TURNING WASTE INTO ENERGY

Ecogas is preparing for its biogas plant at Reporoa to become fully operational this year and planning is underway to create similar facilities across the country to help support New Zealand’s decarbonisation efforts.

The Waikato facility takes organic waste that would normally head to landfills and uses it to create biogas and organic fertiliser.

Alzbeta Bouskova, General Manager at Ecogas, says the Reporoa plant will eventually be able to supply around 9,000 homes with net carbon zero gas, biomethane.

“We plan to replicate this across the country, with our plants processing organic waste and supplying homes, vehicles, and industry with renewable gas energy,” she explains.

“We’re working on projects in Canterbury and Manawatu and hope to have three more plants open in the next five years to help the wider community deal with food waste and energy security.”

The plant at Reporoa is designed to take 75,000 tonnes of organic waste—a combination of household food scraps and preconsumer food waste, along with industrial waste from the food processing industry.

Ecogas has a contract to secure two-thirds of the waste it needs from Auckland Council over the next 20 years.

Bouskova says the operation benefits the waste sector by diverting organic waste from landfill; the energy sector by creating renewable energy; and primary industries by providing renewable fertiliser for the farming sector.

Besides “closing the loop” by recycling food waste products, she notes biogas is a good substitute for natural gas and can be piped through existing infrastructure. The biomethane produced at the site will be injected into the natural gas grid in Reporoa.

“Once fully operational, we will generate electricity and heat for our own purposes so the plant will be self-sufficient,” says Bouskova.

“Some excess gas will help produce renewable heating for the neighbouring glasshouses to grow tomatoes. Finally, the remaining portion of biogas will be upgraded to biomethane and renewable CO2, with the former being injected into the natural gas grid.

“It’s a straight injection of the biogas because the quality of the biomethane is largely the same as natural gas. A portion of the renewable CO2 will be supplied to the tomato growers.”

She notes First Gas has negotiated approval from WorkSafe to inject the biogas and work is underway to produce a biomethane standard to inject gas into the national grid.

“There’s enough potential to replace all natural gas with biomethane but it needs government direction and support. We’re working through a gas transition plan at the moment and putting a biogas roadmap in place.” using renewable gas, plans are afoot to offer specialised training for plumbers and gasfitters about the emerging energy supplies.

“Master Plumbers is already looking at models to train fitters on renewable gas and hydrogen. This is about to commence in Australia and we’re in conversations with them about what their training looks like.

“We work really closely with Australia on trading standards and gas standards and there’s a lot we can learn from them.”

Master Plumbers CEO Greg Wallace says taking a transTasman approach makes good sense for the trades and from a cost delivery perspective.

“We are working with our Australian counterparts to develop joint standards for hydrogen and biomethane, with the goal of then incorporating an aligned gasfitter training regime.

“The Master Plumbers’ Association of Queensland is at the forefront of launching a new hydrogen training programme and we are in discussions around acquiring this programme for New Zealand.

“However, if we are to go ahead with this significant investment, we must first have absolute commitment from the current government that this is the future direction for the gas industry.”