Components of Solar Energy Systems

Photovoltaic Cell Arrays

• All solar energy systems begin with a collector of solar energy, the photovoltaic (PV) cell. As sunlight bombards the PV cell it looses electrons, which are carried by wire to provide electricity. As the wire system returns to its source in a circuit, the electrons are returned to the cell. Solar panels containing PV cells can be several feet across and permanently fixed to a roof or tower or as small as a single cell. Solar panels in 2011 are so advanced that panels can be made flexible and rolled up for easy transport and mobile applications.

Deep Cycle Battery Banks

• Solar energy is stored in battery banks for use in homes and by portable electric devices. PV cells produce DC power, or direct current. To store and use this electricity, a bank of batteries must be linked together in a series circuit. The more power that is needed for a home or application, the more batteries must be wired in the battery bank. Because of the constant drain and recharging, deep cycle batteries must be used. Deep cycle batteries are used in golf carts and fork lifts among other uses; businesses that use these vehicles might let you have their used batteries for free. Supposedly "dead" batteries can be refurbished using a desulfator.

12 Volt Charge Controller

• The final necessary component is a 12v charge controller. Wired between the solar panels and the battery bank, the charge controller keeps the batteries from overcharging, which could cause leaking or explosion. High-quality charge controllers will also keep the electricity stored in the battery bank from draining back into the solar panels during the night. Some charge controllers feature a digital readout which displays the current charge of the battery bank. Set a charge controller to turn on the current when the battery bank charge dips below 11.7 volts and to shut off when the charge exceeds 14.3 volts.

Wiring and AC Inversion

• Wiring and inversion systems will vary greatly depending on the needs of the power system and how it is assembled. In remote areas where the user relies entirely on the solar power system, it is worthwhile to wire the house or building with DC wiring and electrical outlets to maximize the amount of usable power. Light bulbs and fixtures will have to be changed to DC fixtures and bulbs in certain circumstances to make the best use of your stored electricity. Normal household appliances that run on AC power will need an AC inverter to use DC current. If your solar system is part of an enhancement to an "on-grid" power system then you might hook an AC inverter to the solar generator where it connects to the house. If you are in a remote situation relying solely on green power, you'll want to use DC wiring and systems as much as possible and use small, indoor AC inverters with built in outlets for standard appliances.