>What I don't understand is how anyone who isn't benefiting from the tax credits could bid at or below zero. It's also a pretty cheap way of advertising a mark

>What I don't understand is how anyone who isn't benefiting from the tax credits could bid at or below zero. It's also a pretty cheap way of advertising a market opportunity and driving investors' expectations: your money would be better spent on a new aluminum smelting plant being our customers rather than a new coal or natural gas plant being our competitors. Believe it or not, in the early days, the oil industry also had this problem of "excess supply". In the UK in the 1900s they dealt with this by lobbying Winston Churchill (before he was prime minister) to shift the navy from running largely on coal to running on oil.