In some suburbs of the greater Brisbane area, nearly 50% of residential roofs are equipped with solar panels – among the highest rates in the country. Many of these homes – and many more yet to install solar – may also be interested in solar battery storage to maximise their solar usage and minimise their reliance on the electricity grid. This article takes a look at solar battery storage in Brisbane, covering some of the main questions that shoppers may have about this increasingly popular technology.
What do you need to know about solar battery storage in Brisbane?
Let’s say you are an energy storage shopper in Brisbane. What you’ll be looking for will depend first and foremost on your current situation with regard to solar panels. You probably fall into one of three categories, discussed below.
- You have solar panels and benefit from a generous solar feed-in tariff under the state’s generous Solar Bonus Scheme. Unless you move house, you will continue to receive this benefit until 2028. Since the scheme generously rewards you for exporting your excess solar power into the grid, it makes little financial sense for you to install batteries – you’ll save more money by selling your solar power rather than using it yourself.
- You have solar panels on your roof but don’t have a strong feed-in tariff (i.e. you installed your panels after the Solar Bonus Scheme closed to new applicants). Batteries may make sense for you because the electricity you are sending into the grid probably nets you only around 6-10c/kWh – while you may pay nearly 3x that amount for electricity you purchase from your retailer. Having an energy storage system could help you to increase your solar self-consumption rate – you would want to install enough battery capacity to capture your excess solar power.
- You do not yet have solar panels, but you’re in the market for them and are also interested in learning about batteries. You could install a system with batteries, 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?)
Let’s take a look at each of these situations in more detail.
Category 1: Brisbane home with existing solar system, receiving 44c/kWh on Solar Bonus Scheme
We’ve already pointed out that battery storage probably isn’t an attractive option for households in Category 1 thanks to the generous rates paid out under the state’s Solar Bonus Scheme. If you’re not concerned about the economics, but are instead just dead-set on increasing your energy self-sufficiency, then you should follow the guidelines for Category 2 households that we’ve outlined below. If you’ve moved house (away from one that had a solar array and into one with no solar), check out the guidelines and example provided in Category 3.
Category 2: Brisbane home with existing solar system, no feed-in tariff incentive
If you’re in category 2, you probably harbour a certain resentment against your electricity retailer for not rewarding you for the excess solar energy that you send into the grid (currently, the best rates in the state are around 10c/kWh). 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.
Example: A Brisbane home with a 3kW solar PV system, using about 15kWh per day on the ‘Double hump’ usage pattern (described in more detail here). This home could be exporting around 8kWh of solar to the grid on the average day – and this is roughly the amount that they would want to be able to capture in their battery bank. Assuming 95% round-trip storage efficiency and 80% maximum recommended depth of discharge (DoD), 9kWh of battery capacity would help the household meet this goal.
Energy flows for Brisbane home with 3kW solar system, 15kWh daily electricity usage (on average) and 9kWh of battery storage. With the battery storage, this home would utilise close to all of the electricity produced by the 3kW solar array. (Key: Grey shaded area is grid electricity consumption, orange shaded area is solar self-consumption, and shaded purple area is battery storage usage. The yellow line is solar system power output, while the purple line is battery state of charge – aligned with right axis. The blue bars represent solar into batteries, while the red bars represent solar into the grid.)
Category 3: Brisbane 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.
Example: A Brisbane home that consumes 15kWh per day on average throughout the year would like to reduce their grid reliance by as much as possible within a $10,000 budget (the typical amount a home would be willing to spend, according to a recent survey). Let’s start with a 3kW solar system for about $3,400 (on the low end of the spectrum according to our August 2015 PV Price Index). his would allow for about $6,600 to be spent on batteries. Assuming (optimistically) a battery storage price of about $1,200 per kWh, the home could afford about 6kWh of battery capacity (with 95% efficiency and 80% DoD). With this 3kW solar + 6kWh storage system, the home would only meet about 45% of its own electricity needs (and using on average about 72% of the solar produced). Payback periods are another question altogether – but indicative assessments would suggest 10+ years – which may cause this household to question whether it’s a good idea to invest in the battery portion of the system at this point.
Energy flows for Brisbane home with 3kW solar system, 15kWh daily electricity usage (on average) and 5kWh of battery storage. The home would still be heavily reliant on the grid for electricity. (Key: Grey shaded area is grid electricity consumption, orange shaded area is solar self-consumption, and shaded purple area is battery storage usage. The yellow line is solar system power output, while the purple line is battery state of charge – aligned with right axis. The blue bars represent solar into batteries, while the red bars represent solar into the grid.)
Compare your energy storage options in Brisbane
Solar Choice recently launched Australia’s first Battery Storage Comparison service, which will allow you to compare installer offerings at a glance in an apples-to-apples format. This service is currently available only to new solar-plus-storage customers – not to those with existing systems (but this will soon change).
If you are looking for a new solar-plus-storage system:
Fill out your details in our Solar Quote Comparison request form to compare your options now (Click the ‘Battery Storage Comparison’ tab). Potential commercial clients are also invited to register their interest.
If you are looking to retrofit batteries onto an existing solar system:
Please enter your details into the form below and we will get in touch when battery storage only functionality becomes available.
Top image via the APVI.
© 2015 Solar Choice Pty Ltd