On 30th April 2017, renewables were highly influential on the UK power market, decreasing the share of fossil fuel generation to just 18 per cent for four hours in the middle of the day, according to energy data analyst EnAppSys. 

During this period, the solar peak was relatively strong, reaching 4.9 GW, but the combination of high solar and wind meant a well-supplied system.

Coal and gas-fired power stations have dominated the power market since its inception, with only nuclear plants making significant inroads against fossil generators prior to 2010. In the years running up to 2010, levels of fossil fuel power generation have typically amounted to 75-80 per cent of total generation, but this dropped to around 50 per cent in 2015 as levels of renewables and power imports rose.
Solar panels
Rob Lalor, senior analyst at EnAppSys, said: “Sunday 30th shows that the GB market now appears to be getting close to the point where a sunny, windy and low-demand day could see electrical demand entirely met by a combination of renewables, imports and nuclear.  Once this point is reached it will be interesting to see how National Grid handles the situation.”

“The rest of the week generally saw a much lower share of power generation from renewables.  This highlights the variations now being seen in a market that used to see very predictable generation shapes, and this continues to create challenges for thermal generation without quite creating the volatility required for storage to enter the market in large volumes.”

“Of the current storage in the market, one 100 MW pumped storage unit was importing power over this renewable peak. Mainly though, the existing storage was either generating for services to support overall grid stability, or inactive during the peak renewable periods, with net levels of storage import/export amounting to a positive export onto the system.”