Q2 2017: Capacity and production statistics

by Dr Iain Staffell – Imperial College London 

Output from renewables is up 25% on this quarter last year, while output from fossil fuels is down 16%.

Over the last 12 months, wind and solar accounted for 80% of new capacity installed.

Coal fell to less than 2% of the generation mix. This quarter saw the first full day when no electricity was produced from coal, on April 21st. There were 315 hours this quarter with zero coal output, already twice as many as during all of 2016. Coal stations ran at just 4% of full output over the quarter, seeming to have found a new ‘floor’ of generating 600 MW on average, from 14,000 MW of capacity. There were only eight days in the quarter when coal produced more than biomass, and five days when it produced more than wind or solar.

Prices eased back to £40/MWh day-ahead and £41.50/MWh real-time, after a small rise over winter. Negative prices were seen in 12 hours over 7 days, including four hours overnight on June 7th, and four hours in mid-afternoon on June 24th. At the other extreme, prices spiked to £388/MWh day-ahead (over £1,500/MWh real-time) on May 17th, when wind and solar output dropped by two-thirds from the previous day, margins were tight, and several coal units were started up to fill the gap.

Britain’s electricity supply mix in the second quarter of 2017

Installed capacity and electricity produced by each technology¹

Authors: Dr Iain Staffell, Professor Richard Green, Dr Rob Gross and Professor Tim Green

1. Other statistical sources give different values because of the types of plant they consider. For example, BEIS Energy Trends records an additional 900 MW of wind, 600 MW of biomass and 500 MW of solar, respectively producing 1.4, 1.2 and 0.2 TWh extra per quarter. These plants and their output are not visible to the electricity system and so cannot be reported on here. ↩
2. In absolute percentage points. ↩
3. These are the raw values from National Grid and Elexon without modification. ↩