Customers receive their district heating in the heat distribution centre which, in turn, delivers heat from the district heating network to the heat distribution equipment in the customer’s property, i.e. to radiators or ventilation equipment. The heat distribution centre heats up tap water for the use of customers according to their particular needs.

The heat distribution centres are factory-made units, which are reliable and durable. The space required by the equipment is small because there is no need for separate boilers, accumulators or fuel stores. The customer’s equipment normally needs very little maintenance.

Heat is conducted to customers as hot water in a dual-pipe district heating network located underground, usually under streets and cycle paths. Once cooled down, the water of the district heating network returns from the heat distribution centre to the production plant for reheating.

 

 

District heat with the environment in mind

The flexibility of the production system in the long term is one of the absolute strengths of district heat. District heat can be produced in a number of different ways and, if necessary, the production form or source of energy can be changed on the customer’s behalf. Therefore, the customer will not have to make any investments in order to change the production form.

The key individual fuels used in Finland are wood-based fuels, such as wood chips and industrial wood residues. Natural gas, coal and peat are also important fuels. Different kinds of waste heat from industry and urban operations are also utilised in the production of district heat. It is predicted that various types of renewable energy sources will increase strongly in the future.

 

Superior energy efficiency

Efficient district heat production, especially combined heat and power generation, reduces the environmental burden and climate impacts. The superior energy efficiency and environmental compatibility of district heating are based especially on the fact that district heating utilises heat energy generated in electricity production and as waste heat from industrial and other processes, etc., which would otherwise be wasted. Combined heat and power generation is almost twice as efficient as separate generation of electricity and heat. District heat is also produced in separate heating plants. This process uses an increasing amount of renewable fuels. For example, wood combustion is more effective in larger units than in small ones. The same amount of fuel will provide more energy for utilisation.

 

Towards a healthy living environment

District heating is part of community technology: it substantially reduces local emissions and boosts the enjoyment of our surroundings. Therefore, energy production has a particular responsibility for the management of environmental and climate impacts. Many district heating companies have certified their operations that have an environmental impact. These measures guarantee constant development of environmental issues and environmental awareness in all activities. The development of environmental protection is described in environmental reports, which are published in connection with annual reports or as separate reports.

Investments are made in the flue gas cleaning of power plants and heating plants in accordance with the requirements of the environmental permit. Flue gases are conducted into chimneys that can reach to a height of more than a hundred metres, which contributes to the reduction of emissions. Constant air quality measurements ultimately ensure a healthy living environment.

 

 

Part of the smart energy system of the future

District heating is constantly evolving. It is part of the smart energy system of the future. District cooling systems with an operating principle that is similar to that of district heating have started to appear next to district heating systems. Customers receive cooled water in the closed dual-pipe district cooling network to cool down premises and processes.

 

Efficient trigeneration

In the future, district heating and cooling will be strongly coupled together as it is possible to produce electricity, heat and cooling in the same process. This is called trigeneration. Customers’ surplus heat can also be recycled and processed for further use in the combined district heating and cooling system.

In cities, the district heating system can be used for transferring heat from places where there is too much of it to areas with a higher demand for it.

New heat sources and production forms, such as heat pumps and solar heat, are also introduced in the district heating systems. The system is optimised to be increasingly energy efficient by utilising accurate and up-to-date metering data and consumption forecasts.