“Before and after” electricity bills – see the real difference solar panels can make

By Finn Peacock – Chartered Electrical Engineer, Ex-CSIRO, Founder of SolarQuotes

Last Updated: 23rd Jul 2020

You’ve probably seen a lot of ads online, on the telly, and in the paper spruiking solar.

Many of these ads promise the “electricity bill-busting” potential of solar panels for your home. The heavy-handed salesmanship in these ads probably triggers your BS-detector!

This is frustrating for me because well designed solar really can give you tiny electricity bills! As an example – my latest (autumn) bill came with a $38 credit.

I’ve even created a nifty solar calculator here that can estimate your bills after installing solar panels.

But – I know that even a tool like that will leave people sceptical.

So – I went and asked my website visitors to share the real impact solar energy had on their bills. Then I compared it with my calculator’s prediction of their electricity bills. The results that came back were amazing.

I want to use this real-world proof to refute two objections I hear over and over again:

1) “Solar isn’t worth it without batteries!”

2) “Solar isn’t worth it because I’m not home during the day!”

So read on, and see how much people have really saved with solar power – and how much you can too.

A note – the bills provided by my customers have had any personally identifiable information removed. I’ve also included my solar calculator’s prediction of their electricity bill vs what they got in reality – so you can judge its accuracy for yourself.

Example #1 – Phil in SA – Autumn/winter bills of $957 reduced to $377, using a 10.8 kW system with NO battery.

Winter 2018 bills (no solar) compared to Winter 2019 bills (with solar)

Winter 2018 bills (no solar) on left, winter 2019 bills (with solar) on right – a $580 reduction!

Located in: South Australia

System size: 10.8 kW

Battery: No

Feed in tariff: 10c/kWh with Simply Energy, 20c/kWh after switching to AGL

Year-on-year bill reduction for the quarter: $580

Phil has a 3 phase property in South Australia, and put on a 10.8 kW solar system – without batteries. This bill is a great example of why I tell people to put on as much solar panel capacity as they can.

I’ll point out that they switched from Simply Energy to AGL after installing a solar power system to take advantage of a better overall electricity plan (with higher feed in tariffs) offered by AGL.

Just by switching retailers, they went from a 10c/kWh feed in tariff with Simply Energy to a 20c/kWh feed in tariff – increasing their savings and accelerating their payback period.

You’ll always get the lowest savings from your system in winter. This is because you have less sunlight during the daytime overall, as well as many more cloudy/overcast days compared to summer.

To compare the real result this homeowner had with my calculator. My calculator gives bills by season. Phil’s bill was half winter, half autumn – it predicted an average electricity bill for this period, post-solar, of ($609 + $44) divided by 2 = $326.50

before and after

 His billing period was midway between autumn and winter – so the average of those two bills in the calculator is approx $326

So – his real result and my calculator’s predicted result were pretty damn close!

For the data nerds among you – let’s do a deep-dive into the details of his electricity bill – I’ll show you something interesting:

Example #2 – Shane from QLD – Late autumn/early winter bills of $733 reduced to $55 

before/after bills

 Autumn/winter 2018 bills on left, autumn/winter 2019 bills (after solar) on right.

Located in: Queensland

System size: 9.3 kW

Battery: No

Feed in tariff: 18c/kWh with Energy Australia

Year-on-year bill reduction for the quarter: $678

Now – let’s take a look at a ‘best-case’ (summer) quarterly savings example to contrast…

Example #3 – George from NSW – Late summer bills (hello aircon!) of $427, turned into a $134 credit!

Summer 2018/2019 bills

Left – summer 2018 bill. Right – summer 2019 bill (after solar)

Located in: New South Wales

System size: 6.6 kW

Battery: No

Feed in tariff: 20c/kWh with Origin

Year-on-year bill reduction for the quarter: $571

Example #4 – Henry from Adelaide turns a $460 summer bill into a $168 credit

Summer period - before and after solar

Summer 2018 (left) compared to summer 2019 (right)

Located in: South Australia

System size: 6 kW

Battery: No

Feed in tariff: 16.3c/kWh with AGL

Year-on-year bill reduction for the quarter: $628

Finally – let’s take a look at a system that has solar panels AND a battery…

Example #5 – David from NSW saves $1,171 in a quarter after installing solar + battery. But how much did the battery contribute to the savings?

Located in: New South Wales

System size: 6.7 kW

Battery: Yes – 10kWh Sonnen battery

Feed in tariff: 12.5c/kWh with Energy Australia

Year-on-year bill reduction for the quarter: $1,171

before and after a solar battery

Before and after summer bills, with a solar + battery system

In summary

All of the electricity bills listed on this page are for solar-only systems with NO batteries, except for example #5.

All of these households – except #5 – had a self-consumption ratio of 30% or below, which is what I’d expect the typical 9-to-5 household to have.

I hope this evidence from real homeowners has proven, once and for all, that solar power really is worth it – without batteries, and without needing you to be home during the week. 

If you’re considering installing solar panels for your home or business, SolarQuotes can help you get quotes from high-quality installers quickly and easily:


About Finn Peacock

I’m a Chartered Electrical Engineer, solar and energy efficiency nut, dad, and founder of SolarQuotes.com.au. My last “real job” was working for the CSIRO in their renewable energy division. Since 2009 over 350,000 Australians have used my site to get quotes for high quality PV systems from pre-vetted solar installers.

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