3 thoughts on “Electric Vehicles: Climate Saviors, or Not?

  1. Mary Mangan

    It’s fine to look at all these different levels, and I see the value in that. But you can also look at the individual level for an even more detailed analysis.

    We know from surveys that many people with EVs have solar on their homes (at least in the US). In fact, this was my process as well: I installed more capacity than I needed with the plan to purchase an EV subsequently. And that’s what I did. Also, I charge it only during sunny days. Because I can.

    EV owners don’t buy these cars on a whim. You have to understand the range issues, and in my experience owners are very conscious of their environmental impact. If they can’t have solar on their own homes, many pay to have green energy support for their homes. The program I bought my car from, “Mass Energy Drive Green” even offers wind sourcing as part of their efforts. Many owners plan to charge at workplace charging stations during the day, when presumably more solar is online.

    So of the broader-brush higher-level evaluations have led to misunderstandings and misinformation about how low emission these vehicles can be. I think there’s more to be considered.

  2. Albert Rogers

    If the entire electric industry were supplied with enough production-line produced generation IV nuclear (see Thorcon and others), to meet peak demands, there would be plenty of clean spare off peak electricity to charge vehicle batteries, and let’s not forget electric trains.
    Until then, I’m skeptical, But even so, electric vehicle battery charging is a far more appropriate use for wind and solar than attempting to supply an AC electric grid.

  3. lukafoto

    I have the maximum permissible solar PV on my home. It doesn’t go any where near offering enough power to charge an EV. At best it’s 22 kWh on a long summer’s day – infrequent in UK. In winter it might only produce 0.3kWh. Solar PV panel manufacture has it’s own CO2e & other environmental costs.

    A family of 4 living in a small (by US stds) house might save 1/3 on their electricity bills (not including EV charging). We saved 2/3rd on heating bills by installing Solar Thermal panels that are 75% efficient and reduce fossil buring to heat a thermal store.

    There is no mention in this article about battery degredation. A 2014 BMW i3 BEV now (Spring 2017) gets 40 miles range even with preconditioning for a mild (10deg C) day. The consumption stated by the onboard computer is for battery to wheel not grid to wheel. So whilst some i3 owners claim 5 miles per kWh from the grid this can be 2.5 miles per kWh when measured from the electricity bill.

    BMW warrants the battery for 100,000km and 8 years. This is done by having a larger pack that is accessible to the user. As the battery degrades the car goes in for a “service” where more of the pack is made available to “top up” the range again. To replace the pack it costs 9000 euros in Germany. That includes returning your old pack.

    As for charging and discharging losses to meet grid demand there are degradation issues and energy losses that need to be addressed.

    Electric motors are very efficient but the poor energy density of batteries means EVs waste energy from a vehicle efficiency point of view. A Tesla Model S can have a 750kg battery pack. That takes energy to move. A BMW i3 60Ah pack is around 250kg for 40 miles winter / 80 miles summer. Compare this to a 17 year old, 250,000 mile Audi A2 that can go 100 miles on 4kg of renewable, low Nox, low PM #HVO any time of year.

    We also need to look at battery pack manufacture and the sources of elements like Cobalt, Nickle, Copper, Lithium etc. At present (low demand, slow economy) there are 40,000 children mining Cobalt for our batteries in the DRC. The official open cast mining also affects rain forests.


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