Low carbon energy sources accounted for 42.9% of the UK’s electricity supply in 2015.
According to provisional data from DECC, that was due to higher generation from nuclear power plants, which accounted for 23% of output last year.
A growth in renewables, mainly from wind farms, also helped in boosting low carbon production, it added.
Primary energy generation rose by 9% on a year earlier to 123.1 million tonnes of oil equivalent. This first increase since 1999 was due to a rise in oil and gas output.
Production of crude oil rose by 12.8% due to the start-up of new fields and less maintenance activity.
Gas production increased by 8.5% – the first “significant” rise since 2000, stated DECC.
Norway remains the key source of imports, accounting for 61%.
LNG imports were also up by 21%, with Qatar exporting 92% to the UK.
Production of coal fell by 27% to a “record low” due to mine closures and other mines producing less coal as they come to the end of operation.
Last year the government announced it plans to close coal-fired power plants by 2025.