Join the more than 30,000 Tasmanian households who are already harnessing the sun to generate electricity! Rooftop solar is a great way to contribute toward Tasmania achieving 100% renewable electricity. While rebates and feed-in tariffs aren't as generous as they once were, product prices have tumbled, and so solar panels still give great bang-for-buck.
(Also be sure to check out our posts on Solar Basics and Detailed Solar Research)
Bigger solar is better
A bigger Solar PV system is likely to pay for itself quicker than a smaller system including in Tasmania, according to a report by the Alternative Technology Association (ATA). Generally a 5kW solar power system is likely to pay for itself quicker than a smaller 2kW system, even if household electricity consumption is low. A larger system will also allow you to get more out of your home battery system and electric vehicle when you purchase these down the track (while they might not be affordable for you yet, they likely will be well within the life of your solar panel system)!
If you're on the grid...
We recommend you stay on the grid - at least for now. To go 'stand-alone' is much more expensive and worse environmentally too if the grid is already at your door.
Electricity generated by your solar panels first goes to power your home, saving you what you would've paid at the standard tariff (~26c/kWh). Any shortfall is met by the grid, costing you the standard tariff. Any excess is fed back into the grid, for which you are paid the 'feed-in tariff', which is much lower (~9c/kWh).
So, how much solar panels will save you depends on how much of the their energy you use at home versus exporting to the grid. If you used it all on site they will take only 3 years to pay themselves off at current prices! If you export it all the payback period is 10 years. The vast majority of systems will pay themselves off in 5-7 years (by our calculations, and confirmed by the ATA's study). Given panels last more than 20 years, they are a positive investment that will likely save you many thousands of dollars over their lifetime.
You may be tempted to add batteries to create a 'hybrid' system. Then, excess energy from your solar panels can be stored for when you want it in the evening. Rather than feeding it back in at the low feed-in tariff, you'll effectively save the standard tariff rate. However, it is still not economic to do this as the cost of the batteries is greater than the savings made (by both our calculations and those in the ATA report). But with battery prices tumbling, it's only a matter of time before this becomes a positive investment financially. Even then - at least in the Tasmanian context - adding batteries will hurt, not help, the environment! In Tasmania we don't need more storage (the hydro system has plenty). To achieve 100% renewable electricity we just need more renewable generation. So, except in exceptional circumstances (e.g. at the end of long, weak grid connections like Bruny Island and the Tasman Peninsula) adding batteries to your home won't help anyone... not you or the environment.
If you're off-grid
You'll need a stand-alone system, consisting of solar panels and batteries (and possibly wind and/or micro-hydro, and a likely back-up diesel/petrol generator too). It's still relatively expensive, and so minimising your electricity usage is vital. Use passive solar and wood for heating and water heating to minimise your electricity consumption. For everything else be frugal and efficient. Only then will a stand-alone system be affordable. Seek expert advice before installing a stand-alone system.