With round about four decades in business, the German-Slovak Thermosolar Group is one of the oldest solar thermal manufacturers in Europe. It began producing collectors in 1972 in Slovakia and started offering a special evacuated flat plate collector in 1997. Last November, long-time sales manager Markus Beslmeisl (see photo) acquired the remaining shares in the company from Johann Kollmannsberger. Solarthermalworld.org spoke with the new managing director about Thermosolar’s special solar heat pump system, called Duo Premium.

Photo: Thermosolar

“Thermosolar has always been a producer of high-quality solar thermal systems with unique properties,” Beslmeisl said. “We will continue with our strategy to expand the range of applications for solar thermal technology.” The company’s main target markets are in Eastern Europe, a region which had already contributed 60 % to total annual sales last year.

According to Beslmeisl, the Thermosolar Duo Premium System, or DPS, was a product to extend the scope of solar thermal usage. It combines TS 400 evacuated flat plate collectors and a compact brine water heat pump and has been designed specifically for space heating. Instead of a pipe register set up in the garden, the heat pump of the Duo Premium System is supplied with low-temperature solar heat from evacuated flat plate collectors on the roof. This set-up requires no additional geothermal source or outside air unit (see the following diagram). 

Schematic diagram of the Duo Premium System. Depending on the temperature of the collector field, the solar system can provide thermal energy for either the buffer tank (centre) or the heat pump’s brine tank (right). The solar thermal pump system has been added to the existing boiler (red on left), which keeps rooms warm via a floor heating system.

Chart: Thermosolar

“While solar water heaters usually work only at temperatures above 40 °C, the Duo Premium System can be operated at a temperature of as little as 5 °C. The entire range from 5 °C to 40 °C can be used to produce more energy on the roof,” Beslmeisl explained. The heat pump’s additional brine buffer tank, which includes control equipment (see left side of diagram), allows for the use of roof-captured solar heat at temperatures too low for space heating or hot water production. 

Thermosolar sells its products in more than 55 countries and is one of the market leaders in Eastern Europe. Beslmeisl now hopes that the Duo Premium System will help Thermosolar grow in highly competitive markets such as Germany. “In early 2016, Germany extended the duration of the incentive schemes for replacing or retrofitting heating systems. The DPS is eligible for them, so our clients can get financial support for their installation,” he said.

In cooperation with the Slovak Photovoltaic Industry Association, Slovak-based Thermosolar Žiar offers workshops to installers for obtaining certificates valid in all European Union member states. Nearly every second PV and solar thermal installer in Slovakia had completed the certification programme at Thermosolar, Beslmeisl said. In the past three years, the company had trained around 700 installers from Bulgaria, the Czech Republic, France, Poland and Slovakia. Alfréd Gottas, Managing Director of Thermosolar Žiar, is also the vice president of the Czechoslovak Solar Energy Society, a long-time member of the International Solar Energy Society.

Organisations mentioned in this article: 

Thermo Solar Group: www.thermosolar.com

Slovak Association of Photovoltaic Industry: www.sapi.sk

Czechoslovak Solar Energy Society: www.solarnispolecnost.cz