I suspect it's a question of what you do with the waste heat. Combined Heat and Power (CHP) stations are very efficient, but you need a way to distribute heat

I suspect it's a question of what you do with the waste heat. Combined Heat and Power (CHP) stations are very efficient, but you need a way to distribute heat around the neighbourhood, which is expensive. A home fuel cell could generate electricity efficiently, plus put the waste heat right where you need it for space heating or hot water.