargo bikes are typically a good bit longer and a lot heavier than standard-model bikes. That makes them more complicated to store. You probably won’t be able to carry a big cargo bike up stairs to an apartment, and you might not sleep well if you have to leave an expensive cargo bike locked on the street.

If you only occasionally need to carry larger amounts of cargo, you’re likely to get tired of riding a needlessly heavy and bulky bike the rest of the time.

If you occasionally carry your bike on a bus, train, or on a rack behind a car, a long cargo bike may be difficult or impossible to transport the same way.

Depending on the form factor, you may find a cargo bike doesn’t handle well in spite of its large weight capacity. Long-tail cargo bikes, with an extra-long rack over the rear wheel, can carry a lot of weight when that weight is distributed evenly on both sides of the rack. But if the load is a single heavy object, you may find it difficult to strap the load on the top of the rear rack so that it doesn’t topple bike and rider to one side or the other. (As one who has tried to load a big reclining chair onto a rear rack and ride down the road, I can attest that it’s harder than it sounds.)

Long-tail cargo bike. Photo by Richard Masoner on flickr.com, licensed via Creative Commons 2.0.

 

Box-style cargo bike in Lublin, Poland. Photo by Porozumienie Rowerowe, “Community cargo rental”, via Wikimedia Commons.

The large box style cargo bikes known as bakfiets solve those balance problems, but are typically heavy, long, and thus difficult to store. They can be ideal for moving around a city with children, though many parents will not feel comfortable doing so unless there is a great network of safe streets and protected bike lanes.

For people who have a secure storage space such as a garage, and the budget to own more than one bike, and for whom it will often be helpful to be able to carry loads of 100 kg or more by bike – a cargo bike might be a great buy. Or, perhaps a cargo trailer will be more practical, since it can add great cargo-carrying ability to an ordinary bike on an as-needed basis.18

Ideally, though, every urban area will soon have a good range of cargo-bike businesses, and some of those businesses will rent or loan cargo bikes to the rest of us who just occasionally need that extra capacity.

• • •

In the next installment of this series on transportation, we’ll look at a sector in which no significant device-level fixes are on the horizon.

References

1 See A Visual History of the Cargo Bike, from Mechanic Cycling, Haverford, Pennsylvania.

2 For an overview of a wide range of new cargo bikes and urban delivery initiatives, see the annual magazine of the International Cargo Bike Festival.

3 In North America wattage restrictions vary but many jurisdictions allow e-assist bikes with motors up to 750 Watt output.

4 Stakeholder’s Guide: Expanding the reach of cargo bikes in Europe, published by CycleLogistics and City Changer Cargo Bike, 2022.

5 “A Bicycle Built for Transporting Cargo Takes Off,” by Tanya Mohn, New York Times, June 29, 2022.

6 Tanya Mohn, New York Times, June 29, 2022.

7 Tanya Mohn, New York Times, June 29, 2022.

8 Large-tired and tested: how Europe’s cargo bike roll-out is delivering, 18 August 2021.

9 Stakeholder’s Guide: Expanding the reach of cargo bikes in Europe, 2022.

10 Stakeholder’s Guide: Expanding the reach of cargo bikes in Europe, 2022.

11 Tanya Mohn, New York Times, June 29, 2022.

12 Tanya Mohn, New York Times, June 29, 2022.

13 “5 Best Electric Cargo Vans for Professionals”, Merchants Fleet.

14 “10 Best Electric Cargo Bikes for Families and Businesses in 2022,” BikeExchange, Sept 1, 2022.

15 “10 Best Electric Cargo Bikes for Families and Businesses in 2022,” BikeExchange, Sept 1, 2022.

16 5 Best Electric Cargo Vans for Professionals”, Merchants Fleet.

17 “How much do Tesla’s batteries weigh?”, The Motor Digest, Nov 27, 2021.

18 One example is the Bikes At Work lineup. I have used their 96” long trailer for about 15 years to haul lumber, slabs of granite, voluminous bags of compost and many other loads that would have been awkward or impossible to move with most cargo bikes.

Photo at top of page: “Eco-friendly delivery with DHL in London: a quadracycle in action,” by Deutsche Post DHL on flickr.com, Creative Commons 2.0 license.

Hypermobility hits the wall

Also published on Resilience

Imagine a luxurious civilization in which every person has a motorized travel allowance of 4000 kilometers every year, with unused amounts one year carried forward to allow more distant journeys, perhaps every few years. Imagine also that non-motorized travel is not tallied in this quota, so that a person who makes their daily rounds on foot or bicycle can use all or most of their motorized travel quota for those occasional longer journeys.

It’s true that a motorized travel quota of 4000 km per year would seem a mite restrictive to most people in wealthy industrial countries. But such a travel allowance would have been beyond the dreams of all of humanity up until the past two centuries. And such a travel allowance would also mean a significant increase in mobility for a large share of the global population today.

Still, as long as we “electrify everything” why should we even think about reducing the amount of travel?

Australian scholar Patrick Moriarty floats the idea of a motorized travel allowance of 4000 km per year1, based on a recognition that the environmental harms of high-speed and motorized mobility go far beyond the climate-destabilizing emissions that come from internal combustion cars, trucks, trains, planes and ships.

In several articles and a recent book2 Moriarty and his frequent co-author Damon Honnery provide perspective on what Moriarty refers to as “hypermobility”. The number of passenger kilometers per person per year exploded by a factor of 240 between 1900 and 2018.3

“This overall 240-fold rise is extraordinary, considering the less than five-fold global population increase over the same period. It is even about 30 times the growth in real global GDP.”4

The global average for motorized travel is now about 6,300 km per person per year. At the extremes, however, US residents average over 30,000 km per person per year, while in some countries the average is only a few hundred km per person per year.5

Could the high degree of mobility now standard in the US be extended to the whole world’s population? Not likely. Moriarty calculates that if each person in the world were to travel 30,000 km per year in motorized transport, “world transport energy levels alone would be about 668 EJ, greater than global total commercial energy use of 576 EJ for 2018.”6

Increasing mobility services for the world’s poorest people, while decreasing motorized mobility for the wealthiest, is not only an environmental necessity, it is also a matter of equity. As part of examining those issues, we need to ask this simple question: what good is transportation?

We’re moving, but are we getting anywhere?

