Solar heat for manufacturing

Zehnder now have an evacuated tube collector solar thermal system connected directly to the production process, the first of its kind in Switzerland

Green Alliance

Gränichen, August 2012. Europe’s leading indoor environment specialist Zehnder officially began operation of a large-scale solar thermal system at its production plant in Gränichen on 16 July 2012. Installed on the roof of the new logistics hall, solar panels covering 400 m2 of area will ensure that in future up to 50% of the energy needed for the process heat of the paint shop will be met by the sun. The solar thermal system operates using highly-performing evacuated tube collectors. This is therefore the first evacuated tube collector system in Switzerland which is connected directly to the production process. With this special system configuration, Zehnder has taken the lead in developing environmentally friendly practices within its country.

Immediately after the start-up of the solar-thermal system, water at a temperature of 110 °C streamed from the roof of the production and logistics hall into the new heat storage tanks of the central heating plant. Two boilers are now supported in their production of process heat and central heating water by a concentrated supply of solar energy. “In the best conditions they can even be turned off completely”, explains Jan Neyrinck of solar thermal system manufacturer Ritter XL Solar GmbH. Thanks to the innovative evacuated tube technology, the 400 m2 collector field is able to meet the high heat requirements. The evacuated tubes, fitted with CPC mirrors, generate high temperatures even when the sunshine is weak. While Ritter XL Solar GmbH supplied the collectors, Eisenmann Anlagenbau GmbH & Co. KG from Holzgerlingen in Germany were responsible for the integration of the solar technology into the industrial processes of Zehnder.

Environmentally-friendly, energy efficient and economical

With this large-scale solar thermal system, Zehnder optimise the energy balance in their production. The energy costs for the generation of process heat for the lacquering of radiators can, with ideal solar conditions, be reduced by up to 50%. The minimum solar yield is guaranteed to be 157.6 MWh per year. Working with this figure, the annual reduction in fossil fuel energy comes to around 200 MWh. This corresponds to a reduction of 16,800 kg of propane, around 20,000 litres of oil or 58,800 kg of wood chippings. If the support programme of the Bundesamt für Energie is also taken into account, the system will become profitable by its fifth year of operation. It should come as no surprise, therefore, that plans for the extension of the solar capacity on the roof of the Zehnder production hall are already in the pipeline.
The Zehnder Group is pleased with its investment in an ecological and future-proof large-scale system. “We want to be the most attractive provider of energy efficient solutions for a healthy and comfortable indoor environment; that applies not only to our products and system solutions, but also to our own buildings and production lines”, announces project leader Heiner Schürch. With the connection of solar thermal energy to a pre-existing process system (currently unique in Switzerland), this commitment has been strongly underlined.

Picture captions for the Zehnder solar thermal system

Picture 1:
Dr. Jürg Ammann, member of the management team of Zehnder Group and leader of European operations, opens the loop for the hot water (with temperatures above 100 °C) from the solar collectors at the inauguration of the solar thermal system.

Picture 2:
The collectors on the roof of the new logistics hall, which cover an area of just over 400 m2, will henceforth provide up to 50% of the energy needed for the process heat used in the paint work of Zehnder.