Photovoltaic power systems

Energy from the sun

Photovoltaic systems convert sunlight into electricity. While the photovoltaic system itself is a significant investment, its running costs are extremely low, and it can divert any power not used in the home to the state's electricity supply network, for which the householder is paid.

The average household produces fifteen tonnes of greenhouse gas each year. A photovoltaic system, particularly when used alongside a solar hot water system, makes a direct contribution to eliminating greenhouse gas emissions by using the sun's energy to power the home.

Photovoltaic solar panels capture solar radiation and convert it into direct current (DC) power (in contrast to solar hot water systems, where the sun directly heats the water). An inverter converts this DC power to alternating current (AC) the type of electricity that your home uses to power lights and appliances.

The electricity is fed into your home's existing power supply and will run your appliances just like electricity from traditional sources. If the system produces more electricity than you need, it will be passed back to the electricity grid.

Your electricity supplier can fully install a solar energy system for you and connect it to the supply network. That allows you to draw additional energy as you need it or sell excess energy back to your participating retailer.

Under the Commonwealth Government's Photovoltaic Rebate Programme, which commenced on 1 January 2000, cash rebates are available to householders and owners of schools and community-use buildings who install grid-connected or stand-alone photovoltaic systems.

In Queensland the home owner component of the program is administered by the Sustainable Industries Division of the Environmental Protection Agency. Schools and community use applicants will need to apply directly to the Department of Environment and Water Resources for these grants.

Getting the most out of photovoltaic power

In a three-bedroom home:

• A typical 1050 watt photovoltaic system will generally produce enough power to cover the annual energy requirements of lights, and many kitchen and lounge appliances.
• A typical 1575 watt photovoltaic system should produce enough power to cover the annual energy requirements of lights and all kitchen and lounge room appliances (and possibly more if you have gas cooking).
• When a photovoltaic system is generating less electricity than is immediately needed by the home, the utility provides the difference, spinning the meter forward. When the photovoltaic system generates more power than the household can use, the excess electricity flows into the statewide grid, spinning the electric meter backwards and building a credit against the electricity bill. This is called 'net metering' and it is standard practice in most states.
• Photovoltaic systems substantially boost property values, due to the continuous cost savings available to the home’s occupants.

Installing photovoltaic power

A home photovoltaic power system includes solar panels, a grid-interactive current inverter, rooftop mountings and a full wiring system.

All photovoltaic systems should be installed by a Sustainable Energy Industry Association (SEIA) certified installer.