When you think of renewable energies, what comes to mind? Hydropower? Wind energy ?
In fact, these have proven to be the most popular in recent years. Hydropower in its current form is the cheapest among renewable energies. Wind power, in turn, is the fastest growing.
However, there is renewable energy that is far more versatile and has the potential to achieve a higher ROI than the above. It is an energy supplier that we all see and feel every day: the sun .
While both wind and hydropower meet a wide range of needs, solar energy has the potential to change our lives in a far-reaching way.
But how do we use this change? And how will it play out?
What are solar cells and how do they work?
Solar systems convert the enormous, inexhaustible power of the sun into electricity. Solar cells, also known as photovoltaic cells, are the means to accomplish this transformation.
Many of us combine solar energy with large-scale systems in the desert or the smaller, dark-colored solar roofs on residential buildings and office buildings.
Solar cells absorb sunlight, attracted by the dark, anti-reflective coating on the cells. At the moment, no solar cell can process 100% of the sun’s rays. This property is the biggest limitation that researchers are currently working on to improve.
The light penetrates the solar cell, which consists of two layers of semiconductors with opposite charges. These absorb the light and convert it into electrical current.
Each cell is designed so that it can only generate a certain amount of electricity and due to the absorption rate it is typically only a small power, which is why there are many interconnected cells in most solar systems. These connected solar modules usually deliver directly to the respective electricity collection point.
The performance of the cells and the current they generate depend on several conditions:
Size of the overall system or the total number of panels connected in a row
Amount and intensity of the sun
Sunshine duration on the system
And all factors that can prevent the sun’s rays from penetrating, such as clouds, dirt or dust that deposits on the solar cell
It can be expected that the longer a solar cell is exposed to intense, direct sunlight, the more electricity it generates …
Solar energy compared to other renewable energies
What sets solar energy apart from wind and hydropower is its versatility in both large and small projects.
For example, hydropower certainly makes sense when it comes to supplying a nearby electricity network. However, it is limited to local resources and is therefore quite inflexible. Likewise, wind energy requires locations where the wind blows fairly evenly. Another disadvantage is the strong influence of large wind turbines on the landscape, which often leads to an outcry from local residents. Hydropower requires an intervention in nature and often also the diversion of a water source.
In contrast, solar energy offers a much broader range of applications: On the one hand, the sun is available almost everywhere (except, of course, in the most remote places on earth). It is also the energy that has the least impact on the landscape and nature.
Solar cells can be attached to existing structures as an independent energy source or more easily integrated into materials and can even be used on the go, which is probably the greatest advantage.
Imagine that your car could be driven completely or at least partially by the sun or that you could heat your tent with the help of solar cells sewn into the fabric while at the same time charging a mobile device? How would you like to be able to charge your smartphone with a solar cell sewn into the jacket?
As solar cells are getting cheaper and the possibilities are increasing, the following models and applications will certainly become more common and popular in the future:
Transparent solar cells
As the name suggests, this advanced shape of the solar cell is largely transparent – not complete, as otherwise the light would be transmitted directly, but sufficient for numerous new applications. The researchers succeeded in developing a design with organic salts that absorbs enough UV and infrared light to convert sun rays into energy.
While the use of energy-generating transparent surfaces immediately creates a picture of large glass towers or houses with windows that extend from floor to ceiling, the practical use is not quite as large.
Imagine the screen of a tablet or smartphone with this type of solar cell. Or the windshield of a car. Transparent solar cells are therefore far more attractive than the typical, dark-colored modules and have a much wider range of applications.
Organic solar cells
In most cases, solar modules are made of silicon, as this is the most effective material for converting the sun’s rays into energy. On average, a silicon cell converts around 19% of the sunlight received. A particularly effective specimen even achieved an efficiency of 27%.
Organic solar cells made of plastic and carbon, which were long regarded as inefficient, are currently catching up on the market: In the past, carbon-based cells could not come close to silicon. Now they can keep up with them with efficiencies between 15 and 25%.
Since organic solar cell materials are flexible, light and easy to handle, they can be used in a variety of applications. They can be used, for example, in movable structures, incorporated into textiles or accessories or in materials that require semi-transparent materials, such as windows.
Researchers have also made a breakthrough in solar cells from living organisms.
The genetically modified cells are characterized by their ability to function even in low sunlight. Although this type of solar cell technology is still in its infancy, this could mean an advance over existing technologies in the future.
The aim is not to replace the existing materials for the generation of solar power, but to create an opportunity to enable solar yields even in areas that receive less sunlight.
Flexible and wafer-thin
For a long time, solar energy was synonymous with large, dark panels that produce a dazzling reflection in the midday sun.
MIT researchers have now succeeded in developing a solar cell that is so small and light that it can be placed on a soap bubble without causing it to burst.
With this size, it is not difficult to imagine solar cells that can be sewn into clothing, integrated into the surface of a tablet or smartphone or the body of a car.
In addition to these small-scale applications, the innovation could also be viable for large structures. Instead of large roof panels, buildings could in future be encased with a modern solar cell facade that supplies the entire complex with electricity.
While the wafer-thin solar modules are not yet scalable enough for the mass market, this time will surely come soon. As soon as this is the case, this could revolutionize the use of solar systems.
A street made of solar cells
You read that right – a street.
One of the main disadvantages of electric vehicles is the shorter range compared to a petrol-powered engine and the need to charge it more often. The charging process also takes considerably more time than the normal filling process of a petrol engine.
One way to overcome these drawbacks is to supply electric cars with a constant energy source. While some suggestions include installing wireless charging stations at traffic lights, there are other ideas on a much larger scale.
The testing of such solar roads was very scattered in places like China, France, the Netherlands and in the USA. This shows that the innovation is of global interest and should be used all over the world. While costs and earnings are still an obstacle, there are already first promising application attempts, such as the installation of the new technology in parking lots.
As already mentioned, most of us combine solar energy with the dark solar modules on the roofs of energy-conscious homeowners.
While these are effective, not everyone perceives them as particularly aesthetic: for some, they are elegant, future technologies of the future, for others they are not a pretty sight. Fortunately, the design adapts more and more to the design of house roofs.
Photovoltaic “tiles” integrate existing roofs and in some cases the roof even consists entirely of the ultra-modern solar panels. The advantages remain the same as with conventional panels:
Reduction of CO2 emissions
Lower electricity bills
… only the new version even comes in an attractive look.
With this innovation, there are many possibilities to do justice to the aesthetics of almost every house and still keep the costs of building a house too low – a real win-win situation.
Solar cells and solar energy in general are still in the development phase – with great potential for improvement. The state-of-the-art solar technologies mentioned will soon become part of everyday life.
In view of the versatility associated with solar energy, such as solar cars or solar cells sewn into clothing, there is no doubt that these are the most promising among renewable energies.