Low UK demand outlook presents summer balancing challenges: Grid

London — The coronavirus lockdown could push UK electricity demand down to between 96% and 80% of usual daytime levels this summer, making it challenging to balance the system, National Grid said Thursday in its annual Summer Outlook.

Lower summer demand would increase the amount of work needed to manage high voltage levels on the power transmission network, National Grid said.

It was "actively developing strategies to manage a wider range of scenarios for this summer than we have previously considered to ensure we have the necessary tools and services for all such scenarios."

A pre-virus forecast based on business-as-usual put high summer peak demand at 32.1 GW. The medium-impact scenario now put that figure at 27.9 GW, and 25.7 GW in a high-impact view.

Forecast minimum generation of 34.9 GW, meanwhile, was comfortably above forecast peak demand figures.

However, if planned maintenance was cancelled over the summer due to the crisis this could have a knock-on impact by pushing maintenance into the winter and potentially changing generation fleet supply profiles, the TSO said.

"Based on current data we expect to be managing periods where inflexible generation output plus flexible wind output exceeds minimum demand more often than usual as a result of COVID-19," it said.

It also expected increased periods where inflexible generation output alone could exceed minimum demand.

To handle this Grid said it could:

• request pumped storage units to increase demand by moving water back to top lakes
• curtail flexible wind farm output at a national level via the Balancing Mechanism or via direct trade
• trade to reduce the level of interconnector imports
• issue a local or national Negative Reserve Active Power Margin (NRAPM), allowing the system operator to request additional plant flexibility.

UK POWER DEMAND: PRE AND POST COVID-19 SUMMER 2020 SCENARIOS (GW)

Source: National Grid

Interconnection

Meanwhile the operator noted potential continental European effects on UK interconnectors.

"Across Europe, we may see changes to market behavior which falls outside what we have seen historically as industry participants adapt to the constraints that COVID-19 is placing on normal operations," it said.

Forward prices for summer 2020 were expected to remain higher in the UK than continental Europe, the TSO therefore expecting net imports on interconnectors for most of the summer.

Finally two new UK-France interconnectors in development, IFA2 and ElecLink, would not now be fully operational until after the summer, Grid said.

PLANNED, CURRENT INTERCONNECTOR OUTAGES

Source: National Grid