The forecast is based on the joint Nordic MetCoOp weather forecasting system. The solar PV power plant is assumed to be a 1 kWp (kilowatt-peak, nominal power) system facing south, with a slope angle of 30 degree from the horizontal. The nominal power of 1 kWp is chosen for easy scalability. A 5 kWp system with the same orientation will produce five times the forecasted power.

Based on the forecasted weather conditions, we first estimate the amount of solar radiation received by the inclined PV panel surface. Because the solar PV production efficiency depends on the temperature of the PV panels, the efficiency corresponding to the forecasted weather conditions is then calculated on the basis of solar radiation, temperature and wind. By combining these, the forecast estimates the expected solar PV power production.

Unit and time stamp: the unit of the PV forecast is kWh (kilowatt hour). The data point of a specific time stamp represents the estimated electricity production during the preceding hour. Example: the 10:00 data point represents the time window between 9 and 10.

The wind power forecast is based on the joint Nordic MetCoOp weather forecasting system. The forecast combines forecasted wind conditions with information on where Finnish wind turbine locations, including information on hub heights and power curves of the individual turbines.

Unit and time stamp: the unit of the wind power forecast is GW (gigawatt). The data point of a specific time stamp represents the estimated instantaneous electricity production.

The methods used for creating the solar and wind power forecasts have been developed in projects funded by the Strategic Research Council, Academy of Finland, Nessling Foundation and Business Finland.