Capture Price
Volume-weighted average price for a technology
What is it?
The Capture Price is the average price that a generation technology "captures" in the market, weighted by its output each half-hour. Unlike the simple baseload average, it reflects when the technology actually generates.
This is critical for renewable energy economics because wind and solar often generate when prices are lower (due to their own production suppressing prices), a phenomenon called cannibalization.
Formula
Where:
- Pricei = Market price in settlement period i
- Generationi = Technology output in period i (MW)
- Sum over all periods in the calculation window (day, month, year)
Key Points
Unit
£/MWh
Typical Values
85-95% of baseload (varies by tech)
Calculation
Derived from price + generation data
Technologies
Wind, Solar, Hydro, Nuclear
Example
Consider a simplified day with two periods:
| Period | Price (£/MWh) | Wind Output (MW) | Revenue (£) |
|---|---|---|---|
| 1 (Low wind) | £80 | 100 MW | £8,000 |
| 2 (High wind) | £40 | 400 MW | £16,000 |
| Total | 500 MW | £24,000 |
Baseload Average: (£80 + £40) ÷ 2 = £60/MWh
Capture Price: £24,000 ÷ 500 MWh = £48/MWh
Wind captured only 80% of baseload because it generated more when prices were low.
Why It Matters for PPAs
If you sign a PPA with a fixed strike price of £55/MWh but wind only captures £48/MWh, the generator needs to pay you the £7/MWh difference each month. This is why:
- •Strike prices for wind PPAs are lower than for baseload contracts
- •Shape factors are negotiated upfront and can make or break project economics
- •Cannibalization is expected to worsen as renewable penetration increases
API Endpoint
GET /uk/analytics/capture-price/{year}/{month}Returns capture prices for wind and solar with shape factors.
{
"year": 2024,
"month": 12,
"baseload_price": 53.20,
"wind": {
"capture_price": 48.50,
"shape_factor": 0.91
},
"solar": {
"capture_price": 45.30,
"shape_factor": 0.85
},
"unit": "GBP/MWh"
}