Railroads are about to take a leap forward in technology as the first energy storage system that runs on supercapacitors is installed in the US.
Siemens is installing the technology on the new TriMet Portland-Milwaukie Light Rail Transit Line in Portland, Oregon. The line opens in 2015, expanding the system to 60 miles and 97 stations.
There will also be bridge for light rail trains, pedestrians, cyclists, and the future, Portland Streetcar:
The southeast Portland Tacoma substation will house a unit that stores energy created through braking and then re-uses it either to send energy to the grid or for voltage stabilization during peak demand times. TriMet will use the system in voltage stabilization mode.
In voltage stabilization mode, Siemen's Sitras SES prevents problems that have caused disruptions in mass transit operations. The system maintains steady voltage even if a number of locomotives accelerate simultaneously, which previously caused voltages to drop below critical levels, disrupting service.
In energy savings mode, the energy storage unit absorbs the energy generated by braking and stores it until the system can safely feed it to the grid as trains accelerate.
Maxwell Technologies (Nasdaq: MXWL) is supplying the ultracapacitor units, which will be attached to the roof. It is expected to save 2.8% of energy a year.
TriMet got a $4.2 million grant for the project from the Department of Transportation's TIGGER program (Transit Investment for Greenhouse Gas and Energy Reduction) to improve the efficiency of its 100 light rail vehicles.
In Spain and Germany, these energy storage units cut energy demand at Cologne Transit Authority substation by 15,000 kWh in one month. The use of just a single energy storage unit could save 500,000 kWh per year, says Siemens.
Last month, we reported that Amtrak is getting 70 new electric locomotives, Amtrak Cities Sprinters, to serve the Northeast corridor starting this fall. Also built by Siemens, they have similar capabilities but do not use ultracapacitors.
Amtrak's CEO, Joseph Boardman, calls it the "rebirth of rail manufacturing in America," because almost all the parts are made in the US. Siemens, which makes about a third of North America's light-rail vehicles, produces them at its Sacramento, California plant, which is powered by renewable energy. Parts are being supplied by about 70 suppliers across 23 states.
35 light rail systems operate in the US and 13 more are being built, making light rail is an increasingly important method of transportation.
Los Angeles is taking a slightly different approach, using flywheels to capture the energy created through regenerative braking and using it for acceleration. Philadelphia is also using trains that send regenerative energy back to the grid.
Ultracapacitors have been under development for some 30 years and are finally taking off. Their use is expected to grow from just $28.2 million in 2011 to $284.1 million by 2016.