As previously noted, kinetic energy reclamation would seem a needed enhancement in the transport of freight by rail and road. This blog has gone so far as to suggest gathering and reusing kinetic energy from rail transit could occur not only by electricity generated when electric motors become generators while being used for braking, but also from application of Bose Suspension on railroad cars.
Now Green Car Congress relays an announcement from the US Federal Transportation Administration. The FTA is soliciting proposals for the demonstration in rail transit of 1) regenerative braking and 2) energy storage technologies (on-board or/and wayside). Total funding available for the project is $300,000.
There are a total of 11,110 heavy rail vehicles and 1,645 light rail vehicles in revenue service across the US, according to 2007 APTA Public Transit Factbook. Respectively, they consumed an estimated 3,768,605 MWh and 570,718 MWh of electricity annually. A substantial percentage of the life cycle energy use is for the operation of the rail vehicles, particularly the propulsion system.
Rail systems have the potential for recovering substantial amounts of lost kinetic energy through regenerative braking of rail cars. Recovered energy can be directed to the third rail or catenary to be used by nearby trains, or stored in on-board or wayside energy storage devices.
Regenerative braking combined with energy storage technologies could increase the efficiency of rail propulsion systems by substantially reducing energy losses.
The selected proposal will need to include a transit agency operating an existing rail system. The project partners shall work with the transit agency, or vice versa, to identify and select the technologies to be retrofitted to the existing rail transit system, make any adjustments to operating procedures, safety standards and guidelines, install the system, conduct training, and perform and evaluate the system demonstration.
Proposals must be submitted electronically by 3 October 2008.
As just one recent example of a regenerative braking approach, UK train operators Southern and Southeastern earlier this year became the first train operators in that country to introduce regenerative braking on the third rail DC network. The first Class 375, 377 and 376 Electrostar trains return electricity back into the rail system when braking. Any other train in close proximity will benefit from the electricity transferred back to the third rail.
Southern and Southeastern worked with Booz Allen Hamilton, Bombardier (the train manufacturer), Network Rail and the various safety approval bodies to develop a design solution that would not impact the safe and reliable operation of the railway. The principal technical challenge was to ensure that significant levels of energy were regenerated without impacting the ability of Network Rail’s power supply system to work reliably and to detect faults.
This was resolved through the joint design of train protection settings, detailed modelling of the behavior of electrical sections on the Southern network, and the completion of a comprehensive infrastructure testing program.
GCC commentator HarveyD asks, “What’s new here? Subway cars have been equipped with similar systems for many years.” And, I added that it would seem somewhat short-sighted to restrict innovation only to recovery of lost kinetic energy through regenerative braking. The real challenge is efficient storage and transfer of the energy when transfer must be delayed.