Collectors are the most important and visible part of every solar thermal system. They are usually installed on the roof, where they use the sunlight to heat water. Consumers can choose between different types of solar collectors. This overview for Solar Panels Claims presents the most important types and shows their advantages and disadvantages.

What is the function of solar collectors?

To gain heat from the sun’s rays, homeowners need three things: solar storage, a control unit, and solar collectors. In it, a so-called absorber collects the heat and releases it to a heat transfer medium. For most solar collectors, this is a water mixture. So easy, so ingenious. However, there are different types of solar collectors on the market from which the consumer must choose. This overview presents you the quality label “Solar Keymark” and the most important solar collectors: from the widespread flat collector over the tube collector up to niche variants like the hybrid collector or the air collector.

A flat collector is a solar collector with a flat, flat absorber surface. This is protected by a sturdy glass cover and housing. Flat plate collectors are the most common collector type in Germany. A significant advantage is the often good price-performance ratio.

Flat plate collectors explained

Flat plate collectors are most commonly found on our roofs. In them, the sun’s rays are caught like in a hothouse. Their name derives from their design: The rectangular, thermally insulated housings made of aluminum or stainless steel has no elevations. The sun-facing side has a cover made of sturdy glass. It should transmit as much sunlight as possible into the interior of the solar collector and at the same time protect it from rain, hail or falling branches.

The absorber, a heat-conducting and dark-coated metal sheet inside, ensure that a lot of sunlight is converted into heat and transferred to the solar storage tank. A flat plate collector usually weighs between 15 and 25 kg / m 2. He achieved an efficiency of about 60 to 85 percent.

In a solar thermal system for hot water is a rule of thumb a collector area of ​​about 1.5 m 2 per person needed. If the heating is also to be supported, it is around 3 m 2 per person. The additional energy yield from tube collectors would not have offset our significantly higher investment costs. That’s why we chose flat-plate collectors.

What are the advantages and disadvantages of flat plate collectors?

The biggest advantage of flat plate collectors is their often good price-performance ratio. Flat plate collectors are easy and quick to set up. They can be fully integrated into the roof, making them look almost like skylights. Also, flat plate collectors are robust and durable and achieve relatively high efficiency. The cleaning is easier. A disadvantage of flat plate collectors is the higher space requirement compared to tube collectors.

What are the costs for flat plate collectors?

The prices for flat-plate collectors start at around 240 dollars per collector or around 120 dollars per square meter of collector area. Depending on the efficiency, the price can rise significantly. The average value is a price of 220 to 550 dollars per square meter of collector area.