SOLAR & BATTERY

Energy generation and storage

Getting the sun to work for you

Rooftop solar panels allow you to generate your own power directly from the sun. A battery lets you store this power and use it when the sun isn’t shining.

Solar panels use photovoltaics (PV) to generate direct current (DC) electricity from sunlight. An inverter converts this to an alternating current (AC). This energy can then be used to power your household or, when you generate more than you use, earn a ‘feed-in tariff’ for sending it back into the grid.

You can also store any excess electricity in a home battery. When your home system is not providing sufficient power, you will draw power from the grid in the normal way.

  • Emissions reduction

  • Lower energy bills

  • Energy independence and security

During operation, solar panels emit zero carbon.  While manufacturing solar panels generates a carbon footprint, it doesn’t remotely compare to the continuous use of coal or other fossil fuel generated electricity. 

BENEFITS

PLANNNING AND PRACTICALITIES

Know your electricity consumption and your household bills.

Your bill should show your average daily energy usage. Solar systems are designed to generate around 4kWh every day for each 1kW of solar panels. So, a 7.5kW system will generate around 30kWh on a sunny day under good conditions.

Solar panels without a battery will provide savings, especially with daytime consumption, and can last for over 25 years, with slight losses of efficiency over time.

Obtain multiple quotes to get a competitive choice. Choose quality installers and products accredited by the Clean Energy Council. Understand the economics including rebates and feed-in tariffs. The federal rebate is based on the number of solar panels installed up to a limit.

To ensure that your solution is future proofed, make sure that it allows for the inclusion of a home battery (if not required immediately) and for electric vehicle charging (again, if not required straight away). If you decide to include a consumption monitor within your solution, you can use it to track your energy generation and household consumption to identify further savings.

BATTERY

  • Batteries are not yet at a price point where the economics alone stack up for many households, but you will reduce emissions, and have your own energy source.

  • A battery can be retrofitted to an established PV system.

  • Battery systems can provide backup when the grid goes down, if factored into design and build. This may require some rewiring of your switchboard.

  • A battery can provide more savings if grid prices rise and feed-in tariffs fall.

  • Payback period is likely to be 3-5 years depending on household usage for PV.

COSTS AND PAYBACK PERIOD

As at May 2023, approximate prices for good quality solar panel systems in Australia, including full installation, are in the range of: 

  • Batteries are not yet at a price point where the economics alone stack up for many households, but you will reduce emissions, and have your own energy source.

  • A battery can be retrofitted to an established PV system.

  • Battery systems can provide backup when the grid goes down, if factored into design and build. This may require some rewiring of your switchboard.

These prices include the rebate discount. Installing a reasonably sized battery will at least double the system’s price.

In Perth, the feed-in tariff is 2.25c/kWh (10.0c/kWh from 3pm - 10pm). Electricity from the grid can cost ~30c/kWh. This means, consuming your own solar electricity during the day can be worth more than 10 times as much as exporting it to the grid - in this example you would save 26c/kWh.

Based on this, the payback period for a solar system without a battery in Perth is less than ~6 years. There can be significant variation, depending on how and when you use electricity, so analyse your own situation based on a typical week of usage.

You can reduce your payback period and save money by shifting your energy usage to daylight hours where possible for energy intensive tasks (washing machines, electric vehicle charging, air conditioners), as that way you will be using power generated by yourself rather than the grid. 

Exactly how much money a solar system will save you depends on: 

  • The size of your system, in kW. 

  • The output of your home’s solar power system (which spread over a year is very consistent!) 

  • Your ‘self-consumption ratio’. This is how much solar electricity you use in the home vs exports to the grid. 

  • Your usage tariff. This is what you pay for grid electricity. 

  • Your feed-in tariff. This is what you are paid for electricity fed into the grid.        

There is the option of solar leasing: where a company installs and maintains your system and you make monthly payments. Be fully aware of all charges and exit penalties.

INSTALLATION

Include a consumption monitor within your solution. This will typically inform an ‘app’ that you can use to monitor your daily generation and home consumption. A concurrent solar and battery installation is by far the most effective approach.

Single-phase homes - The maximum inverter size is 5 kilowatts and when installed with a battery, up to 7.5 kilowatts to 10 kilowatts of solar panels can be provisioned (panel sizing dependent on inverter brand).

Three-phase homes - Much greater latitude exists to install up to 15 kilowatts of  inverters with 30 kilowatts of panels when installed with a battery (this suits medium to large homes with significant energy needs like EV charging).

Many homes provisioned with single-phase can be upgraded to three-phase. The cost for this can be highly variable. Factors include the distance from the switchboard to the ‘green dome’ connection point (typically found in you or your neighbour’s front yard); whether there’s any obstructions in the way (like concrete driveways or prized rose bushes…); and the age and size of the existing switchboard. 

The benefits of three-phase are many but include the ability to significantly increase solar system size and the ability to have much faster charging for EV’s.

RESOURCES

FUNDING SUPPORT

There is a federal rebate for installs which should automatically be factored into quotes from installers.

This rebate effectively covers the complete wholesale cost of the panels.

For this reason, it is very cost effective to install the largest possible coverage of panels. The remaining cost is for other equipment and labour.

Currently, WA does not have a subsidy for batteries. Subsidies are mobile (they come and go), so explore what is/is not available. 

HELPFUL WEBSITES

solarquotes.com.au provides a range of independent quotes

CONTRACTORS IN CURTIN

This is not a comprehensive list of contractors in or around Curtin, but an example of some businesses that our volunteers are familiar with. This is not an endorsement of any of these business by Kate Chaney MP or Electrify Curtin. Please do your own research to decide what’s best for you.