Published on October 26th, 2017
Is solar for you?The sun is shining brighter every day as we head towards summer – what better time to think about solar energy? Most Australians will have experienced significant increases in their power bills over the past couple of months, making a domestic solar system more tempting than ever. But how do you know what system you need, and is it really cost effective? We crunch the numbers for you to help the decision along.
Solar systems explained
Solar panels are made up of multiple solar cells, which convert direct energy from sunlight into direct current (DC) electrical energy. This is then converted into alternating current (AC) power to be used in your home. Any excess energy can be fed back into the electrical grid.
Solar panels are most effective when installed facing north, and unimpeded by trees or high buildings that block direct sunlight. Surprisingly, they work best on a relatively mild day: 25 degrees is optimum.
Because solar panels work during the day, when the sun is out, you will get the maximum benefit if you can change your routines to use your appliances during the day as well. That might mean setting the washing machine and dishwasher to run while you’re out at work instead of overnight.
How much do you need?
Look at how much electricity your household uses during the day, when the panels are at maximum output. Your latest electricity bill should give you this information. If, for example, your household uses 20 kW per day but only half of that amount is produced in the daytime, your solar system should generate 10 kW per day to be of maximum use.
Depending on where you are in Australia, a 1kW system generates around 4kWhs of energy per day. If you want to generate 10kWh, a 3kW system would be sufficient.
The space you have available for solar panels may also dictate the maximum size of your system. Solar panels are all around 1.6 square metres, although they vary slightly in length and width. Some have a higher power rating, meaning that less panels are needed to obtain the same output. a 3kW system has 12 panels and would require around 20 square metres of roof space.
How much can you save?
South Australians, with their high level of sunlight and even higher power prices, are likely to save more than Tasmanians who enjoy lower levels of both. Try one of the online calculators to see how much you can save based on your own personal energy usage and size of system.
Solar systems are also subsided by a federal scheme which is worth about $525 per kW installed. Most advertised prices for solar panels have already included this subsidy, but it’s always worth asking. To obtain it, make sure your system is installed by a Clean Energy Council accredited professional using panels and inverters approved for use in Australia.
Early adopters of solar power enjoyed high feed-in tariffs. That means that any excess energy generated could be fed back into the grid and a credit applied to your power bill. Feed-in tariffs for new systems, however, have diminished or disappeared altogether, depending on your state, and should not be relied on to offset costs.
The tariff applies to the system, rather than the owner. That means that if you are buying a house with an existing solar system, you may be eligible to receive the existing feed-in tariff that applies to that address. The higher the tariff, the older the system, though, so make sure that it will suit your needs before making it a search priority.
Ultimately, whether a solar system will pay for itself quickly is going to come down to buying the right size system for your needs and changing your usage to maximise sunlight hours. Contact a reputable solar comparison website for quotes before making a decision.