Retired couple, at home most of the day · standalone three-bedroom house, double-glazed.
When you sit down at night and you realise that all that power that's stored during the day is powering you through the evening, you just feel so good.
Upgrade: solar panels and battery storage
Upfront cost: $30,000
Install time: ~6–7 weeks from quote to install
Grid use: July 1,077 kWh (2025) to 795 kWh (2026), down ~26%
Generation: ~9,800 kWh a year (installer's estimate)
Louise and John's home gets plenty of sun through its big windows, and it's warm when the sun is out. They're both retired (Louise semi-retired), so they're home most of the day and need heat around the clock.
Dunedin in winter is cold. When the sun shines in this house it's warm. When the sun doesn't shine in, it's warmer than before with double glazing, but it's still cold.
The house has underfloor and ceiling insulation but none in the walls. Power was a big monthly cost on a fixed income.
Solar had been on Louise and John's list for years. It made financial sense, and as John puts it, it's something that needs to be done to help the planet. When they moved in, it was one of the first things they talked about. But as the household treasurer, Louise insisted the urgent jobs came first: roof repairs, double glazing, curtains and the garden. They also didn't want to borrow.
We're very aware that we're paying a lot of power to a big power company and our income is pretty fixed now. We have to live as sustainably as possible, but also as economically as possible.
They thought of it as an investment. The interest would come back as savings on their power bill rather than from money sitting in the bank. They did think hard about whether they'd stay long enough to get the value back. That's why they decided against replacing the roof at the same time as installing the panels.
Friends helped too. One had used an out-of-town installer and said communication was the hard part, so her advice was to go local. She'd also heard good things about Think Solar Dunedin.
Louise and John came across Cogo's Electrification Tool at the end of January, and it connected them with installers. Think Solar visited in February and had a proposal to them by early March. They also got a quote from an Auckland-based company over Zoom, and had an initial chat with a third company that couldn't meet their needs.
The prices were about the same, but the Auckland firm would have had to bring a crew down from Christchurch. Louise and John went local:
What we liked about Think Solar and needed was that they're there all the time and they said they will always follow up.
The install took about six to seven weeks from accepting the quote. The crew was on site for two days and the system was connected in early May. Louise says the crew were efficient and pleasant, checking with them as they went. When the couple pointed out shading from a neighbour's trees, the crew rearranged the panels on the spot, without needing to check with head office. The house's high ceilings meant the wiring couldn't go through the roof space, so they ran it via the outside meter box down to the battery in the garage, with no unnecessary drilling or cables hanging outside.
Since then, the installer has helped with all the follow-up questions that come with a new piece of technology, like why the battery keeps 19% in reserve for power cuts.
Louise's new hobby is the Tesla app.
It's a bit addictive looking at the app and checking what's going on. For me it's interesting. I've worked out and I found out so much about our power use that I didn't actually know.
She now understands how much power the old hot water cylinder draws, and she switches things off more. Even on grey winter days, she enjoys seeing that a faint bit of sun can start filling the battery. For John, it's peace of mind:
I feel really good that we've got solar panels on. I feel like we're doing everything we can now.
They've also inspired their neighbours. New neighbours put up a much bigger system soon after, and others on the street have started asking about it.
It's really nice. Influencing the neighbours is always quite fun, especially since we've got the smallest house.
The system cost about $30,000 for 20 panels, a Tesla Powerwall 3 and a gateway. Think Solar estimates it will produce around 9,800 kWh a year.
So far, the clearest result is power use. In July 2026, the household used 795 kWh, compared with 1,077 kWh in July 2025, about 26% less in the darkest month of the year. They're even exporting a little power back to the grid and earning buyback credits in midwinter.
The bill hasn't fallen as far as their usage yet, because their power company moved them onto a higher rate after the install, and Louise is pushing back on that. With summer ahead and the panels doing much more, they expect the savings to grow.
Cogo set us on the right track. You know, it's actually not difficult to make it happen. You don't have to do endless plans yourself, there are people out there who will help you.
On how Cogo helped:
It really helped with getting us started, because the guidebook is written in really straightforward English and it doesn't use lots of technical words.
Setting up the initial interviews with different companies was fantastic. That was a really good starting point.
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