Cleantech Investor

First published in Cleantech magazine, November/December 2009. Copyright Cleantech Investor 2009

by Denis Gross

Hydrogen is the only clean fuel available that is able to meet future stringent automotive emission requirements: when used to power an engine or a fuel cell it has zero carbon emissions. Programmes have been undertaken worldwide to test hydrogen-fuelled buses, cars, scooters and logistics vehicles like forklift trucks.

Hydrogen is often associated solely with the fuel cell vehicle (FCV) to power an electric traction system. It can, however, also be used to power today’s internal combustion engines.

The automotive industry is divided in terms of which technology to pursue. BMW, Ford and Mazda have developed hydrogen internal combustion engines (HICEs), while DaimlerChrysler and General Motors are investing in fuel cells. Mercedes Benz, which has developed its own fuel cell technology (the F-Cell has been introduced into the B-Class), has been working with fuel cells since 1994, and since 2003 has been running extensive testing of fuel cells in cars, vans and service buses.  General Motors, which has reached its fifth generation fuel cell technology, has built up a team of around 500 fuel cell technologists: significantly, GM is moving this team from its advanced development laboratories to core engineering functions. Ford has looked at both technologies.

Japanese and Asian auto companies have also been highly active in looking beyond the hydrocarbon era. Honda has been running its FCX fuel cell demonstrator cars on US roads for a number of years, with about 20 in current use. Nissan’s X-TRAIL FCV, which uses Nissan’s fuel cell technology, has been made available for chauffeur-driven hire-car services.

In the same way that hydrogen-fuelled vehicles emit only water vapour at the exhaust, FCVs powered by pure hydrogen emit no pollutants. Moreover, while conventional petrol engines are less than 20% efficient in terms of converting the energy in petrol into propulsive power, FCVs are typically 40-60% efficient. Similarly, hydrogen engines can be in excess of 40% efficient.

There is currently strong interest in electric vehicles (EVs), with auto manufacturers and battery manufacturers both engaged in substantial research and development programmes. However, it should be borne in mind that a fuel has advantages over battery power, particularly in terms of its ability to be stored for long periods of time and the speed of refuelling.

One particular issue on hydrogen is its ‘greenness’ – with the majority of hydrogen generated today originating from reformed natural gas.  However, there are developments under way to utilise electricity from renewable sources – so that when the wind blows at 3am in the morning the energy can be stored as a clean fuel, thus harnessing intermittent supplies from wind turbines and solar – and carbon-free ‘green’ hydrogen is becoming a practical reality.

This is confirmed by Dr Graham Cooley, Chief Executive Officer of UK company, ITM Power. “The use of modern, electrolyser technology can produce “green” hydrogen which is easy to store as a compressed gas without costly, large-scale infrastructure programmes; and provide a much needed method of storing energy from renewables when the sun does not shine or the wind does not blow,” he says.

Hydrogen remains surrounded by misconceptions; for example, the need for a substantial infrastructure to deliver the hydrogen to the point of use. This need not be an issue, as ITM Power is demonstrating with its prototype mobile hydrogen generator. This is installed in a standard container unit and deployed on site where it generates a clean fuel at the point of demand using water and electricity supplies. Installed at depots, this does away with the need for expensive concrete infrastructure and so offers flexibility in deployment; it negates the need for fuel deliveries, so eliminating carbon in the fuel supply chain; and, through the site’s power purchase agreement, can ensure green electricity is used in the process.

A consequence of the perceived need for infrastructure is the belief that hydrogen is around 10-15 years away. While it may take that long for FCVs to become commercially viable, existing ICE cars and vans can be modified to bi-fuel HICE, with an option to switch to hydrogen or petrol, with only modest alterations to current engine designs. BMW and Mazda have demonstrated this, as has ITM Power in the Ford Focus that it adapted for hydrogen, and the Ford Transit vans by Revolve Technologies.

According to Dr Cooley, “today’s car engines can be modified to run on hydrogen now. They can run for 100 miles or more and can be refuelled in minutes . This technology is available today and is being used successfully in modified Ford Transit vans and Ford Focus cars.”

At mass production volumes, the cost of this adaptation becomes negligible. Ultimately the near term adoption of HICE vehicles could shorten the lead time and facilitate the mass introduction of FCVs , as the widespread provision for hydrogen refuelling stations will be place sooner with an early demand for hydrogen. 

The challenges

Whilst there remain challenges, technological developments are addressing the issues to allow hydrogen to play an active role in transport today. On-board storage technology has to be vastly improved, as currently it is difficult to store sufficient hydrogen to give a hydrogen-burning vehicle or FCV an acceptable long distance range. It is therefore envisaged that return-to-base fleet delivery vehicles, such as logistics fleets, will be the early adopters of hydrogen as a fuel. Storage solutions currently being pursued are high pressure composite tanks, cryogenic liquid hydrogen and the use of metal hydride storage systems. One reported problem with liquid hydrogen is the significant loss rate of the fuel in transportation – this isn’t the case if the hydrogen is stored as a gas. Most fuel cell and HICE vehicles now utilise high pressure storage of hydrogen that allows for rapid dispensing and increased vehicle range. As a result of the research being undertaken, hydrogen storage technology is constantly improving.

ITM Power is developing a range of technologies for carbon-free hydrogen that would exploit green electricity to generate hydrogen by electrolysis and then compress it for storage at high pressure (350 bar) – for example in a hydrogen tank in a HICE  or FCV. The company’s low cost (thanks to its proprietary technology) refuelling system promises to make hydrogen affordable.

The recent announcement of an agreement between ITM Power and Revolve Technologies to develop a hydrogen refuelling infrastructure and vehicles for potential customers and demonstration projects is a positive move towards introducing hydrogen into transportation. The collaboration will include joint marketing of refuelling infrastructure and vehicles, including vans (Ford Transit). Thus the ITM Refuelling System and the Revolve modified HICE vehicles can be offered to customers as an integrated low cost package.

Behind this announcement lies a substantial amount of complementary development. As already mentioned, ITM Power has developed a range of materials and technology to reduce the cost of hydrogen production, via electrolysis. The company is developing equipment to convert renewable energy to a clean fuel; storing the energy as green hydrogen for decarbonising transport, industrial and residential applications.

Revolve Technologies serves a diverse portfolio of multi-tier automotive and non-automotive clients across a broad spectrum of industries including car and commercial vehicle, transportation, infrastructure, agriculture, defence and energy. Revolve has OEM recognition as a powertrain and vehicle integration engineering services provider.

According to Dr Cooley, “ because of the relatively predictable duty cycles and limited travel ranges of city delivery vans and buses, we may see hydrogen versions of these on the streets before we have hydrogen cars in our own garages”.

There is thus much exciting work being undertaken globally on hydrogen and hydrogen fuel cell vehicles. Several issues such as cost, storage and government incentives have to be addressed before petrol and diesel powered vehicles, which are also being extensively developed to become cleaner and more efficient, can be superseded.  However, it looks as if hydrogen fuelled vehicles will soon be on the road in significant numbers.