Irrigation is the best daytime match for solar there is
Design, financing and installation management for Canterbury irrigation. Pumps run hardest in the sunny months; we size solar to that load and prove it on your bills first.
The short answer
Pumped irrigation is the strongest daytime match for solar, and Canterbury holds around two thirds of New Zealand's irrigation. A system sized to the pumping load offsets daytime power at 25 to 45 cents per kilowatt hour through the dry months, and the Investment Boost deduction reduces the net cost from year one.
Pumped irrigation is the best daytime load for solar in the South Island, and Canterbury holds around two thirds of the country's irrigation. Pumps draw hardest through the dry, sunny months, exactly when panels generate most, so an array sized to the pumping profile offsets that load in real time rather than exporting it at a low buy-back rate. Add a rising power cost and the case is straightforward.
We are not an installer. Involve Energy models the system against your own pumping load and bills, arranges the financing stack and project-manages SEANZ-certified local crews through to commissioning, so you own the asset with an independent model behind it.
Why the daytime match matters
Self-consumed solar avoids the 25 to 45 cent retail rate you would otherwise pay; exported solar earns only 7 to 17 cents. Irrigation is valuable precisely because it lets you use generation on site instead of exporting it. We size to your daytime pumping load so most of what the array makes offsets full-price power. The mechanics are in our guide to buy-back rates and why self-consumption wins.
How it works
- 1
Feasibility
Send twelve months of power bills, ideally half-hourly data. We model system size, generation against your actual load, self-consumption, cost, savings and payback on your numbers, not industry averages.
- 2
Financing
We apply the Investment Boost deduction and match the remainder to the best available green or interest-free business lending, sized so the repayment sits at or below your current bill wherever the numbers support it.
- 3
Installation
Certified local crews install and commission the system, whether roof-mounted at the pump shed or ground-mounted nearby. We manage the lines company approval, the electrical certification and the programme around the irrigation season.
- 4
Monitoring
Once live, we watch performance, flag anything underperforming and report your actual savings against the model, year after year.
Start with a conservative estimate below, then send a year of bills for the half-hourly version. The wider costs and payback picture is in our commercial solar guide.
What the numbers look like
| System size | Indicative installed cost | Indicative annual saving | Indicative payback |
|---|---|---|---|
| 30 kW | $54,000 to $78,000 | $8,000 to $9,000 | 5.5 to 9.5 years |
| 60 kW | $98,000 to $135,000 | $16,000 to $18,000 | 5 to 8 years |
| 100 kW | $140,000 to $180,000 | $26,000 to $31,000 | 4.5 to 6.5 years |
| 250 kW | $275,000 to $375,000 | $65,000 to $77,000 | 3.5 to 5.5 years |
Run your own numbers
Conservative assumptions, fully disclosed, no contact details needed.
Your indicative numbers
Conservative, ex GST, modelled not promised
System size
72 kW
Sized to your daytime load
Installed cost
$112,320 to $152,640
Confirmed with certified installers
Investment Boost, year one
about $7,419
A 20% immediate tax deduction, worth this in cash at the 28% company rate. Not a discount.
Estimated annual saving
$18,662 to $22,118
80% of generation used on site
Indicative payback
5 to 7.5 years
Net of the Investment Boost benefit
Asset life
25+ years
Panels keep producing long after payback
Bank green business loans: 1.0% for 3 years
Your current bill
$4,000/month
Loan repayment
$2,257/month
Estimated saving
$1,699/month
The loan caps at $80,000, so the repayment shown covers that portion; the remainder is financed separately. The full financing stack is part of the feasibility study.
On these numbers the monthly repayment of $2,257 sits at or below your current bill of $4,000 while the loan runs, and the power keeps getting cheaper after it ends.
How this is modelled (assumptions v2026-06-v3)
- Power valued at $0.25 to $0.30/kWh ex GST (savings are never valued at the top of the commercial tariff range).
- Export credited at $0.08/kWh, the conservative end of current buy-back rates.
- Installed cost interpolated from 30 kW ($1,800 to $2,600/kW) down to 500 kW ($1,100 to $1,500/kW), 2025/26 working ranges.
- Canterbury yield modelled at 1200 kWh per kW per year.
- Self-consumption capped by your daytime usage profile and held below typical vendor claims; sizing targets 90 percent of daytime load.
- Investment Boost stated as the year-one cash value of the 20 percent immediate deduction at the 28 percent company rate. It is a tax timing benefit, not a discount.
- No power price escalation and no panel degradation in simple payback; omitting escalation outweighs degradation, so the net effect is conservative.
Indicative only; not financial or tax advice. The feasibility study models your site from twelve months of actual bills.
Get these numbers checked properly
The real model is built from twelve months of your bills. Send your details and we will do it for you; we reply within one working day, no obligation.
Straight answers
Why is irrigation such a good match for solar?
Pumped irrigation is a large load that runs through daylight in the dry months, exactly when solar produces most. Canterbury holds around two thirds of the country's irrigation, so the region pairs the best daytime load with a real and rising power cost. It is the strongest daytime match we model.
Can solar run irrigation pumps directly?
In practice the array feeds the same connection the pumps draw from, so generation offsets pumping in real time whenever the sun is up and the pumps are running. Sizing matches the system to that daytime pumping profile so most generation is used on site rather than exported at a low buy-back rate.
What does irrigation power cost, and how much can solar offset?
Irrigation including electricity cost around 31 cents per kilogram of milk solids on the average irrigated Canterbury dairy farm in 2020-21 (Farmers Weekly), and farm power prices have risen sharply since. A system sized to the pumping load can offset a large share of daytime consumption at the 25 to 45 cent retail rate you would otherwise pay.
What happens outside the irrigation season?
Irrigation runs hardest through the sunny months, so generation and pumping rise and fall together, which is ideal. Out of season the array still offsets any other load on the connection and exports the surplus. The annual model accounts for the full seasonal shape rather than assuming year-round pumping.
How is an irrigation solar system financed?
The same way as any on-farm system: the Investment Boost tax deduction stacked with rural green lending, including dated rural offers such as ASB's Smart Solar Loan (0 percent for five years up to $150,000 for rural customers when available; check what is live). Sized well, the repayment can sit below the pumping-season power saving.
See your pumping numbers before you commit
Send a recent power bill and we will model system size, cost, savings and payback against your actual pumping load. Independent, no obligation, yours to keep.