Hydrogen Cell Technology
HYDROGEN FUEL CELL PROPULSION FOR STREET CARS (cont)
At first blush, streetcars may not seem worth devoting much effort to. Many Americans think of them as a quaint anachronism retained by a few cities like New Orleans for nostalgia’s sake. But more than a dozen municipalities around the world have restarted and extended trolley car lines because they attract wealthier riders than buses and inspire new, high-density property development. What’s more, streetcars—because of the low rolling resistance of steel wheels on rails—require much less energy than the rubber-tired buses that elbowed them aside decades ago. For these and other reasons, says the American Public Transit Association, some 50 cities in the United States are planning new streetcar lines.
Choosing a streetcar design based on hydrogen could save such municipalities millions of dollars per kilometer, say advocates. A 2006 assessment found that roughly one-quarter of the total cost of a planned 16-kilometer rail extension connecting the city and surrounding suburbs would have gone toward installing a catenary system, according to Brian Nadolny, interim project manager for the Charlotte Area Transit System (CATS).
Transit operators are cautiously optimistic about hydrogen-powered trolleys. ”If the technology is proven viable, it could revolutionize the industry,” says Keith T. Parker, CEO of Via Metropolitan Transit in San Antonio. Parker explains that in addition to saving the installation cost of a catenary system and support poles, the operator would save the maintenance costs.
”The biggest issue with [hydrogen trolleys] is that there isn’t one on the ground and running, so municipalities don’t have anything to test that would allow us to make a decision about whether to purchase one,” says Parker.
Proterra, in Golden, Colo., may be the first to deliver a prototype. It makes a plug-in hydrogen-electric hybrid bus with a battery pack that can be fully recharged in 10 minutes. The bus can travel roughly 50 to 70 km between charges, enough for 2 to 3 hours of operation.
Proterra’s system carries more batteries than hydrogen-fuel-cell stacks, because the system can draw most of the energy it needs for a day’s travel from the grid, charging periodically at high-voltage links when the bus is in service and via lower-voltage connections when it’s out of service. Hill says Proterra hopes to demonstrate to Charlotte’s CATS system the potential for turning the bus into a pseudo-trolley by putting it on steel wheels.
”The more widely the issue is discussed now and the sooner a proof-of-concept hydrogen trolley system is formally demonstrated, the smaller the risk that transit systems’ investments in overhead trolley planning will be for naught,” says H. Stan Thompson, chair of the hydrogen economy advancement team at the Mooresville–South Iredell (N.C.) chamber of commerce.
Of course, hydrogen fuel cells aren’t the only way to untether trolleys. Bombardier’s German subsidiary has rolled out a system based on contactless inductive transfer of electricity to pickup coils on a streetcar’s undercarriage from cables buried beneath the track bed. Shanghai’s Sunwin Bus Co. has fielded battery-powered trolleys that quickly draw power every few stops, extending an arm hidden on the top of the car. And Kawasaki Heavy Industry’s SWIMO light-rail vehicle travels 10 km or more between stops on a 5-minute charge of its Gigacell batteries.
French firm Alstom pioneered the wireless streetcar movement with its
Citadis tram, which went into service in Bordeaux, France, in 2003 and
has cars powered by a segmented ground-level third rail. Only the segment
that is completely covered by a train is electrified.
By User from Mooresville, NC - Sep 19, 2009 12:40:58 PM ET
The Charlotte City Council voted on Monday night, September 14, 2009, to continue to fund planning for the town's first streetcar line. The line would pass through the center of the city, connecting two campuses of Queens University with Johnson C. Smith Univeristy, Johnson and Wales University and Central Piedmont Community College creating a university corridor as part of the city's new rail transit network.
The historic but unremarked implication of the vote is that the planning may be the first anywhere to weigh the possibility of a hydrogen hybrid wireless streetcar line.
In the last year or so there has been a surge in development in of wireless streetcar ("tram") technology in Europe and Asia. Unlike the USA, those areas have a large embedded base of overhead wire, externally powered rolling stock, much of which can be converted from overhead power to "crypto-catenary" systems.
These systems eliminate the continuous overhead catenary power supply by replacing it with intermittent charging points at passenger stops. From sources under or above the vehicle, power is taken aboard rapidly to reach the next charging stop.
The up-side is the ability to recoup much of the value of existing vehicles. The down-side is that the capital costs may be as much or more than a new catenary system.
By contrast, there is comparatively little embedded trolley plant in the USA, though over 50 new systems are planned. New "from scratch" wireless streetcar lines stand to be MUCH less expensive than external (overhead) systems: US$4.5- to $6.0 million per mile less.
There is general awareness of the high cost and aesthetic negatives of visible trolley wires. Much less visible, but perhaps of greater importance, is the electrically induced corrosion of buried water, sewer and other utility plant caused by the ground-return path for the overhead wire. For this reason, studying buried utility locations is the first major expense in planning a new streetcar line.
But when the electricity is stored onboard as hydrogen, there is no return path—no risk of exacerbated utility corrosion.
If Charlotte becomes FTA's demonstration site for wireless onboard streetcar power, pulling the plug on 120-year-old trolley technology, the national savings for 50+ new systems with (say) 10 miles per system at US$6 million per mile could be in the US$3 billion range, of which $1.5 billion would be saved by the US DOT/FTA.
If DOT/FTA applies just one percent of this (US$15 million) to a Charlotte hydrolley demonstration, the Federal Government may save a billion and a half dollars over the next several years. And urban dwellers may be spared the site of 500 miles of tacky, outdated aerial plant strung through American cities.
As the Institute of Electrical and Electronic Engineers' Spectrum Magazine said this month, the simplification could "power a streetcar revival."
click photos once to enlarge, twice for maximum enlargement.