Governments around the world have increasingly started to complement traditional combustion-based heat production with solutions that utilize electricity, waste heat, and thermal energy from the surroundings. Thermal and power plants are no longer the sole source of heating; instead, a large portion of the energy comes from decentralized sources such as data centers, buildings, and different energy networks.
Oilon plays a pivotal role in this transition; the industrial heat pumps we deliver enable operators to utilize waste heat in their energy production at an industrial scale. We have supplied heat pumps for more than 120 district heating projects.
The new logic behind district heating: heat is generated everywhere
Traditionally, district heating has been based on large CHP plants and combustion. Oilon’s solution recovers energy from existing thermal energy streams. Examples of these include data center cooling, refrigeration equipment in supermarkets, wastewater, and building cooling. Typically, heat sources have a temperature between −15 °C and +50 °C, encompassing everything between sub-zero outdoor air to different waste heat streams.
The capacity of a heat pump plant can range between 40 kilowatts all the way up to 80 megawatts. High-capacity heat pumps boost the temperature of low-temperature streams to a level suitable for district heating, which is around 70–95 °C. This allows new solutions to be connected directly to even older high-temperature networks without major changes to the infrastructure.
Waste heat from data centers – a new bulk energy source for district heating
One of the most significant development trends in the sector is utilizing waste heat from data centers. In projects completed in Finland, the heat generated by server room cooling is recovered and refined into district heating.
In winter months in Tampere, for example, heat pumps are used to turn recovered heat into 95 °C water that is fed directly into the district heating network. The solution alters the flow of energy streams: what was previously considered a problematic source of emissions has been turned into an energy asset.
Espoo and Kirkkonummi, which are both part of the Helsinki metropolitan area, are home to the largest data center waste heat recovery and recycling system in the world. The Oilon-supplied heat pumps in the plants will soon collect the waste heat generated by data center cooling, boost its temperature, and transfer it to the local district heating network. Once the plants are fully operational, they will account for 40% of the district required by Espoo, Kauniainen, and Kirkkonummi and reduce CO2 emissions by as much as 400,000 tonnes per year.
District heating from sub-zero outdoor air
Another solution adopted in Espoo, Finland demonstrates where heat pump technology is headed: it is already possible to utilize very cold outdoor air to produce 95 °C water for district heating. This is especially important in the Nordic countries where the networks are intended for high temperatures.
The increasing popularity of low-emission power generation will lower the carbon footprint of district heating even further.
From consumers to producers – the evolving role of buildings in district heating
In Oilon projects, buildings are no longer confined to the role of heating consumers. In hybrid systems, a building can both use district heating and supply heat back to the network.
In new residential areas, for example, the energy recovered from building cooling, refrigeration equipment, and wastewater can be sold to district heating companies. This way, a single block can serve as a small energy plant and help balance the entire network.
This development promotes the adoption of bidirectional district heating networks where energy flows in both directions when required. Oilon has been recognized with the EHPA Heat Pump Award already twice for such solutions.
Towards energy-positive city districts
In European development projects, Oilon heat pumps have been used in areas where the goal is to create an energy-positive city structure. City districts can generate more heating than they consume, as long as all local thermal energy streams are captured and funneled to the district heating network.
In these solutions, a heat pump acts as a “node” that combines buildings as well as cooling and district heating into a unified system.