The tipping point is real and it is not about the planet
Meridian Energy’s Richard Sanford called it this week: New Zealand has hit a solar tipping point. Weekly app registrations are up 214% over six months, and Sanford says the shift reflects Kiwis seeing “how moving away from a reliance on fossil fuels – where they can – would make financial sense.”
Note the framing. Not environmental sense. Financial sense. That distinction matters because the residential wave now underway has a commercial counterpart that most business owners have not seriously modelled.
The price scissors that changed the equation
Two forces have been moving in opposite directions for a decade. Solar and battery prices have dropped approximately 90% since 2016. Meanwhile, MBIE’s quarterly survey puts the national average domestic electricity price at 39.3 cents per kWh, with regional extremes reaching 48.88 c/kWh in Balclutha. Commercial tariffs, loaded with network capacity charges, often push effective rates higher still.
The result is solar now qualifies as the cheapest form of electricity in most countries, including New Zealand, according to Victoria University’s Paul Hume writing in April 2025. Westpac’s economic analysis projects solar could grow ten-fold by 2050, with the technology having grown 28% per year globally over the past decade.
Residential returns set the floor, not the ceiling
EECA’s 2025 study of 50,000 homes found rooftop solar delivers 6-14% IRR annually depending on location. EECA spokesperson Gareth Gretton said in June 2025: “There’s a pretty wide range of return but it’s pretty much never below 6 percent.”
A standard 5kW residential system costs roughly $11,000 installed. For households, this is now a straightforward investment decision. But the commercial picture is more nuanced, and more interesting.
Network charges are where commercial solar earns its keep
EECA’s 2021 commercial-scale solar study analysed 144 sites from 10kW to 1MW across eight centres. IRRs ranged from 0.4% for big box retail in Dunedin to 8.6% for manufacturing in Auckland. The critical insight: IRRs above 5% were only achieved where network cost savings were significant. Energy savings alone were not enough.
This is the nuance most coverage misses. A manufacturer running heavy daytime loads on a high-capacity network tariff captures savings that a retail warehouse with flat overnight consumption simply cannot. A 20% reduction in capital costs, which has likely already occurred since 2021, increases IRR by approximately 35%.
For the right business profile today, commercial solar returns likely match or exceed the residential 6-14% range. For the wrong profile, they do not. The difference is entirely site-specific.
Your retailer will not tell you this
Newsroom’s Ben Fahy put it bluntly in February 2026: solar is “a distinct threat to the business models of the big electricity companies because it is now so much cheaper than what they can offer.” Businesses waiting for their electricity retailer to suggest solar are asking the fox to redesign the henhouse.
The same piece cited analysis involving Reserve Bank chief economist Paul Conway showing $11 billion in savings available through rapid electrification. This is not activist advocacy. It is a macroeconomic efficiency argument made by the country’s central bank.
The grid risk that exists independently of cost
New Zealand’s electricity system is 85.5% renewable but hydro-dependent. Renewable generation actually fell from 88.1% in 2023 to 85.5% in 2024 due to dry conditions producing the lowest hydro output since 2013. Businesses generating their own daytime electricity carry less exposure to the price spikes that dry years produce. This is a risk management argument that sits entirely apart from the cost case.
Solar generation itself hit a record 601 GWh in 2024, up 62% on the prior year. The trajectory is clear.
Batteries are not the play yet
Storage currently reduces rather than improves returns for most commercial operators. The near-term value sits in maximising solar self-consumption through hot water diverters, timers, and load scheduling. Time-of-use pricing is improving battery economics gradually, but for most businesses, the correct first move is panels without storage.
The cost of not deciding
Fahy’s warning deserves attention: “If electricity prices get too high, many of the economic benefits of electrification disappear.” But the inverse is also true. If grid prices eventually fall through other means, the window where solar capex delivers strong returns against elevated alternatives narrows.
Right now, the window is open. Every year a qualifying business delays is a year of savings against 39 c/kWh grid power that never comes back. The businesses that have not run half-hourly consumption modelling against their specific network tariff are not being prudent. They are making a decision by default, and paying for it every month on their power bill.
Sources
- ‘Tipping point’: Kiwis switch to electric cars, solar as fuel prices stay high (2026-05-04)
- Power prices spark up an electric election (2026-02-04)
- EECA research shows the economic benefits of solar (2025-06-24)
- How to get the best payoff from solar panels (2025-06-24)
- Solar power cuts electricity bills and carbon emissions – NZ needs to scale up faster (2025-04-02)
- Commercial-scale solar in New Zealand (EECA) (2021-08)
- Powering New Zealand: The economic case for solar (Westpac) (2025-08-19)