In the Danish city of Silkeborg, with 44,000 inhabitants, the world’s largest solar thermal plant was installed in 2016. The 12,436 large collectors are mounted on agricultural areas in front of the city’s gate. Solar heat in district heating complements classic gas-driven cogeneration plants. The collector field delivers 80,000 MWh yearly and has a nominal power of 110 Megawatts. It covers 20% of the heat demand in the district heating network of Silkeborg and the complete summer load.
The plant does not include seasonal thermal energy storage, despite its dimensions. This results in particularly low heat costs and is facilitated by the size of the city of Silkeborg, which has a high enough summer load to utilize all the solar heat directly when produced.
Besides gas and solar thermal energy, wind electricity is expected to supply an increasing portion of the heat in the district heating network of Silkeborg.