Solar power and an ice cream dropped

Solar is a common topic, there are experts in every office and at every BBQ but the detail, when you ask, for it is elusive. I’m going to preface this by openly admitting I’m not an expert, but I’m happy to share our experience, the numbers and the detail. As an adviser there’s a focus on the financial side of things – but isn’t that one of the main reasons we are all starting to think about it?

For a couple of years, we’ve been weighing up whether or not to get solar installed at home. Making a decision without detail, without numbers, isn’t something I’m comfortable with. We deferred, delayed and procrastinated but we reached a tipping point recently with a $1,200 electricity bill for the winter quarter.  

We decided to get it done, and 1 month in, apart from turning me into the sort of guy who now watches the weather and the power generation vs use daily, here’s how its working out for us.


We put a 6.6kWh system on the roof with a 6kWh inverter. We have a north facing roof with no obstructions. We didn’t get a battery. Once you’ve selected a system, you’ve got to pay for it. Please check this bit out carefully.

On offer was a 5 year interest free deal. Please remember that interest free is not free of charge. We got the kids to work out the true cost of borrowing – the one off setup fee and the monthly admin fees. We also got them to work out how much needed to be repaid each month so that it’s paid out at the end of the 5 years. We wanted them to understand buy now pay later and what it means to get into debt. That’s some pretty fancy maths for a 9 year old and a 6 year old, bit of a proud financial adviser dad moment. It stacked up so we’ve made use of it.

The shift we’ve seen has been significant. We average 35 kWh across the year. Probably a bit on the high side, but some of us love a bit of aircon. We’re in spring so the aircon get used less, but we are at home more through Covid and school holidays. Over the last month we’ve used 30 kWh on average per day – lighter than usual and certainly lighter than it will be in summer.

Here are the numbers…

Power usage – before and after shown as a quarterly number

No change in what we use, but the beauty is that we are now paying for 40% of what we use – we generate the other 60% ourselves.

Cost of power – excl the fixed daily charge

We pay $0.26 per kWh for the electricity from the grid

Money generated by the solar system

We exported 17kWh per day back to the grid. We receive $0.096 per kWh for the electricity we export to the grid.

Finally we have to add in the cost of repayments – the cost of the system. In order to pay the system off at the 5 years mark so we don’t pay any interest, the repayments are $360 per quarter.

Was it worth it?

Based purely on the numbers I’ve seen so far, yes. It does work now, but once the loan is paid off, it gets significantly better.

Changes in behaviour

We now have an app that allows us to check how much power we are using. It means we can consciously choose what to use and when to use it.

The single best example of that impact is the ongoing battle to switch off lights (and just like that I’ve become my Dad). We have heat lamps in the bathrooms. Do we need them 9 months of the year? Absolutely not, but they are there so they are used and often left on. I’ve asked politely, I’ve got grumpy, but it simply hasn’t changed the behaviour.

Free ice cream

Using the app, the kids and I worked out how many kWh the lamps use when they’re left on and not being used. We worked out that if they left them on for 2 hours it’d cost around $0.50 per day. “Wow dad, that’s pretty cheap” wasn’t really where I wanted it to go, but we multiplied that out to see the cost per year at $182.50. I gave them a choice:

  • leave the lights on and nothing changes or
  • switch the lights off and at $7 per ice cream you can have 26 for the year

I knew I’d hit gold when my youngest son said to his brother, you just left the heat lamp on again – you know what that means? It means you just dropped an ice cream on the floor.

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