Learn
UK grid constraints, explained
Plain-English guides to the markets behind wind curtailment in Great Britain. Every figure links to its source.
Guides
-
Wind curtailment in the UK, explained
Why Great Britain pays wind farms to switch off, what it costs, where it happens and what could reduce it.
Last updated
-
Demand turn-up in Great Britain, explained
What demand turn-up is, which NESO services pay for it, which sites can take part and how payments work.
Last updated
-
Balancing Mechanism bids and offers, explained
How bids, offers and acceptances work in the Balancing Mechanism, and why they matter for constrained generators.
Last updated
Key terms
- Curtailment
- When NESO pays a generator to reduce its output, usually because the network can't carry the power to where it's needed.
- Constraint
- A limit on how much power the transmission network can safely carry across part of the grid.
- Boundary
- A line across the transmission network that NESO uses to monitor power flows. The B6 boundary runs roughly along the border between Scotland and England.
- National Energy System Operator (NESO)
- The public body that runs Great Britain's electricity system in real time and buys the services needed to balance it.
- Balancing Mechanism (BM)
- The market NESO uses to balance supply and demand and manage constraints, one half-hour settlement period at a time.
- Bid
- In the Balancing Mechanism, a price to reduce generation or increase demand.
- Offer
- In the Balancing Mechanism, a price to increase generation or reduce demand.
- Bid-Offer Acceptance (BOA)
- An instruction from NESO accepting a bid or offer, which tells a unit to change its output or demand.
- Demand turn-up
- Increasing electricity use when there is surplus power on the grid, in return for payment.
- Demand Flexibility Service (DFS)
- A NESO service that pays energy users to change when they use electricity.
- Local Constraint Market (LCM)
- A NESO market that buys extra demand from sites behind the Scottish boundaries when the network is congested.
- Virtual Lead Party (VLP)
- A company that registers and dispatches flexibility from smaller sites, grouped together, in the Balancing Mechanism and wholesale markets.
- Elexon
- The company that runs the Balancing and Settlement Code and publishes Balancing Mechanism data.
Latest from the blog
Britain pays wind farms to switch off
Why constrained wind goes unused, and how Turn-Up is being built to turn flexible demand into paid demand.
The Balancing Mechanism is priced for plant you already have
Why market access alone does not give smaller generators a trading desk, and how Bid Copilot is being built to help.
Turn constraints into revenue
Nodal Shift is opening early access for flexible sites and independent generators.