The amount of fossil fuel expended to move a electric motor x miles is less than that expended for the internal combustion engine. Electric motors are vastly more efficient than internal combustion engines. The internal combustion engine is terribly inefficient.
There are numerous ways of generating electricity to charge a EV, whereas internal combustion engines require a single source.
Germany has demonstrated that solar does work by building a vast network of solar arrays on residential housing. By day, power is being supplied to the grid, when demand is the highest. The government subsidized the solar array program partly because it's less expensive to increase power capacity via a distributed solar array network than it is to build another power production plant. And it is more sustainable.
ROI should not always be measured months or a few years. We need to start thinking in terms of generational ROI.
Know a couple of folks that drive Prius's. They love them. One couple has over 150,000 on theirs, never had any problems with it. That's a whole lot of gas stations they have passed.
Measure twice, cut three times, start over. Repeat as necessary.