Guide

Solar for cold stores and packhouses: refrigeration is the load

Michael Wilkins · Updated 11 July 2026 · 2 min read

The short answer

Cold stores and packhouses suit solar because refrigeration, up to 85 percent of their energy use (EECA), runs through daylight and peaks in the warm months with the sun. The year-round refrigeration base load keeps self-consumption high, which is what makes the payback work; a 100 kW system costs roughly $140,000 to $180,000 installed in 2026.

Refrigeration is a near-perfect solar load

A cold store is a refrigeration business, and refrigeration is close to a perfect solar load: it can be up to 85 percent of site energy use, it runs through daylight, and it works hardest in the warm months when the sun is strongest. That is why coolstores, packhouses and food processors are among the strongest commercial solar cases in New Zealand.

Year-round load beats a seasonal peak

A packing line runs for a few busy weeks; a cold store runs every day of the year. That steady daytime base load is what makes refrigerated sites pay: the system serves real demand almost every daylight hour, so self-consumption stays high and little generation is wasted on low-value export. Self-consumed solar avoids about 20.4 to 25.5 cents a kWh in our model; export earns only 7 to 17 cents.

Designing around the cold chain

Panels usually go on the coolstore or packhouse roof, or on structure alongside, and the work is programmed around your operating calendar so the cold chain is never at risk. A battery is a separate decision for outage resilience, not a requirement for the savings (when a business battery pays). The full method is in our feasibility study guide.

For region-specific numbers, see our Canterbury cold store and packhouse page, the Central Otago orchard and packhouse page or the Nelson Tasman page, which sets a Nelson array's year against the apple calendar and Network Tasman's lines charges, or run a first estimate in the calculator below.

Orchard packhouses and cool stores sit alongside dairy, irrigation and vineyards in our overview of farm solar.

Your numbers

Run your own numbers

Conservative assumptions, fully disclosed, no contact details needed.

Your farm or business

What kind of operation?Region

Monthly power spend (ex GST)

When do you use power?Cooling, pumping or processing through the sunny hours.

Your indicative numbers

Conservative, ex GST, modelled not promised

Measure

Power used: 188,235 kWh a year; Your spend at 25.5c a kWh ex GST, the national commercial average.
Power bill: $48,000 a year

Design

System: 78 kW; Sized to your daytime load.
Generates: 102,180 kWh a year
Used on site: 80%; The rest exports at 8c a kWh.
Installed cost: $119,006 to $160,011; Confirmed with certified installers.

Finance

Investment Boost, year one: about $7,812; A 20% immediate tax deduction, worth this in cash at the 28% company rate. Not a discount.
ASB Smart Solar Loan: $2,325 a month; 0% for 5 years. Reverts to a floating business rate after five years. Terms checked against asb.co.nz on 8 October 2026. ASB may change or withdraw the offer; the calculator only shows it while it matches.
Estimated saving: $1,700 a month; Mid estimate, set against the repayment while the loan runs.

Outcome

Saving: $18,311 to $22,480 a year
Payback: 5 to 8 years; Net of the Investment Boost benefit.
Emissions avoided: 6.0 t CO₂e a year
Asset life: 25+ years; Panels keep producing long after payback.

How this is modelled (assumptions v2026-10-v7)

Power valued at $0.20 to $0.26/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 1310 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.

Next step

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

The questions we get asked

Why do cold stores suit solar so well?

Refrigeration can be up to 85 percent of a coolstore or packhouse's energy use (EECA), it runs through daylight, and it peaks in the warm months when solar output peaks. That load shape is close to the best match there is for solar, which is why refrigerated sites are among the strongest commercial cases in New Zealand.

Does year-round refrigeration help the payback?

Yes, more than a seasonal peak. A cold store draws power every day of the year, so a solar system serves a steady daytime base load rather than a few busy weeks. That keeps self-consumption high, the share of generation used on site, which is what makes the payback work.

What does a packhouse or cold-store system cost?

It scales with the refrigeration load. A 100 kW system runs $140,000 to $180,000 installed at 2026 pricing and 250 kW around $275,000 to $375,000, with per-kW cost falling as size rises. The Investment Boost deduction returns about 5.6 percent of the cost in year-one tax cash for a company taxpayer.

Do I need a battery to protect the cold chain?

Not to save money; refrigeration is a daytime load solar serves directly. A battery is worth modelling where outage resilience has real value, since a standard grid-tied system shuts down in an outage for line-crew safety and will not back up your coolstore on its own. We model storage separately so the numbers decide.

Does solar work for produce and seafood processing too?

Yes. Any site where refrigeration or freezing dominates the load, packhouses, coolstores, seafood and meat processing, dairy factories, shares the same daytime, warm-season demand that solar serves well. The stronger and steadier the refrigeration base load, the better the case.

For your industry and region

See what solar does for your refrigeration load

The calculator models self-consumption first, on conservative assumptions. Two minutes, no contact details, or send a year of bills for the full study.

Get your numbers