Rooftop solar has emerged as one of the more unexpected policy contests of New Zealand’s election campaign.

National has proposed low-interest, rates-based loans for solar panels, batteries and other home electrification upgrades, while Labour has floated similar finance alongside subsidies of up to $3,000 and support for renters to install plug-in solar.

The pledges follow recent government initiatives to make residential solar easier to install, as well as new electricity rules enabling more households to export surplus electricity back to local networks.

But are these measures, while important steps, enough to drive solar uptake at scale?

Our new research, which surveyed professionals across New Zealand’s building and energy sectors, suggests cost is only one piece in the puzzle.

We found households also weigh expected long-term returns, electricity market settings, whether their home is designed for solar, and whether government policy stays stable.

When support doesn’t equal uptake

We looked at rooftop solar power within the Passive House framework – an international standard for building ultra-low-energy homes and offices. Because these buildings already use so little energy, they........

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