Wind generation output in December was the highest all year
There is more evidence of the move to a lower carbon electricity system in our latest BSC Operations Headline Report for December 2019 which showed that wind generation produced a monthly total of 5,613 gigawatt hours (GWh) for the GB Market. This was the largest monthly total for wind in 2019.
Wind generation up fossil fuel generation down
During December, wind contributed on average 23% to the GB electricity mix, and exceeded 40% of total generation on eight days during the month.
As wind generation increased, GB dependency on electricity from fossil fuels decreased. Fossil fuel generation produced 9,729GWh of electricity in December 2019, and registered the lowest average share of the GB electricity generation mix (37%) ever recorded.
Curtailment of wind output to balance the system
At times during December there was too much electricity on the system. National Grid ESO, the system operator, had to ask for wind farms and other generators to reduce their output and other BSC Parties such as suppliers were paid to use electricity.
The curtailment of wind generation contributed 82% of negatively priced bid volume. The negatively priced bids will impact the System Price when the Net Imbalance Volume is negative (i.e. the system is long). The System Price is derived from the actions the ESO has taken to reduce the energy (bids) in this scenario.
Too much electricity generation on the system during the night of 7 December and morning of 8 December resulted in a new record being set for the longest continuous period of negatively priced System Prices. You can read more about this in Emma Tribe’s Elexon Insight: Sub-zero electricity prices in December.