Bloomberg: The Japan Electric Power Exchange will start trading United Nations-emission credits and carbon- free electricity next month, a bourse official said. The exchange plans to charge a 2,000 yen ($20.61) commission on each transaction of 10,000 tons of the certified emissions credits, known as CERs, the official said under condition of anonymity because the details haven’t been announced yet. Tokyo Electric Power Co., Marubeni Corp. and Merrill Lynch & Co. are among exchange …