Airline’s poo-power plan to make sustainable aviation fuel from human waste

Wizz Air has pledged to source 500,000 tonnes of fuel made from human effluent. Photo / Antek, Unsplash

A Hungarian airline is looking at an unlikely source for sustainable aviation fuel — human waste.

Wizz Air says it is working with biofuel company Firefly Green Fuels in trials to source next-generation fuel from sewage. The airline’s UK fleet base signed an agreement last year to buy 525,000 tonnes of sustainable aviation fuel (SAF) over 15 years.

But could human waste be fertile ground for low-carbon fuels?

The carrier invested £5 million ($10.5m at today’s rates) in December in the company’s process for converting poo into a future power source.

It takes about 228 tonnes of poo to create 1 tonne of aviation fuel. However, with the UK producing about 57 million tonnes of human effluent a year, the company says as “a low-value waste product available in large quantities”, there is no shortage of stool.

The company sources “biosolids” from water treatment facilities in the UK.

Firefly chief executive James Hygate said although biosolids were “kind of disgusting stuff”, they are “an amazing resource”.

“We’re turning sewage into jet fuel. I can’t really think of many things that are cooler than that,” he said.

Despite the abundance of poo, the process is extremely expensive compared with producing conventional A1 aviation fuel.

However, sustainable aviation fuel does produce far less carbon than traditional fuels. It can also be used directly with jet engines, blended with kerosene. Meaning it requires far less investment from airlines to get the new technology off the ground.

The chemists in South Gloucestershire are refining the process to make the poo-to-fuel process more efficient. However, the biggest hurdle is regulatory, with Firefly still waiting for approval to use the fuel in aircraft.

Firefly chief operating officer Paul Hilditch says there’s no reason for regulators to “pooh-pooh” the process.

The world is sitting on a vast, untapped source of power.

In 2021, the UK government pledged $30 million to realise the pipe dream of making aviation fuel from human effluent. It’s a process that Firefly says is now bearing fruit.

There’s enough biosolids in the UK for more than 200,000 tonnes of SAF. That’s enough to satisfy about half the mandated SAF demand in 2030, Hilditch said.

Wizz Air is aiming to source 10 per cent of its fuel supply from SAF by 2030.

While other sources would be needed for the quota, Hilditch says human waste could make a “significant contribution” to meeting SAF demand.

If the process takes off, it’s a contribution we might all soon be making.