Day-Ahead Price
Wholesale price for next-day delivery
What is it?
The Day-Ahead Price is the wholesale electricity price determined by auction for delivery on the following day. It represents the market clearing price where supply meets demand for each half-hour period.
In the UK, the main day-ahead auction is run by N2EX (Nord Pool) with results published around 10:00 UTC for the following day. This is the most liquid and widely-used reference price in the GB wholesale market.
Key Points
Unit
£/MWh (GBP per megawatt-hour)
Auction Time
Results published ~10:00 UTC daily
Granularity
Half-hourly prices (48 per day)
Typical Range
£40-100/MWh (varies with demand and fuel costs)
How It's Determined
The day-ahead price is set through a blind auction process:
- 1Generators submit sell orders (price at which they will produce)
- 2Suppliers submit buy orders (price at which they will purchase)
- 3Orders are stacked from cheapest to most expensive (merit order)
- 4Clearing price is where supply equals demand for each half-hour
Note: Renewables typically bid at £0/MWh (zero marginal cost), so the clearing price is usually set by the marginal gas plant needed to meet demand.
When It's Used
PPA Settlement
Many Power Purchase Agreements use the day-ahead price as their reference index. Monthly averages of day-ahead prices are commonly used for baseload PPA settlement.
Hedging & Trading
The day-ahead auction is the main venue for short-term physical hedging. Most wholesale volume in GB clears through this auction rather than bilateral contracts.
Capture Price Calculation
Technology capture prices (wind, solar) are typically calculated using day-ahead prices weighted by actual generation volumes.
API Endpoint
GET /uk/prices/day-ahead/latestReturns the most recent day-ahead auction prices.
{
"data": [{
"settlement_date": "2024-12-21",
"settlement_period": 1,
"price": 68.45
}, {
"settlement_date": "2024-12-21",
"settlement_period": 2,
"price": 65.20
}],
"unit": "GBP/MWh",
"source": "N2EX"
}