As the industry faces pressure to meet net zero emission by 2040, innovator Jo Bamford discusses the possibilities of alternative fuels in agriculture. Ewan Pate reports.
Battery powered electric vehicles are widely expected to oust their diesel and petrol counterparts within a decade or two but they have limitations.
Jo Bamford, executive chairman of Oxford-based Reese Hydrogen, reckons that once gross vehicle weight exceeds 10 tonnes, conventional battery power is no longer a practical proposition.
This is even more the case with large agricultural machines such as tractors, forage harvesters and combines which typically work at full power for many hours at a time. The weight of battery required and the need for frequent recharging would rule out using this technology in such applications.
It might seem to leave diesel power to reign supreme in agriculture, but Mr Bamford, who is also a board member of the family owned JCB business, sees hydrogen as being a fuel of the future. Reese Hydrogen is currently pioneering the use of hydrogen fuel cells in buses, but with an eye to other applications.
Aberdeen City Council has been one of the early adopters of the technology with 15 new buses due for delivery in November. These will be operated by First Aberdeen and could be the first of many delivered to bus companies throughout the UK.
Mr Bamford predicts Northern Ireland-based Wrightbus, a company he bought out of administration in October last year, could manufacture 3,000 vehicles by 2024. Aberdeen will also be home to a new hydrogen manufacturing site.
Mr Bamford says: “Scotland is ideally placed to be part of the new hydrogen economy because it has plenty of wind to produce renewable energy and plenty of water. These are the only ingredients needed to produce hydrogen gas. It is an ideal opportunity to move from an over-reliance on North Sea oil.”
The decision to concentrate initially on buses for use in an urban setting is driven partly by the need to have vehicles with zero emissions – the fuel cell emits only water from its exhaust system.
However, economics play a larger part. A hydrogen refuelling station comes with a £2.5 million price tag, but such an investment can be justified if 200 buses are refuelling daily from a central depot, says Mr Bamford.
“It is scalable and as the technology develops it should be possible to have storage and fuelling facilities suitable for farm installation. I think JCB will manufacture hydrogen powered loaders, but we are at least 10 years out from that.”
The future may depend on continuing innovation but the fuel cell itself is not new. It was developed in 1842 by Welsh judge and scientist Sir William Grove.
Recognised as the Grove Voltaic cell, it produced power by continuously passing hydrogen gas across an oxidising agent, thus producing an electrical charge as it recombined with oxygen to form H2O.
The same principals are used today. The produced electricity is then used to power what is essentially an electric vehicle with a continuously charging ‘battery’.
Hydrogen gas can be manufactured in a number of ways, but using renewable energy to power the process of separating water into its hydrogen and oxygen components is a particularly neat way of providing green power, says Mr Bamford.
“The beauty of hydrogen in an agricultural situation is that it closely replicates what you do already in terms of quick and not too frequent refuelling.
“There was actually a prototype tractor with a fuel cell built in the 1950s, but it could not carry enough gas to give it a useful range. Tanks are far better now. Using carbon fibre technology, the gas can be safely compressed to 250 bar.”
The same rules of scale apply to vehicles, with a hydrogen-fuelled bus currently costing about twice as much as a conventional diesel-powered version.
“Scottish Government and Aberdeen City Council have been very forward looking in investing in green technology. In my view, if we were to receive government-backed orders for 4,000 buses across the UK the price would become competitive.
“Everything is going to have to become greener, so we want to be on the front foot as soon as and as much as we can,” says Mr Bamford.
“Agricultural kit is quite complicated but theoretically it is possible that we will see hydrogen powered off-road equipment in a decade or maybe a little longer.”