Moriarty calls attention to an issue that is so basic it is often overlooked: “What people really want is not mobility itself, but access—to workplaces, schools, shops, friends and family, entertainment etc.”7

Sometimes more mobility also means more access – for example, a person acquires a car, and that means many more workplaces, schools, and shopping opportunities are within a practical daily travel distance. But other times more mobility results in little or no gain in access. As two-car households became the norm in many rural areas, grocery stores and even schools consolidated in bigger towns, so that a car trip became necessary for access to things that used to be a walkable distance away in each small town.

Sometimes more mobility for some people means less accessibility for others. When expressways cut through urban neighbourhoods, lower-income residents of those areas may face long hikes across noisy and polluted overpasses just to get to school or a store.8

In the sprawling suburbs of North American cities, people typically drive much farther to get to work every day than their parents or grandparents did 25 or 50 years ago. But to what end? If you can now travel 50, or 70, or 100 km/hr on your commute, but the drive still takes an hour because you go so much farther, what have you gained?

Moriarty asks us to consider to what extent the explosion in mobility – hypermobility – has actually improved the quality of life even for those privileged enough to participate:

“Personal travel levels in wealthy OECD countries are several times higher than in 1950, yet people then did not regard themselves as ‘travel deprived’.”9

While the benefits of hypermobility are unclear, the costs are crushing and unsustainable.

Death rides along

Motorized transportation always comes with environmental costs. These costs are especially high when each individual travels in their own motorized carriage. Only a fraction of these environmental costs go away when a car or truck fueled by internal combustion is traded for an equivalent vehicle powered by electricity.

Many researchers have cited the high upfront carbon emissions involved in building a car or truck. Before the vehicle is delivered to a customer, a lot of carbon dioxide has been emitted in the mining and refining of the ores, the transportation of materials and parts, and the assembly. For currently produced electric cars and trucks, the upfront carbon emissions are typically even higher than the upfront emissions from an equivalent combustion vehicle. It will be a long time, if ever, before that manufacturing and transport chain runs on clean energy sources. In the meantime every new electric car signifies a big burst of carbon already emitted to the atmosphere.

If only the damage stopped there. But building and maintaining roads, bridges and parking lots is also a carbon-emissions intensive activity, with additional negative impacts on biodiversity and watershed drainage.  And though an electric vehicle has no tailpipe emissions, that doesn’t mean that electric driving is pollution-free:

“[N]on-exhaust emissions of fine particular matter from tire wear is actually greater than for equivalent conventional vehicles, because EVs are heavier than their conventionally fueled counterparts.”10

Finally, there is the direct toll from the inevitable, predictable “accidents” that occur when multi-tonne objects hurtle along roads at high speeds:

“In 2018, some 1.35 million people were killed on the world’s roads, with millions more injured, many seriously. Paradoxically, most of the casualties occur in low vehicle ownership countries, and are pedestrians and cyclists, not vehicle occupants.”11

Death reliably accompanies high-speed transportation – but the fatalities disproportionately accrue to those not privileged enough to travel.

Slowing the machine

To recap the argument: the mass production of high-speed vehicles has made possible an explosion in mobility for a privileged portion of the global population. But the energy costs of transportation increase exponentially, not linearly, with increases in speed.  Hypermobility was fueled overwhelmingly by fossil fuels, and even if we could recreate the infrastructure of hypermobility using renewable energies, the transition period would result in a burst of upfront carbon emissions which our ecosystem can ill afford. Finally, if we concentrate on ramping up renewable technologies to serve the rapacious energy demands of hypermobility, it will be more difficult and will take longer to convert all other essential energy services – for producing and distributing foods, for heating and cooling of buildings, and for distributing clean drinking water, to name a few examples – so that they can run off the same renewable electricity sources.

It is clearly possible for a society to prosper with a lot less motorized travel than our hypermobile society now regards as normal. Given the manifold environmental costs and manifest social inequality of a hypermobile society, we need to rapidly cut down not only on the use of fossil fuel in transportation, but also the total amount of motorized transportation as measured in passenger-kilometers (p-k) per person per year. This is the underpinning for Moriarty’s “tentative proposal for an average aspirational target of 4000 vehicular p-k per person per year.”12

But how to begin applying the brakes?

In an article titled “Reducing Personal Mobility for Climate Change Mitigation”, Moriarty and Honnery have examined the likely impacts of various factors on overall motorized mobility. Neither new information technology services, carpooling, or land-use planning changes are likely to result in significant reductions in travel, particularly not in the 10 – 25 year time frame that is so critical for staving off a truly catastrophic climate crisis. Large and rapid increases in the market price of fossil fuels, on the other hand, would dramatically hurt lower-income people while allowing high-income people – who consume by far the most energy per capita – to maintain their current personal habits. Thus Moriarty and Honnery conclude:

“The only equitable approach is to reduce the convenience of car travel, for example, by large travel speed reductions and by a reversal of the usual present ranking of travel modes: car, public transport, and active modes.” [emphasis mine]13

Expressed graphically, that reversal of priorities would look like this chart from Mikael Colville-Andersen’s book Copenhagenize:

From Copenhagenize, by Mikael Colville-Andersen, Island Press, 2018; reviewed here.

At the outset of the motor age, walking and cycling routes were as direct and convenient as possible. As streets were dedicated to fast, dangerous cars, walking and cycling routes started to zigzag through many detours, or they simply disappeared, while priority was given to auto routes.

To make our cities safer and healthier, while also reducing the voracious energy demands of motorized transport, we need to flip the hierarchy once more, putting active transportation first, public transit second, and cars third. That way we can improve access to essential services even as motorized mobility drops.

Within cities where most people live, I think Moriarty and Honnery are right that this change would result in a substantial reduction in overall motorized kilometers per capita, and would do so in a generally equitable manner.

Easier said than done, of course. While many European cities have made major strides in this regard, even timid moves to de-privilege cars are tough for city councils to enact in North America.

A personal travel allotment of 4,000 km per year will seem outrageously low to most North Americans, and it is hard to imagine any North American politician – at least anyone with a hope of ever being elected – saying a good word about the idea.

Yet the luxury of any high-speed travel at all is a recent phenomenon, and there is no reason to take for granted that this extravagance will last very long. We do know that we need drastic, rapid change in our energy consumption patterns if we are to avoid civilization-threatening environmental instability.

We might not find it within ourselves to voluntarily steer away from our high-speed, hypermobile way of life. But if, a few decades from now, our society is in free-fall due to rapid-fire environmental disasters, the complex infrastructure needed for widespread motorized transport may be but a faint memory.

