The potential for biogas in New Zealand

The energy, agricultural and waste sectors should collaborate to reduce New Zealand’s emissions by capturing biogas produced from organic waste, an independent report commissioned by Powerco, Clarus and Ecogas says.

In doing so New Zealand would reduce its emissions and waste volume, and grow the percentage of renewable energy being used, the report says.

The Blunomy report formed part of a submission to MBIE on the Gas Transition Issues Paper in November 2023.

The report found that there’s currently 4.9PJ of biogas being produced in New Zealand annually, most of which is being flared as part of waste processing.

With a further 9.5PJ of untapped potential in the North Island and 9.1PJ in the South Island, up to 23.5PJ of biogas could be produced annually across New Zealand.

Currently, the 290,000 homes connected to natural gas use 6.8PJ annually.

Powerco’s General Manager for Gas, Don Elers, says the report shows biogas is worth exploring as part of the overall energy transition.

“Gas is a critical part of New Zealand’s energy mix.

“We’ll continue to need natural gas to support the energy transition so we can continue to supply our customers with reliable energy while the electricity sector increases its capacity using intermittent renewables like wind, solar and hydro and while other options like battery storage come onstream.

“We also need to look at more sustainable gas options – like biogas.

“What excites me about the opportunity presented by biogas is that there are complementary objectives between the agricultural, waste and energy sectors here – they’re looking at how to be more sustainable and so are we,” he says.

“We can collaborate to create positive solutions for Aotearoa.”

If biogas’s potential was fully captured, New Zealand would reduce its annual emissions by 3.7mtCO2-e – contributing up to 27 percent of the Emissions Reduction Plan target of reducing emissions by 14 – 28mtCO2-e by 2050, the report says.

It would also contribute 23 percent of the reductions of waste from landfill required to meet New Zealand’s annual target of 2.5Mt municipal landfill waste per annum by 2050.

If 11PJ of biogas was supplied through the gas network, it could increase New Zealand’s use of renewable energy by 9 percent, contributing to the goal of 50 percent renewable energy by 2035.

With such a compelling case to increase the production of biogas and use it in the gas network, the Powerco team is now looking at next steps to make the opportunity a reality.

Don Elers says collaboration will be the key to success.

“We need to be working in a much wider eco-system than just energy – looking not just at our own network footprint or our own solution, but to be part of solutions that address the broader range of sustainability challenges like reducing waste, and other sectors’ emissions,” he says.

“We’re 100% behind a net-zero carbon future for Aotearoa. To get there, New Zealand will need a mix of energy options including renewable low and zero-carbon gases like biogas and hydrogen.”

Read the full report Vision for biogas in Aotearoa New Zealand.