Farm electrification: where are we at?

Broadacre sectors have traditionally been heavily reliant on non-renewable energy, with the huge majority of heavy machinery running on diesel.

Farmers are familiar with diesel engine technology and maintenance, and know that it can produce a lot of torque at low speeds. There is also a strong supply chain for new machines and spare parts so the risk of downtime is relatively low.

However, the heavy reliance on fossil fuels has led growers to become increasingly concerned about fuel price volatility.

If anything, the COVID-19 pandemic has revealed the fragility of fuel security with sovereign nations intervening in fuel supply chains. Limited domestic fuel oil reserves has left our nation’s ag sector exposed, leading many to think about transitioning away from diesel in the medium to long term in order to achieve a low carbon future.

However, recent advances in technology is rapidly changing this dynamic, including the development of battery technology. Energy engineers believe the move to electric tractors will be the biggest step in electrifying the farm.

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According to the NSW Department of Primary Industries, the overall agricultural sector’s consumption of diesel is gradually increasing and comprises 86 per cent of total usage.

Electricity consumption, on the other hand, totals six per cent while natural gas takes up one per cent.

However, with larger broadacre growers’ diesel bills often going over $400,000 a year, experts are looking at ways to help farmers “trim the bill”.

“The Federal Government’s Liquid Fuel Security Review in 2019 revealed Australia was exposed to changes in fuel with the nation having small stocks,” said NSW Department of Industries (DPI) climatologist, Mike Cashen, who spoke at the ‘Exploring Beyond Diesel’ webinar earlier this year.

Cashen is currently overseeing an Energy Efficiencies Solutions project for the NSW Government aimed at helping reduce industry’s vulnerability to rising energy costs and in turn increase farm profitability and competitiveness.

The program will fund and oversee the piloting of a series of projects to identify and verify trends in energy productivity; as well as develop a practical education program aimed at improving energy efficiency in the primary industries.

A total of 21 submissions were received under the project with 11 proposals awarded funding for feasibility assessments, and six proposals shortlisted for pilot funding.

Ag “well on the way” to neutralising carbon footprint

NSW Farmers president, James Jackson, was also a guest speaker at the webinar and said high electricity costs are forcing farmers to switch to diesel, especially with lower diesel costs due to the pandemic.

“Diesel has become critical in the energy mix for agriculture and is essential as a power source for generators, plant and machinery,” Jackson said.

“It’s relatively cheap at the moment due to the demand collapse of the pandemic but the competition for this diminishing resource will become more intense.”

However, with some education and solid government action, the ag sector is not too far off from achieving a carbon neutral future, he said.

“If we can transition to alternate fuels like hydrogen, it will hold us in good stead with our free trade agreements with Europeans, and they are willing to pay for it.

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“The idea that nothing is happening in Australia is nonsense – there are thousands of acres of solar panels going in and there are solar pumps, it is turbocharged at the moment in the ag sector.

“Unlike many sectors of the economy, the ag sector is well on the way to neutralising its carbon footprint.

“The fact Australia’s net carbon position has been achieved by farmers is not well known and the inequitable approach has damaged the trust in farmers around this topic.”

Jackson added opportunities around hydrogen are exciting with significant research underway for use on-farm.

“Regulators have to open opportunities for farmers to be involved in the energy market whether it is using cheap midday power to create hydrogen or whatever,” he said.

“Farmers have been engaged in this space for a long time – if we are given a regulatory framework we will embrace it and engage in the solutions.”

Farmers could make small steps now towards a carbon neutral future of electric farm vehicles, renewable hydrogen generated on-farm and a zero reliance on grid power, said Pitt & Sherry senior energy engineer, Charles Luo.

According to Luo, all aspects of a farm would be electrified in a carbon neutral future. Diesel tractors would be replaced by electric or hydrogen powered vehicles, diesel pumps replaced by solar or hydrogen driven pumps, and the only energy inputs being sunlight or wind.

“To effectively replace diesel tractors, the battery needs to have a power rating around 100 kilowatts or 130hp,” he said.

“The battery that best fits these requirements is the Lithium-ion battery – these have risen in popularity thanks to its flexibility, lightweight, how much power it can deliver and the relatively long discharge time.

“There is no one-size fits all battery at the moment. There is a lot of research around Flow and Pumped Hydro batteries.

“These technologies will change the grid as we know it and make a fully renewable electricity network a reality.”

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The price of Lithiun-ion batteries has fallen 85 per cent in the past decade, from US$1160/kWh in 2010 to US$156/kWh in 2020.

“The good news is the price is continuing to fall as more manufacturers enter the market and reach economies of scale in production,” Luo said.

“Safety and reliability are also improving. This means the battery powered tractor is a reality with John Deere making a model back in 2016.

“A fully autonomous GPS guided electric compact tractor was unveiled in Japan in January.

“Moving to electric tractors will be the biggest step in electrifying the farm.”

Besides cheaper battery storage, there are other reasons why electric tractors are gaining traction, Luo said.

“An electric motor is far better suited to performing agricultural work compared to diesel,” he said.

“At low engine speeds, the torque of an electric motor is higher than diesel, making it a far more effective machine.

“However, when it comes to the cost of energy delivered by the motor into the driveshaft, diesel is slight cheaper ($0.217/kWh) than electricity ($0.294/kWh). So, it’s still not fully financially feasible to electrify pumps and tractor if energy costs are the only consideration.”

He said electrification must be done in conjunction with local renewables and battery storage at this stage to give a cheap cost of power.

Some of the current hurdles to on-farm electrification that Luo has identified include weakness of the grid, poor farm access to electricity, lack of knowledge on repairing and servicing electric machinery, and high demand loads during extreme temperatures.

“All of this makes the prospect of plugging in a 100kW charger for a tractor on every farm a big challenge for the network operators,” he said.

“Artificial intelligence can be installed at the operating level on farms to control charging times so each farm can charge at a different period to spread the load across the network.”

Electric aside, there is currently a range of alternative fuels farmers can look at to power their machines and pumps such as renewable hydrogen generated using sunlight and water; biogas, biodiesel, bioethanol and portable solar systems.

“If you can secure a supply of waste vegetable oil, biodiesel is a feasible solution,” Luo said.

“The equipment to produce biodiesel range from backyard chemistry kits for around $20,000 all the way to a dedicated refinery.

“Bioethanol is a useful fuel for petrol replacement and hasn’t been explored much in Australia yet but it is an option where there is a sugar waste stream to tap into.

“It might not be feasible now but we need to keep our eyes open for when the opportunity does arise- batteries are on the cusp of being able to replace diesel usage so understanding where to adopt this new technology on your farm is vital.”