Solar buy-back rates for businesses: export is not the prize

What retailers actually pay

New Zealand has no government feed-in tariff: every retailer sets its own buy-back rate, and as at mid 2026 the going range is 7 to 17 cents per kWh, with premium battery plans paying more for evening-peak export. Comparison sites refresh the league table constantly because the rates churn. Check them on the day you decide, and then weight the result correctly: not very much.

The commercial catch above 10 kW

Advertised buy-back rates are residential products, and most cap eligibility around 10 kW of inverter capacity. A commercial array of 30 kW or more usually needs a negotiated export agreement with the retailer, at a rate that may differ from anything advertised (published commercial examples sit around 14 cents). If a vendor proposal leans on a residential buy-back rate for a 100 kW system, that is a red flag about the rest of the model.

Why export is not the prize

EECA's Kaiwaiwai Dairies case study makes the ratio concrete: the farm earns roughly $267 a year from export and saves $17,000 to $20,000 a year through self-consumption, with more than 90 percent of generation used on site. Export revenue is a by-product, not a business case. Systems should be sized so most generation lands on your own load, which is exactly how our sizing approach works: we target covering most of your daytime consumption and treat the export tail as noise.

The 2026 rule changes, and who they actually help

Two Electricity Authority changes land this year, both aimed at households and small businesses. From 1 April 2026, distributors must pay rebates for power exported into network peaks, but the rule only requires them for connections up to 45 kVA exporting up to 45 kW (a network may go further), and retailers are not required to pass the rebate on. And retailers with at least 5 percent of connections that were not already offering time-varying plans for both consumption and export had to offer them by 1 October 2026, to residential and small business customers with smart meters. Both reward export at evening peaks, when the sun is down, and most commercial sites sit outside them.

Read that carefully: the new rules mainly reward batteries, which can hold midday generation and discharge it into the peak windows. They do not change the core economics of panels, and they are not a reason to oversize an array today. They are a reason to design battery-ready, and to revisit storage as prices fall (when a business battery pays).

What this means for sizing

We size systems to cover around 90 percent of daytime consumption rather than maximising the array, because the marginal panel that mostly exports earns 7 to 17 cents while the panels serving your load avoid about 20.4 to 25.5 cents in our model. The full decision framework, including costs and payback by system size, is in the commercial solar guide.