What is photovoltaics?
Photovoltaics refers to the direct conversion of (sun) light into electricity. "Photo" is derived from the Greek word for "light". The second component refers to volts, the unit of voltage. Photovoltaics is a technology that allows homeowners to generate climate-friendly green electricity themselves and use it directly. Photovoltaics have long been considered the most expensive form of electricity generation from renewable sources. Drastic reductions in the cost of system components have now made this view obsolete. In 2020, the International Energy Agency found that photovoltaic systems built in favorable geographic locations and favorable institutional conditions are now the cheapest form of electricity generation in history.
Difference photovoltaic and solar systems
There are many and sometimes confusing concepts associated with solar energy. The two most important are photovoltaic and solar thermal. Both are technologies that use the sun's energy to generate power - in different ways. With a photovoltaic system, solar energy is converted into electricity that can then be used in the home. Solar thermal systems are different: Instead of solar panels, solar collectors capture the sun's rays. This heats the liquid in the thin tube, creating steam. In this way, the solar heat reaches storage tanks in the house, where it can be used. This describes the main differences: photovoltaic generates electricity, solar thermal generates heat. But which of the two systems has the advantage? After all, each square meter of roof or facade surface can be used only once, and the advantage of photovoltaics is its versatility: electricity can be used for all household appliances, including electric vehicles. It can also power a heat pump heating system. Solar thermal systems, on the other hand, can only do one thing: generate heat. Theoretically, it is also possible to use heat exchangers for cooling, but this is rarely economical - compared to modern heat pumps, which can do both in combination with comfort ventilation. In addition, only photovoltaics can feed energy into the grid.
How big should my photovoltaic system be?
Recommended PV system sizes for single-family homes range from 4 to 10 kWp or even higher. Homeowners should get the most out of their roofs. This way, the house's electricity needs are well covered in the fall. It's best to think about an electric car or heat pump right away - even though it may be years before you actually buy them.