We compare the effectiveness and efficiency of cap-and-trade and carbon tax policies in a generation
expansion planning framework. The effectiveness refers to a policy’s capability to control the amount
of carbon emissions, and the efficiency is measured with respect to seven criteria: average emissions
price, actual emissions, renewable energy portfolio, total generation, total profit of Gencos and grid
owner, economic welfare, and emissions adjusted economic welfare. Cap-and-trade and four variations
of carbon tax policies are integrated in a game-theoretic based generation expansion planning model
to assess their impacts on new investment in renewable energy generation capacity. A case study is conducted
on a 30-bus test system, and numerical results provide insights on the advantages and disadvantages
of these policies.