Will battery or hydrogen power make rail carbon free?
TRIALS continue to take place to demonstrate that battery and hydrogen technology can replace the use of fossil fuels for routes that are not electrified.
A new initiative by Great Western Railway, supported by Network Rail, is to enter into an agreement with Vivarail to trial battery-charging technology for use with Class 230 rolling stock. The aim of the project is to demonstrate fast charging equipment in a real-time operating environment for services using the Greenford branch (see news story, p10).
Chiltern Railways commenced operations in February with a converted Class 168 unit described as a ‘HybridFLEX’ after modification supported by the rolling stock leasing company Porterbrook and Rolls-Royce, which enables the train to operate as both a diesel and battery powered set. An MTU power pack has been fitted which also acts as a generator with the battery system also able to recover power from train braking energy. The aim has been to convert the unit No. 168329 (formerly No. 170309 before transfer to Chiltern Railways) to a self-charging hybrid, meaning it can operate emissions-free in stations and designated low emission zones. The 100mph operating capability has been retained. (More details in First Impressions in the May issue).
ENTER THE BEMU
The use of battery power as an aspiration for rolling stock is by no means new. When the first Derby Lightweight diesel units were built for use on British Railways in the 1950s, construction included two cars equipped for battery operation. As built, they were supplied without power equipment and converted at Cowlairs works becoming numbers Sc79998/79999.
Operations commenced in 1958, with the train working on the long-closed Deeside line between Aberdeen and Ballater. The combined weight of the lead-acid batteries was 17.5 tonnes and charging points were provided at both ends of the route. There were reliability issues and modifications were made but when the Ballater line closed in 1966 the unit was allocated to departmental stock, eventually passing into preservation. It would be half a century before the UK would once again take the notion of battery powered trains seriously.
Another strand in the development of carbon-free rolling stock is the option of providing hydrogen cells to provide sufficient battery power at times when high output is necessary, particularly for starting tractive effort. This concept has been proved in regular service in Germany with the Coradia iLint rolling stock built by Alstom, but Network Rail gauge restrictions prevent a transfer of the design to the UK as the hydrogen cells are mounted on the roof of vehicles.
Instead, design and development for operations in Britain is taking place at Derby now that the plant is owned by Alstom. Funding is being provided by the Eversholt rolling stock leasing company with the aim of building a fleet a 10 threecar HMU’s with a most likely allocation to Tees Valley services, where access to hydrogen fuelling facilities is being planned.