Solar Generation
Electricity produced from solar photovoltaics
What is it?
Solar Generation is the amount of electricity produced by solar photovoltaic (PV) panels connected to the GB grid. The UK has approximately 15 GW of installed solar capacity, including both utility-scale and rooftop installations.
Solar output follows a predictable daily pattern (daylight hours) but varies significantly by season. Summer days can see solar meeting 20%+ of demand, while winter contribution is minimal.
Key Points
Unit
MW (megawatts) or MWh (energy over time)
Update Frequency
Half-hourly (48 readings per day)
UK Capacity (2024)
~15 GW total installed
Peak Output Time
11:00-14:00 local time (varies by season)
Generation Profile
Solar has a distinctive generation profile that affects its market value:
- 1Daily Pattern: Zero at night, ramping up from sunrise, peak around midday
- 2Seasonal Variation: Summer output can be 6x winter output in the UK
- 3Weather Sensitivity: Cloud cover can reduce output by 50-80%
- 4Embedded Generation: Much UK solar is "behind the meter" and not fully metered
Shape factor: Solar typically captures 90-100% of baseload price, better than wind, because peak solar coincides with daytime demand peaks.
When It's Used
PPA Settlement
Solar PPA settlement uses solar-specific capture prices. The solar shape factor is often more favorable than wind, making solar PPAs attractive to offtakers.
24/7 Matching
Companies pursuing 24/7 carbon-free energy need to track hourly solar generation to match consumption with renewable supply on a time-matched basis.
Grid Balancing
System operators use solar forecasts to predict the "duck curve" - midday oversupply followed by evening ramp when solar drops off and demand peaks.
API Endpoint
GET /uk/generation/solar/latestReturns the most recent solar generation data.
{
"data": [{
"timestamp": "2024-12-20T12:00:00Z",
"settlement_period": 24,
"solar_mw": 8200,
"estimated_embedded_mw": 3500
}],
"unit": "MW",
"source": "NESO",
"note": "Includes estimated embedded generation"
}