The GB BESS index increased 33% in April to £43k/MW/year, its highest level since October 2023. Revenues had previously increased to £32k/MW/year in March, after lows in January and February. With Capacity Market revenue included the index rises to £54k/MW/year in April.
We’ll be reporting on the GB BESS index, including Capacity Market revenue, from now on. The GB BESS Index on our platform now also includes Capacity Market by default.
Why have we made this change? Previously, we only reported revenues earned across shorter-term markets to represent value that’s exposed to changes in market conditions. However, with falling revenues the Capacity Market has now become a much larger part of a battery’s revenue stack. By including Capacity Market, we are now providing a complete picture of total battery revenues.
So, what caused the 33% increase in battery revenue in April?
- Great Britain broke the record for low carbon intensity twice in April, with the new record at 19gCO2/kWh.
- This was helped by high wind generation between April 6th and 16th, which caused 53 hours of negative power prices this month.
- This contributed to batteries increasing wholesale revenue by 8% to £16k/MW/year.
- Batteries were dispatched more than ever before in the Balancing Mechanism, resulting in a 50% increase in BM revenue.
- Frequency response revenue increased by 50% due to increased clearing prices in every service.
Negative prices got the headlines, it was the increase in frequency response prices, especially Dynamic Containment, that caused the biggest increases in revenues. Across Dynamic Containment, Dynamic Regulation, and Dynamic Moderation combined revenues increased by £8k/MW/year - 67% of the total increase in April.
Negative power prices cause wholesale spreads to rise
High wind generation in the first half of April caused day-ahead power prices to fall during periods of low demand, and sometimes turn negative. Power prices turned negative for 53 hours in April, a record for this time of year and almost half the total reached in 2023.