We continue our crash course to learn where electricity comes from . Today's lesson is a monograph on the Sun, the largest generator of energy ever known.
How do its rays transform into the light of light bulbs ? Magic? No. It's just science.
We are going to focus on solar photovoltaic energy, which is the most widely used and directly transforms radiation into electricity. But there is also solar thermal energy , which uses the sun's heat to raise the temperature of water to generate steam that moves a turbine.
Photovoltaic energy
To transform sunlight into energy, semiconductor metal sheets are needed: photovoltaic cells .
These cells have one or more layers of a semiconductor material and are covered with transparent glass that allows radiation to pass through and minimises heat loss.
The solar panels that can be seen on the roofs of many houses are made up of these photovoltaic cells. Although their installation may seem expensive, the data show that the purchase pays for itself , with savings of around 30% of consumption that in the long term (25 years) means paying between €20,000 and €30,000 less. Another advantage is that they do not require a lot of maintenance.
The power of the sun converted into electricity
The sun's rays are composed of photons that reach the photovoltaic cells of the plate, generating an electric field between them and, therefore, an electric circuit. The more intense the light, the greater the flow of electricity.
Photovoltaic cells convert sunlight into electricity in the form of direct current with a graduation that varies between 380 and 800 volts . To improve the obtained result, an inverter is used that transforms this energy into alternating current , which is what we use in our homes.
Finally, this alternating current passes through a meter that quantifies it and supplies it to the general electricity grid.
Where do photovoltaic cells come from?
The father of this energy was the French physicist Edmond Becquerel , who at just 19 years old built the world's first photovoltaic cell in 1839.
Shortly after, in 1883, it was the American inventor Charles Fritts who developed the first solid-state cell by coating the semiconductor selenium with a thin layer of gold to form the junctions. His device only achieved 1% efficiency, but its structure paved the way for what is today the transformation of sustainable solar energy.
“Solar photovoltaics will be the cheapest source of electricity in the world.”
Uses of solar energy
The electricity produced by photovoltaic cells can be used in:
An isolated installation . Solar energy supplies electricity indonesia whatsapp mobile number to places that are difficult to access, where, for example, there is no power line. This electricity is intended for self-consumption.
A grid-tied facility . The energy produced is fed into the power grid as if it were another generating plant . Meanwhile, the owner continues to buy the electricity consumed while selling what is produced.
Satellites . They orbit the Earth and have solar panels in their structure to take advantage of the energy provided by the nearby Sun.
Independent structures . Thanks to solar panels, many small infrastructures can benefit from and become self-sufficient in energy: radio and television repeaters, SOS posts on roads, radars, military structures, forest surveillance posts, switching centres , etc.
The future is solar
According to the International Energy Agency, solar photovoltaics will become the cheapest source of electricity in many countries over the next few decades. In addition, photovoltaic systems have a long lifespan , as they are estimated to last an average of 30 years (with an efficiency of over 80% of the initial one after 25 years). And if this were not enough, all of its components can be recycled .
Talking about drawbacks, intermittency (damn clouds! damn night!) and storage problems are the main disadvantages of solar energy. However, blessed technology is on the way to remedying these problems, developing increasingly long-lasting batteries and researching how to install panels where the sun always shines... In outer space.
