Here are some more instances of negative electric power costs: "Negative prices in wholesale electricity markets indicate supply inflexibilities"
http://www.eia.gov/todayinenergy/detail.cfm?id=5110
Here are some more instances of negative electric power costs: "Negative prices in wholesale electricity markets indicate supply inflexibilities"
http://www.eia.gov/todayinenergy/detail.cfm?id=5110