The database is subject to the IEA’s Terms and Conditions, available at https://www.iea.org/terms. The IEA’s Energy Technology RD&D Budgets database allows users to track trends in spending by energy technology in IEA countries back to 1974. Data is collected from central or federal government budgets, as well as the budgets of state-owned companies, for spending on a range of sectors including energy efficiency, renewables, nuclear power, fossil fuels, hydrogen and fuel cells, and more. All figures refer to total public energy RD&D expenditure data, converted from current prices in national currencies to US dollar PPPs in constant prices.