As a general contractor, Savosolar built a solar thermal system on behalf of Fernwärme Ettenheim GmbH for the largest possible solar feed-in into the existing district heating network. 112 pieces Savo 15 SG-M large collectors generate fuel-free healthy heat, which is temporarily stored in two 100 m³ buffer storage tanks.
This also allows the operating hours of the CHP and the biomass boiler to be optimized. The scope of delivery included the fence and video surveillance system, as well as the creation of a meager meadow to enrich local biodiversity.
The construction work was temporarily interrupted due to the COVID19 restrictions. All system hydraulics were completely housed in a container. The keys were handed over in October 2020.
A PV system still to be built on the east side will generate the electricity for the pumps in the future.
The picture on the left shows the boiler house and the buffer storage tank. Handover of keys from Jari Varjotie, CEO Savosolar Oyj, to Peter Blaser, managing director of the customer.


In collaboration with Eiffage Energy Systèmes, Summa Energy is providing a solar thermal plant on trackers to supply heat to the greenhouses of Les Serres Vermeil, an organic vegetable grower located in Palau-del-Vidre, France.
Summa Energy with provide a turnkey solar thermal field of 396 Savo15S collectors, as well as all the engineering of the plant and the supervision software.
Swimming halls are very well suited for solar thermal production. Typically, their heat consumption is big and the required temperature level tends to be relatively low. In such cases solar thermal collectors are operating with a very high efficiency.
However, quite often swimming halls are closed some time of the year and summertime closure may mean extra challenges for solar heat supply.
For Hämeenlinna swimming hall Savosolar solved this issue by feeding surplus solar energy in summer to the nearby district heating network. Thus, the solar system is producing heat all days and depending on the swimming hall’s actual heat demand, the facility is either a district heating provider or a consumer.
Lolland forsyning’s district heating plant in Søllested is located on the island of Lolland and was the first installation, where Savosolar’s double glazed collectors were used. The double glazing reduces heat losses through the glass side of collector and offers a higher efficiency, especially at higher operation temperature levels and during the darker months of the year. Søllested district heating plant has ca. 500 customers and also uses a 5 MW straw boiler and an oil burner to produce its heat.
The collector field in Søllested has a so-called hybrid field, with both single and double glazed collectors. The single glazed collectors are in the cold end of the collector rows and increase the low temperature as rapidly as possible, while the double glazed collectors are located in the warm side of the collector rows where it is more important to reduce the heat losses.
In Søllested, Savosolar was faced with a special challenge since the customer’s land has a sewerage pipe running through it. Since the owner of the sewer pipe needs to be able to access it in case of maintenance, Savosolar supplied a collector field which both optimised the use of the available land, while still providing access to the sewer pipe