Dan Gilkes reports on the progress of JCB’s research into the use of hydrogen to power construction machinery as the industry continues to seek solutions to environmental challenges
THE UK Government has announced the ban of sales of new petrol and diesel cars and vans by 2030, with hybrids following five years later. In 2040, it will add heavy trucks to that list, pushing all road users towards a range of zero-emission solutions. With shipping and aviation also searching for options, as they progress along their own roads to zero, construction and agricultural markets will have to play a part in this seismic shift.
Many manufacturers have already started, with electric mini-excavators and compact wheeled loaders now a common option at the lighter end of the market. But what of the heavier machinery, the excavators, loaders and haulers that operate away from urban mains power supply? How will they meet the challenge of what JCB calls the Off-Road to Zero.
Tim Burnhope, JCB’s chief innovation and growth officer, explained that the company has certainly not been slow in looking at the various options on offer. With one of the first electric mini-excavators on the market, electric Loadalls, Teletruks and access platforms, JCB has already mastered the art of battery electric operation for compact machinery.
“We believe there is a real place for electric machines under four tonnes and in urban operations,” he said.
Above that weight however, things become a little less positive. Whereas the four batteries that power JCB’s mini-excavator produce 20kW and cost around £8,000, upscaling that to a 20-tonne machine would require a huge number of batteries, at a cost that would be unacceptable to customers.
“Technically you can electrify anything, but it’s not financially viable for the customer,” said Mr Burnhope.
The company has been investigating hydrogen fuel cell technology, building a 20-tonne excavator with a fuel cell almost two years ago and testing a second-generation machine in its R&D quarry ever since. However, what this research has revealed, is that a fuel cell is too delicate for heavy machinery use. It is also slow to start and relatively unresponsive to the operator’s inputs. Alongside the actual fuel cell stack, the machine has to have hydrogen tanks, a DC/DC converter, power electronics, power batteries, motors and inverters.
As Mr Burnhope said: “The fuel cell excavator is too complicated, not robust enough and too expensive.”
That’s not to say that the hydrogen that powers a fuel cell is not suitable for construction machinery though. JCB believes that hydrogen has a big future within its machines. Hydrogen, which can be transported as a liquid or a gas, carries roughly three times the energy density of diesel and, if it is created as green hydrogen using renewable energy, it can be a true zero-emission fuel, with its only emission being water.
Driving Efficiency
Taking a step back, the company has been working for years to improve the efficiency of its diesel engines. Between 2010 and 2020, JCB cut the overall fuel consumption of its machinery by around 50%, finding efficiencies within the engine and hydraulic systems. It will continue to improve those diesel machines, cutting a further 50% of the remaining emissions by 2030.
The firm’s engines have also been certified to run on a range of alternative fuels, including HVO (hydro-treated vegetable oil) and e-fuels. In all cases though, these are not true zero-emission solutions.
The answer, according to JCB chairman Lord Bamford, is hydrogen. He set the engine team at JCB Power Systems a challenge in July 2020, to make one of its engines run on hydrogen by the end of that year. He was so determined that this was the future direction for the company, that the resulting hydrogen motor bears the initials AB H2 on the cylinder head.
While the engine block will look familiar to those with experience of JCB’s 444 diesel engine, the hydrogen motor comes with a totally new cylinder head. The engine features a new combustion system, with much lower injection pressures than for diesel. The air charge is ignited using spark plugs and the engine features a far larger turbocharger, to increase compression of the air.
As well as the challenge of operating on hydrogen, Lord Bamford insisted that the engine had to produce the same power and torque as the firm’s diesel units and operate for just as long between services. It also had to drop straight into existing JCB machinery, making it easy for customers to adopt.
“It is a totally new engine, not a conversion,” said Ryan Ballard, engineering director at JCB Power Systems. “Lots of people have tried to do a hydrogen engine, but the problem has been that it’s always been a conversion.”
Not only does the hydrogen engine have to meet the performance criteria of the existing diesel models, it will have to be built on the same assembly lines in Derbyshire and in India, two facilities that between them produce 400 engines a day. This too has been achieved, with five of JCB’s dynamometer test cells now running hydrogen engines, rather than diesel-powered motors and the very first hydrogen engines rolling off the line.
Making It Work
So, it is not only possible to run an engine on hydrogen, that engine can produce just as much power and torque and be no more costly to service. How about installation on the machine? Visitors to JCB’s test quarry will find that there are hydrogen backhoe loaders, Loadall telehandlers and a Fastrac running on the fuel.
While their white and green livery is certainly distinctive, there is very little else to let the casual passer-by know that these machines are running on H2.
On the 3CX backhoe loader for instance, the body panels are unchanged, with the engine fitting under the same sloping bonnet. The diesel tank has been replaced by composite hydrogen tanks, operating at 350 bar pressure. The backhoe uses around 8-10kg of hydrogen to work for a full day, which is easily held on-board.
Having got the machines to run on the gas, JCB has also looked at how construction sites could distribute hydrogen. It is delivered to site in tube trailers, road-going trailers that are filled with hydrogen tanks operating at around 700 bar pressure. The JCB Refueller is a smaller version of the tube tanker, carrying around 100kg and fitted to the back of a Fastrac tractor, also powered by the hydrogen engine.
Like a conventional bowser, this Refueller would be able to travel around the site, filling each machine in turn. With a flow rate of 1kg/min, the Refueller can top-up the backhoe loader in just 6-7 minutes, far faster than having to recharge batteries on an electric machine.
“To succeed with larger machinery, we believe that you need to take the fuel to the machine, not take the machine to the fuel,” said Mr Burnhope.
With this growing range of hydrogen-engined equipment on test, JCB has certainly proven that the gas offers a zero-emission solution for a variety of construction and agricultural machinery. By also offering contractors a means to refuel those machines on site, the company has taken a vital second step towards a potential hydrogen-powered future.
There are no launch dates confirmed for a JCB hydrogen machine yet, but for the company to provide such a clear vision of how this fuel could provide customers with a viable alternative to diesel, it can only be a matter of time. It is certainly a big step further along the Off-Road to Zero.
