Solar Power

How Solar Power Works And The Types of Use

The sun is power packed.  Its photovoltaic energy fosters the continuation of life as we know it.  The sun causes plants to grow (through photosynthesis) which in turn make oxygen that create the ozone layer protecting us from the suns intensive rays.  The amount of light given off the sun in one hour could provide energy to the whole planet for an entire year.  So why isn’t solar power more readily available?  Solar power seems like the greatest alternative to a world desperate for energy, however harnessing this energy has proven difficult.  Although the sun is a powerful force, its energy varies the further you are from the equator.  Shorter days and less sun are issues in parts of the world.  Solar power is being investigated and improved on but we are fighting high cost and efficiency ratings.  Approximately 10,000 homes in the United States are set up with solar panels which definitely increase the value of the home:  An investment of $20,000 could yield a return of $30,000 or more.  Many government programs give incentives to use solar power, and of course using the power of the sun definitely helps our environment.   There are two types of solar energy technology that we use today; Photovoltaic and Thermal.

In solar photovoltaic systems, sunlight photons hit the solar panels, which are made of silicon, knocking electrons that are in the material loose.  This creates an electrical current.  Silicon itself isn’t a very good conductor, so other materials or “impurities” as they are called, are added to the silicon making it more conductive.  It can be mixed with materials such as phosphorus, copper, or boron to help it along and give it that extra burst of energy.  Depending on the “impurity” added, silicon will produce positive or negative energy.  Separately, positive and negative energy cannot generate electricity…but together they provide voltage to the cell.  When light hits the silicon panels, the negative energy pushes energy to the positive side which creates electricity that can then be harvested and used as solar power.   Sunlight, being easily reflected, is a problem for Photovoltaic Energy production http://www.eere.energy.gov/basics/renewable_energy/photovoltaics.html.  To help remedy the loss from the reflection, solar panels are often coated with an anti-reflective coating.  They are also covered with protective glass to protect them from the elements of weather.  However, solar panels are expensive and the most efficient panels to date are only at 20%.  New research is being done to use parabolic trough mirrors to concentrate the suns power on the solar panels.

Solar Thermal Energy is the other form of solar technology.  This energy is much easier to harness because it is collecting what the sun gives off most…heat. The Sun provides about 300 BTUs of heat per square foot per day. This Heat is collected through parabolic systems which provide hot water via rooftop water heaters and create solar powered electric plants. Solar Thermal Energy brings big potential in the area of solar power.  Many of the largest electrical plants are powered by thermal energy.