On 17 September, EirGrid published its Annual Renewable Energy Constraint and Curtailment Report 2019 which sets out the amount of wind and, for the first time, solar energy, that is available but cannot be used by the system (i.e. the dispatch-down of energy).
Overall, the dispatch-down of energy from wind in Ireland and NI increased from 6% in 2018 to 7.7% in 2019. The report notes that, in 2019, 1,008GWh (7.7%) of the total 11,994GWh wind energy generated was dispatched-down, representing a 301GWh increase in dispatch-down energy since 2018.
However, during 2019 an additional 918GWh of wind energy was generated compared to 2018. The dispatch-down energy from solar resources was 5.6GWh, representing 4.2% of the total available solar energy.
The level of dispatch-down is affected by a number of factors which vary from year to year, such as the amount of wind installed on the system, and the capacity factor of the wind generation. Total wind capacity island wide rose by 467MW in 2018, while the average wind capacity factor increased by 1% to 27% in 2019.
Figure A: All-Island Historical Wind Dispatch Down Percentages
We can expect this trend to continue as more wind capacity is installed across the island. These developments come in light of the Department for the Economy in Northern Island publishing at the start of the month that the renewable share of the generation mix in Northern Island reached a record high in June this year.
The Electricity Consumption and Renewable Generation in Northern Ireland: Year ending June 2020 report was published on 3 September, which details the percentage of electricity consumption in Northern Ireland generated from renewable sources
For the 12 month period July 2019 – June 2020, 47.7% of total electricity consumption in NI was generated from renewable sources. This represents an increase of 3.6% on the previous 12 month period (July 2018 – June 2019) and is the highest rolling 12 month proportion on record.