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The Electric Car

Transportation consumes and enormous amount of energy, especially in this country. One of the most recent developments/innovations in this sector is the looming possibility of the electric car. General Motors’ engineers are working in overdrive in a “bet the company” attempt to develop the Chevy Volt by 2010. Daimler recently announced that it would stop making internal combustion engine cars by 2015.

When I first saw these announcements I thought that the companies were crazy. As I’ve been reading through MacKay’s book however, I’m beginning to think that it might just be genius. It might just be beginning of the end of the carbon based economy. I’m formulating a theory in my head that I’ll expound upon later in this series. The gist of the theory however is that the electric car is the key to everything.

The electric car will spur the development of new renewable electricity. I can’t stress how important that this would be. As the cost of renewables has come down possibly the biggest restraint on its growth has been the sunk cost of carbon based electricity generation. You don’t simply throw away a good coal power plant just because a similar cost renewable source is now available.

But in a move to an electricity based energy infrastructure you need massive amounts of new electric capacity. Not to replace current generating capacity but rather to supplement and expand it. The electric car becomes the cattle prod which spurs the development of wind, nuclear and solar.

With that little teaser, I digress. We must first understand if the electric car is feasible.

Is There Enough Lithium?

If we hope to power the world with electricity and batteries, then we probably want to make sure ahead of time that there is enough lithium in the world to make the requisite batteries. Fortunately, MacKay sees no issue here.

Is there enough lithium to make all the batteries for a huge fleet of electric cars? World lithium reserves are estimated to be 9.5 million tons in ore deposits. A lithium-ion battery is 3% lithium. Fisher et al. [2006] If we assume each vehicle has a 200 kg battery, then we need 6 kg of lithium per vehicle. So the estimated reserves in ore deposits are enough to make the batteries for 1.6 billion vehicles. That’s more than the number of cars in the world today – but not much more, so the amount of lithium may be a concern,

There’s many thousands times more lithium in sea water, so perhaps the oceans will provide a useful backup. However, lithium specialist R. Keith Evans says “concerns regarding lithium availability for hybrid or electric vehicle batteries or other foreseeable applications are unfounded.” And anyway, other lithium-free battery technologies are being developed, such as zinc-air rechargeables. I think the electric car is a goer!

You’ve shown that electric cars are more energy-efficient than fossil cars. But are they better if our objective is to reduce CO2 emissions, and the electricity is still generated by fossil power-stations? This is quite an easy calculation to do. Assume the electric vehicle’s
energy cost is 20 kWh(e) per 100 km. (I think 15 kWh per 100 km is perfectly possible, but let’s play skeptical in this calculation.) If grid electricity has a carbon footprint of 500 g per kWh(e) then the effective emissions of this vehicle are 100g CO2 per km, which is as good as the best fossil cars. So I conclude that switching to electric cars is already a good idea, even before we green our electricity supply.

How Much Energy Do Various Types of Transportation Consume?

Electric cars will be more efficient than our current models. But how will they compare with other types of short-distance transportation. After all, if we’re going to struggle to create enough renewable energy, then might we not need for everybody to get on the bus or the train?

MacKay does the math.

Car (doing 33mpg)
Single Occupent 80 kWh per 100 km
Four Person Car Pool 20 kWh per 100 seat-km
Electric car
Single Occupent 11 kWh(e) per 100 km
747 42 kWh per 100 seat-km
ICE at 125mph 3 kWh(e) per 100 seat-km
Victoria line (subway) 4 kWh(e) per 100 passenger-km
London transport trains 70 kWh per 100 actual passenger-km
London buses 24 kWh per 100 actual passenger-km


Trains and buses are potentially much more efficient than cars, if only they were full. But the way we do public transport at present, trains and buses are not that much more energy-efficient than cars. There remain many other good reasons for encouraging a switch to public transport (for example avoiding congestion and reducing accidents), but don’t expect to reduce energy consumption enormously by a switch to public transport.

This is huge. One thing that I am fairly convinced of is that any American solution to climate change will not involve changing our lifestyles precipitously. If at all. I think that Americans can be convinced to fully embrace a societal shift to renewable energy. I think that Americans will embrace electric cars. I don’t think that it will happen however if it is couched in terms of “sacrifice” and “changing your habits.” Americans will pay for renewable energy. You couldn’t pay them to change their lifestyles.

The problem goes beyond a general unwillingness to change however. Since the suburban explosion after World War II the United States has based its entire society on three inter-related things: cheap energy, flexible transport and cheap housing. Each of these three items are necessary components of how we live. Cheap housing exists in the suburbs not the city center. Trains and buses are less convenient than the automobile for suburban living. Cheap energy is necessary for the mass use of the automobile.

Recent spikes in energy costs have led to ridiculous predictions in the media about the death of the ex-urbs. Predictions of recently built housing developments full of 4000 square foot McMansions becoming ghetto-ized apartment dwellings.

I’m not going to examine population projections for the United States in this article. Suffice to say, given the expectation of 50% population growth in the coming decades I expect that the major population centers will become more dense but it will also lead to the further growth of the suburbs and exurbs. Provided of course that the automobile remains at the center of our transportation infrastructure.

In the short term of course, expensive energy will put a dent in this growth. If a carbon free world would force Americans to abandon the mobility provided by the automobile then predictions of a re-ordering our living arrangements might hold more water. But if the energy consumption of trains and buses and electric cars are similar then there will be no need to make changes to how we live.

Americans will eagerly embrace a move to electric cars powered by renewable energy if it is cheap, convenient and allows them to maintain their current lifestyles.

Related Reading:
Part 1: Is There Enough Alternative Energy to Power the United States?
Part 2: Can the Electric Car Save the American Way of Life?
Part 3: How Much Renewable Energy Does the U.S. Produce?
Part 4: Carbon Sequestration. Of Jet Emissions?
Part 5: Professor David MacKay’s View of Future Britain’s Energy Use
Part 6: Wind Power: Can We Get to 300 GW by 2030?
Part 7: The Solar Pipe Dream?
Part 8: World Energy Consumption Per Capita
Part 9: Dealing With the Intermittency of Wind and Solar Power