The global demand for heat in industries vastly exceeds the demand for electricity. However, sourcing heat from renewables remains a challenge. Within the Danish district heating industry, large electrical air-to-water based heat pumps have proven to be a valuable asset in creating integration and balance between energy systems.

Heat pump to boost the efficiency of solar heating plant

Aalborg CSP received the order from the Danish district heating plant, Ørum Varmeværk to deliver a 2.5 MW electrical air-to-water integrated heat pump system. The solution is customized to fit the district heating plant’s individual energy needs, which includes integrating the system with the plant’s existing 6,376 m^² solar heating plant and hot water accumulation tank.

“At Ørum Varmeværk, our main focus is to ensure our consumers a low cost and price-stable heat supply. Today, our energy production is based on natural gas supplemented with solar heat. Integrating a heat pump system into our supply allows us to lower the energy costs by reducing the gas consumption and by making the energy production more flexible. We can produce electricity and heat using gas, when the price of electricity is high while we can use electricity for the heat pump, when the price is low and thereby help balance the grid. Moreover, this flexibility provides our consumers with energy optimal and sustainable heating” says Jan Hoberg Østergaard, chairman of Ørum Varmeværk.

The heat pump will help optimize the temperature in the solar heating plant during months with the least amount of sunshine thus boosting the overall efficiency of the plant.

“In Ørum, we are integrating the heat pump with the district heating plant’s existing solar heating system in an intelligent way, which enables the solar collectors to harvest more energy during the seven coldest months. At the same time, the energy we borrow from the solar heating system will help to improve the efficiency of the heat pump during those periods, where it has the greatest value for the overall efficiency” says Per Aasted, Sales and Project Engineer at Aalborg CSP.

With a capacity of 2.5 MW at 5 °C, the plant is capable of producing approx. 10,000 MWh heat annually. Combined with the district heating plant’s existing solar heating plant it will cover approx. 93% of the customers’ heat consumption.

Besides offering a cost competitive solution for heat production, the integrated heat pump system also prevents the emission of at least 1,580 tons of CO₂ per year.

Project Facts:

• Client: Ørum Varmeværk a.m.b.a.
• Location: Ørum, Denmark
• Capacity of the plant: 2.5 MW at 5 °C
• Annual energy production: 10,000 MWh heat/year
• of customers: 696
• Technology: Integrated air-to-water heat pump system
• Suppliers: Aalborg CSP A/S in collaboration with Innoterm and Frontmatec
• Scope of supply: Turnkey delivery of integrated heat pump system, installations and building as well as integration with existing district heating solution.
• Expected system lifetime: 20 years
• CO₂ savings: 1,580 tons/year