Power your existing hot water cylinder with solar

Our award-winning electric hot-water system helps you spend less on your monthly power bill. It’s efficient, easy to install and proven to reduce household energy use by up to 50%.

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A shower being heated by solar hot water heating

Make savings, not compromises.

OneEnergy helps you take control of your power bills without the expense or hassle of a full solar installation. Our modern solar-electric system is wired directly into your existing hot water cylinder, harnessing the sun to heat your water efficiently. No thermal tubes, no plumbing, no complex setup - just reliable technology that fits into daily life and delivers results from day one.

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Why homeowners are choosing OneEnergy.nz

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Simple

No complicated or messy install, fits directly to your hot water cylinder.

Efficient

Every watt produced goes into heating your cylinder.

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Affordable

Smart technology that lowers upfront costs and delivers ongoing energy savings.

See why Kiwi’s love us

View all testimonials

We have a new build and I was going to purchase a hot water heat pump. I wasn’t aware of solar-electric hot water and stumbled upon this through a friend. The One Energy approach makes so much sense and I’m super pleased with how it performs. The guys have supported me with my queries from time to time and couldn’t be more pleased with my choice.

Jamie
Dyerville, Martinborough
Review Date 8-10-2025

I had my 6 panels installed within 10 days of the order and the impact was immediate. I’m tracking the savings daily on my app and what I really like is the extra heat storage we get into our cylinder. Our tank now heats up to 72 degrees on the cloudless days and we’re loving the extra hot water

Ben
Waipapa, Northland
Review Date: 16-11-2025

I didn’t realise what a drain hot water was on my power bill, until I looked into the One Energy approach. And now, I can’t believe I waited this long to get their system. It just works and I don’t even know it’s there working away for me. It has my recommendation.

Roger
Blenheim
Review Date: 27-11-2025

Once I saw how much of our bill was just heating water, switching made sense. I’d looked at older systems, but they felt dated. The One Energy setup is modern, fully electronic, and easy to manage. The team were great to deal with — straight-up and helpful. Since installing, the app makes it simple to let solar do the heavy lifting, and the savings are clear. I’d highly recommend One Energy for smart tech and outstanding service.

Nardus and Nadine
Maraetai, Auckland
Review Date: 03-10-2025

Over the last eight months, we’ve clocked an average 33% decrease in our monthly kWh power usage. Seeing those numbers and the related cost drop while our comfort stays the same is a great feeling. A smart bit of kit installed by a One Energy team that takes genuine care and responds if there are any issues.

Simon & Nicolette
Beachlands, Auckland
Review Date: 24-11-2025

Our family loves taking long showers and so our electricity bills have always been high. Adding OneEnergy’s solar hot water heating has made a big difference to our power bills, especially in sunnier months. Installation was quick and simple, and the online dashboard clearly shows how and when we are saving money. Thanks, OneEnergy!

Mike
Cashmere, Christchurch
Review Date: 21-11-2025

Four simple steps to solar hot water

We make moving to smarter energy as simple as using it. Our process is streamlined, and designed to get you up and running with zero hassle.

01

Let’s get started

Share your details and our team will be in touch to help you take the first step toward smarter energy.

02

Custom Proposal

We'll let you know how your panels will look and what estimated hot-water energy savings to expect.

03

Easy Installation

Installation takes just three to four hours, delivering a reliable solar-electric hot water system and instant energy savings.

04

Enjoy Savings & Sustainability

Enjoy lower energy bills, smaller carbon footprint, and reliable hot water all year round - even on rainy days.

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Commonly asked questions

What is the return on my investment ?

A full installation in an average household will have an expected payback of under 5 years, and your panels will produce electricity for more than 25 years - that's a great return on investment of almost 20% p.a.

Will I be locked into a long term contract for my system ?

Absolutely not, the system is owned outright by you to enjoy the benefits of solar hot water heating powered by the sun for many years.

Will I have hot water on cloudy or rainy days ?

Yes - if there is not sufficient Solar heating, the system will automatically top-up with grid power to make sure you are never without hot water.

Can I get a Green Home Loan ?

Yes - OneEnergy's Hot Water qualifies for green home loans from all NZ banks.

Illustration of a house with solar panels on the roof connected by colored wires to an electricity meter and hot water tank inside, with a bathtub in the foreground.

Get your no obligation quote today!

We’ll create a tailored, no obligation proposal showing exactly how your solar-electric system will look on your home, including panel placement and estimated hot-water energy savings.

Illustration of hands holding a paper labeled 'Power Bill' with a green wallet icon on it.
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