How home solar energy systems work
Learn how a solar energy system delivers power to your home.
Residential solar energy systems can save you money and are good for the environment but how do they work?
It starts with the solar panels, the most visible element of your system that all Queenslanders will be familiar with.
Nearly every street in the state will have a house with panels on its roof delivering solar energy to power appliances in the home.
Solar panels work by generating DC (direct current) electricity as sunlight, or solar irradiation, stimulates electrons to move though solar cells on the solar panels.
It is sunlight, not heat, that generates the electricity.
Household appliances require AC (alternating current) electricity to operate, so solar panels send their DC electricity into an inverter that converts it into AC current.
Your inverter sends AC solar electricity to your main switchboard, which in turn sends it to your home’s appliances, giving you free power.
Any excess power generated during the day is fed back into the main grid. A State Government scheme means you will usually be paid a feed-in tariff from your electricity retailer for any excess power your system generates.
Your smart meter, installed as part of the system, will record and track all energy flows. It will automatically feed the excess solar electricity into the grid.
The smart meter also allows your home to automatically draw power from the grid when needed, such as at night.
Nearly every roof in Australia is suitable for solar panels.
Most residential roofs in Australia are constructed out of metal or tile.
Metal is the cheapest roof to install a solar system on while tile roofs can often have extra installation costs.
Different roof pitches, or angles, can affect the performance of your solar panels.
The best way to maximise the efficiency of your solar panels is to have an inclined angle of about 10 degrees above horizontal to prevent rain and other dirt from accumulating.
If your roof is either flat or very steep, your solar system may require tilt frames (and additional expense) for optimum sun exposure.
Solar panels are relatively light, but with the average system size increasing to at least 6kW, 20 or more panels can have a significant weight factor, so it is crucial for solar technicians to assess your roof before installation.
Some roofs may not be strong enough for solar panels. In this case, additional frame structure may be necessary before installation.
Ideally, your roof allows panels to face north, west, or east. Since south-facing panels receive less sun exposure in Australia, they are generally not recommended.
If you live in a part of Queensland which can be affected by cyclones, you will need to have a cyclone-certified solar mounting system.
Sources: Australian Energy Foundation, GEM Energy.