Photovoltaic panels and solar hot water panels both provide useful benefits for the buildings they are attached to, but sometimes there is limited space on the roof, and usually only one or the other is installed. Solimpeks, a solar panel manufacturer based in Turkey, has been producing solar panels for a long time, and has an elegant solution to the problem: a panel that produces both electricity and hot water. It turns out that the Solimpeks Volther dual-use panels increase efficiency more than you might expect.

Photovoltaic solar panels actually lose efficiency as they get hotter. For every 1 degree (Celsius) temperature rise, a typical PV panel will lose about 0.5% efficiency. But combining water heating and PV in the same panel helps to keep the PV elements cooler, thereby increasing the power output. And, the panels produce both electricity and hot water for the building, which is particularly useful for apartments and multi-tenant buildings where there is more demand than there is roof area for the necessary equipment.

In tests, Solimpeks’ hybrid panels have shown an improvement in electrical generation of 20% over conventional PV-only panels, while also delivering water at 140-160 degrees (Fahrenheit). In addition to increased production efficiency, keeping the panels cooled also extends the life of the panels, so they stay in service longer.

Solimpeks makes two versions of the Volther panels.  One (called PowerTherm) is optimized for hot water production, and the other (called PowerVolt) is optimized for electricity production. PowerTherm produces over 600 watts of water heating, plus 160 watts of electricity, while PowerVolt produces about 450 watts of heat and 175 watts of electricity. The dual panels are a more flexible option than the Solar Sandwich system we recently saw, since they are a system of panels, rather a whole roof system.

The hybrid panels are more expensive than either standalone PV or solar hot water panels, and the installation cost is slightly more, as well. But you get the dual benefit of both electricity and hot water from these panels, as well as an extended useful service life. Solimpeks distributes throughout Europe, and is starting to be seen in the US, although they don’t have an exclusive dealer in North America, yet. If you are interested, these hybrid panels can be ordered directly from the manufacturer.

Photo credits: Solimpeks; noticed at Building Green.