I don't think it really adds up. It's an inconvenient install location and roofs are replaced every 10-20ish years. It makes sense from an efficiency standpoint but the capital costs outweigh that.

IMHO a pergola or carport is going to be better. You lose solar efficiency but gain the benefit of something that provides shade. Especially as solar panels have become an economical roofing option if you don't care about perfect waterproofing.