* * *

Though I only came across Moriarty’s work a few years ago, for most of my adult life I unwittingly lived within a motorized travel allotment of 4,000 km/yr – with one major exception. More than 40 years ago, as a new resident of an urban metropolis, I realized it was a bizarre waste of horsepower to use a car simply to haul my (then) scrawny carcass along city streets. Besides, I found it healthier, cheaper, more interesting, and definitely more fun to ride a bike to work, to concerts, to stores, and nearly everywhere else I wanted to go. I was fortunate, too, to be able to choose a home close to my workplace, or change my workplace to be closer to my preferred home; throughout several decades I never needed to regularly commute by car.

But: I did get on a plane once or twice a year, and sometimes several times a year. For many years these air journeys accounted for most of my motorized transport kilometers. Later I learned that of all typical modern travel modes, air travel was the most environmentally damaging and the least sustainable.

In upcoming installments in this series I’ll look at the energy needs, both real and imagined, for personal transportation within cities; and at the impact of hyper-hypermobility as embodied in routine air travel.

Illustration at top of page courtesy of pxhere.com, free for personal and commercial use under CC0 public domain license.

References

1 See his brief article in Academia Letters, “A proposal for limits on vehicular passenger travel levels”, published in September 2021.

2 Patrick Moriarty and Damon Honnery, Switching Off: Meeting Our Energy Needs in a Constrained Future, Springer, 2022.

3 P. Moriarty, “Global Passenger Transport,” MDPI Encyclopedia, February 2021.

4 P. Moriarty, Academia Letters, “A proposal for limits on vehicular passenger travel levels”.

5 P. Moriarty, “Global Passenger Transport”.

6 P. Moriarty, “Global Passenger Transport”.

7 P. Moriarty, “A proposal for limits on vehicular passenger travel levels”.

8 For more on the trade-offs between mobility and accessibility see my article “The Mobility Maze”.

9 P. Moriarty, “A proposal for limits on vehicular passenger travel levels”.

10 P. Moriarty, “Global Passenger Transport”.

11 P. Moriarty, “A proposal for limits on vehicular passenger travel levels”.

12 P. Moriarty, “A proposal for limits on vehicular passenger travel levels”.

13 Patrick Moriarty and Damon Honnery, “Reducing Personal Mobility for Climate Change Mitigation”, in Handbook of Climate Change Mitigation and Adaptation, Springer, 2022, pages 2501 – 2534.

 

‘This is a key conversation to have.’

This afternoon Post Carbon Institute announced the release of the new book Energy Transition and Economic Sufficiency. That brings to fruition a project more than two-and-a-half years in the making.

Cover of Energy Transition and Economic Sufficiency

In May 2019, I received an email from Clifford Cobb, editor of the American Journal of Economics and Sociology. He asked if I would consider serving as Guest Editor for an issue of the Journal, addressing “problems of transition to a world of climate instability and rising energy prices.” I said “yes” – and then, month by month, learned how difficult it can be to assemble a book-length collection of essays. In July, 2020, this was published by Wiley and made accessible to academic readers around the world.

It had always been a goal, however, to also release this collection as a printed volume, for the general public, at an accessible price. With the help of the Post Carbon Institute that plan is now realized. On their website you can download the book’s Introduction –which sets the context and gives an overview of each chapter – at no cost; download the entire book in pdf format for only $9.99US; or find online retailers around the world to buy the print edition of the book.

Advance praise for Energy Transition and Economic Sufficiency:

“Energy descent is crucial to stopping climate and ecological breakdown. This is a key conversation to have.” – Peter Kalmus, climate scientist, author of Being The Change

“This lively and insightful collection is highly significant for identifying key trends in transitioning to low-energy futures.” – Anitra Nelson, author of Small is Necessary

“The contributors to this volume have done us a tremendous service.” – Richard Heinberg, Senior Fellow, Post Carbon Institute, author of Power: Limits and Prospects for Human Survival

“For those already applying permaculture in their lives and livelihoods, this collection of essays is affirmation that we are on the right track for creative adaption to a world of less. This book helps fill the conceptual black hole that still prevails in academia, media, business and politics.” – David Holmgren, co-originator of Permaculture, author of RetroSuburbia

“The contributors explain why it is time to stop thinking so much about efficiency and start thinking about sufficiency: how much do we really need? What’s the best tool to do the job? What is enough? They describe a future that is not just sustainable but is regenerative, and where there is enough for everyone living in a low-carbon world.” – Lloyd Alter, Design Editor at treehugger.com and author of Living the 1.5 Degree Lifestyle: Why Individual Climate Action Matters More Than Ever

Some sources for the print edition:

In North America, Barnes & Noble

In Britain, Blackwell’s  and Waterstones

In Australia, Booktopia

Worldwide, from Amazon

Your gas tank is not an oil well. Your battery will not be a power plant.

Also published on Resilience.

My car comes with an amazing energy-storage, demand-management-and-supply system; perhaps you’ve heard of it. It’s called the “gas tank”.

Thanks to this revolutionary feature, if I get home and the electric grid is down, I can siphon gas out of the tank and power up a generator. In a more urgent energy crunch, I can siphon out some gas, throw it on a woodpile, and get a really hot fire going in seconds. If a friend across town has no power, I can even drive over there, siphon out some fuel, and run a generator to provide power in an alternate location. It’s beautiful! I can shift energy provision and consumption both temporally and spatially.

There is one minor drawback, to be sure. If I siphon the fuel out of the tank then I can’t actually drive the car, at least not more than a few kilometers to the nearest fuel station. But let’s not let that limitation cast a shadow over this revolutionary technology. If this flexible load-management system were widely adopted, and there were cars everywhere, think how smoothly our society could run!

These thoughts come to mind when I hear someone rhapsodize about the second coming of the electric car. Recently, for example, a Grist headline proclaimed that “Your Electric Vehicle Could Become a Mini Power Plant. And that could make the electrical grid work better for everyone.” (June 21, 2021)

Stephen Peake, in Renewable Energy: Ten Short Lessons (review here) wrote that “new fleets of electric vehicles parked overnight could become another mass source of electricity storage and supply.” (emphasis mine)

One more example: an Oct 2020 article at World Economic Forum says that “When electric vehicles are integrated into a city’s energy system, the battery can provide power to the grid when the sun is down or the wind isn’t blowing.”

The key to this supply-and-demand magic is “bidirectional charging” – the electric vehicles of the near future will have the equivalent of a gas tank with a built-in siphon. Thus their capacious batteries will not only be able to quickly suck power out of the grid, but also to empty themselves out again to provide juice for other purposes.

