You are talking about spot market prices, not wholesale power prices. Most of the wholesale prices are established in forward markets (several months to a day a

You are talking about spot market prices, not wholesale power prices. Most of the wholesale prices are established in forward markets (several months to a day ahead) and I don't remember ever seeing them negative. So following your logic it would be unfair that some power plants can run and earn positive income (when their production is sold forward) at the same time when other need to pay to run (when their production is sold on spot market). But there is nothing wrong in this - that's how balancing in power markets works. Also you mentioned that wholesale and retail power prices can be very different. There are multiple of reasons why this is the case, but the important result is that consumers do not understand how balancing market works and why prices can be one hour $1000 and the next negative. If we want to encourage solar power installations by retail customers the pricing should also be based on retail model. So I would disagree that your comment about negative prices is relevant to how prices should be set for power produced by home solar panels. But I do agree - it is quite complicated question as most questions concerning power grid.