How to choose the right solar quote

Posted in Getting solar

Man comparing solar quotes

If you’re ready to get solar, the first step is to shop around and get a few quotes. But between the kWs, the dollar amounts and the different products recommended in each, it can be hard to know which one to go with. 

Once you’ve got a few quotes, there are two main components to focus on: the solar system that’s been recommended and the installer or supplier that has developed the quote. 



1. The solar system

Solar system size

When developing your quote, your solar installer or supplier should take into consideration your energy usage, budget and future energy goals. With this information, they’ll be able to size up a solar system for you. 

But when you get a few quotes all recommending different sized solar systems, it can be tricky to know which is most suitable. 

As a general rule, if you have a three bedroom home it’s probably not worth your while getting a solar system any less than 3-4kW. This is because the cost associated with getting it installed may make the smaller system comparatively more expensive in relation to the savings it will deliver. So if you have the budget and the roofspace, go for a 4kW system or larger. 

For example, for an average three bedroom home:

  • A small solar system (3-4kW) could save you around $600 – $900 per year
  • A medium solar system (4-6kW) could save you $800 – $1200 per year
  • A large solar system (6.6kW) could save you $1000 – $1750 per year

These are estimates. There are many factors that will determine your actual savings, including how much solar energy you use in your home vs how much you export to the grid, your usage rates and feed-in tariffs, not to mention geographical location (Queenslanders tend to save more than Victorians, for example). 


Solar battery inclusion 

It can be hard to know whether a battery is right for you, especially when some quotes include one and others don’t. However if you’re getting a solar system over 4kW or so, chances are you’d benefit from a battery. Why? 

  1. With just solar panels, an average home sells around three quarters of their solar power back to the grid for as little as a third of the price they pay for electricity. With a battery, that same home can save up to 80% on their energy bill by using their stored solar power later in the day.
  2. If you’re getting solar panels, now is the most cost-effective time to get a battery too. This is because you’ll cut out extra installation costs and combine the two components’ payback into one, shorter payback period. 

However ensuring you get the right size battery for your home is important. While with solar panels bigger is usually better, it’s a different story for batteries.

Our solar experts analysed the energy use of around 1500 of our electricity customers and found that most people couldn’t actually fill a big battery on most days. So there’s no point paying for more capacity than you can use. 

When it comes to batteries, the goal is to get a battery that you can use all year round, even in winter when your solar system will be generating less electricity. 

While it will differ household to household depending on your energy usage and motivation for going solar, as a general rule we’d recommend a 4-6kWh battery for 3-4kW solar systems, a 6-8kWh battery for 4-5kW solar systems and a 8-13kWh battery for solar systems that are 6.6kW or larger.

If your quote includes a battery that’s too much bigger than this, your installer might be trying to sell you a bigger and more expensive battery than you’ll really need so we recommend asking why they think you need such a big battery.


Solar products and warranties

When comparing solar quotes, ensure the quality of the system components are all the same. For example, that the solar panels quoted are all tier 1 panels from a reputable and reliable supplier. 

It’s also important to look at the warranties on offer. Solar panels should last at least 25 years, so ensure the system is covered under warranty to match.

Warranties should typically include:

  • Workmanship – 5 years per the CEC Approved Solar Retailers Code of Conduct.
  • Panels – Minimum 10 year product warranty (some offer a product warranty of 25 years)
  • Inverter – Minimum 5 years 
  • Battery – Minimum 5 years (ideally 10 years) 

When it comes to warranties, it’s also worth checking whether the manufacturer is based in Australia for ongoing, local support. 


Solar system costs and pricing transparency

Once you know you’re comparing similar products with good warranties that are configured into the right size solar system for you, it’s time to look at cost. 

Make sure you’re comparing the costs without any rebates included, just in case you don’t qualify for them. Most government schemes have very strict eligibility criteria, so quotes that give you system prices with rebates already included can be misleading. Similarly, beware of quotes with financing ‘built in’. You may end up paying more than you need to in hidden finance costs. 

If you have a quote that is much less than the others, it might be an indication that the installer is cutting corners to accommodate the cheap price. Don’t be afraid to ask them why their quote is so much cheaper, or ask another installer to take a look at it for you. When it comes to solar, there are many great value, good quality systems available. It’s never worth sacrificing quality for a cheap price.



2. The installer

The other main component to get right is the solar supplier and/or installer. It’s important to ensure your installer is accredited by the Clean Energy Council and that they come to your home to do an assessment before providing your final quote. This is because the configuration of your home, your switchboard and other individual factors can impact the final price. 


Asking the right questions

When comparing quotes, don’t be afraid to ask the installer any and all questions you have. Solar is a big investment and there are no silly questions when it comes to getting the most out of it. 

Some good questions you might like to ask include:

  • What is your CEC accreditation number? (You can check that at
  • How long have you been in business? Who are your owners and are they committed long term? 
  • How many installations has your company done?
  • Do you have any testimonials or the contact number of a recent customer I can talk to?


Ready to go solar? We’re here to help!

Our Solar and Redback Battery Package brings world-leading, tier 1 solar panels together with an Australian-designed battery solution in one streamlined, cost-effective package.

If you’re getting solar panels installed, now is the most cost-effective time to think about a solar battery too. For example, our mid-sized solar and battery package (including installation) can pay for itself in 7 less than years*. 

The package comes in a range of sizes depending on your energy needs, household set-up and budget. It comes with great warranties and the battery component of the package is one of the top 3 performers in independent Australian testing.

Your quoted price includes installation and our installers are all accredited by the Clean Energy Council. We’ll provide you a clear and transparent online pricing estimate and then the installer will visit your home so we can deliver a final quote with everything considered.

Plus there are financing options available so you can start saving with your solar and battery system now, and pay it off over time.

View the solar and battery package



*This scenario is the 6.6kW system and a mid sized battery (7kWh). Assuming typical generation in Victoria and assuming battery gets cycled 90% of the time at 90% depth, solar savings are estimated at $1,734 ($0.20 average value of the solar generated, which could be 10c FiT and 30c usage rate at 50/50% as an example). Battery savings would be an additional $440 per annum, for total savings of $2,174.

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