Getting the most impact from School Solar

Using the government's solar roll-out to demonstrate innovative alternatives to costly lines upgrades

The government is taking a significant step in distributed generation with an investment of $30 million in solar for up to 500 schools. This will help solar on community facilities gain momentum, but the potential is much larger. This investment should just be the start of a more comprehensive rollout to the over 2400 state owned or majority-funded schools, where 1 in 6 people in the country spend most of the day, 5 days a week, 40 weeks a year.

Identifying non-network solutions

We previously analysed school solar potential nationwide. In this post we identify the schools and communities most likely to benefit, given the limited initial scope and funding. The most compelling opportunities for solar investment are for those places where generation potential is correlated with patterns of electricity consumption. This provides a direct benefit to schools, but it also provides broader benefits. A significant proportion of the cost of electricity goes to local distribution networks. These costs made up 25% of the average electricity bill in 2025 and were approved by the Commerce Commission to increase by up to 44% between 2025-2030 to cover the cost of maintaining and investing in new infrastructure.¹

Avoiding upgrades to the network can mean smaller increases to lines charges, but if solar and batteries can increase electricity usage while also not increasing peak distribution demand, the distribution costs will be spread over more electricity. Smarter utilisation of existing assets is critical to an efficient and low-cost electrified future. The Electricity Authority, Commerce Commission and EECA have jointly called for greater use of non-network solutions to achieve this.

Focus areas for solar investment

A feasible large-scale solar investment on schools could involve installing systems equivalent to 10% of available roof space, giving 216 megawatts of solar panels. The proposal for 15 megawatts in total under the government’s current plan means that the rollout needs to be well targeted to demonstrate the wider potential.

There are areas in which overall electricity demand matches up particularly well with solar generation, so could be matched with larger systems that generate strongly throughout the year, directly reducing demand on the networks with any excess production in sunny months able to be consumed locally. Major school sites with solar panels and batteries could generate and store electricity during the day and provide it back to their local communities for the evening peak when staff and students have gone home.

While New Zealand’s overall electricity demand peaks in the winter, 22% of local electricity distribution zones have their peak during summer, 8% in Spring, 4% in Autumn, and 62% in Winter. There are 242 state and integrated schools with 49,000 students that are located in an area where the local substation’s peak demand is in summer, and 48 of these schools are located in zones that are already over capacity during that peak. Another 177 state and state integrated schools with 24,000 students in areas where the local substation’s peak demand is in Autumn or Spring, of which 20 are over capacity.

Future investment opportunities

There are 481 schools which are located in over capacity winter peak zones. Schools will generally not be using significant capacity during the evening peaks and batteries could be deployed in these locations to support the network and lower peaks during these times.

The published regulatory data in NZ isn’t detailed enough to identify all the areas that would benefit most, with only the season identified and no information about the typical time of day, duration, and month of the peak. This does not need to be the case: all necessary data could be recorded at some point in the distribution chain and should be readily available.

Lines companies in Australia publish historical 15-minute interval load data for zone substations under the National Electricity Rules, which makes it a lot easier for Australian market participants to identify areas that have issues and what the best solutions are (batteries, demand response, or traditional poles and wires). The Electricity Authority is currently consulting on an approach to increase disclosure requirements. Some networks like Powerco and Orion among others are starting to increase the detail they publish, but the frequency of the data isn’t high enough or standardised across the country.

We need the data ecosystem and access to support this future. Consumers pay on average 4.5% of their bill for metering costs. Despite this significant expense, smart meter data is not easily accessed and used by market participants and metering costs are not tightly regulated or subject to a competitive market.

More information

An interactive map showing all these schools and comparing them to their local demand peak is published here.

1. https://www.comcom.govt.nz/regulated-industries/electricity-lines/understanding-why-changes-to-lines-charges-may-impact-your-electricity-bill/