You'd probably be cutting it close with the life of the panel (though maybe electricity price increase will save you) For CO2 I think it pays itself off fairly

You'd probably be cutting it close with the life of the panel (though maybe electricity price increase will save you) For CO2 I think it pays itself off fairly quick. It's probably the best investment you could make from a CO2 and local air quality perspective, maybe if your insulation is very bad or switching to a bike from a large personal car