The renewables share was up from 24.5% in 2016, said the Department of Business, Energy and Industrial Strategy (BEIS).
The growth was driven by onshore wind output that surged 39% and a 27% increase in offshore generation, both to new record levels, thanks to extra capacity and higher wind speeds.
Solar and hydropower also did their bits, increasing by 11% and 10% respectively, the data shows.
The UK’s renewable power fleet generated a total of 99.3TWh, a 19% uplift on 2016’s figure.
The growth in renewables was mirrored by a fall in coal generation, which saw its share decrease to 6.7% in 2017 from a year-earlier 9%.
The UK government this week underlined its commitment to the offshore wind sector by pledging auctions for new capacity every two years through the 2020s.
However, the country’s renewables sector continues to warn of a dip in capacity growth if onshore wind and PV remain locked out of the main CfD support mechanism.
UK renewables’ share of total energy consumption reached 10.2% in 2017, up from 9.2%, as measured under EU directives.