The future of gas

By Estelle Sarney |

Within the next 10 years we could be cooking on gas made from waste, and using renewable gas for a whole lot more.

LinkedIn    Facebook
 

Cameron Jardine of the LPG Association says that while renewable gas is still in its infancy, the technology is expected to rapidly develop as countries and industries confront the need to reduce their carbon footprint.

The Government also recognises the opportunity. Minister of Energy and Resources Megan Woods said in March that renewable gases represent a major opportunity to help New Zealand transition to a sustainable future.

“They offer an opportunity to lower our emissions, while retaining gas for applications where it is still required, such as in commercial kitchens and high-temperature process heat,” Woods said.

New Zealand homes and businesses use two types of gas – natural gas which flows through piped networks, and LPG, delivered in bottles. Gas is favoured by hospitality outlets for its high heat for use in cooking, and by businesses ranging from laundromats to those in manufacturing and agriculture. And that’s not counting the hundreds of thousands of households that use gas for their backyard barbecues, cooking, heating and hot water.

“New Zealand has great potential to grow a renewable gas industry as we have feedstocks, or sources for production,” says Jardine, listing wood waste and municipal or dump waste as agents of renewable gas. Some appliance companies have already started testing existing appliances with early versions of renewable gases.

Jardine says natural gas could be replaced by renewable gas – investment and research is already some way down the track. Fossil LPG could be replaced by a green version that has the same chemical composition, but is made from renewable sources such as agricultural waste or wood waste. The two can be blended and stored in the same bottles until there is enough quantity of renewable LPG to replace the fossil version entirely.

He adds that trials of bio jet fuel and bio diesel could lead to a by-product of renewable LPG.

“We could get alongside those industries and offer to buy their renewable LPG off them, which improves their business case,” says Jardine. “It’s exciting that we can take products like waste and bio diesel and draw extra value from them that will help reduce our carbon footprint – why wouldn’t we?”

Europe and the United States are leading the way in the development of renewable LPG, and its precursor, renewable DME, and Gas NZ is keeping abreast of progress.

Gas NZ is importing a container of DME for appliance testing. The overall aim is to encourage investment in a New Zealand supply chain and start working through the changes required.

Jardine is also the General Manager of LPG & Small and Medium Enterprise Customers at Genesis, and says the company is active in helping New Zealand business to become more sustainable.

“Renewable gases are an exciting resource which could complement renewable electricity in enabling businesses to reduce their carbon footprint.”

Case study: Turning waste into electricity

You don’t expect to hear landfills described as “modern marvels”, but after listening to Ingrid Cronin-Knight of Waste Management you understand why she’s so enthusiastic.

Five of the company’s landfills throughout the country capture more than 90% of the methane and CO2 produced in waste breakdown, use it to create electricity, then feed the power into the national grid. Each year the sites generate enough electricity to power 25,000 households.

“What happens to waste these days is a fascinating and empowering story,” says Cronin-Knight, Waste Management’s General Manager of Strategy, Customer & Sustainability.

 

Far from the smelly holes in the ground of old, the company’s landfills are carefully constructed to eliminate run-off and create the optimum environment for bacteria to create methane and CO2. The gas is captured in wells before being funnelled through engines that drive electricity generators, which in turn are connected to the national grid.

“We then take some of that electricity back to power our EV vehicle fleet,” says Cronin-Knight, noting the company runs 92 electric light vehicles, and 30 electric rubbish trucks.

One truckload of waste generates enough gas to power 270 houses and an EV truck for the following day.

“The Redvale Landfill & Energy Centre on the North Shore is the largest green gas field in New Zealand, and we also run the country’s largest commercial EV conversion workshop in Auckland – we like to think we run a circular economy.”

Not all of Redvale’s gas goes to generating electricity – some CO2 is piped to a greenhouse next door to feed a crop of hungry aubergines.

After all, being a good neighbour is part of the sustainability story.

To get the latest news and articles in your inbox, subscribe below.