The energy market is going through a dramatic change. Extreme weather conditions confirm the climate challenges, and the Paris Agreement brings all nations into a common cause to undertake ambitious efforts to combat climate change. Solar energy is predicted to take a leading role in the modern energy mix, and there are two main approaches for the energy production, solar electric power (PV, photo voltaic), and solar heating. PV is the approach that most are familiar with, but our position is that it is important to also focus on solar heating, in order to satisfy the portion of the energy requirement with green, renewable solar energy. So, we simply asked one of our internal experts the question what are solar collectors, and what separates the solar collectors from solar cells?
John, who is the general manager of Inaventa Solar, answers the question this way:
A solar collector is a device that transforms the radiative energy from the sun into heat in a useful temperature.
A PV panel is converting the same radiation into electricity.
There is a big difference between the technologies, which means that if you want to transfer the energy into heat, you get a very high efficiency – up to 70-75% of the energy in the radiation can be converted into useful heat, while there are fundamental limitations when it comes to production of electricity. The efficiency of a PV panel is rarely more than 20%.
But we need both electricity and heat. For the heat demand, actually the major demand of energy, a solar collector will be more efficient and appropriate than a solar cell, but for electricity you have to use a PV panel.
Both solar collectors and solar cells can be installed as integrated modules in roofs and facades, substituting other cladding. A simple way to get aesthetically quite good installations of energy producing elements.
We need both heat and electricity so why not use both solar collectors and solar PV panels in combination?