03 Jul 2023
Wendel Hortop

Negative prices reach an all-time low: Sunday 2nd July 2023

Power prices hit extraordinary lows on Sunday 2nd July 2023 across almost all of Europe, with negative price records set across much of the continent. Why? Because high levels of wind and solar generation coincided with lower demand.

Record low power prices in Great Britain

  • 🔻 A new record low was set in the EPEX hourly day-ahead market at £-70/MWh.
  • ⌛ Day-ahead prices remained negative across 17 consecutive hours
  • 💥 Intraday prices at one point reached a low of £-120/MWh

Batteries win big with the right strategy

Negative prices mean batteries can be paid to charge. But because day-ahead prices were negative for so long, there was only one trading cycle opportunity in this market: in the evening when prices increased.

Most systems have short durations, so the value for charging at negative prices is limited unless there's a route to sell this power.

Therefore, trading across different markets and services was essential to maximizing the value of storage on the day.

  • The intraday and imbalance markets offered up opportunities for additional cycling, with prices flipping between positive and negative several times.
  • Offers were available to batteries in the Balancing Mechanism, giving storage another route to sell energy.

Frequency response prices were higher on the back of negative power prices

Prices increased in the frequency response services, which could be stacked alongside trading.

Dynamic Containment prices jumped as National Grid ESO procured additional volume to secure the system. Overnight it procured just over 1.4GW of volume for the low-frequency service on 2nd July 2023, and again on the morning of 3rd July 2023, setting a new record of 1,425 MW procured.

Even higher prices were available in the Dynamic Regulation Low service. Only 94 MW was procured on average, despite offering a good opportunity for batteries during negative prices. Dynamic Regulation High prices remained low despite volumes clearing at their lowest levels since January - just 48 MW during EFA block 2.

These are the headlines, but we’ll dig into just how strategies for battery storage differed across the day soon.