Design & Installation of Photovoltaic Systems

A photovoltaic cell converts sunlight into electrical energy.

Developing technologies make increasingly efficient use of the sun's energy to produce electricity. Photovoltaic (PV) cells, also known as solar cells, convert sunlight to electricity using a variety of semiconductor materials. PV cells connect together to form PV modules, which connect together to form PV arrays of varying sizes and power output. An array, combined with mounting hardware, electrical connections and power-conditioning equipment, make up the components of a PV system. A PV system, installed on the ground or on a rooftop, may be used to power a home or business, to feed the power grid or to store electricity for later use.

Things You'll Need

• Calculator
• Compass
• Electric usage history
• Solar array
• Electrical connectors
• Power inverters
• Battery storage system (optional)
• Mounting brackets
• Measuring tape
• Hammer
• Screwdriver

Instructions

1. Determine electrical usage. This usually involves adding total yearly power usage in kilowatt hours, then dividing by 12 months to get average monthly use. Design the PV system with the number of solar panels required to generate enough electricity for the highest usage month. The total system may be limited by roof size or a structure's weight-bearing limits. Solar panels may be built, or purchased from a variety of retailers. Provide the appropriate amount of power inverters, electrical connectors and wiring to connect the PV system to the electrical system.

2. Determine the location of the solar panels, with exposure to sunlight the most important consideration. To optimize sunlight exposure, mount panels facing south and where trees or structures will not shade them.

3. Mount the system using appropriate mounting brackets. Solar panel mounts come in three varieties: pole mounts, roof-ground mounts or flush mounts, depending on location. A solar array may be mounted on a roof, on the ground or even on top of a recreational vehicle.

4. Connect the PV array with wire to a power inverter, which converts the direct current produced by the PV cells to the alternating current required for the electrical system. Then connect the inverter to the electrical system and, if using one, the battery storage system.

Tips & Warnings

• Find PV system size estimators online for easy calculation of needs.

• Check federal, state and local government programs for renewable energy rebates.

• Micro-inverters maximize power coming from individual PV cells, extending the life of the system.

• Research solar renewable energy credit (SREC) programs to earn money from the solar energy system.

• Ask local utilities about selling electricity back into the grid, also known as "back-metering."

References

• U.S. Department of Energy
• Free Sun Power
• Solar Power Info