By Jennifer Sensiba, Clean Technica, February 3, 2021
A recent article at Bloomberg gives readers a really cool set of infographics showing how much energy EVs could save the US economy. They answer the question of “where would all that electricity come from” and make some really good points.
A recent article by Liam Denning and Elaine He at Bloomberg gives readers a really cool set of infographics showing how much energy EVs could save the US economy. They answer the question of “where would all that electricity come from” and make some really good points. The biggest one is that changing to mostly EVs by 2030 would allow a much greater amount of economic activity using less energy than we do today.
To do this, they took data from Lawrence Livermore National Laboratory and simplified it. I can’t show the Bloomberg charts here due to copyright laws, but as a government agency, the National Laboratory’s works aren’t subject to copyright. They use a Sankey diagram to show the flows of energy from fossil fuels, solar, nuclear, hydro, and everything else from raw fuel to the final uses of the energy.
The cool thing the Bloomberg team did was to make it simpler, explain what “rejected energy” means (mostly wasted), and otherwise make it more readable. They also created a projected chart of what it would look like if the US switched away from fossil fuels for transportation and made the grid cleaner. The final result is a really cool looking overlay Sankey chart that compares today to the goal for 2030.
I’ve been using the Lawrence Livermore Sankey flow charts for years when discussing fossil fuels with people on social media for years. In fact, I started writing for CleanTechnica after my online arguing got noticed by some of the staff. Don’t let anyone tell you that you’re wasting time arguing on social media, it could, in rare cases, make your life better! (kidding, mostly)
The big point I make to people is that around four-fifths, or 80%, of energy from oil gets wasted when we burn it in internal combustion engines. This, of course, varies by engine type. Some newer diesels and variable compression gasoline engines achieve as much as 40% efficiency (40% of the energy burnt goes to moving the car), but most vehicles are nowhere near that efficient.
The chart’s numbers are in “quads,” a unit of energy that is roughly equal to 8 billion gallons of gasoline, 36 million tons of coal, or 5 times the energy released in the Tsar Bomba nuclear test, the most powerful ever.
When people think about electric cars, they seem to know that gas-powered vehicles use a lot of energy, and they assume that an electric car would need an equivalent amount of energy. Were that the case, there would be reason for panic because the grid may struggle provide it. What they don’t know is that EVs are far more efficient.
Instead of wasting 60-90% of the energy, an EV converts between about 75 to 90% of the energy to actually moving the car. This depends heavily on driving speeds, the relative heaviness of the driver’s right foot, and whether the vehicle can take advantage of regenerative braking. With so little waste, an EV needs far less energy than a gas car, and thus don’t need the equivalent of a gas car’s gasoline energy.
In fact, a gallon of gas contains about 33.7 kWh of potential chemical energy. Most EVs go well over 100 miles on that much battery power.
With all of this in mind, it’s not surprising that switching most vehicles to EVs would save a lot of wasted energy. Instead of throwing away 3/4 of the energy, we’d use 3/4 of it. This makes it possible to not only lower pollution and improve the climate change situation, but it also allows us to do a lot more work with less energy used.
By 2030, the economy will be bigger and the population will be bigger. There will be more cars and trucks. There will be a lot more useful energy needed. If we use more efficient technologies to generate, use, and re-use energy, we’d be able to handle all of that extra economic activity while using less energy than we presently do.
So, the next time somebody asks, “But where will all that electricity come from?,” have a bookmark for this article on hand. You’ll be able to send them the information from Lawrence Livermore National Laboratory and from Bloomberg. You won’t be able to convince all of the people arguing against EVs, but the ones willing to accept new information will get some good resources from you.
When the Electric Car Is King, Less Energy Is More
President Joe Biden wants to electrify the federal vehicle fleet. Tesla Inc. just sold half a million plug-in cars and expects to increase that by 50% a year. General Motors Co. and Ford Motor Co. are even working on electric Hummers and F-150s.
So where’s the power going to come from? EVs are already greener than cars running on gasoline even with our current electricity grid. But mass adoption only makes sense as part of a do-over of the entire energy system, so the question of what will power all these plug-ins is valid.
And here’s a surprising answer: Electrifying U.S. vehicles wipes out the equivalent of our entire current power demand.
The U.S. consumes a lot of energy; last year, about 100 quadrillion BTUs (equivalent to 17 billion barrels of oil; which, we’ll admit, is only marginally less abstract). But only about a third of that is ultimately used in terms of actually lighting lights, turning wheels and so forth. The second law of thermodynamics means, for every unit of thermal energy we actually put to useful work, roughly another two end up wasted as heat.
How we don’t use energy is just as important to understand as how we use it. Here’s a simplified version of a Sankey diagram from the Lawrence Livermore National Laboratory showing the various inputs to the U.S. energy system and where they end up.
Large-scale waste is unavoidable with a thermal energy system, or one where we mostly burn stuff or split atoms (97% of the inputs in 2019). Burning fossil fuels also generates the carbon emissions causing climate change; so wasted energy is a proxy for the damage being done (apart from nuclear power). In contrast, renewables such as wind, solar and hydropower capture energy directly from infinite sources. While a small amount is lost in transmission, the vast majority is used.
