A 30-day map of GB demand, half-hour by half-hour. The grid's job isn't to deliver power on average — it's to deliver it at the worst moment. Knowing exactly when those moments are is the foundation of every flexibility market, every storage business case, and every conversation about peak demand.
Every cell is the average demand for that hour-of-day on that day-of-week, across the last 30 days. The hot band running through the early evening is the system peak — the moment NESO has to balance against. The cool strip in the early hours of the morning is when wind has the easiest time covering the system.
Hour-by-hour demand averaged across the period, with weekdays and weekends shown separately. Weekday demand shows the classic morning ramp and evening peak; weekends are flatter and start later. The gap between the two is the workday signal — about 4 GW at peak.
Each vertical line shows a single day's range, from minimum to maximum. The size of that swing is the flexibility envelope every battery, every demand response programme, every interconnector arbitrage trade operates inside.