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Nano-Coated Solar Collectors Revolutionize Heating & Cooling

renewables, smart grid, heating, cooling, HVAC, green building, smart cities

The Concept: a Finnish company uses an innovative combination of nano-coatings, improved mechanical design, and larger panels to provide unprecedented solar thermal efficiency at the district level.

The world’s most efficient commercial solar thermal collectors are currently manufactured in a small town in Finland. Solar thermal systems provider Savosolar (Nasdaq: SAVOS) leverages proprietary optical coatings that they apply to completed and pre-assembled absorbers. The coatings enable solar collectors to boost efficiency up to 90 percent.

Savosolar’s business is to ensure that its customers on four continents reach their environmental and business targets by significantly reducing heating and cooling costs. To do that the company uses a unique technology in its absorber manufacturing process.  The technology is based on a nano-coating consisting of three thin ceramic layers that ensure that the coating remains stable at high temperatures and provides high performance over wide incline angles. The coating and the anti-reflective glass maintain 98% of the panel’s efficiency when the solar incident angle is +/- 50 degrees off center. The process also enables pre-assembled structures and components to be coated.

However, the coating technology is not their only competitive edge. Savosolar focuses on large scale heating and cooling solutions, and therefore its collectors are among the largest in the world (20.2 x 8.5 ft). These collectors borrow a configuration from heat exchangers in the automotive industry, using multiport extrusion (MPE) for built-in connection tubes that minimize heat loss from absorber to connector.  The absorbers can be mounted with only 1.5 inches distance from each other.  It allows for the highest possible amount of thermal energy to be produced from the available area.

multiport extrusion solar collector

The heat from the collectors is funneled directly through built-in channels rather than transferred to a tube via a seam in the collector. Graphic: Savosolar.

Record breaking efficiency

In 2016, Savosolar was awarded a two-million-euro contract for a collector field with from the Danish district heating plant Jelling Varmeværk. After the installation of the first stage of the solar collector field in June 2016, thermal collectors showed a record-breaking efficiency. According to the customer’s measurement, the collector field produced 0.46 kWh per square foot (4.97 kWh/m2) during a single day on its first weekend in production. According to information available to the company, this represents a new record in Denmark, which leads the world in solar-based district heating systems, with over 100 large-scale installations. The total collector area at Jelling Varmevaerk is equal to three American football fields (two soccer fields).

At another Savosolar installation built last year in Søllested, a village in southern Denmark, the facility provides 20% of the town’s annual heat from the sun. This field consists of 317 collectors with a total area of 1.25 acres. The delivery was a turnkey system and part of a co-operation between Savosolar and Dansk Energi Service (DES).

Strong position in the Danish market

Denmark’s goal is to use 100% renewable energy by 2050, so the country has been developing solar thermal district heating solutions for the past 20 years. It is a highly competitive market. Savosolar is the only foreign solar thermal company that has succeeded in entering the sector. The company is now the second largest supplier in Denmark.

Savosolar has a subsidiary in Denmark, and just recently, Savosolar established a subsidiary in Germany to enhance its position as a supplier and support its efforts in German-speaking countries.


Note: Neither Cleantech Concepts nor the authors have any financial interest in the companies described.

About Anne Irene Leino (8 Articles)
Anne-Irene Leino is a freelancer writer based in Helsinki, Finland. She is interested in sustainability, recycling and waste management, and energy efficiency. She covers clean technology in Europe, including R&D advances in Russia.

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