Do Fossil fuel Taxes Promote Innovation in Renewable Electricity Generation?

We evaluate the role of a fossil fuel tax and research subsidy in directing innovation from fossil fuel toward renewable energy technologies in the electricity sector. Using a global firm-level electricity patent database from 1978 to 2011, we find that the impact of fossil fuel taxes on renewable energy innovation varies with the type of fossil fuel. Specifically, a tax on coal reduces innovation in both fossil fuel and renewable energy technologies while a tax on natural gas has no statistically significant impact on renewable energy innovation. The reason is that easily dispatchable energy sources like coal-fired power plants need to complement renewable energy technologies in the grid because renewables generate electricity intermittently. Our results suggest that a tax on natural gas, combined with research subsidies for renewable energy, may effectively shift innovation in the electricity sector towards renewable energy. In contrast, coal taxation or a carbon tax that increases coal prices has unintended negative consequences for renewable energy innovation