Causalien
Prime 8 ball Oracle
Telling them your car is powered by rooftop solar unusually stops "most" of their argument, until they tell you how its made or some other tangent to avoid your facts.
They are going to start arguing that rooftop solar pollutes more than normal shingle rooftops. Then argue about the pollution from production of solar cell, the waste. How dirty transporting it to each house is going to be. It's going to be dirtier than just have coal fired power plant providing power (DUH. More stuff = more CO2, but over the lifetime, solar has less).
I seriously had an argument with people the other day (when they lost the argument that EV produces less CO2 over its lifetime than gasoline cars) who argued that Hydro pollutes more than coal because it produces more methane than we originally thought. Therefore, BC with 95% hydro pollutes more than Alberta at 45% Coal and 41% natural gas.