http://www.dallasnews.com/business/energy/20160405-what-do-texas-and-california-have-in-common-negative-power-caused-by-renewables-glut.ece What do Texas and California have in common? 'Negative power' caused by renewables glut Average, wholesale power prices in Southern California have gone negative on about a dozen days over the past year, falling as low as minus $23.87 a megawatt-hour, grid data compiled by Bloomberg show. A year earlier, it happened once. Interesting article.