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Hybrid / EVs and CO2
In areas using electricity generated from coal, highly efficient hybrids are markedly superior to EVs from a global warming and CO2 emission point of view. A typical EV in the form of a class B or C car, powered by coal generated electricity, causes emissions of about 160 g CO2 / km.
The same vehicle powered by a highly efficient hybrid power train just causes 76 g CO2 / km (tank-to-wheel), and 93 g CO2 / km well-to-wheel, i.e. including also transport and refining of fuel, which gives a fair comparison. Above we have also ignored that EVs tends to be slightly heavier as batteries for obtaining practical range are heavy. This more than offsets any gains in lighter EV power trains. Plug-in hybrids will cause CO2 emissions somewhere between that of HVs and that of EVs depending of how much of their energy that comes from the electric grid.
This is not highly controversial. But is the specific electricity used for charging EVs made by fossil fuels?
Today 66% of world electricity is generated from fossil fuels, mostly from coal. In the EIA reference scenario, fossil fuels will increase from 66% to 73% until 2030. More than 50% of added electrical energy will be based on coal, from 7 to 15 Trillion kWh per year. We hope for and might even expect a more sustainable development than described in the EIA reference scenario, but it is still unlikely that we will experience a decisive global reduction of electricity generated from fossil fuels within the next 20 years.
The marginal consumption of electricity will probably to a very high extent be fossil/coal based, even in the long term. The situation in Sweden is a good example. Sweden is almost uniquely independent of fossil fuels for electricity. Less than 5% of electricity is based on fossil fuels, of which about 2% is coal. However, if electrical consumption increases on a 20 years horizon, about 90% of that added consumption is estimated to result in fossil fuels being used, mostly coal. The study quoted below also shows this will hold true in most political scenarios. Only radical policy changes in EU, such as an increase of CO2 penalties with a factor of four, is considered to give real impact (penalties of 45 EUR/ton are considered necessary, approx. 10 EUR/ton today).
The situation and policies in Sweden might change radically (it is not that painful to replace 5% of capacity), but this still highlights that long term marginal electricity tends to result in coal/fossil fuel being used to a higher degree than in the existing energy mix. EVs are good examples of such marginal usage of electricity, i.e. usage not existing today.
It will require a major effort and many years just to reach close to 5% fossil based electricity for most countries. And even then a substantial part of added marginal consumption used by EVs might well still be generated by coal, as the marginal electrical energy mix in Sweden of today suggest.
Carbon capture and storage (CCS) systems would make coal power acceptable. According to IPCC, CCS is not likely to have major global impact before 2050-2100.
And finally very small part of coal power generation uses generated heat to other purposes, in US about 2-3%.
Conclusion
Today, highly efficient hybrids are markedly superior to EVs from a global warming and CO2 emission point of view. This is true globally and in most areas, i.e. where energy used for EVs is coal-based to a large degree. Sometime in the future EVs will be more advantageous. The timeline depends primarily on radical and global policy change. It is not certain, or even likely, that this will occur before 2030-2050.
If all consumers of electricity claim they are using non-fossil generated electricity, but at the same time 2/3 of world electricity is generated by fossil fuels, we are in effect just fooling ourselves, and as community not taking global warming seriously.
