The UK’s energy system has had its greenest ever summer, from a power generation perspective, according to data released by National Grid.

A surge in wind and solar power has impacted further on the contribution of gas and coal-fired power plants, with NG reporting that 52 per cent of the country’s power demand coming from low carbon sources. This compares to about 35 per cent for the same period four years ago.

The low-carbon boom was led by renewables which made up almost a quarter of all power from June 21 to September 22 from less than 10per cent four years ago, and a fifth last year.

The country was completely coal free in April, while later in May, one quarter of energy demand came from 7 GW of solar power supplying electricity to the grid.

Rob Lalor, senior analyst at energy data monitoring firm EnAppSys told Power Engineering International, “This activity noted by National Grid has come as half of that clean energy has come from nuclear plants and another half from a mix of biomass, hydro, solar and wind generators. Of the remaining sources of electricity, only a nominal share (3 per cent) of total generation came from coal plants, with high levels of interconnector imports coming into the country from the continent.”

One of the most commonly asked questions about renewables – which has particular interest given this activity – is the impact of their intermittency over time and the effect this can have across the market on a day-to-day basis.”

“Comparing this period considered by National Grid in 2017 against the same period in 2014, shows very little change in the levels of generation – and the variations in levels of generation – at gas-fired power stations,” Lalor says, adding, “The comparison also highlights the growth in renewable generation, which has driven down levels of coal-fired generation as levels of clean generation have climbed.”

“If the market continues to shift towards renewables and potentially away from nuclear generation, the impact of renewables may indeed start to climb. However, so far the intermittency of the levels of renewable generation have not had a particularly disruptive impact upon the wider market and have instead merely acted to help push coal plants out of this market.”

For more analysis from EnAppSys go to