So here’s a thought experiment: What if the entire U.S. light-duty vehicle fleet (currently about 270 million cars and trucks) were electrified by 2030 and we expanded wind and solar generation at a rapid pace, while eliminating coal power, at the same time?
The result is that we not only end up with a drop in U.S. carbon emissions of almost 30%, but also a far more efficient system overall.
Let’s go back to that Sankey diagram and show what happens to the inputs of 2019 by 2030 under a few simple assumptions:
- •Solar generation rises by 20% a year; wind by 10%; coal and oil generation drop to zero.
- •Energy consumption rises as per the Energy Information Administration’s long-term forecasts…
- •…But with the added adjustment that light-duty vehicle energy demand converts entirely to electricity.
- •The additional electricity required that isn’t met by solar or wind is generated with natural gas.
The power-generation system transforms from one dominated by fossil-fuels both in terms of inputs and useful energy to one that is essentially half natural gas and half non-fossil, with the majority of that being wind and solar. Despite the electrification of light-duty vehicles, inputs to the grid actually fall slightly. The replacement of coal-fired power by more efficient gas turbines and the rapid expansion of non-thermal renewable power means useful electrical energy rises by more than a third anyway.
That efficiency gain feeds into an even bigger one: the replacement of inefficient internal combustion engines.
Despite the assumed retention of these by heavier vehicles — an unsafe assumption, but just keeping it simple — and increased use of petroleum in industrial processes, the amount of oil funneled into the top of the energy system drops by more than one-third. Assuming that’s all gasoline, it equates to more than six million barrels a day of demand dropping away. That’s peak oil demand right there. Along with that, the wasted energy from transportation, which accounts for more than a third of the total today, drops by more than half.
Throw in the efficiencies on the grid itself, and the amount of wasted energy saved is equal to one-sixth of current U.S. energy consumption. Overall, U.S. primary energy consumption drops by 13%.
That saving is bigger than the entire amount of electricity we draw from the grid today — despite a bigger population, a bigger economy and an utter transformation of the American vehicle fleet.
Even under this scenario, more than half the energy inputs of 2030 would still be wasted as heat. But with the grid and the vehicle fleet now much more efficient, the industrial sector becomes the single biggest user of fossil fuels and source of wasted energy.
Such an enormous project requires enormous investment; in EVs, of course, but also in everything from new wind turbines to electric-vehicle chargers. At current capital costs, the build-out of solar, wind and gas-fired capacity required under our simple projection adds up to about $80 billion a year. But “current” does a lot of work there; renewable technology costs have dropped precipitously over the past decade and BloombergNEF projects a further drop of 40% and 20% for solar and wind-power, respectively, by 2030. Moreover, focusing only on costs ignores the benefits of investment: At a notional $50 a tonne, the value of negated carbon emissions adds up to $83 billion in 2030. At $50 a barrel, $115 billion worth of annual oil demand disappears.
Gas producers, with all that extra demand for power, would no doubt be happy. But since gas is just the plug in this simplistic model, don’t go buying that plot in Appalachia just yet. Resulting higher gas prices would have their own impact. Also, wind and solar-power might grow faster than our assumptions as prices keep falling. Meanwhile, lithium-ion battery pack costs, having dropped by almost 90% since 2010, are projected to drop another 60% by 2030.
The point here is that alternatives to the thermal energy system that has powered us simultaneously to modernity but also a gathering climate crisis are available. And their less-is-more efficiency gains offer a compelling reason to embrace them.
 You will notice our version adds up to 96.3 quadrillion BTUs of primary energy consumption rather than Lawrence Livermore National Laboratory’s 100.2 quadrillion. This is because the latter treats renewable energy sources as if they were thermal in order to make them comparable to the dominant sources such as oil, natural gas and coal. This grosses-up the renewable energy numbers; we’ve adjusted them down to remove this.
 Forecasts are taken from the Reference case in the EIA’s Annual Energy Outlook 2020, published in January 2020.
 This forecast is derived as follows. Light-duty vehicles account for 54% of U.S. petroleum-derived energy demand, according to the “Supersankey” chart created by Otherlab for the Advanced Research Project Agency of the Department of Energy. This implies 13.9 quadrillion BTU of primary petroleum demand, for useful energy consumption of 2.9 quadrillion at assumed 21% thermal efficiency. That 2.9 quadrillion is equivalent to 3.8 quadrillion of electricity from the socket, assuming all vehicles are electrified at 77% efficiency (see this). Vehicle miles traveled are forecast by the EIA to grow by 9% through 2030, implying the electricity required from the socket for the fleet would be just over 4.1 quadrillion BTUs.
 Apart from coal, oil, natural gas and renewable power, all other electricity sources are kept constant to keep things simple.
 As per “Capital Cost and Performance Characteristic Estimates for Utility Scale Electric Power Generating Technologies” (Energy Information Administration, February 2020).
 Forecast change in levelized cost of electricity for U.S. utility-scale solar and onshore wind power from 2020 to 2030, as per BloombergNEF’s “New Energy Outlook 2020” (November 2020).
 Source: BloombergNEF’s “New Energy Outlook 2020” (November 2020). The projected decline in battery costs assumes continuation of an 18% learning rate.