Grand Designs solar doesn’t get much better than this: Sunshine Solar designed and installed a 16.34kW solar and battery system on The Three Chimneys, the striking Martinborough home featured on Grand Designs New Zealand. The result is a forever home that now runs on 100% of its energy from the sun — quietly generating more than 18,000kWh a year amongst the vines of the Wairarapa. Here is how one of NZ’s most ambitious builds went solar, and what it can teach the rest of us.
What is the Three Chimneys house?
The Three Chimneys is a forever home built by Tim and Sally Roach on Te Muna Road, in the heart of Martinborough wine country. It featured on the 2026 season of Grand Designs New Zealand, where host Tom Webster watched an ambitious vision come together amongst a young vineyard.
Designed by architects Designgroup Stapleton Elliot, the home is a study in contrast — charred black Yakisugi timber paired with pale Oamaru stone, anchored by the three chimneys that give the property its name. It is exactly the kind of complex, high-end build we love working on.
For more than 20 years, Sunshine Solar has consulted closely with leading architects and designers on builds just like this — from heritage homes to exclusive country lodges and retreats. You can see more of our work on our projects page.
Why does a Grand Designs solar build make so much sense?
A rural Wairarapa home like this draws serious power — and Martinborough sits in one of the sunniest, driest pockets of the lower North Island. That combination makes a Grand Designs solar system an easy decision: high energy use, excellent sun, and a roofline designed with generous north and west-facing planes.
The Three Chimneys was estimated to use around 18,000kWh of electricity a year. Rather than buy all of that from the grid at rising prices, the Roaches chose to generate and store their own. It is the same logic behind every system we design for residential solar customers, just at a grander scale.
The bottom line: A big, sun-soaked rural home is the perfect candidate for solar. The more power you use during daylight — and the more you can store for the evening — the faster solar pays for itself.
Solar also fits the ethos of a build like this. As we always say, we do only solar — and pairing a beautiful, sustainable home with clean, self-generated energy simply makes sense. If you are weighing it up for your own place, you can calculate your solar savings in a couple of minutes.
What solar system did Sunshine Solar install?
This is a complete, premium energy system — not just panels on a roof. Every component was selected for performance, longevity and looks, so the array disappears into the home’s dark roofline rather than fighting it. Here is exactly what went on the Three Chimneys.
| Component | Specification |
|---|---|
| Solar array | 16.34kW — 38 × TW Solar (Tongwei) TWMND-54HS430 430W N-type panels |
| Inverters | 3 × Alpha ESS G3 S5 hybrid inverters (15kW total) |
| Battery storage | 20.2kWh — 2 × Alpha ESS G3 10.1kWh (LiFePO4) |
| Annual generation | ~18,004kWh per year |
| Warranties | 30-year panel performance, 10-year battery, 5-year inverter |
The panels are Bloomberg Tier 1 N-type technology — the latest generation of cell, with better low-light performance and a 30-year performance warranty. The two Alpha ESS G3 batteries use LiFePO4 chemistry, the safest battery type available, rated for around 10,000 charge cycles. You can read more about the gear we trust on our products page and our guide to solar battery storage.
Why the battery matters
With 20.2kWh of storage, the Three Chimneys soaks up surplus solar during the day and runs the home through the evening and overnight — including during any power cuts. That is how a home reaches 100% of its energy from solar.
What does the Grand Designs solar system actually save?
The numbers on this Grand Designs solar build are genuinely impressive. The system is projected to cover 100% of the home’s energy needs — with around 70% used directly on site and the remaining 30% exported back to the grid for a credit.
18,004 kWh
Clean energy generated every year
In its first year, the system is estimated to save the Roaches around $4,309 off their power bills, with a payback period of roughly 7 years and 1 month. Over the life of the system, the projected savings climb past $213,000 as electricity prices keep rising. It also avoids around two tonnes of CO₂ every year.
| Outcome | Result |
|---|---|
| Energy from solar | 100% |
| First-year bill savings | ~$4,309 |
| Payback period | ~7 years 1 month |
| Lifetime savings (projected) | $213,000+ |
| CO₂ avoided | ~2 tonnes per year |
Want to see what those kinds of returns look like for your home? Use our savings calculator or read our breakdown of how much a solar system costs in NZ.
Ready to See Your Solar Savings?
Use our free calculator to see your estimated savings based on your power bill and roof.
What can your home learn from this Grand Designs solar project?
You do not need a vineyard or a TV crew to get the same result. The principles behind this build apply to almost any Kiwi home thinking about going solar.
- Design solar in early — Working with the architect from the start meant the panels sit flush and discreet on the roofline, not bolted on as an afterthought.
- Size the system to your usage — A bigger home needs a bigger system. We tailor every design to how, and when, you actually use power.
- Add storage to unlock the evenings — A battery is what takes a home from partly solar to near-total self-supply, while keeping the lights on during outages.
- Choose Tier 1 gear — Cheap panels are a false economy. Quality components with 30-year warranties are what make the long-term numbers stack up.
It is the same approach we take whether we are working in the Wairarapa — including Martinborough, Masterton, Carterton and Greytown — or back home in Christchurch. Don’t just take our word for it; have a read of our customer testimonials.
Common questions about this Grand Designs solar build
Did Sunshine Solar really install the Three Chimneys solar system?
Yes. Sunshine Solar designed and installed the complete 16.34kW solar and 20.2kWh battery system on the Three Chimneys in Martinborough, the home featured on Grand Designs New Zealand. We have been installing solar across NZ since 2004.
What solar panels and battery were used?
The system uses 38 × TW Solar 430W Tier 1 N-type panels, 3 × Alpha ESS G3 S5 hybrid inverters and 2 × Alpha ESS G3 10.1kWh LiFePO4 batteries. You can see the full range on our products page.
Can my home run on 100% solar like this?
Many can, especially with a battery and a system sized to your usage. The best way to know is to calculate your solar savings or request a free assessment for your specific roof and power bill.
Do you only work on big, high-end homes?
Not at all. We install everything from standard family homes to commercial and large-scale projects. Every system, big or small, gets the same in-house design and installation team.
What does a system like this cost?
This was a large premium system. Most home systems cost considerably less — see our guide to solar system costs in NZ and the bank loans that can spread the cost.
SEANZ Approved Installer
Sunshine Solar is a member of the Sustainable Energy Association of New Zealand, with 8,000+ installations completed since 2004.
Calculate Your Solar Savings
Enter your details to see how much you could save with solar panels.
Ready to Go Solar?
Find out how much you could save with a solar system designed for your home or business.
Or call us: 0800 SUNSHINE (786 744)
