The WSJ article doesn't properly explain where the negative prices come from. It only briefly mentions "subsidies", but I don't think that is a complete explana

The WSJ article doesn't properly explain where the negative prices come from. It only briefly mentions "subsidies", but I don't think that is a complete explanation. My understanding is that the negative prices come from a tension between long-term agreements and short term markets. For example, a solar or wind farm may enter into an agreement with a company which promises to buy all the produced energy over a certain period, at a fixed price per MWh. (In practice this seems to be implemented as a "contract for difference", but it amounts to the same thing.) The buyer does this because they estimate that it will result in a cheaper energy bill overall. Even if they sometimes have to pay for energy they don't need. And even if they sometimes have to pay a positive price while the short term market prices are negative. The seller is then shielded from short term prices, and will continue to produce and get paid for energy which isn't needed. The price signal isn't getting through. If it would turn out that balancing the grid becomes problematic, then I think this could be fixed with regulations that forces some of the short term price signals to always "get through". E.g. on the producer side, it could be forbidden to get paid a positive price for energy produced when the short term price is negative. On the consumer side, certain types of consumption that can be scheduled (like charging an EV) could be forced to use a contract that follows the short term market price.