I live in a region of coal mines and power stations. That’s probably why any suggestion that coal power does less harm that renewables disgusts me.
Limiting discussion to batteries and fuel cells, the question comes down to cost versus benefit. Environmental harm is a substantial component of cost.
Any production process has some extractive industry component. So what are they made from and what are the impacts of mining/refining/transporting materials?
Nothing lasts forever, so what is the comparative service life? Tesla’s projected battery life is 5 years or 100,000 miles. The fuel cell in Toyota’s Mirai is warrantied at 100,000 miles. Both degrade over time, whether in service or not.
Clearly, we can’t just dig stuff up, use it once, then throw it in a hole, so what is the impact of recycling? Of course, before that becomes a real question, we’ll need to get our recycling act into gear.
Next is full-cycle efficiency. As mentioned above, batteries are typically 80% efficient. The figure for fuel cells is around 30%. Power from renewable sources might be close to free, but needing to build more than twice as much capacity is going to have impacts.
This is just off the top of my head. I haven’t answered every question. I haven’t asked every question.
