All manufacturers are exploring alternatives to diesel. But many challenges remain.
Electricity, hydrogen, methane… manufacturers are exploring new avenues of motorization. But there are still significant challenges to overcome, especially in terms of cost, range and supply. The electric solution mainly collides with autonomy. An average tractor with a diesel engine requires a reserve of 400 liters of fuel. In its electrical equivalent, the lithium-ion battery weighs 9 to 10 tons and represents a volume of 5,000 litres. This is to perform the same 8 hours of work. Conclusion: the future of 100% electric lies more in small machines, which remain close to the farm for recharging or intended for indoor work. “Larger tractors would exceed acceptable weight limits and consequently create highly damaging and unsustainable soil compaction,” according to Cema (European Agricultural Machinery Association). Reload times are another obstacle. Some manufacturers bet on the hybrid first. The German Claas imagines it as a step, by 2028. “We are studying concepts to anticipate the scenario of a drastic anti-pollution standard,” explains Simon Loquais, director of strategy for tractors. “The electric assistance will make it possible to reduce consumption of the diesel engine, this before the launch of 100% electric. Further on, the American John Deere is already offering partial electrification of its 8 series, which is one of the brand’s largest tractors. The idea is to equip machines over 400 HP with a transmission whose hydraulic part is replaced by the electric one – the engine remains thermal. “An advantage is the increase in performance,” emphasizes marketing director Julien Saint Laurent, announcing the first deliveries in spring 2023. This technology makes it possible to distribute the power between the tractor and the attached implement.
A gas farm tractor
Running the tractor on fuel produced on the farm: gas offers this possibility. New Holland is actively interested in this. The Italian is “the only manufacturer to mass-produce a non-diesel agricultural tractor” that runs on methane (natural gas for vehicles). A dozen copies were delivered to France in the spring and will be “twenty in service at the beginning of the school year”, promises marketing manager Nicolas Morel. The manufacturer is particularly targeting farmers who own a methanisation unit. After a compression stage, their biogas is used as fuel. You still need a charging station. The investment represents between 50,000 and 60,000 euros for self-consumption for 1 or 2 tractors. New Holland is also speaking of an additional cost of 20% on the purchase of the tractor. But range remains the big disadvantage compared to diesel. “You need a tank four times as large, i.e. 800 liters for a day’s work,” acknowledges Nicolas Morel. At best, the manufacturer offers four and a half hours of autonomy with its gas tractor, against an ideal of eight hours with a full load. An additional 270-litre tank is then positioned in the front of the machine, in addition to the 190-litre standard version. The T6 Methane Power tractor also exhibits diesel-identical levels of performance, longevity and maintenance intervals. New Holland also promises savings of around 20% on the fuel bill.
The fuel cell has to prove itself
“For medium to large tractors, the fuel cell seems interesting, because its operating time and energy density are better than the electric battery,” says Gaël Guégan, engineer at Cetim (technological institute). New Holland also made headlines in 2009 with a fuel cell tractor concept. Problem, the purchase cost is 3 times higher than the diesel version. The duration remains limited, approximately 5,000 hours. Obstacles that today seem difficult to overcome. “This technology still presents challenges in terms of integration (cooling and air conditioning), refueling infrastructure and total cost of ownership (including purchase price and running costs),” underlines Gaël Guégan.
Hydrogen comes into play
British JCB is investing heavily in hydrogen. No less than 110 million pounds (about 125 million euros), a team of 150 engineers is mobilized on a heat engine using the basis of diesel. The first hydrogen-powered equipment – a backhoe loader and telehandler were unveiled last year – are expected to be launched by the end of 2022. “It is fully replicable to agricultural tractors,” says general manager Philippe Girard. The technology is known. Hydrogen, mixed with air, is injected into a combustion chamber to drive the engine. In terms of architecture, weight, nothing changes compared to diesel. The only difference is the color of our machines: traditionally yellow, it changes to green and white. However, the price is higher, around 10% for the hydrogen engine. JCB also announces an autonomy of one working day. As for charging, no worries from the manufacturer. “France will produce green hydrogen very quickly,” believes Philippe Girard, noting in passing the possible contribution of farmers, thanks to solar panels, to methanisation.
