The Balancing Mechanism (BM) is a real-time process operated by NESO to maintain system balance:

It operates from Gate Closure (1 hour before delivery) through real time and is the final stage of physical system balancing.

The BM is best understood as a real-time constrained optimisation process under uncertainty, implemented through the acceptance of bids and offers.

Role

Forward and day-ahead markets cannot fully resolve:

  • Forecast errors (demand, wind, solar)
  • Plant outages
  • Network constraints
  • Intra-day trading changes

The BM enables NESO to correct these imbalances in real time.

Key Properties

  • No forward commitment required
  • Availability declared dynamically
  • Actions are based on submitted bids and offers

Interpretation

  • The power system is continuously out of balance
  • The BM is the mechanism used to correct this in real time