Optimal capacities of distributed renewable heat supply in a residential area connected to district heating
In this paper, residential area of 16 buildings with average annual 5.6 GWh heat consumption is studied in terms of distributed renewable energy supply with gradual separation from the local district heating network. Optimal heat supply and heat production capacities in the area are estimated by using hourly linear optimisation model for two separate model years and for normal and low district heating temperature cases. Results indicate that disintegration from district heating supply inflict 12-24% higher annualised total costs. However, completely removing the areal district heating network increases total costs considerably. Solution for heat supply in building area is a package consisting of ground source heat pump, heat storage and photovoltaics panel. Centralised ground source heat pump with centralised heat storage completes the heat supply cost-efficiently with low district heating supply levels. Solar collectors and exhaust air heat pumps are not cost-efficient solutions due to high investment costs.