The bidding round for heat purchase of the next 24 hours starts before 8:00am where the heat consumption forecasts for the water and steam production of the next 24 hours must be sent to Ørsted and Hofor. Afterwards Varmelast receives bidding range at a daily basis from both Ørsted and Hofor and Varmelast calculates the most economic way to cover the heat requirement. Hereafter Varmelast.dk orders the required amount of hot water and steam from each producer.
Then Ørsted and Hofor calculate the most economic way to meet Varmelasts heat orders for hot water and steam, hour by hour, considering the power production, fuel prices, CO2 quotas and energy taxes. The tax structure of the different types of fuel encourages biomass based fuels to be prioritised before fossil fuels.
When Varmelast has received the preliminary heating plans of the producers, they are adjusted with regard to the hydraulic limitations in the district heating network compared to the most optimum utilisation of the heat accumulators at Amager Power Plant and Avedøre CHP Plant based on the marginal expenses of the producers. At the end the final heating plans are sent to each producer, including a specification of the exact heat production for the individual blocks – hour by hour within the next 24 hours.
Heating plans must be in place before 10:30am so the production companies know how much heat they need to produce – and thus how much power they can offer for sale at Nordpool.
However, forecasts are one thing – reality another. Therefore the heating plans are adjusted to the actual district heating requirement five times a day, se the Intraday-schedule above, and the published spot price of power and unforeseen events at the CHP plants.
