Easter Balancing Mechanism

This Week in Flexibility: Unexpected events trip the system

Each week, we take a look at the week in flexibility trading that has just been, and a look at what’s next. Enjoy our latest instalment.

The steady but unseasonably warm weather made for a stable start to last week as we started refrigerating our chocolate eggs, eagerly beginning the countdown to Easter.

The calm wasn’t to last though, with Wednesday and Thursday bringing some unexpected events and interesting market reactions in a week where System Prices swung from -£61 to £98/MWh).

Wednesday provided a key moment in the flexibility market. Correct response to instruction is the cornerstone of the balancing mechanism, but sometimes even the largest power plant can fall short and we do see rare moments where system / mechanical failure can take place.

At c.5am Wednesday we saw National Grid instructing Peterhead Power Station (T_PEHE-1) to come on for 1180MW. However, it unexpectedly only managed to generate 480MW of the requirement, creating a situation where the NIV was short and prices were fairly high across the day (especially in SP17-19 where we saw it settle at £98/MWh). Due to this situation, National Grid lost a significant amount of generation unexpectedly and flexible units had to be called upon at higher prices to make up the difference.

Limejump’s new Gas BMU’s (comprised of gas engines) sprang into action during this time to extend their generation for an additional 2.5 hours during these periods (2__MANGE001 & 2__AANGE001 were the units that responded to the call).

Friday was not to be outdone though and bought a different kind of interest to grid balancing in the UK. As we basked in the bank holiday sunshine, the speedy response of the BM came into its own as the French Interconnector (the HVDC Cross-Channel) tripped off between 2.15 and 5pm (causing a 49.6hz frequency event).Power Station Trip

The flagged events experienced on Wednesday and Friday aside – System Prices displayed volatility earlier in the week, as a balanced system fluctuated between slightly long to slightly short, with prices flipping between circa £31 and £53. Elsewhere over the bank holiday, System Prices remained relatively low with the highest peaking at £65MWH and the lowest reaching £15MWh.

This week has kicked off with wind generation just above its 5GW forecast with a sharp contrast from the weekend’s high temperatures to be felt over the day as wind gradually rises to 8GW by midnight. The week ahead is forecast to see a return to cooler seasonable norms, potentially leading to interesting market activity as the citizens of the UK miss the warmth and reverse decisions to switch off their central heating.

Flex in numbers:
  • Total number of instructions for Limejump: 69
  • Top System Price of the week: £98.00
  • Lowest System Price: – £61.00



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