The spring-like weather of the last few days and weeks spoiled us with lots of sunshine and temperatures well above 20 °C. Spring 2020 is sunnier than any spring before. The sun not only provides us with vitamin D - but can also be used to generate energy.
Solar energy is the energy that can be obtained from the rays of the sun. This includes not only the energy generated by converting solar radiation into electricity, but also direct solar heat and the thermal utilisation of solar radiation.The radiant power of the sun is based on the electromagnetic radiation released at the surface of the celestial body - with an estimated, hardly imaginable temperature of approx. 5500°C.
How does the use of solar energy work physically?
The sun's rays that reach us are products of the nuclear fusion that takes place inside the sun. When the rays hit the Earth's atmosphere, they still have an intensity of about 1367 watts per m². Part of the solar radiation is already stopped, dispersed or reflected in the atmosphere suspended matter. And the atmosphere itself is already heated by the solar radiation and thus absorbs a considerable amount of the radiation.
What remains reaches the earth's surface and unfolds its effect there. The incident solar rays are used by plants for photosynthesis, i.e. the conversion of carbon monoxide into oxygen. We owe the air we breathe to this process.
When people use solar energy, they do so in different ways with the help of photovoltaics or photothermal energy:
- Using solar cells in photovoltaics to generate direct current
- Gaining heat through solar collectors within the framework of photothermics
- Power generation in the solar thermal power plant via heat and water vapour
- Power generation through sun-heated air in so-called updraft power plants
- Solar ovens or cookers for heating food, medical equipment, etc.
- Solar balloons, whose ability to fly is based on the hot air inside them
What are the advantages and disadvantages of solar power?
When it comes to using solar energy, experts distinguish between solar collectors and photovoltaic systems. With the help of solar collectors, for example, water can be heated for household needs; a storage medium is not provided here. However, the collectors only perform at their best when the weather is very fine and the sky is clear. At night, as soon as the heated water supply is used up, it's time to stop showering.
Photovoltaic systems, on the other hand, can generate electricity that is fed into the grid. The electricity generated in this way is paid to the producer. Conversely, households with a photovoltaic system can feed electricity into the grid during the day and then, conversely, draw electricity from the grid at night.
Of course, such systems are much more expensive to purchase than the quite simple collectors. In addition, users must calculate how large or powerful the system is in order to be able to amortise it sensibly. If you have enough roof space, you can write off a photovoltaic system of 20-30 m² within about 15 years.
It is also costly to store the solar energy produced. Work is still underway on appropriate chemical storage media; the use of hydrogen cells is conceivable.
How great is the benefit of solar energy?
Larger photovoltaic systems are complex panels of semiconductors that convert solar radiation into direct current. This is converted and can be fed into the electricity grid. The systems have become much more affordable than they were 10 or 15 years ago and are one of the most important sustainable methods of generating electricity. Since modern solar cells have an extremely high conversion rate, they also work well in northern latitudes.
But the possibilities are far from exhausted. At least a quarter of the energy demand could be covered by solar power by the middle of the century. And solar energy can be used not only for the electricity needed, but also for heating water and rooms - both actively and passively, ideally in combination with appropriate renovation and insulation of buildings.
Passive and active use of solar energy
Solar energy has been used passively for thousands of years - especially in the orientation of buildings. In this way, the maximum amount of light and heat should be captured through the windows. At the same time, so-called "passive houses" must, of course, also have appropriate thermal insulation so that the "captured" solar heat stays inside.
If, on the other hand, solar radiation is to be actively used, a solar collector is needed to produce hot water or a photovoltaic system to generate electricity. No matter what users choose, the panels or other components can be incorporated into the design of a building.
Using solar energy - it's possible almost everywhere
With highly efficient new solar panels, the power of the sun can be converted into energy even in northern latitudes. Even the slightest irradiation of light is utilised. And mobile solutions have also been thought of in the meantime. There are solar pads, for example, which are an ideal way of supplying energy for outdoor enthusiasts. The pads are actually portable solar cells. They can be attached to a backpack or the roof of a car and at the end of the day have generated electricity for a mobile phone, camera or hot shower water. So solar energy is not only incredibly sustainable - it's also eminently portable!
NIKIN - for a more sustainable approach to the environment
Although at NIKIN we are primarily concerned with sustainable materials in the fashion industry and fighting global deforestation, it is important to us to think sustainably in other areas of life as well. We want to motivate people to rethink their lifestyle and possibly make it more sustainable. It is time to think about alternative energy sources than the conventional ones. One of these is the use of solar energy, which is gradually becoming more affordable due to technical progress and is also experiencing an upswing in Switzerland.
