What you look for when you buy them and what type you need

In today’s climate, when energy prices have reached alarming levels in many parts of the world, people are paying particular attention to ways – such as solar panels or wind turbines – that they can produce their own electricity.

Wind turbines can’t be installed just anywhere, so most people choose solar panels. Their advantages are many. First of all, they can cover part or all of a household’s electricity needs, generating significant cost savings. People also have the option of feeding excess energy into the national grid for a fee.

Moreover, homes equipped with solar panels typically have higher selling prices because they are more attractive to customers, according to studies.

Last but not least, by consuming the energy produced in this way, a person is helping to combat global warming.

How the main types of solar panels work

There are two main categories of solar panels that are widely used in the world: photovoltaic (PV) panels and concentrating solar-thermal power (CSP) panels.

PV panels are made from photovoltaic cells. The sun emits radiation (also known as electromagnetic radiation) that is absorbed by the cells, which become electrically charged. Direct current is converted by an inverter into alternating current, which can be used in homes.

PV panels are also of several types, depending on the materials used in their construction: monocrystalline (a cell is made of a single high purity silicon crystal), polycrystalline (made of polycrystalline silicon; have several crystals per cell), hybrid or thin film (substituting silicon with other materials).

There are even bifacial models, where both sides can produce electricity.

CSP systems, used mainly in solar parks, use a system of mirrors that focus light to the receiver that collects it and converts it into heat. The heat is then used to produce electricity.

Obviously, much simpler photovoltaic panels are installed on people’s roofs and in their yards.

Important things to look for when buying solar panels

Type. The patterns commonly used in households are monocrystalline or polycrystalline. Monocrystalline PV panels have a higher yield than polycrystalline panels and produce more energy in cloudy weather. However, they lose efficiency as the temperature rises (by up to 0.39% for every degree Celsius increase). This is why polycrystalline models are recommended in lowland areas, for example. Monocrystalline panels are more expensive than polycrystalline panels by about 15%.

Thin Film technology is an option for those living in areas with bad weather, where, for example, hail or thunderstorms are common. These designs are lighter, more flexible and more resilient.

Power. The power of a solar panel matters more than its size. The higher the power, the fewer panels will be needed for a user to meet their energy needs. Those who have a lot of space to install these devices can buy more panels of lower power, but cheaper.

Lifespan. Most solar panels have a lifetime of around 25 years. There are also models that are supposed to last 30 years, and some with much shorter lives. As they age, these devices produce less energy. Many manufacturers guarantee 90% of the advertised output for the first 10 years of use.

Sources: CNET, Wich?, Energy.gov