But allow me this skeptical observation: electric car batteries do not have huge batteries because the drivers want to offer aid to the “smart grid”. Electric car batteries are huge because cars are huge consumers of energy.

(True, electric cars don’t consume quite as much energy as internal-combustion cars of similar class and weight – but they consume a whole lot more energy per passenger/kilometer than intelligently routed electric buses, trains, or especially, electric-assisted bicycles.)

And let’s be clear: neither an electric car vehicle nor its battery provide any “energy supply”. The car itself is a pure energy suck. The battery is just an energy storage device – it can store a finite capacity of energy from another source, and output that energy as required, but it does not produce energy.

As with internal-combustion powered cars, when the tank/battery is drained for a purpose other than driving, then the car ceases to be a functional car until refueled.

That will leave some niche scenarios where vehicle batteries really might offer a significant advantage to grid supply management. The Grist article begins with one such scenario: three yellow school buses which run on battery power through the school year, and serve as a battery bank while parked for the summer months. If all 8,000 school buses in the local utility service area were EVs, the article notes, their fully-charged batteries “could collectively supply more than 100 megawatts of power to the grid for short periods — or nearly 1 percent of Con Ed’s peak summer power demand.”

When parked for the summer, electric school buses would not need to be charged and ready to drive first thing every weekday morning. So they could indeed be used simply as (terribly expensive) battery cases for two or three months each year.

OK, but … let’s be careful about singing the praises of school buses. This might be a slippery slope. If big buses catch on, soon Americans might start taking their kids to school in giant pick-up trucks!

Of course I jest – that horse has already left the barn. The top three selling vehicles in the US, it may surprise people from elsewhere to learn, are pick-up trucks that dwarf the pick-ups used by farmers and some tradespeople in previous generations. (It will not surprise Canadians, who play second fiddle to no-one in car culture madness. Canadians tend to buy even larger, heavier, more powerful, and more expensive trucks than Americans do.)

The boom in overgrown pick-ups has not come about because North Americans are farming and logging in record numbers, nor even, as one wag put it, that a 4X8 sheet of plywood has gotten so much bigger in recent years. Yet urban streets, parking lots, and suburban driveways are now crowded with hulking four-door, four-wheel-drive, spotlessly clean limousine-trucks. Those vehicles, regardless of their freight-carrying or freight-pulling capacity, are used most to carry one or two people around urbanized areas.

If we are foolish enough to attempt electrification of this fleet, it will take an awesome amount of battery power. And as you might expect, car culture celebrants are already proclaiming what a boon this will be for energy transition.

A pre-production promo video for Ford’s F-150 Lightning electric pick-up truck gets to the critical issue first: the Lightning will accelerate from 0 – 60 mph (0 – 97 km/hr) “in the mid-4-second range”. But wait, there’s more, the ad promises: the battery can “off-board” enough power to run a home “for about three days”.

Keep that in mind when you start seeing big electric pick-up trucks on the road: each one, in just a few hours of highway driving, will use as much power as a typical American home uses in three days.

Keep it in mind, too, when you see a new bank of solar panels going up in a field or on a warehouse roof: the installation might output enough electricity each day to power 100 pickup trucks for a few hours each – or 300 homes for the whole day.

Given that we won’t have enough renewably produced electricity to power existing homes, schools, stores and industries for decades, is it really a good idea to devote a big share of it, right at the outset, to building and charging limousine-trucks? Are the huge batteries required by these vehicles actually features, or are they bugs?

Granted, an electric car battery can provide a modest degree of grid load-levelling capability in some situations. It can be drained back into the grid during some peak-power-demand periods such as early evening in the heat of summer – as long as it can be recharged in time for the morning commute. That’s not nothing. And if we’re determined to keep our society moving by using big cars and trucks, that means we’ll have a huge aggregated battery capacity sitting in parking spots for most of each day. In that scenario, sure, there will be a modest degree of load-levelling capacity in those parked vehicles.

But perhaps there is a better way to add load-levelling capacity to the grid. A better way than producing huge, heavy vehicles, each containing one battery, which suck up that power fast whenever they’re being driven, while also spreading brake dust and worn tire particles through the environment, and which significantly increase the danger to vulnerable road users besides. Not to mention, which result in huge upfront emissions of carbon dioxide during their manufacture.

If it’s really load-levelling we’re after, for the same money and resources we could build a far greater number of batteries, and skip building expensive casings in the form of cars and pick-ups.

Other factors being equal, an electric car is modestly more environmentally friendly than internal-combustion car. (How’s that for damning with faint praise?)  But if we’re ready for a serious response to the climate emergency, we should be rapidly curtailing both the manufacture and use of cars, and making the remaining vehicles only as big and heavy as they actually need to be. The remaining small cars won’t collectively contain such a huge battery capacity, to be sure, but we can then address the difficult problems of grid load management in a more intelligent, efficient and direct fashion.

Illustration at top of post: Energy Utopia, composite by Bart Hawkins Kreps from public domain images.

Sunshine, wind, tides and worldwatts

A review of Renewable Energy: Ten Short Lessons

Also published on Resilience

Fun physics fact: water carries so much more kinetic energy than air that “A tidal current of 3 knots has the same energy density as a steady wind stream at 29 knots (a fair old blow).”

And consider this: “Ninety-nine per cent of planet Earth is hotter than 1,000 °C (1,832 °F). The earth is, in fact, a giant leaky heat battery.”

Stephen Peake uses these bits of information and many more to lucidly outline the physical bases of renewable energy sources, including solar and wind energy, geothermal energy, wave energy and tidal current energy. But the book also touches on the complex relationship between the physics of renewable energy, and the role energy plays in human society – and the results aren’t always enlightening.

Peake takes on a formidable task in Renewable Energy: Ten Short Lessons. The book is part of the “Pocket Einstein” series from Johns Hopkins University Press (or from Michael O’Mara Books in Britain). He has less than 200 small-format pages in which to cover both the need for and the prospects for a transition to 100% renewable energy.

Key to his method is the concept of a “worldwatt” – “the rate at which the world uses all forms of primary energy.” Peake estimates the rate of energy flow around the world from various potential renewable energy sources. Not surprisingly, he finds that the theoretically available renewable energy sources are far greater than all energy currently harnessed – primarily from fossil fuels – by the global economy.

