The scientific data on climate change are overwhelming. We need to save our planet and do whatever we can to combat climate change. After all, this is the only planet we have, so not killing it - and ourselves in the process - seems like a really good idea. This year’s horrific forest fires on the west coast are yet another example of what we will have more of in the future if we don’t do something. But no matter how much some people wish it were true and how often they might say it, a Battery Electric Vehicle (BEV) is not on its face necessarily ‘environmentally friendly’. The hard facts are that it primarily depends on how the electricity is generated to charge the EV.
Electricity is not ‘free’. It doesn’t just come out of a wall socket on its own. Some other primary energy source must be used to generate the electricity. Most promotion of BEVs ignores this.
The fundamental problem is that right now, fossil fuels still provide about 63% of the electricity generated in the US, with nuclear an additional 19%. There are significant regional differences, but overall only about 11% of US electric power is generated from renewable sources:
https://www.eia.gov/tools/faqs/faq.php?id=427&t=3
A BEV can make more sense in a place like Oregon that gets 70% of its electricity from ‘clean’ sources (hydro and wind), but not so much in Minnesota that is heavily dependent on coal and natural gas, or the country at large.
California gets about half its electricity from renewable sources, but also about half from fossil fuels, mostly natural gas. It might make sense for California to push for BEVs, since they would actually be half natural gas plus half renewable source powered (and hopefully more by the 2035 timeline), but that’s not necessarily the case for the rest of the country.
Globally, China currently gets 60% of its electricity from fossil fuel, mostly coal, which changes the BEV calculation there. Shockingly, Japan is building 22 new coal powered electric generating plants, which together will release about as much CO2 as all the cars sold in the US:
https://www.nytimes.com/2020/02/03/c...fukushima.html
As a result, in aggregate BEVs essentially have a ‘long tailpipe’ to whatever form of primary energy was used to generate the electricity. A report in Scientific American estimated that a Nissan Leaf and Toyota Prius both produce on average about 200 grams of CO2 per mile (though it would be about 100 grams/mile CO2 in California, and 300 grams/mile CO2 in Minnesota):
https://www.scientificamerican.com/a...ssarily-clean/
There is also a fundamental problem with how BEVs are promoted and the resulting perception of their ‘environmental friendliness’. The way MPGe numbers used for BEVs are calculated assume 100% efficiency in converting fossil fuel to electricity. This violates the laws of thermodynamics. In actuality, only 30-40% of the energy contained in fossil fuels can be converted into electricity in any thermal process (though newer combined cycle natural gas power plants can reach 50%). That means about 2/3 of the energy is wasted (plus about 10% lost in transmission). This has been widely discussed and reported:
https://dothemath.ucsd.edu/2011/08/m...electric-cars/
https://personal.ems.psu.edu/~radovic/Chapter4.pdf
https://www.forbes.com/sites/warrenm.../#54dc4b4929de
https://www.nrel.gov/docs/fy17osti/67645.pdf
With only about 30-35% of the energy contained in fossil fuel actually converted into usable electricity, this means that to put 85 kWh of electric charge into a BEV requires 269 kWh of fossil fuel or nuclear energy. Thus, a Nissan Leaf that is advertised with ’99 MPGe’ in an apples-to-apples comparison is actually getting the equivalent of 28-36 real world MPG. Not bad, but certainly significantly different than what the flawed MPGe number suggests, and objectively not much better than a modern ICE car.
When financial subsidies are taken into consideration, the picture gets murkier (though of course multi-millionaire Tesla buyers enjoyed getting unneeded discounts on their purchases):
https://www.politico.com/agenda/stor...ronment-000660
The calculation becomes even less favorable when taking into account the environmental impacts of lithium and rare Earth metal mining, battery disposal at end of life, etc.
Nuclear fission energy is also not the answer. Nuclear energy (being a thermal process) is also about 30% efficient in converting the heat released by the fission of uranium into electricity. Nuclear power generates 19% of the electricity in the US and does not directly generate carbon emissions. However, mining and processing of uranium requires massive amounts of energy, impacts water supplies, as well as the thorny problem of disposing of nuclear waste (spent fuel), so nuclear fission might not be the best option for increased electric power in the future (fusion is another story, but unfortunately we’re not there yet).
https://pubs.acs.org/doi/full/10.1021/es702249v
Of course the situation would be completely different IF electricity were predominantly generated from renewable sources (solar, wind, tidal, geothermal, etc.). But at present, only 11% of electricity in the US comes from renewable sources. Hydro generates an additional 7% but has its own issues, including the environmental impacts of flooding regions when dams are built, questions about the future reliability of hydro power because of climate change, and the fact that it’s already fully developed in the US with little expansion ability.
Like most things in life, the solution is going to be complicated, and not simply buying more electric cars. At its core, a fundamental need is to change the US, and world, electric generating grid to renewable sources. That will take a lot of money. Just for the US it would cost $5 trillion:
https://www.renewableenergyworld.com...e-spending-go/
Especially in the new coronavirus reality, with the world likely heading into several years of economic recession if not outright depression, and the US having to deal with trillions of dollars already spent on ‘economic recovery’, it’s hard to see where and when the money could come from to convert to renewable sources.
So unfortunately, the bottom line is that with the CURRENT US electric energy grid, one would probably be better off simply burning fossil fuel directly rather than converting it into electricity to then power a BEV. As much as it might sting to some people the think about it, in many areas of the country, and world, a BEV essentially just has a ‘long tailpipe’ back to whatever power plant is generating the electricity – which more often than not is still fossil-fuel powered. It still comes back to having to change the US electric grid and how electricity is generated. Unfortunately, we are not going to save our planet one Nissan Leaf at a time. Until then, we’re just kidding ourselves with artificial and inaccurate ‘MPGe’ numbers that might make some people feel good, but don’t reflect reality.
If we really want to save the planet - and ourselves - we need to elect political leaders with the courage, wisdom, and willingness to make the massive financial investments needed to create an electric power grid fueled by renewables such as solar, wind, and tidal sources. With Trump’s actions of cutting corporate taxes and reducing government revenues, and the increasingly short-term thinking by private companies focused on instant profits, it’s hard to see where all the money will come from without some dramatic changes.
This BEV push might make sense for California, with half of their electricity coming from renewable sources and hopefully more by the 2035 mandate. But in general, wishful thinking about BEVs doesn’t change the facts that they don’t really make sense yet for the country or world as a whole as long as the electric grid is primarily generated by fossil and nuclear fuels.