The total renewables share of generation rose to a record quarterly high of 30% in Q1 2018 in the UK. Official government statistics show that wind and solar generation remained higher than nuclear output, which was the UK’s second largest source of electricity. Overall, final electricity consumption increased by 2.0% year-on-year to 82.4 TWh. Cold temperatures increased domestic and commercial consumption. However, final consumption by industrial users (including iron and steel) fell by 4.1%.
Q1 2018 saw wind generation increase by 38% due to an increase in both capacity and wind speeds. Overall, low-carbon electricity generation (renewables plus nuclear) increased its share from 45.8% in Q1 2017 to 48% in Q1 2018. This was mostly due to a 19% increase in wind capacity. However, increased renewable capacity does not always mean an increase in generation share because renewables output is affected by weather conditions including wind speeds, daily sun hours, and volume of rainfall.
While the Q1 figures are positive for wind generation, the dry hot weather recently experienced in the UK resulted in unusually low wind speeds in June and July, highlighting the challenge brought by the intermittency of renewables, particularly as capacity grows. While reduced wind generation was partially offset by higher solar output, increased reliance was placed on gas and nuclear.
Further detail from the Q1 statistics show that coal’s share of the generation mix stood at 9.4%, down 1.7% when compared to the same quarter in the previous year. Reduced levels of coal-fired generation in recent years has lowered the carbon intensity of the UK’s power supply. In 2017, electricity generation produced an average of 225g CO2/kWh, compared to 483g CO2/kWh in 2012. At the time of writing, the carbon intensity of the grid stands at 178g CO2/kWh as windy conditions mean that wind is providing 15.5% of the energy mix.
Indications are that investment in offshore wind will continue to grow. Energy minister Claire Perry has recently announced that Contract for Difference auctions will be held in 2019 and every two years after that. Referring to a strike price of £57.50/MWh for offshore wind, which would have been unimaginable a few years ago, the government believes the auctions could bring 1 to 2 GW of new offshore wind every year in the 2020s.