This paper was prepared for the OECD-IEA Climate Change Expert Group (formerly called the Annex I Expert Group) for the purpose of providing useful and timely input on specific topics relevant to international negotiations under the United Nations Framework Convention on Climate Change (UNFCCC)....

The paper at hand examines the power system costs when a coal tax or a fixed bonus for renewables is combined with CO2 emissions trading. It explicitly accounts for the interaction between the power and the gas market and identifies three cost effects: First, a tax and a subsidy both cause...