But how do we get from estimates of theoretically available energy, to estimates of how much of that energy is practically and economically available? Here Peake’s book isn’t much help. He asks us to accept this summation:

“Taking a conservative mid-estimate of the numbers in the literature, we see that the global technical potential of different renewable sources adds up to 46 worldwatts. There is a definite and reasonable prospect of humans harnessing 1 worldwatt from 100 per cent renewable energy in the future.” (page 31)

But he offers no evidence or rationale for the conclusion that getting 1 worldwatt from renewable sources is a “reasonable prospect”, nor how near or far “in the future” that might occur.

A skeptic might well dismiss the book as renewable energy boosterism, noting a cheery optimism from the opening pages: “There is an exciting, renewable, electric, peaceful, prosperous, safer future just up ahead.” Others might say such optimism is the most helpful position one can take, given that we have no choice but to switch to a renewable energy way of life, ASAP, if we want human presence on earth to last much longer.

Yet a cheerfully pro-renewable energy position can easily shade into a cheerful pro-consumptionist stance – the belief that renewable energies can quickly become the driving force of our current industrial economies, with little change in living standards and no end to economic growth.

Peake briefly introduces a key concept for assessing which renewable energy sources will be economically viable, and in what quantities: Energy Return On Energy Invested (EROEI). He explains that as we exploit more difficult energy sources, the EROEI goes down:

“As wind turbines have become larger and moved offshore, the EROEI ratio for wind over a twenty-year lifetime has declined from around 20:1 in the early 2000s to as low as 15:1 in recent years for some offshore wind farms.” (page 84)

Affordable renewable energy, in other words, doesn’t always “scale up”. The greater the total energy demanded by society, the more we will be impelled to site wind turbines and solar panels in areas beyond the “sweet spots” for Energy Return On Energy Invested. Peake’s book would be stronger if he used this recognition to give better context to statements such as “Renewable electricity is now cheaper than fossil electricity …” (in the book’s opening paragraph), and “solar is now the cheapest electricity in history” (page 70).

While Peake expresses confidence that a prosperous renewable energy world is just ahead, he doesn’t directly engage with the issue of how, or how much, affluent lifestyles may need to change. The closest he comes to grappling with this contentious issue is in his discussion of energy waste:

“We need to stop wasting all forms of energy, including clean renewable sources of heat and electricity. The sooner we shrink our total overall demand for energy, the sooner renewables will be able to provide 100 per cent of the energy we need to power our zero-carbon economies.” (page 141)

Near the end of the book, in brief remarks about electric cars, Peake makes some curious statements about EVs:

“Millions of [electric vehicles] will need charging from the network. This presents both a challenge and an opportunity in terms of managing the network load.” (page 130, emphasis mine)

And a few pages later:

“In the future, new fleets of electric vehicles parked overnight could become another mass source of electricity storage and supply.” (page 134 emphasis mine)

In my next post I’ll take up this concept of the electric vehicle as energy storage, supply and load management resource.

In conclusion, Renewable Energy: Ten Short Lessons is a valuable primer on the physics of renewable energy, but isn’t a lot of help in establishing whether or not the existing world economy can be successfully transitioned to zero-carbon energy.

Photo at top of page: Wind Turbines near Grevelingenmeer, province of Zeeland, Netherlands

 

Can big science be sustained?

Reflections on Fundamentals by Frank Wilczek

Also published on Resilience

During a long career at the frontiers of physics Frank Wilczek has earned many honours, including a Nobel Prize for Physics in 2004. Fortunately for general readers he is also a gifted writer with a facility for explaining complex topics in (relatively) simple terms.

Perhaps you have, as I do, an amateur fascination with topics such as quantum electrodynamics (QED) and quantum chromodynamics (QCD), and questions such as “To what extent do the laws of physics work the same running forward in time or running backward in time?” If so I heartily recommend Wilczek’s latest book Fundamentals: Ten Keys to Reality. (Penguin Random House, January 2021)

Wilczek shares with us the sense of wonder and beauty that has kept him excited about his work for the past 50 years. You might realize, as I did, that with Wilczek’s help you will understand aspects of particle physics, cosmology, and the nature of time better than you ever thought you might.

Yet from the opening pages of the book, Wilczek drops in assertions about history, society and the role of science that I found both troubling and worthy of a more focused examination.

What makes western science so great? (Or not.)

In Fundamentals Wilczek spends most of his time discussing scientific developments during the 20th century, particularly developments that weren’t even mentioned in high-school textbooks the last time I took a course in physics. But he grounds his discussion in a celebration of the Scientific Revolution of the 17th century.

“The seventeenth century saw dramatic theoretical and technological progress on many fronts, including in the design of mechanical machines and ships, of optical instruments (including, notably, microscopes and telescopes), of clocks, and of calendars. As a direct result, people could wield more power, see more things, and regulate their affairs more reliably. But what makes the so-called Scientific Revolution unique, and fully deserving of the name, is something less tangible. It was a change in outlook: a new ambition, a new confidence.” (Fundamentals, page 4)

In subsequent centuries, the applied science that grew from this scientific revolution led to internal combustion engines, electric motors, all manner of telecommunications, digital cameras, lasers, magnetic resonance imaging and the Global Positioning System – to name just a few of the technologies that have transformed ways of life.

I count myself a fan of the scientific method, and I haven’t personally known anyone who is either ready, willing or able to live without any access to any of the technologies Wilczek cites as outgrowths of this method. But can these technological successes be credited solely to a new and superior approach to inquiry?

In the opening pages Wilczek states that “prior to the emergence of the scientific method, the development of technologies was haphazard.” (page 3) He then slips in an observation that to him requires no elaboration, presenting a graph of GDP growth with this comment:

“This figure, which shows the development of human productivity with time, speaks for itself, and it speaks volumes.” 

Graph from Fundamentals, by Frank Wilczek, page 3.

The graph speaks for itself? And just what does it say? Perhaps this: when at long last humans learned to extract ancient deposits of fossil energy, laid down over millions of years, and learned how to burn this energy inheritance in a frenzy of consumption, with no worries about whether successive generations would have any comparable energy sources to draw on, only then did “economic growth” skyrocket. And further: it’s not important that a great deal of wealth – from accessible fossil energy reserves to biodiversity to climate stability – has gone down as fast as that graph of GDP has gone up. It doesn’t matter, since in GDP’s accounting for economic growth there is no need to distinguish productivity from consumptivity.

As you might guess, what I glean from that GDP graph may not match what Wilczek hears, when he hears the graph “speak for itself.” But I think the relationship of science to the larger human enterprise, including the economy, deserves further scrutiny here.

