How does heating water with solar panels work?

Solar panels are the components of a photovoltaic system that make harnessing solar energy possible. They obtain energy from solar radiation and convert it into electricity (photovoltaic solar panels) or into thermal energy by heating water (solar thermal panels). 

Both systems are quiet, clean and have a long service life. In addition, they generate decentralised energy, so each building can be a photovoltaic or thermal power plant. Because energy is produced close to where it’s needed, there’s no need for structures to transport it. That translates into efficiency, sustainability and savings. Check it out!

On a technological level, however, they have little in common. While a solar panel or photovoltaic module transforms solar energy into electricity through the photovoltaic effect of its semiconductor elements, a solar panel or thermal collector heats the hydraulic circuit inside it with the help of the sun. That liquid can be glycol, water or a mixture of the two. The heat from this liquid is transferred to the domestic water by means of a heat exchanger in the solar thermal collector.

With these thermal collectors, water can be heated to above 100º, although 40º-45º is enough to have hot water or enjoy underfloor heating, and only a little more is needed for conventional radiators. 

Now you know how a solar panel heats up water. What you might not know is that the sun can satisfy almost all of your energy needs. As well as being a source of clean energy, it's infinite. The best part? Spain enjoys more than 1700 hours of sun per year. How lucky are we!