Can agriculture be weaned off diesel? Some farmers are finding it harder than others to decarbonise

Across the world, farmers and machinery producers are stepping up to the challenge of reducing greenhouse gas emissions by electrifying essential equipment and exploring alternative fuels.

According to the Australian Farm Institute, diesel accounts for about 85 per cent of the energy used on farms, so switching to renewable and low-emission fuel will be critical in the push to reach net zero.

Just like the domestic road vehicle market, major machinery producers have committed to launching electric tractors with models up to 100 horsepower starting to become available in Australia.

In New Zeland’s Otago, cherry producer Mike Casey has been running a 6-hectare orchard without using any fossil fuels. 

Last year, it produced 80 tonnes of cherries for local and export markets.

His fleet of 21 electric machines includes prototypes and traditional vehicles that have been converted to electric.

Mr Casey said the move to electrify had proved to be a sound financial decision.

“I never envisioned us going fully electric; I was just sort of thinking there will be some things that we can do to cut out diesel and cut our emissions,” he said.

“But what actually happened is we discovered we’d save about $40,000 a year of energy costs on our farm.”  

Enough power for Australian conditions?

In Australia, large-scale grain growers face conditions that make the industry especially hard to decarbonise.

Challenges including rural and remote locations, long operation cycles and the power requirement to propel heavy vehicles like combine harvesters were among those identified by lobby group Grain Growers in a recent report.

Advocacy and Rural Affairs Manager Sean Cole said the answer lay in a shift to a combination of biofuels, green hydrogen, and renewable electric power. 

He expected biofuels to be an important interim step while new technology like hydrogen became more cost-effective.

“If it can get to $2 a kilo, then this type of equipment running on hydrogen for high torque applications, such as headers and trucks and tractors, starts making sense,” Mr Cole said. 

He said price meant diesel was the only realistic option for now.

Agnostic on power

The report noted future vehicles may be capable of running on a variety of power sources.  

This is the concept behind an hybrid electric combine harvester being developed by South Australian company Linttas.

Founders Terry Krieg and Malcolm Lucas recently lodged a patent for a component of the machine that would replace all moving parts of a grain harvester with electric motors that run via a diesel generator.

“We eliminate all of the belts, pulleys, and gearboxes, no hydraulics. It is all electric, and doing that we can save 30 per cent of the energy,” Mr Krieg said.  

“At some later stage, we’ll be able to convert that diesel to hydrogen if hydrogen ever becomes commercially available and distributed.”

Farmers’ eyes on developing technology

The Kondinin farm improvement group research manager Ben White said electric motors powered by a diesel generator was the best way to lower emissions on large farm machinery.

“If you look at, say, diesel electric locomotives, they have been using this technology for years, so it is not like it is new,” Mr White said.