Since 2009, Furrer+Frey has developed a multi-modal ultra high power charging station for battery-powered vehicles that is already radically changing the way traction power is delivered to road and rail vehicles. In particular, the Furrer+Frey Railbaar system targets existing low traffic diesel traction routes as well as new light rail and tram projects. The technology applies to battery powered trams and trains (Railbaar), buses (Busbaar) and trucks (Trukbaar) with a design rooted in proven Swiss electric rail technology already successfully deployed by Furrer+Frey across Europe and the world.
The railway industry has utilised electrification for improved efficiency and reliability, and now as part of a wider sustainable mobility solution using electricity from renewable sources. However, the initial high capital investment for standard Overhead Line Equipment (OLE) has always been a problem for low volume lines, and diesel traction remains common not only on rural and low-traffic sub-urban routes but also for city transport.
Furrer+Frey’s RailBaar bridges this gap by providing ultra-high power charging infrastructure for battery powered trains, trams and light rail. On-board batteries and high power charging stations eradicate the need for overhead lines by expanding the scope and range of battery powered trains. This innovation is a game changer which dramatically reduces the costs of electrification, and makes feasible many electrification projects that were considered too costly in the past
For example, a good candidate for battery trains is the Ormskirk to Preston line near Liverpool England. This line is a 20 mile stretch of unelectrified track that connects two electrified systems. A few old diesel locomotives provide an infrequent hourly yet popular service feeding into the Liverpool electric metro system. A local community group has been requesting electrification for years, but Network Rail considers the investment in OLE to be cost prohibitive for such a low frequency service. Estimates for full OLE electrification run about 2 million pounds per mile, so 40 million pounds for this route. However, the incremental cost of electrification using battery trains that provide every 30 minute service is estimated to be about 10% of this cost, plus avoids the inconvenience of transferring from the diesel train to the electric metro system at Ormskirk.
Good candidates for battery rail lines are relatively short with infrequent service that are currently uneconomical to electrify using OLE. There are large numbers of these in the U.K., Denmark, the Netherlands, and other countries. Converting these lines to electricity using batteries and fast chargers is an economic way to provide a sustainable, fast, and reliable transportation service. Instead of replacing these lines with buses that are slow and subject to traffic jams, upgrading an old polluting diesel rail line to a battery electric line makes for a better and faster commute that is appreciated by everyone.
The RailBaar is an ultra high-power charging station for battery-powered electric trains and is based on Furrer+Frey and Opbrid’s BusBaar charging station for battery buses. The Opbrid BusBaar has been in successful use on buses since 2010, and is helping to reduce fuel and energy consumption. For instance, the system has helped Volvo to reduce fuel consumption by over 80% and total energy consumption by over 60% on the three buses using BusBaar charging station installed at two locations on a network in Gothenburg. Furrer+Frey has supplied control systems, the charger and software along with the mechanical infrastructure of the charging station. The Opbrid Busbaar system in Umea Sweden transfers power at 650kW, over 10 times more powerful than typical fast chargers for cars.
The charging station is equipped with an inverted aluminium pantograph which is fitted with copper conductors. These are connected to a power source via cables and have a flexible design to suit charger capacity. Trains require even higher power transfer rates than buses, which the Railbaar handles with ease. One MegaWatt or higher power transfers are possible using the Railbaar. The pantograph is stored in a protective hood and can be lowered to the height of any train and then raised to a safe height when not charging.
The train roof is subsequently equipped with fixed in-line current collectors. To operate, the inverted pantograph automatically lowers to make contact with the collectors to enable charging to take place as the train arrives in the platform. After charging pantograph withdraws to the hood, returning to a safe de-energised mode, the connectors are also live only when the train is at the station. In addition, the physical geometry of the system ensures that the correct contact is always made to prevent overheating or sparks during high-power charging.
The RailBaar charger works on either low voltage or medium voltage AC power supply, with output voltage in the range of 500 to 1000V DC (depending on internal voltage of the rolling stock). The system has a capacity of up to 1200kWH to provide ultra high power charging and to allow trains to receive an ultra-fast charge when waiting at the platform. The battery can be charged fully at end stops with top-ups at intermediate stations if necessary. The charging time to 100% capacity varies from 5-30 minutes depending on the battery size. For example, on a 3 coach train, a 650kW charger can add up to 65km of range in 6 minutes. The range of travel is dependent of terrain, stoppage time and battery size, and typically varies from 30 to 65km, with speeds up to 120 km/h. With the RailBaar charging station, a battery-powered electric train can run 24 hours a day with only a few minutes of charging required at charging stations. Additionally, braking energy is recovered and stored in the batteries, further saving energy.
Batteries can also be used inside the Railbaar charging station to lower peak grid demand during charging. This can be important in places where the grid can become overloaded at certain times, for example Tea Time in the U.K. It is also possible to connect local renewable energy to this battery storage and time shift this electricity to peak travel times.
The charging system’s versatile design can integrate with road and rail transport to create a multi-modal transport network. The mechanical lowering contacts are able to charge buses, trams and rail vehicles, with auto adjustment to different vehicle heights. The charging stations are also interchangeable throughout the transport modes of the network, without need for design modifications. Buses and trams can use the same charge station. Common electrical infrastructure can be used at interchanges reducing costs. The charging infrastructure can also be used by refuse trucks or delivery trucks during times that it isn’t used by the public transport. Also, the charging station concept is flexible and makes extending transport network routes easy through modular design. Networks can grow with strategic placement of further charging stations.
The technology also offers substantial potential savings compared with conventional overhead line electrification. The estimated cost of installing the mechanical and battery infrastructure along with two RailBaar charging stations on a prospective 20km installation is around a sixth of the similar cost of installing overhead electrification, excluding rolling stock upgrades. An existing diesel unit can be converted to a battery powered train at a much lower costs with a payback time of just over 3 years. In addition, by eliminating diesel engines or electric traction equipment, the weight of the train is dramatically reduced, improving performance and capacity. Long lifetime LTO batteries typically last over to 10 years on 15-charge cycles per day.