When we think about the future energy sources for mankind, we have to include solar energy because the Sun is the main source of clean and renewable energy in the Solar System.
Even the energy stored in ancient plants and animals that is used today as fuels for energy and heat production (fossil fuels) was once produced by the Sun.
Solar power is an energy source of the future because the Sun will be here for at least another 5 billion years to send us light and heat, so is considered a renewable, clean and sustainable source of power.
For the moment, solar energy represents less than 2 percent in the energy mix of the planet, but new inventions in the field are likely to change that.
How Can Solar Energy Power the Future?
Today, a small amount of land is covered by solar panels and this is the reason why solar energy has such a small share in the energy mix of the planet.
Areas suited for solar energy production are limited, and because the price of silicon, which is the main material used to produce photovoltaic (PV) cells is quite high, the generation capacity for solar grows quite slowly.
To make solar a major source of power for mankind, we have to change a few things.
1. Solar Panels Over Croplands and Water Surfaces
You may think that the deserts of the planet would be the perfect place to install solar panels because those areas are always sunny and hot, but maybe you don’t know the fact that solar panels become less efficient in very hot environments.
Dry and hot deserts are not the ideal place to install solar power plants, so scientists have decided to install them over croplands and over water surfaces where the temperatures do not exceed very often 77°F or 25°C.
Croplands are usually located in moderate climates, where usually is very hard to find a place to install solar panels.
To overcome this issue, researchers have decided to install solar panels over farming crops, which is a process called agrivoltaics, and is used to produce solar energy while boosting the food production and reducing the water consumption.
Solar panels installed over crops are cooler due to the fact that the plants are releasing water through their leaves. Plants start releasing water (like sweating) and the water evaporation process removes heat from the plants and cools the surrounding area.
The solar panels located over the crops work this way in a cool environment, so they become more efficient.
Researchers at the University of Arizona found that between May and July 2019, solar panels installed over croplands were 3 percent more efficient than solar panels installed in the same region but not over croplands.
Solar panels were also placed over bodies of water for the same reason (cooler environment), and they worked much better in terms of efficiency.
Solar panels installed over croplands and water surfaces already exist all around the world, but they are becoming more popular, so we may see them more often in the future.
2. Increasing the Efficiency of the Panels
Solar panels have a top efficiency of about 20 percent today, which means that 80% of the sunlight is lost instead of being converted into clean electricity.
To overcome this problem, scientists have decided to help the panels face the Sun during the entire day.
Traditional solar panels are installed at a certain angle and to face South in the Northern Hemisphere and North in the Southern Hemisphere, to receive the most amount of sunlight during the day.
However, this is not the perfect solution because the angle of the sunlight is changed during the of the day and the season.
To overcome the issue created by the angle of the sunlight, researchers decided to use photovoltaic trackers.
Photovoltaic trackers or simply PV trackers, move the solar panels along tracks that follow the movement of the Sun in the sky.
The trackers make sure that the sunlight is always hitting the panels heads-on, and this way the panels can reach an efficiency of up to 45 percent (depending on the geographic location).
3. Solar Windows
Scientists have also realized that the windows used to allow the light to enter our homes or businesses can also be used to generate solar power.
Giving the fact that solar panels convert only about 20 percent of the sunlight into electricity, the rest of 80 percent can be used to illuminate the room.
However, to do this, solar panels need to be made from something lighter and more transparent than silicon.
Researchers developed this way a new type of solar cell made of organic compounds (thin layers of polymers and dyes) that do the same thing like silicon cells but they are transparent.
Beside glass (for windows), scientists realized that they can print the dyes onto thin materials like rolls of plastic.
Organic solar cells are designed to absorb mainly infrared light and they allow visible light to pass through.
This way, organic solar cells have become fairly transparent because they let through about 43 percent of light.
These PV cells are less efficient, but they are lighter and cheaper to produce than silicon cells, so by using them on a mass scale (by replacing traditional windows with solar windows), we can seriously increase the share of the solar power in the energy mix of the planet.
4. Solar Cells Will Become More Present in Everyday Life
To make solar energy a major source of power for humanity, we have to install and use solar cells in a variety of devices and places.
From transparent windows and phone screens, and even clothing or car roofs, solar cells will be more present in our life in the future, because this way, even people will be turned into small solar power plants to produce at least the energy consumed by our gadgets.
5. Energy Storage Will Become More Efficient
Today, only solar thermal power plants can store solar energy for periods of time longer than one or two days.
These power plants use an agent (molten salt) which is heated at very high temperatures during a sunny day (up to 1292°F or 700°C), and that heat is used to produce steam, which will spin a turbine and produce electricity using a large generator.
However, molted salt can store heat for longer periods of time (more efficient than lithium-ion storage), and this way the power plant can supply power day and night (like a conventional coal-fired power station).
The agent can maintain heat with minimal losses until another sunny day arrives, and the large mirrors will reheat the molten salt using concentrated sunlight.
Conclusion
The good part here is the fact that researchers are continuing the work to find new ways how to make solar more efficient and affordable, while others are trying to improve the battery technology used to store renewable energy, and all these things only mean that solar will become a major source of power for humanity in a not so distant future.
