Am Bratach No. 234
April 2011

Researchers in Stornoway and Oxford are fired up by hydrogen
by Mandy Haggith

“It should be possible to replace both petrol and diesel with a fuel containing a hydrogen additive within two to three years.” — Stephen Voller, Cella Energy

As fuel prices rocket and concerns grow about climate change emissions, scientists exploring alternatives to diesel and petrol predict that cheaper, greener fuels could be pumping into our car and boat engines in the not-too-distant future.

Alasdair Macleod’s laboratory team on Lewis has already developed a simple technique for converting a conventional diesel engine to burn hydrogen by co-firing it. 

Hydrogen is seen as the key to these alternatives. In the popular imagination, hydrogen is still associated with exploding airships, but new technologies have tamed it. Engineers from the most prestigious research centres in the UK, in partnership with oil companies, are rushing to get low-carbon, hydrogen-rich fuels onto petrol station forecourts. Meanwhile researchers in the Western Isles are also doing cutting-edge research and development on hydrogen as a marine fuel.

Cella Energy, a spin-off company from the Rutherford Appleton Research Unit at Oxford University, has developed a technology which converts hydrogen into a pumpable fuel usable by regular car engines without needing any conversion. The company is claiming that their “synthetic fuel of the future” could be cheaper than petrol or diesel.

The company’s chief executive, Stephen Voller, explains that their technology uses chemical engineering techniques to bind hydride molecules with a micron-scale layer of a polymer. The result is non-explosive in air, behaves just like a liquid fuel and is safer than petrol. “The fuel consists of millions of tiny beads but it looks like murky water,’ he said. “It can either be mixed with existing fuels, as an additive to reduce carbon emissions, or it can be used as a pure hydrogen fuel.”

Fuels containing a proportion of the synthetic hydrogen additive could be used in standard petrol and diesel engines, which Cella Energy expects will be the first commercial application of their idea. The pure hydrogen fuel would require engines to be converted.

Alasdair Macleod, who leads research into hydrogen alternatives to fossil fuels at the University of Highlands and Islands Green Space Research unit, on Lewis, believes that in fact the chance of hydrogen being used as a car fuel is diminishing. “For the car industry, battery technology is winning.”

Car manufacturers are certainly investing huge sums in electric cars but they are likely to be mostly an urban or island phenomenon, as even the best battery technology will only drive a car for 100 miles between charges. For drivers in North West Sutherland, who might occasionally need to make the trip to Inverness and back, electric cars will be completely impractical.

Mr Macleod believes that the marine industry has a huge opportunity to use hydrogen. “On large scale marine applications, batteries will be too expensive,” he said. “The volumes of hydrogen that need to be stored in a tank can be large, but on most large marine vessels there is plenty of space onboard, so that is not a problem.” He is therefore looking into hydrogen-burning alternatives to marine diesel engines.

Whereas a standard petrol engine can burn hydrogen, because the spark plugs will ignite it, a diesel engine causes combustion of the fuel by compression and this will not cause hydrogen to ignite. So, burning hydrogen in a diesel engine requires a two-stage combustion, with diesel fired to raise the temperature enough that the hydrogen can ignite. Alasdair Macleod’s laboratory team on Lewis has already developed a simple technique for converting a conventional diesel engine to burn hydrogen by co-firing it.

Although hydrogen is not likely to be on widespread sale soon, the scientists believe it will be with us in years rather than decades. Asked if it might be technically feasible for the CalMac ferries plying between the Hebrides and the mainland to be running on hydrogen before long, Alasdair Macleod said: “The ferries could be using hydrogen within five years, with no difficulty at all.”

Stephen Voller is also forecasting that Cella Energy’s product could be on sale fairly soon. “It should be possible to replace both petrol and diesel with a fuel containing a hydrogen additive within two to three years. This will mean lower carbon emissions and it should also be cheaper than regular fuel.”

Currently, 63% of the cost of petrol and diesel at the forecourt is tax, and Cella Energy is confident that their additive-enriched fuel should attract a reduced fuel duty. “There are precedents for taxing fuel with lower emissions at a lower level,” said Mr Voller. He gives liquid petroleum gas (LPG) as an example, which is taxed at only 17p/litre.
In terms of the 37% which is the cost of the actual diesel or petrol, Cella Energy believe that with their hydrogen-enriched fuel, they will be able to compete as long as oil is £100/barrel or more. At the moment the oil price is £116/barrel.

Ironically, because of our extremely high fuel prices, Mr Voller believes that the north-west of Scotland could be one of the early beneficiaries of the low-carbon fuels. “Our technology could well be implemented in areas like the Highlands and Islands earlier than elsewhere because of the price differential,” he said.

Highland Council has said that it is seeking support to subsidise the fuel pump network in remote areas, and exploring community ownership of pumps. Councillor Ian Ross of Golspie said: “As well as lobbying the UK and Scottish governments we want to explore innovative solutions such as the introduction of electric and hydrogen vehicles as a pilot in local communities.” Government subsidy would be far more feasible if it was to support the development of a network of provision of cleaner, greener fuels.

Alasdair Macleod is cautiously optimistic that hydrogen could be the energy future for remote parts of the Highlands and Islands. He points out some of the obstacles that will need to be overcome. “To use renewable energy to generate hydrogen is straightforward, but the electrolytes [needed to break water down into its constituent elements] are expensive. Hydrogen storage is an issue and the logistics of a hydrogen infrastructure is a stumbling block.”

There is only so much electricity that can be used in remote areas, electricity grid infrastructure is enormously expensive and pylons are unpopular, therefore alternative ways of capturing, storing, transporting and using our renewable energy resources will be needed. Replacing our existing oil, petrol and diesel use is the only logical way to go, and hydrogen could well be the alternative.

Mr Macleod agrees. “Once the number of wind turbines and marine renewable systems gets to the predicted levels, hydrogen is the only obvious solution.”

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