Did you ever imagine that the wilted lettuce in your fridge, last night’s leftovers, or even the grass clippings from your Sunday mow could be the secret ingredient in Australia’s next energy revolution?
It turns out that what we toss in our green bins—or flush down the loo—might soon be powering our homes, businesses, and even the industries that keep our country ticking.
While we’ve all become familiar with recycling and composting, biomethane’s a new player in the sustainability game.
This renewable gas is made by transforming organic waste—food scraps, garden trimmings, and even sewage—into a clean-burning fuel that can be used like natural gas.
The best part? It can be piped straight into our existing gas networks, meaning businesses and households can use it without changing a single appliance.
If you think this sounds futuristic, you might be surprised to learn that it’s already a reality in parts of Europe.
Denmark, for example, is leading the charge: Around 40 per cent of its gas grid is already powered by biomethane, and it’s on track to hit 100 per cent renewable gas by the early 2030s.
France, Italy, Germany, the United Kingdom, and even parts of the United States are also injecting biomethane into their gas networks.
Here in Australia, we’ve been a bit slow off the mark, but that’s changing fast. Sydney’s Malabar wastewater treatment plant is already turning organic waste into biomethane, ready to be injected into the gas grid.
And that’s just the beginning. Companies like Optimal Renewable Gas plan to roll out projects across regional Australia, hoping to deliver the first renewable gas to customers by late 2027.
Mike Davis, managing director of Optimal Renewable Gas, is optimistic: ‘We are hopeful of our projects injecting their first renewable gas by late 2027.’
The company has plans for 10 sites, aiming to become Australia’s leading biomethane producer.
How does it work?
The process is surprisingly simple—and a bit like nature’s own recycling system on fast-forward. Organic waste is placed in large, sealed tanks called anaerobic digesters.
Here, microbes break down the waste in an oxygen-free environment over about 30 days. As the waste decomposes, it releases biogas—a mix of methane and carbon dioxide. This gas is then cleaned up, removing impurities, to create biomethane.
When burned, biomethane releases carbon dioxide, just like natural gas. But here’s the crucial difference: plants recently captured carbon in biomethane from the atmosphere, making it part of the ‘short carbon cycle’.
In contrast, burning fossil fuels releases carbon locked away underground for millions of years, adding to climate change.
There’s another environmental bonus: by diverting green waste from landfills, we prevent methane, a greenhouse gas 28 times more potent than carbon dioxide, from escaping into the atmosphere. Instead, we capture and use it, turning a problem into a solution.
Closing the loop
The benefits don’t stop at clean energy. The byproducts of biomethane production—known as biosolids or digestate—are rich in nutrients and can be returned to farms as fertiliser, helping to close the loop on food and waste.
There’s also potential to capture the carbon dioxide produced and use it for other renewable fuels or permanently store it.
While there’s a big push to electrify everything, not all industries can flick the switch.
Manufacturing sectors like steel, glass, and bricks rely on gas for the high, consistent heat that electricity can’t always provide. Food processors, too, often need more power than local electricity grids can deliver.
For these industries, biomethane offers a renewable alternative that fits seamlessly into existing infrastructure.
It could also help power large buildings—think schools, hospitals, shopping centres, and apartment blocks—where going all-electric might be too costly or complex.
And while biomethane is currently more expensive than natural gas, government incentives and economies of scale could bring prices down as the industry grows.
Davis believes biomethane could be vital to Australia’s energy mix as we transition to renewables. He’s calling for more government support, similar to what’s being offered for green hydrogen.
A hidden goldmine
Australia has a vast, untapped resource. According to Enea Consultants, New South Wales alone could produce enough biomethane yearly to exceed the state’s current annual gas consumption.
That’s a staggering amount of potential energy currently going to waste. So next time you scrape your plate or empty your lawnmower, remember: you might just be holding the key to Australia’s clean energy future.
As the world races to decarbonise, biomethane could help Australia keep pace—reducing emissions, supporting industry, and making the most of our resources. It’s a win-win for the environment and the economy.
Have you ever considered where your green bin waste ends up? Would you support adding biomethane to our gas networks? Should Australia be doing more to turn waste into energy? Share your thoughts and experiences in the comments below.
Also read: ‘This is how we know’: Garbage collector reveals surprising way your bins are being tracked
