Every day as the sun breaches the horizon the Earth is saturated in energy in the form of heat and light. This energy is plentiful, produces zero emissions and is free. The trick is turning the heat and light of the sun into storable, useable energy.

Within the sun’s light is energy in the form of photons. This energy then becomes heat when it hits an object. However, certain materials have the ability to absorb the sun’s heat and can convert it into an electrical current.

The older types of solar technology use silicon crystals. The crystals are able to produce an electric current when they are hit by light as the electrons within the silicon start moving around. Silicon crystals are able to convert a large portion of the light their receive into electricity, however silicon solar cells tend to be expensive since large silicon crystals are difficult to grow.

More recent solar cell technology uses smaller and cheaper crystals which are shaped into thin, flexible films. These crystals, like copper-indium-gallium-selenide make solar technology more affordable, but are not as effective at converting light into electricity.

Solar energy and power in the United States only represent for a small portion of electricity generation, mostly due to the fact that solar power is more expensive than other energy sources like coal. Currently solar power costs about five times as much as more conventional energy sources.

Before solar power can make inroads to become a more popular alternative energy more effective and affordable materials need to be created to harness the sun’s energy.

Solar Energy Explained

So how exactly does solar power work? First it starts with a solar cell, which as explained above contains crystals that absorb the sun’s light. When the light hits the crystals, the electrons between the atoms of the crystals get excited and begin to move around, creating a current.

Solar cells work similarly to plants that absorb the sun’s light, except that within the plant the current changes a chemical bond and makes fuel for the plant, whereas solar cells simply create a current which can then be converted to alternating current to be stored in a battery or used directly to power an appliance or light your home.

While it would be certainly be advantageous to somehow get solar cells to create fuel like plants do, this technology is still theoretical. The reason why plants are able to create fuel using the sun’s energy is that the also absorb CO2. If solar cells could do this then the benefit to the environment would be doubled as not only would we be reducing our dependence on polluting fossil fuels but we would also have a way to directly reduce carbon dioxide in the atmosphere.

Efficiency of Solar Cells

Silicon crystal solar cells are able to convert approximately 23% of the light it absorbs into electricity. The more affordable solar cells that use other types of crystals are less efficient and only convert about 15 – 18% of the sun’s light, while the high-quality solar cells used on satellites can convert up to 50% of the light into electricity.

While efficiency is certainly important, one also has to consider the cost to produce and purchase the solar cells. Silicon solar cells are expensive to make and hard to produce on a mass scale, while the thinner panels are more affordable.

Power Options

There are a few options that can be used in conjunction with solar cells to ensure that there is always sufficient energy provided. With a photovoltaic system excess energy can be stored up in batteries, to be used when the solar panels are not providing electricity, such as on a cloudy day or at night.

A grid-tiered solar system is tied in with a conventional electricity line so that regular electricity can be utilized. When power cannot be gathered then conventional power is used. The customer is only charged for the electricity that they actually use from the power company. As an added incentive, additional power produced by the grid can be sent to the electric company for a credit. When your solar cell is not in use, such as in the winter months you can use your credit at the power company for continued free electricity.

It is important that when installing solar panel that special care is taken to place them to receive the maximum sun exposure. Ideally panels should face south and avoid any shade during the day.

As of 2004 the solar production of electricity was approximately 1/1000th of the total power consumption of the United States. Hopefully with the discovery of better solar cell technology this number will change for the better.