As today’s costs of energy rise, solar power is becoming more popular than ever.  There is an annual growth rate of over 30% within the industry.  It is true that a system, purchased and installed commercially, can cost 10’s of thousands of dollars, by doing it yourself and starting small, You can save a lot.  Even installing a small system into your home, you will see a smaller electric bill.

      Your solar power system can fall into two classifications, on grid or off grid.  An on grid system is connected to the local power lines and will supply our home with power only while the panels are producing electricity.  The off grid system is not connected to a power provider, and has it’s own battery bank for storage of energy.  This way energy is still provided by your solar system, even when the sun is not out and available.  A hybrid system is one, which is still attached to the local power supply, and also has the battery storage.

      The variety of components of these systems will be discussed below. 

Solar Panel

      The main, and most obvious part of any solar power system is the solar panel.  Each panel is comprised of multiple photovoltaic (PV) cells.  A PV cell is a small instrument that takes sunlight and converts is into electricity using the photovoltaic effect.  PV cells are also called solar cells.  Each cell produces a relatively small amount of electrical power; therefore, it must be connected to a large quantity of other cells in order to secure worthwhile power levels.  The PV cells are mounted on a sturdy substrate and wired together to obtain the amount of power needed.  The whole thing is then mounted within a frame and covered with a weather-tight layer of glass or Plexiglas.

      Several panels are then attached together and mounted to form a solar panel array.  The array is then placed in the area on or around your home that receives the most amount of sunlight and the least amount of shade.  This can be on the roof, the top of a pole, or even at ground level. 

Solar Power Battery

      The solar power battery is used to store the extra power created by the panels, to be used at night or when the sun is not accessible.  Batteries are electrochemical devices and their performance is determined by age, charge/discharge cycle history climate and temperature.  Though there are many types of battery technologies, lead-acid batteries offer the best performance to dollar ratio and are the most commonly used in solar power systems.

      The capacity of a battery is listed as amp-hours at a specific voltage.  This means that a 100 amp-hour, 12-volt battery will provide 12 volts at 1 amp for 100 hours.  The battery bank should be sized for the ability to store enough power for 5 days without sunlight.  It should also be a deep-cycle battery.  This means that the unit is capable of discharging most of its power before being recharged.  Vehicle batteries are ‘shallow-cycle’ and thus, are not good for solar power uses. 

Solar Power Charge Controller

      To lengthen the life of the battery pack, a controller is normally prescribed.  The controller monitors the voltage of the battery and as the voltage increases it reduces, or completely stops, the charging current; thus preventing over-charging.  When the voltage drops again, the controller allows the current to increase and continue to charge the battery.

      Controllers are rated by the amount of current they can manage.  If there is any chance that you might expand your system in the future, it’s a good idea to install a larger capacity controller right from the start.  Larger controllers are not typically that much more cost wise.  

Solar Power Inverter

      The battery bank stores direct current (DC) power from the solar panels.  The low DC voltage has to be converted into a higher AC voltage, such as 120 or 240 volts, to be able to power appliances.  This is the job of the inverter.  The inverter also creates the AC frequency, which is 60 Hertz (cycles-per-second) for the USA.  It also provides a sinusoidal (sine) waveform, which most electronic appliances require.

      The inverter must be able to accommodate the required system power.  Brand-name inverters are dependable and maintain conversion proficiencies of approximately 90%.