The skies may be gray and the ground dappled with the white stuff right now, but the U.K. can look back on 2017 as its greenest year ever as figures from the National Grid confirm record levels of renewable electricity generation.

The data covers the period of January 1 to December 12 this year and reveals that on 315 days renewables produced more power than coal plants. Broken down by generation source, wind bested coal on 263 days of the year, while solar bettered coal’s output on 180 days of the year.

Between the sunniest months from April to August, coal provided more power than solar on just 10 days. Overall, renewables outperformed coal for 90% of the year, data from MyGridGB shows.

Such a divide between clean energy and fossil fuel-produced power is only going to widen in the coming years, say energy experts, as more coal plants are idled and the U.K. steadily increases its onshore and offshore wind fleet, as well as its solar capacity.

Although a relatively modest year for PV in the U.K., solar growth is likely to top 1 GW this year, having reached a conservative official figure of 902 MW by November. This year also saw the first full day without coal power generation ever, and a series of record solar days in the summer.

However, while coal has undoubtedly been beaten, attention must now turn to gas, which remains the most dominant source of baseload electricity generation power in the country. In 2017, wind outperformed gas on only two days of the year, while for renewables combined that figure is a modest 23 days.

“If we continue to use gas at the rate we do,” warned MyGridGB’s Andrew Crossland, “then Britain will miss carbon targets and be dangerously exposed to supply and price risks in the international gas markets.

“Clearly, refreshed government support for low-carbon alternatives is now needed to avoid price and supply shocks for our heat and electricity supplies.”

Since 2012, the U.K. has halved its carbon emissions from the electricity sector and now operates the world’s seventh-cleanest power system.