Many electricity producers have switched from coal to cleaner shale gas, which is produced in the Dakotas, Texas, and other places, and CO2 emissions have fallen considerably.
As a result, electricity producers are scrambling to ensure an adequate supply.
"These lower emissions were dampened by higher use of coal and less gas by electricity producers," it said.
Mr. Ellis said his utility maintained agreements with 30 small electricity producers, including schools, hospitals and one homeowner.
Mr. Schjoelset said a price of 30 to 40 euros a ton was needed to encourage electricity producers to switch from coal to natural gas, a cleaner fuel.
Software giant SAP aims to push electricity producers to become even more sustainable by developing and implementing procurement guidelines that demand very specific standards.
By selling direct, small electricity producers would be able to charge more per unit and buyers could pay less than current market rates.
But the big one was scrapping the exemption that renewable electricity producers had under the climate change levy, a tax that is meant to help cut emissions.
Obama, who will host the summit in Pittsburgh, will propose a gradual elimination of the tax breaks, cheap loans and other measures extended to oil, gas, coal and electricity producers.
Greece's debt crisis threatens to turn into an energy emergency, with the state natural gas company threatening to cut supplies to electricity producers if they fail to settle their arrears.
In the same way that wind farms supply national grids, and sell renewable electricity, producers are able to sell on the certificates that show how much sustainable oil they have made.
