There is no disputing the fact that the use of solar energy to power our homes has a beneficial effect on both our everyday lives and the environment as a whole. Solar is a clean energy source that has increased in use over the years. One of the biggest arguments against the use of solar power is the efficiency of electricity traditional solar panels are able to produce from the sun. Researches at MIT have developed a method that may allow for solar panels to harvest greater amounts of electricity from the sun’s rays.
How Do Solar Panels Work?
Solar cells produce electrical currents through the use of a semiconductor material such as silicon. The silicon material is sandwiched between two conductive layers. Each solar cells uses two layers of different types of silicon. The top layer contains silicon material with extra electrons and a bottom layer that contains “holes” or spaces for electrons.
As sunlight hits the solar cells, photons generate enough power to knock electrons free forming an electrical current. The current is then used to power all electrical devices in your home. When the electrons return they fill in the “holes” in the silicon and repeat the process. Because electrons are the only moving parts in a solar system, your panels will work properly for decades. The only issue is traditional solar panels generate between 15 and 20 percent of electricity from the sun that strike the solar cells.
How Can We Increase the Efficiency?
The simple answer to creating more electricity is to increase the amount of electrons that are knocked free. The problem is that when electrons are knocked free they may not travel in the direction that you want them to go. First, the photons from the sun’s rays have to be strong enough to pass into the silicon material and knock out free electrons. If the sunlight is not strong enough, they may just be reflected away. Next, the electrons may return to the “hole” they were just knocked free from, the photons energy is lost. The electrons may also scatter across the material dissipating energy in a process known as thermalization.
In order to increase the efficiency of the electrical current, you need to absorb more photons and manipulate the current the instant they are knocked loose.
What the Experts at MIT Found
Researchers at the Massachusetts Institute of Technology have come up with a way to manipulate electrons before they interact with other electrons in the material. Graphene, a ultra-thin material that is a single atom thick, is sandwiched together with a layer of boron-nitride separating the two layers. The ability to control the high-energy electrons can allow for more efficient photovoltaic devices before they lose their energy to thermalization.
In previous experiments, with the use of the same graphene material, researchers used varying intensities of voltage and light and observed the amounts of current being produced from one layer to the other. They found that a strong current could be produced at certain voltages and wavelengths of light. They then altered the voltages and wavelengths to determine how the current flowed between the layers and across the boron-nitride. In order to cause the electrons to jump from one sheet of graphene to the other, the right combination of voltage and light needs to be exposed to the semiconductive material.
How This Can Improve Solar Panel Installation in the Future
By understanding how currents flow with certain voltages and wavelengths of light, we can better improve the effectiveness of residential solar panels. We can apply these techniques to improve solar cells, enabling them to capture and use more photo-exciting electrons which increases the number of electrical currents. Today, solar cells are only able to absorb and use high-energy photons. This means that low-energy, infrared photons are either reflected away or passed through the solar cells and not utilized to produce an electrical current. By improving the infrastructures and applying new technology, more forms of light can be used to generate a controlled flow of electrons.
The solar industry is constantly improving, and Sol-Up is looking to do the same for the city of Las Vegas. Through new technology such as energy storage systems that will allow you to maintain your freedom from the grid. We have a mission to make Las Vegas the solar capital of the world, as it sees the sun over 85 percent of the year. For more information about how you can begin your journey to solar call us at 702-586-9800.