You have to be careful with that as some credits are only available to certain manufactured products that meet certifications and warranties and then only if installed by qualified contractors - that by itself can wipe-out any tax credits and incentives, but you are right as it being the best bang for the buck if you have a moderate to heavy use in a good climate.Nifty said:Payback on thermal solar is suppose to be pretty quick compared to photovoltaic (electric) systems. With the 30% federal tax credit it is a good thing to look into, even if you build yourself or have someone install for you.