Cross-border electricity market effects due to price caps in an emission trading system: An agent-based approach

A common, moderate CO2 auction reserve price results in a more continuous decarbonisation pathway. This reduces CO2 price volatility and the occurrence of carbon shortage price periods, as well as the average cost to consumers. A price ceiling can shield consumers from extreme price shocks. These price restrictions do not cause a large risk of an overall emissions overshoot in the long run. A national price floor lowers the cost to consumers in the other zone; the larger the zone with the price floor, the stronger the effect. Price floors that are too high lead to inefficiencies in investment choices and to higher consumer costs.