Solar energy has the potential to generate over 80% of heating energy from thermal storage for Finnish households, according to researchers at Aalto University.
As the price of heating energy obtained from solar heating systems needed to be competitive with the current heating alternatives, calculations made by the University’s researchers showed that renewable energy could be used to cover 53–81% of annual domestic heating energy consumption depending on the technical implementation method.
In principle, the result of the study is also applicable for Sweden, Norway and other locations at the same latitudes, says Hassam ur Rehman, a doctoral candidate at Aalto University.
The University’s press release describes the research: “The researchers calculated the amount of solar heat obtained for heating the households when excess energy was stored for use during cold periods. The researchers calculated the amount of heat obtained for practical use when energy for heating households was accumulated using solar heating and the accumulated heat was stored for use during cold periods. In their calculations, the researchers studied the use of both above-ground water storage tanks for short-term heat storage and a borehole storage suited for seasonal storage. The results relied on the method of how the heat pumps and the water storage tanks and the borehole storage for storing heat were used together.”
Sirén says it is important to continue the research work, which will require measurement results on a system built and implemented in Finland.
'We are talking about a computational result which includes factors of uncertainty even if the initial values have been carefully selected and the simulations conducted meticulously,' explained Sirén.
The heating of buildings is one of the largest sources of carbon dioxide emissions in Europe. In the EU, heating accounts for 40% of the region’s total energy consumption. Natural gas- and coal-fired power plants are the primary energy source to meet these needs.
'In Finland, more than 80% of the energy consumption in households goes to heating buildings and water, and this is on the increase. Solar energy offers economically sensible solutions for the collection of energy for this purpose, and for the reduction of carbon dioxide emissions, especially in southern Finland where the majority of the population lives,' says Kai Sirén, Professor at Aalto University.
Clean energy boosts district heating market
The drop in prices has already made solar energy a viable alternative in the Nordic countries. In Denmark, for instance, the use of solar energy in district heat production has increased significantly as a result.
In 2016, Denmark’s solar district heating capacity nearly doubled. In that country there are many user-owned non-profit cooperatives which run district heating systems. Those utilities benefit from smart financing based on loans for which the municipality is the guarantor. The German district heating market is also set to grow substantially. Growing investment toward replacement of conventional heat and electricity generating systems with sustainable technologies including combined heat and power (CHP) and solar thermal is set to stimulate the commercial sector. Regulators are planning to increase the CHP electricity generation share from 18% in 2013 to 25% by 2020 through the introduction of incentives on adoption of these technologies.
Adoption of clean energy over fossil fuels and flexibility to choose the heat source is also set to stimulate solar district heating market growth. In 2017, Finland based Savo-Solar announced the development of a new 300MW solar thermal heating system with a view to deliver surplus energy across the district heating networks catering to Hämeenlinna city.