Tunnel with solar system
Foto von Linda Jorde

Linda Jorde

Photovoltaics – History and interesting facts


A journey into the past

Nowadays, using photovoltaic systems to harness the power of the sun and produce solar energy seems entirely normal. But how did we get here? And how has the technology developed? How did we come up with an intelligent way to use the sun as an energy source and who invented photovoltaic technology? We’ve put together 12 interested facts from the history of photovoltaics that you definitely won’t have heard before.


But first of all, what exactly are photovoltaics?

Here’s a brief explainer for anyone new to the topic. Photovoltaic technologies collect solar energy and convert it into electrical energy in order to use it as electrical current. Today, this involves a roof-mounted photovoltaic system comprising solar modules made up of numerous solar cells that collect and convert the energy from the sun. Solar cells are composed of lots of semiconductors, which are made from silicon. Silicon is combined with other chemical elements and structured in a series of thin layers, one on top of the other, inside the solar cells. When sunlight reaches the solar module, a significant potential difference builds up between the layers – direct current flows. This needs to be converted into alternating current by the inverter in the photovoltaic system. Today, generating electricity from renewable energy is as easy as that.


So, why choose solar electricity?

The primary motivation behind using solar electricity is the desire to be independent. With your own solar power system and an energy storage system from SENEC, you are more independent and less exposed to rising electricity prices – no matter how high they rise in the future. Electricity generated on your own roof will always cost the same amount: nothing. You can read more about energy storage systems here.

Plus, by choosing solar electricity you’ll be doing your part to help the environment. Switching to renewable energy therefore protects not only your wallet but also the climate.


Solar technology has travelled a long and winding road to reach its current level of advancement – and we want you to know all about it. Here are the most important and most interesting facts:


12 facts about the development


  • 1. Use in ancient Egypt
    It is believed that people made clever use of sunlight a long, long time ago. Researchers believe that, in ancient Egypt, mirrors were used to direct sunlight into the burial chambers inside the pyramids. Clever, right?
  • 2. The mud-walled house of the Pueblo people
    The Pueblo people were also resourceful. They built multi-storey mud-walled houses designed with the course of the sun in mind, in order to make optimal use of solar energy and avoid freezing in winter.
  • 3. Assyrian lenses
    Assyrian artisans sanded rock crystal so finely that it was able to concentrate sunlight and was probably used as a burning glass to set brushwood or wood chips alight. A ingenious technique that was absolutely crucial for survival back then.
  • 4. First energy-conserving houses in Greece
    The ancient Greeks understood the benefits of harnessing the power of the sun. In fact, they built an entire city following the principles of solar architecture back in 400 BC. The houses were constructed on south-facing slopes, with care taken to ensure that no houses were in shadow. It is even likely that the ancient Greeks managed to store solar energy by using stones and cinder as source of heat in their homes. In winter, these stones would be heated by the sun and ensure that the interiors stayed warmer for longer. Pretty impressive for the time!
  • 5. Fire-raising
    The veracity of this story is disputed, but Archimedes (287–212 BC) is said to have used bronze mirrors and sunlight to set fire to the Roman fleet. However, sources disagree as to the truth in this story.  
  • 6. The Romans’ solar oven
    The ancient Romans were not known for dithering – and built a house that we would now probably describe as a winter garden. Known as the heliocaminus (which translates as “solar oven”), it also made clever use of solar energy as its large, glazed windows allowed sunlight to pour into its interior, while its floor was heated with firewood. Archaeologists believe that the heliocaminus served as a sauna.
  • 7. Burning mirrors for fire-making and distilling
    The ancient Greeks were not the only people to use burning mirrors, such as to light the Olympic flame. In fact, the ancient Chinese, Roman and Incan peoples all used this technique. People in Arabia even used burning mirrors to distill water.
  • 8. The old-school greenhouse
    In 1767, the Swiss natural scientist Ferdinand de Saussure made a discovery: a planted bed is heated more strongly by the sun when the rays shine through a pane of glass. He developed a “heat box” and made use of the photoelectric effect. Some parts of his design still serve as the template for greenhouses to this day.
  • 9. The major discovery
    In 1839, the time had come: Alexandre Edmond Becquerel discovered what we now refer to as the photovoltaic effect. He was measuring electricity in his laboratory when he noticed that the electricity flowed faster when light shone on it. Even though this was a crucial first step, Becquerel was still unable to apply his insights into the photovoltaic effect in practice.
  • 10. A key element
    Around 40 years later, Wiliam Grylls Adams identified another important piece of the puzzle when he discovered that the element selenium produces electricity when exposed to sunlight. However, the efficiency of selenium cells is far too low at around 2%. Nevertheless, his discovery represented a vital milestone: he was able to demonstrate that a solid material can produce electric energy with the help of the sun’s energy. Another step towards solar-powered electricity.
  • 11. Help from outer space
    The next big push forward came from outer space. In 1954, a team of researchers in the US constructed the first solar cell based on silicon. This cell had an efficiency of 6%. The advent of aerospace technology brought about a major upswing for photovoltaic research. Silicon-based solar cell technology is still being developed to this day.
  • 12. Evolution
    The technology underwent continuous development throughout the 1980s, with the potential applications of photovoltaic modules also growing rapidly. Members of the public no longer had to reach quite so deep into their pockets to purchase a solar module, which made the technology markedly more attractive for private individuals.
  • 13. The current state of play
    Nowadays, people are very much aware of our ability to harness solar energy with a photovoltaic system and of the most effective technical means of making optimal use of this energy to generate electricity in our daily lives as well. Renewable energy is the future – something we have certainly come to accept since realising that our fossil fuel reserves will eventually be exhausted.
  • That brings us to an important point: to make the best possible use of the electricity you generate from your own roof, you should supplement your photovoltaic system by purchasing an energy storage system. SENEC offers such devices in four different sizes, so you can choose the right size for your electricity consumption and the amount of electricity you generate. By installing one, not only will you lay the foundations for accessing funding and subsidies, you will also be taking a step towards complete self-sufficiency.