That GDP is a crude economic indicator should become clear if we reflect on the left side of Wilczek’s graph as much as the right side. He credits the scientific revolution with leading to an explosion in productivity – but his graph shows a barely perceptible change in world GDP per capita for the period 1500 – 1800. Significant growth in GDP per capita, then, didn’t arise for at least a century after the scientific revolution, until about the time fossil fuel exploitation began in earnest.

Can this be taken as evidence that there were no fundamental changes in the world economy during the centuries immediately preceding the fossil fuel economy? To the contrary, some of human history’s most epic changes began about 1500, as western european nations colonized the Americas, instituted the slave trade on a massive scale, colonized large parts of Africa and Asia, and began a centuries-long transfer of ecological wealth from both land and sea around the globe, at the cost of hundreds of millions of human lives. Global economic wealth per capita may not have changed much during those centuries – but the distribution of that wealth, and the resulting wealth of a small slice of educated european elites, certainly did change. And it was from these elites that, with few exceptions, came the men (again, with few exceptions) who worked out the many discoveries in the scientific revolution.

It shouldn’t surprise us that these new understandings would come from people who had the economic security to get good educations, acquire expensive books, set up laboratories, make patient observations for years or decades, and test their theories even if any practical applications might be so far in the future as to be unforeseeable. A well-rounded assessment of the scientific revolution, then, should look not only at the eventual technological outcomes that might be credited to this revolution, but also the ecological and sociological factors that preceded this revolution. And a balanced assessment of the scientific revolution should also ask about blind spots likely to accompany this worldview, given its birth among the elite beneficiaries of a colonialism that far more of the world’s population were experiencing as an apocalypse.

In particular, it should be no surprise that among the class of people who do the lion’s share of consumption, the dominant faith in economics has conveniently assured them that their consumptivity equals productivity.

How much energy is enough energy?

Wilczek spends much of Fundamentals illuminating energy in many guises: the energy charge of an electron, the energy that holds quarks together to form protons, the gravitational energy of a black hole as it bends space-time, the dark energy that appears to be causing the universe not just to expand, but to expand at an accelerating pace. His explanations are marvels of clarity in which he imparts the sense of wonder that he himself felt at the outset of his lifelong scientific journey.

When he turns to the role that energy plays in human life and society, unfortunately, his observations strike me as trite. He titles one chapter, for example, “There’s Plenty of Matter and Energy”.

Here he gives us the unit AHUMEN, short for Annual Human Energy, which he calculates at 2,000 calories/day, which over a year comes to about 3 billion joules. With this unit in hand, he notes that world energy consumption in 2020 was about 190 billion AHUMENs, or about 25 AHUMENs per capita. He draws this conclusion:

“This number, 25, is the ratio of total energy consumed to the amount of energy used in natural metabolism. It is an objective measure of how far humans have progressed, economically ….” (p 127, emphasis mine)

If tomorrow we consume twice as much energy as we consume today, then by this “objective measure” we will have progressed twice as far economically. This sounds to me like neither clever physics nor clever economics, but mere mis-applied arithmetic.

Wilczek adds that Americans consume roughly 95 AHUMENs per person, without pointing out what should also be obvious: if the global average is 25 AHUMENs per capita, and Americans consume 95 per capita, that means hundreds of millions of people in our advanced global economy are getting only a few AHUMENs each.

Proceeding with his argument that “there’s plenty of energy”, Wilczek says that if we consider only “the portion of solar energy that makes it to Earth, then we find ‘only’ about 10,000 times our present total energy consumption. That number provides a more realistic baseline from which to assess the economic potential of solar energy.” (page 127)

Indeed, there is and always has been a vast amount of solar energy impacting the earth. That energy has always been enough to fry a human caught unprotected for too long in the desert sun. It’s always been enough to electrocute a human, when solar energy is incorporated into lightning storms. That abundant solar energy can even freeze us to death, when increasingly unstable weather systems push arctic air deep into regions where humans are unprepared for cold.

That energy has always been enough to kill crops during heat waves or to flood coastal cities when storms surge. With each passing year, as our geoengineered atmosphere holds in more heat, there will be more solar energy theoretically available to us, but immediately active in global weather systems. That will make our economic challenges greater, not simpler.

For that abundant solar energy to represent “economic potential”, we need to have technologies that can make that solar energy useful to us, and manageable by us, in cost-effective ways. Wilczek both recognizes and dismisses this concern in a single sentence:

“Technology to capture a larger fraction of that [solar] energy is developing rapidly, and there is little doubt that in the foreseeable future – barring catastrophe – we will be able to use it to support a richer world economy sustainably.” (page 140)

Wilczek himself might have little doubt about this, but I wish he had included some basis on which we could be confident this is more than wishful thinking.

While this discussion may seem to have veered a long way from the core concerns of Wilczek’s book, I suggest that the relationship of societal energy consumption to the needs of the scientific enterprise may soon become a critical issue.

ATLAS detector being assembled at Large Hadron Collider, 2006. Photo by Fanny Schertzer, 27 February 2006. Accessed via Wikimedia Commons.

The energy demands of big science

The work of 20th century physics has come with a high energy price tag. Famously, some of the major steps forward in theory were accomplished by brilliant individuals scribbling in notebooks or on chalk boards, using tools that were familiar to Newton. But the testing of the theories has required increasingly elaborate experimental setups.

The launching of a space telescope, which helps reveal secrets of the farthest reaches of our universe, is one energy-intensive example. But likewise in the realm of infinitesimally small, sub-atomic particles – where Wilczek has focused much of his work – the experimental apparatus has become increasingly grand.

Wilczek tells us about Paul Dirac, a pioneer in quantum electrodynamics who wrote in 1929 that “The underlying physical laws necessary for the mathematical theory of a large part of physics and the whole of chemistry are thus completely known.” Yet much subsequent progress in the field had to wait:

“When Dirac continued, ‘And the difficulty lies only in the fact that application of these laws leads to equations that are too complex to be solved,’ modern supercomputers were not even a dream.” (page 120)

The theoretical framework for the Higgs particle was proposed decades before it could be confirmed, and that confirmation carried a huge energy cost. “In the years prior to 2012, Higgs particle searches came up empty,” Wilczek writes. “We know now, in retrospect, that they simply didn’t bring in enough energy. The Large Hadron Collider, or LHC, finally did.” (page 176)

It’s not just that this collider involved the construction of a circular tunnel 27 km in circumference, nor that while operating it draws 200 MW of electricity, comparable to one-third the electricity draw of the city of Geneva. The power allows experimenters to smash protons together at speeds only 11 km/h less than the speed of light. And these collisions, in turn, result in nearly incomprehensible quantities of data being captured in the Atlas detector, which sends “all this information, at the rate of 25 million gigabytes per year, to a worldwide grid that links thousands of supercomputers.” (page 176)

When the tunnel had been bored, the superconducting magnets built and installed, the Atlas detector (itself twice the size of the Parthenon) assembled, the whole machine put into operation, and the thousands of supercomputers had crunched the data for months – then, finally, the existence of the Higgs particle was proven.

