The nitrogen oxides (NOx) charge in Sweden was introduced in 1992. The charge is based on measured NOx emissions by electricity and heat-producing boilers, stationary combustion engines and gas turbines producing at least 25 GWh of useful energy per year. The charge was raised in 2008 to 50 kronor per kilogram NOx. IEA/IRENA Global Renewable Energy Policies and Measures Database © OECD/IEA and IRENA, [November 2020]