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.


UNDER CONSTRUCTION
Bad Rappenau, Germany (largest flat plate collector plant in Germany)
Summa Energy has been selected as general contractor to build a +20 MW solar thermal system on behalf of Bauer Holzenergie GmbH for its district heating network, which supplies households and an industrial process for drying fruits with healthy heating. Only about 1,800 pieces of Savo 16S large scale high performance flat plate collectors are sufficient to getting combined with an 8,000 m³ heat storage tank and
provide carbon free heat for the needs of all connected consumers.
Additionally, a PV system will be built on site to generate the electricity consumed by the solar pumps, thus
unburdening the local power grid.
Løgumkloster Fjernvarme is a district heating company which annually supplies 35,000 MWh of heat to over 1,500 customers. Heat is produced with a hybrid heating system consisting of a 3 MW pellet boiler, a 1.3 MW hybrid heatpump, a 3 MW absorption heat pump and a solar collector field of 15,300 m2. Additionally, the plant has two gas engines which are capable of producing 7.6 MW of heat and 6 MW of electricity and a 10 MW gas boiler which acts as back-up.
In 2015, Savosolar delivered a 9,700 m2 solar thermal field to Løgumkloster. The second order of 5,600 m2 was delivered and commissioned in the beginning of 2016. The complete field consists of 1030 Savo 15 SG collectors and covers about 20% of the annual thermal energy need of the district heating network. The largest part of the heat demand is covered by the pellet boiler, but Løgumkloster Fjernvarme has plans to change this in the future by extending the solar field and building a large seasonal water storage.
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