Wilczek doesn’t go into detail about the energy sources for this infrastructure. But it shouldn’t escape our attention that the experimental-industrial complex remains primarily a fossil-fueled enterprise. Fossil fuels fly researchers from university to university and from lab to lab around the world. Fossil fuels power the cement plants and steel foundries, and the mines that extract the metals and minerals. Many individual machines are directly powered by electricity, but on a global scale most electricity is still generated from the heat of fossil fuel combustion.

Wilczek cites the vast amount of solar energy that strikes the earth each day as a vast economic resource. Yet we are nowhere close to being able to build and operate all our mines, smelters, silicon chip fabrication facilities, intercontinental aircraft, solar panel production facilities, electricity transmission towers, and all the other components of the modern scientific enterprise, solely on renewable solar energy.

And if someday in the not-too-distant future we are able to operate a comparably complex industrial infrastructure solely on renewable energy, will this generate enough economic surplus to support tens of thousands of scientists working at the frontiers of research?

The U.S. Department of Energy’s Oak Ridge National Laboratory unveiled Summit as the world’s most powerful and smartest scientific supercomputer on June 8, 2018. “With a peak performance of 200,000 trillion calculations per second—or 200 petaflops, Summit will be eight times more powerful than ORNL’s previous top-ranked system, Titan. … Summit will provide unprecedented computing power for research in energy, advanced materials and artificial intelligence (AI), among other domains, enabling scientific discoveries that were previously impractical or impossible.” Source: Oak Ridge National Laboratory. Accessed via Wikimedia Commons.

Just one clue

Wilczek cites a famous quotation from equally celebrated physicist Richard Feynman. During a lecture in 1961 Feynman offered this question and answer:

“‘If, in some cataclysm, all of scientific knowledge were to be destroyed, and only one sentence passed on to the next generations of creatures, what statement would contain the most information in the fewest words? I believe it is the atomic hypothesis (or the atomic fact, or whatever you wish to call it) that all things are made of atoms.’” (Feynman, quoted in Fundamentals, page 61)

And Wilczek proposes this revision:

“Instead of ‘all things are made of atoms,’ we should say that ‘all things are made of elementary particles.’” (page 62)

This may seem nothing more than an intellectual parlor game, with scientific knowledge today increasing at an accelerating pace. Wilczek doesn’t sound worried about the death of scientific knowledge, when he says that “Technology has already given us superpowers, and there is no end in sight.” (page 171)

But as we roar ahead into the climate crisis, I think it would be helpful and appropriate to revise Feynman’s question, replacing the “if” with “when”:

If When, in some cataclysm, all of scientific knowledge were to be is destroyed, and only one sentence passed on to the next generations of creatures, what statement would contain the most information in the fewest words?

We can’t know for sure, of course, whether the climate cataclysm will destroy scientific knowledge. But what we can see is that we are on a so-far unwavering path to climate catastrophe, and that most governments around the world aren’t pledging (let alone fulfilling pledges) to make carbon emissions reductions that are even close to sufficient. With each passing year the challenge of transforming our civilization into a sustainable civilization grows more urgent, time grows shorter, and the consequences of failure grow more threatening not only to individual lives but to the very survival of our species. These threats are being documented and communicated in great detail by our scientific enterprises. And yet the greatest beneficiaries of our supposedly productive global economy (individual examples notwithstanding) lead the charge to the cliff.

So perhaps it’s time to consider seriously “What one sentence of information might be most useful to our survivors?”

Suppose we project our thoughts, right now, into a climate-ravaged future. Earth’s surviving inhabitants contend with a violently unstable climate. They struggle to gather enough food from deeply impoverished ecosystems, they try to build sufficiently robust shelters, they yearn to raise healthy children, and they face these challenges without any useful energy boosts from polluting fossil fuels (fuels which in any case will be hard to extract, since we’ll have already burned up the easily accessible reserves). Our digital networks of knowledge may well have gone dark, and our libraries may have flooded or burned.

In this future, will it be helpful to tell our descendants “All things are made of elementary particles?” Perhaps it will be many generations further on, if all goes well, before they can again support a scientific elite, armed with elaborate experimental apparatus, capable of making sense of these “elementary particles”.

I can’t help but wonder if, in this future, the best advice we might offer would be a simple warning: “Don’t do what we did.”

Photo at top of page: Grappling the Hubble Space Telescope. An STS-125 crew member aboard Space Shuttle Atlantis snapped a still photo of the Hubble Space Telescope after it was grappled by the shuttle’s Canadian-built Remote Manipulator System. Credit: NASA. Accessed at Wikimedia Commons.

Transition to a Low-Energy Future

One project has taken the lion’s share of my work time for the past year, and it has been a project close to my heart.

As long-time readers will have noted, my writings frequently concern the intersection between energy and economics. I was honored and grateful, therefore, to be asked to serve as guest editor of an issue of The American Journal of Economics and Sociology.

After a year’s work this issue is now published, under the title “Transition to a Low-Energy Future”. An issue overview and all individual articles can be found here.

I am now working on the next phase of this project – seeing this published as a generally-available print book. Inquiries and comments on this project are most welcome; please get in touch through the Contact page on this website.

Energy storage and our unpredictable future

A review of Energy Storage and Civilization

Also published on Resilience.org

It’s a fine spring day and you decide on a whim to go camping. By early afternoon you’ve reached a sheltered clearing in the woods, the sky is clear, and you relax against a tree trunk rejoicing that “The best things in life are free!” as you soak up the abundant warmth of the sun. As the sun goes down, though, the temperature drops to near freezing, you shiver through a long night, and you resolve to be better prepared the next night.

And so by the time the sun sets again you’ve invested in a good down sleeping bag, you sleep through the long night in comfort due to your own carefully retained heat, and then you greet the cold dawn by cheerfully striking a match to the pile of dry sticks you had gathered and stacked the day before.

In this little excursion you’ve coped with variable energy flows, using technologies that allowed you to store energy for use at a later time. In short, you’ve faced the problems that Graham Palmer and Joshua Floyd identify as critical challenges in all human civilizations – and especially in our own future.

