Solar and battery energy storage in Perth, WA

Approximately 25-30% of the homes in the Perth area have solar PV systems on their roofs according to the APVI – many of these households are interested in installing a battery storage system as well. This article takes a look at the basics of battery storage for residential solar systems in and around Perth, WA.

Should you install batteries in Perth? It depends on your situation.

Assuming you want to maximise the financial benefits of having solar (as opposed to going off the grid for its own sake), then whether to install batteries will depend first and foremost on your current situation. Perth households generally fall into one of the following categories when it comes to solar:

  1. You have solar installed and you have access to payments through WA’s solar feed-in tariff (which is now closed to new applicants). Unless you move house, you will continue to receive payments for 10 years following the date of your installation. The base rate you receive for your exported solar energy is either 40c per kilowatt-hour (kWh) if you signed up by 1 July 2011 or 20c/kWh if you submitted your application by 1 August 2011. If you’re receiving either rate, batteries probably don’t make economic sense for your home at this point.
  2. You have solar panels on your roof but don’t have a strong feed-in tariff (e.g. you installed your panels after the solar feed-in tariff scheme closed to new applicants or you have moved into a house with a preexisting PV system). Having batteries installed may make sense for you in this case, because your electricity retailer does not reward you for putting your excess solar energy into the grid – you may receive only around 7c/kWh. Meanwhile, self-consuming your solar energy could save you significantly more money on your power bill by allowing you to avoid purchasing a portion of your energy from the grid.
  3. You haven’t installed solar panels yet, but you’re in the market for them and are also interested in learning about batteries. You have the option to install a brand new solar+storage system, but the amount of solar PV and battery capacity you should get will depend on your goals and your budget. (Read more: How much battery capacity do you need?)

Below we’ll look at each of these situations in more detail.

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Category 1: Perth home with existing solar system, receiving 20c-40c/kWh through state-based feed-in tariff

Battery storage probably isn’t a financially attractive option for you if you have access to WA’s solar feed-in tariff. Even if you’re receiving the lower 20c/kWh rate, battery storage installation costs are high enough that it is unlikely to be worth your while to store your excess solar power for evening consumption. The long duration of the solar feed-in tariff payments (10 years from installation) means that for most homes this dynamic will not change for a long time.

On the other hand, if increasing your energy self-sufficiency (or going off-grid) is your goal regardless of how the economics pan out, we’d advise that you consider the recommendations below for those in Category 2.

Category 2: Perth home with existing solar system, no feed-in tariff incentive

If you’re in category 2, there’s a good chance that you are not happy with your solar feed-in rate – your solar energy is worth more to you if you consume it yourself than if you send it into the grid. Check your energy bill to determine how much solar power you are sending into the grid on average per day – you can use this information to choose the appropriate battery system size. If you can, you may even want to install monitoring equipment to find out in more detail how you use electricity throughout the day – thus helping you even more accurately size your battery bank.

Check out Solar Choice’s Battery Storage Retrofit Sizing & Payback Estimator Tool.

Category 3: Perth home with solar system yet to be installed, no feed-in tariff available

If you are in category 3, you’ll either want to install a solar-plus-storage system or just a plain old solar PV system without batteries. In either case, you have a lot of flexibility and a wider array of options than if you already had a solar system. At the moment, most homes will opt to install only a conventional, non-storage PV array (possibly with a battery-ready inverter for future upgrades) – in which case the system should be sized to meet daytime electricity needs (Read more: How to get the most out of your solar system.) However, battery storage may make sense for you if you find the right system at the right price.

Check out Solar Choice’s Solar and Battery Storage System Sizing & Payback Estimator.

Compare battery storage options in Perth: Complete the Solar Quote Comparison request form to the right of this page.

Top image via the APVI.

© 2015 Solar Choice Pty Ltd

Jeff Sykes