Monday, November 5, 2012

Explaining the working principle of photovoltaic cells

The Sun is by far the most abundant form of renewable energy available on our planet. The amount of energy that Earth receives from the Sun is immense, in fact, it has been calculated that the amount of solar energy that Earth receives in one minute from the Sun would be enough to satisfy the energy needs of entire human population for one year. The world, however, uses only a tiny fraction of totally available solar energy, primarily because solar power technologies need to improve their cost-effectiveness (solar panels cost a lot and they are not that efficient).

When explaining the working principle of photovoltaic (solar) cells we first need to know that sunlight is made out of tiny energy pockets called photons and that each individual solar cell is designed with a positive and negative layer thus being able to create an electric field (similar to the one in batteries). As photons are absorbed in the cell their energy causes electrons to get free, and they move to the bottom of the cell, and exit through the connecting wire which creates electricity (flow of electrons). The bigger amount of the available sunlight the greater the flow of electrons, and the more electricity gets produced in the process.

Photovoltaic or solar panels are devices that are used to convert sunlight into electricity. Photovoltaic panels consist of numerous solar cells. By combining these individual solar cells into photovoltaic panels we can produce enough energy to power our homes as well as for many other purposes (space satellites). 

Solar cells absorb photons

Photovoltaic cells are usually made of expensive materials such as silicon, thus explaining the high costs of solar panels. However, solar panel prices have decreased by approximately 70% in the last three years, meaning that they are becoming more competitive with fossil fuels in terms of economics.

Installing solar panels on the rooftops of your home is not that complicated, primarily because solar panels do not have moving parts. Once installed, they operate very silently, and with enough available sunlight will provide emission-free source of renewable energy.

The electricity generated by photovoltaic panels is direct current. This means that there is a need for installing inverter. With the installation of inverter this direct current can be converted into alternating current so it's in sync with mains electricity, and can be used normally.

As already said above, the amount of sunlight at your location plays key role in determining the economics of your solar power installation. Some areas receive more sunlight than other, and in these areas installing solar panels is more economically viable.