When I plug my car in overnight in California, what is the carbon emissions of the energy that comes on line to provide energy to my batteries? One can look up what the carbon emissions per MWh are for California where I live. but using that to talk about my car's emissions are a little goofy. When I plug in my car, no more power is generated from large hydro. We get what we can get from the dam. Similarly, my roof's photovoltaics generate what they generate so I think it's inaccurate to say that my car is powered by my PV. So what I want to know is if I telecommuted instead of driving to work, how much carbon would actually be saved? Do they run a nuke 10 kW hotter overnight to meet my car's demand? or do they run a natural gas plant 10 kW hotter? or something else?