When choosing to install solar power – also called a solar photovoltaic (PV) system – it's important to consider what size will suit your needs. For example, do you want to go carbon neutral, or do you want to add battery storage? What is your budget?
You should speak to your electricity retailer and installer because installing solar power might impact your current electricity tariff. Some energy retailers require solar customers to shift to time-of-use tariff.
In many cases it will be possible to install a PV system that generates as much, or more, electricity as you use in a year. Some of this electricity will be used in your home and reduce your mains electricity consumption, and some will be fed back into the electricity grid.
Other ways to improve energy efficiency and reduce your bills include installing LED downlights, improving your insulation and replacing inefficient appliances. Making your house as energy efficient as possible will reduce the size of the solar PV system you need to buy.
The Solar Homes Program is helping eligible Victorian households take charge of their power bills by providing rebates for solar panel (PV), solar hot water and solar battery systems.
It's important to place photovoltaic (PV) panels so they capture the available sunlight most effectively.
Do you have sufficient unshaded space on your house or shed roof to mount PV panels? Generally, it's best to face your PV panels north but, if roof space is limited, it's also acceptable to face them west or east. Some west facing panels will increase the output of the PV system on summer afternoons when you might be using the air conditioner.
Adjoining properties may overshadow your PV panels. Also keep in mind the fact that adjoining land and dwellings may be developed in the future, or a tree or fast growing hedge may impact the effectiveness of your solar panels.
Your local council's planning and building group can provide information on overshadowing, land use, planning and development in your area, as well as planning permit requirements.
Higher placement of panels, or splitting panel location across north, west or east roof orientations, can minimise the impact of overshadowing on your solar system as a whole.
Avoid placing panels on a roof face with minimal separation from a neighbouring building. A side boundary with a path or driveway increases separation between both buildings and this minimises the risk that shadows will be cast over your panels.
For small systems, placing panels on the roof above a north facing side window is ideal. This is because greater setbacks are required to allow solar access to existing north-facing habitable room windows under the building code. (Note: a setback is the required distance between a building or other structure from a street, road, river, stream and so on).
Despite careful placement of solar panels, some overshadowing may still occur. As long as this is not greater than 20 per cent of the surface area of your system, energy generation will generally still be effective. A multiple string panel set up (or equivalent), where there are at least two groups of panels separately linked to your inverter can help in this situation.
When all panels are connected in sequence. shade on one panel may affect the operation of all the panels. Splitting the system minimises the impact of shade.
Some premium solar power systems are less susceptible to the impact of partial shading on overall system performance. Your solar system retailer should be able to provide you with practical advice.
The needs of every household are different, and the installation of solar power can require significant investment. Make sure you do your research before starting your installation.