Their new book Energy Storage and Civilization: A Systems Approach (Springer, February 2020) is an important contribution to biophysical economics – marvelously clear, deep and detailed where necessary, and remarkably thorough for a work of just over 150 pages.

The most widely appreciated insight of biophysical economics is the concept of Energy Return On Investment – the need for energy technologies to yield significantly more energy than the energy that must be invested in these activities. (If it takes more energy to drill an oil well than the resulting barrels of oil can produce, that project is a bust.) While in no way minimizing the importance of EROI, Palmer and Floyd lay out their book’s purpose succinctly:

“we want to argue that energy storage, as both a technological and natural phenomenon, has been much more significant to the development of human civilizations than usually understood.” (Energy Storage and Civilization, page 2)

Central to their project is the distinction between energy stocks and energy flows. Sunshine and wind energy – primary energy sources in a renewable energy future – are energy flows. Grains, butter, wood, coal, oil and natural gas are energy stocks. And storage mediates between the two:

“Energy storage deals with the relationship between stocks and flows: storing energy, whether by natural or anthropic processes, involves the accumulation of flows as stocks; exploiting stored energy involves the conversion of stocks to flows.” (page 1)

Our current industrial civilization relies on the vast quantities of energy stored in our one-time inheritance of fossil fuels. These energy stocks allow us to consume energy anywhere on earth, at any hour and in any season. If the limited supplies of readily accessible fossil fuels weren’t running out, and if their burning weren’t destabilizing the climate and threatening the entire web of life, we might think we had discovered the secret of civilizational eternal youth.

Fossil fuels are higher in energy density than any previous energy stock at our control. That energy density means we can ship and store these stocks for use across great distances and long periods. Oil is so easy to ship that it is traded worldwide and is fundamental to the entire global economy.

In particular, fossil fuel stocks can be readily converted to electrical energy flows. And electricity, which is so magnificently versatile that it too is fundamental to the global economy, cannot be stored in any significant quantity without being converted to another energy form, and then converted back at time of use – at significant cost in energy losses and further costs for the storage technologies.

This is the crux of the problem, Palmer and Floyd explain. The vision of a renewable energy economy relies on use of solar PV and wind turbines to generate all our electricity – plus electrification of systems like transportation, which now rely directly on fossil fuel combustion engines. A major part of the book deals with two closely related questions: How much storage would we need to manage current energy demand with the highly intermittent flows of solar and wind energy? and, Are there feasible methods known today which could create those quantities of energy storage?

Beyond simple technologies like huge tanks or reservoirs of oil and gas, and stockpiles of coal, our current economy has little need for complicated means of energy storage. Batteries, while essential for niche uses in phones and computers, store only tiny amounts of electrical energy. But in Palmer and Floyd’s estimations, to maintain an economy with today’s energy consumption without fossil fuels, we will need to expand “current technologically-mediated storage capacity by three orders of magnitude”. (page 28)

What might a thousand-fold or greater expansion of storage technology look like? Palmer and Floyd provide some excellent illustrations. Pumped hydro storage is one promising candidate for managing the intermittent energy flows of solar PV or wind generators. Where suitable sites exist, surplus electricity can be used to pump water to an elevated reservoir, and then when the sun goes down or the wind calms, the water can flow down through turbines to regenerate electricity. This is a simple process, requiring two water reservoirs that are close geographically but at significantly different elevations, and is already used in some niche markets.

But for pumped hydro storage to be a primary means of managing intermittent renewable electricity production – that’s another story. By Palmer and Floyd’s calculations, to produce half of current US peak electricity demand via pumped hydro storage, the combined water flow from all the upper reservoirs would need to be far greater than the typical flow of the Mississippi River, and closer to the total flow of the Amazon River (depending on the average elevation differences between the reservoir pairs).

Comparison of required Pumped Hydro Storage flow to major river flows (by Graham Palmer and Joshua Floyd, from Energy Storage and Civilization: A Systems Approach, page 143). This amount of Pumped Hydro Storage would be needed to meet half of current US peak electricity demand.

Building sufficient battery storage is equally daunting. Palmer and Floyd look at the challenge of converting the world’s gas- and diesel-powered passenger vehicles to battery-electric propulsion. Even after making appropriate allowance for the far greater “tank-to-wheels” efficiency of electric motors, they find that to replace the energy storage capacity now held in the vehicles’ fuel tanks, we would need battery storage equivalent to 142 TWh (TeraWatt hours). As shown in Palmer and Floyd’s illustration below, the key material requirements for that many batteries are vast, in some cases greater than the entire current world reserves. And that is to say nothing of the energy costs of acquiring the materials and building the batteries, or the even more difficult problems of electrifying heavy freight vehicles.

Material requirements for batteries for world’s fleet of passenger vehicles (by Graham Palmer and Joshua Floyd, from Energy Storage and Civilization: A Systems Approach, page 141). To match the deliverable energy stored in the fuel tanks, battery production would consume huge quantities of key materials – in some cases exceeding the current world reserves.

Barring unknown and therefore unforeseeable possible developments in storage technologies that might provide order-of-magnitude improvements, then, it is highly unrealistic to expect that we can simply replace current world energy demands from renewable energy sources. Far greater changes are likely: combinations of changes in technologies, trading practices, regulations, social practices, ways of life. The layers of interacting complexity, Palmer and Floyd argue, are beyond the capacity of computer models to predict.

Their book is a bit of a complex system, too. Although many of the ideas they present are simple and they explain them well, there are sections which go beyond “challenging” for readers who have no more than an ancient memory of high-school-level chemistry and physics. (I plead guilty.) Such readers will nevertheless be rewarded by persevering through difficult parts, because Palmer and Floyd do such a good job of tying all the strands together. The second-to-last chapter, for example, provides a lucid explanation of why the “hydrogen economy” offers real potential for replacing some of the energy storage and transport capacities of fossil fuels – while incurring very significant energy conversion penalties that would have major economic implications.

Civilizations both ancient and contemporary need practices that provide a sufficient Energy Return On Investment – but a high EROI is not sufficient cause for a technology or practice to come into wide use. Rather, we need complete socio-technical systems that provide the right combination of adequate EROI, and adequate and flexible energy storage.

Energy Storage and Civilization is a superb overview of these challenges for the waning years of fossil fuel civilization.


Photo at top by Radek Grzybowski – A stack of wood lays in front of a snowy and foggy forest, Gliwice, Poland; from Wikimedia Commons.