GE's Two-Battery Strategy for Fuel-Cell BusesDesign effort could make fuel cells practical while pushing the state of the art in hybrid propulsion for all kinds of vehicles.
Hydrogen fuel cells are still too expensive to be used widely in
vehicles, so researchers at GE are taking a different tack: they're
slashing the size of the fuel cell to a bare minimum while relying on
two distinct kinds of advanced battery technologies to deliver the
necessary horsepower under a wide range of driving conditions.
The technology is essentially an advanced version of today's hybrid-vehicle technologies. While GE is developing it to make a cheaper fuel-cell bus, the resulting technology could be applicable to diesel or gasoline hybrids too--and could make it into cars someday. GE's effort, which will draw on advances in other hybrid projects at the company, is scheduled to produce a prototype in three years. An existing generation of demonstration fuel-cell buses is now three to four times more expensive than ordinary buses, which, along with the necessary hydrogen fueling stations, makes them too expensive to be practical. But in terms of adopting hydrogen as a fuel, buses do hold clear advantages over cars, says Bill Van Amburg, senior vice president of Weststart-Calstart, a not-for-profit organization currently developing fuel-cell buses. A city bus can been filled at a central location (requiring less infrastructure) and has far more room on board to store hydrogen. To address fuel-cell cost, which comes largely from the use of expensive catalysts such as platinum, researchers at GE's labs in Niskayuna, NY, are drastically reducing the size of the fuel cells, which are "by far the most expensive component of the bus"--significantly more expensive than batteries, says Vlatko Vlatkovic, a leader in electronics and energy-conversion research at GE. For the horsepower needed for acceleration or high speeds, the bus will instead rely on advanced battery technology. In fact, GE will use two kinds of batteries to do distinct jobs: one for the big bursts of acceleration power essential to getting the bus moving from a dead stop, and a second for storing lots of electricity to supplement the fuel cell during high-speed or uphill driving. As with hybrid cars, the power for these batteries would come from energy recaptured during braking and from excess charge from the fuel cell. For the first job, GE researchers are evaluating new high-power, yet safe, lithium-ion batteries from A123 Systems, whose batteries are now used in a line of professional power tools (see "Safer Lithium-Ion Batteries"). A123 researchers are redesigning their batteries for the much larger packs needed in buses. Vlatkovic says that the company is also considering ultra-capacitors, another type of energy-storage device that can take in and deliver charge very quickly, although it can't store as much energy as a battery.
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Next Stop: Ultracapacitor Buses
10/19/2009
Massachusetts Institute of Technology
Comments
SVE
11/02/2006
Posts:48
You can burn the Natural Gas in a hybrid engine or use it in a Fuel Cell hybrid. Either way would be more efficient that the non-hybrid natural gas-powered buses that are in use today.
JJP
11/02/2006
Posts:1
Don't you think petroleum was more expensive to harvest than wood was some 100+ years ago. Yet here it is today as our primary fuel of choice. Go figure.
As I have stated many times before, hydrogen should not be our only choice as an alternative, but it certainly should not be ruled out at this point in time. We would be foolish to blind ourselves to possible alternatives, hydrogen or otherwise.
Not only that, but the article states that other fuel sources are being investigated.
Quote:
"Vlatkovic says the effort could be a huge boon to all kinds of hybrid vehicles. "The prime source of energy can be, in principle, anything," he says. Instead of a small fuel cell, GE could use a small advanced diesel engine running on renewable biofuels or equipped to get the most from new ultra-low sulfur diesel"
ny_rebel
11/03/2006
Posts:3
There is also the magnesium metal-air battery — a battery that is ‘refueled’ in a few minutes by filling with fresh electrolyte. The spent electrolyte is recharged at the filling station using electrical power — which is an interesting way of using the electric grid to make vehicle fuel.
The overall advantage of electric propulsion is that an electric drive train is cleaner and more efficient than other propulsion systems. The capture of electric power from regenerative braking can best be accomplished when part of the power storage capacity is ultracapacitors.
The question is, “What is the best way to implement electric drive in a vehicle — to achieve a 250 mile range, a short refuel time of less than five minutes; and reasonable acceleration and speed."
Hybrid electric vehicles (HEVs) can do this — but are only incrementally more energy economical than a vehicle with a conventional combustion engine power train.
A plug-in hybrid electric vehicle (PHEV) has the great advantage of being able to use grid power for all short trips. All it needs is an extension cord — and the addition of advanced-technology deep cycle traction batteries.
The on-board power plant of an HEV or a PHEV can be either a combustion engine or a fuel cell. Examples of fuels that can be used include LPG, CNG, ethanol and methanol — all of which can be used by both combustion engines and fuel cells.
Methanol can be synthesized from non-petroleum sources; and ethanol can be synthesized from cellulosic materials like wood waste, fast growing willow and poplar.
Another power storage option is being commercialized in Scottsdale, Arizona by www.alchemy-energy.com
It’s a mechanically refuelable battery. Electrochemical fuel can be fed into the battery, allowing a high surface exposure of the electrochemical components.
Alchemy licensed the technology from NASA’s Jet Propulsion Laboratories in March 2006.
Alchemy refers to their battery as an electric power cell. It functions by pumping an electrolytic liquid — consisting of the common base-earth metal magnesium, in salt water — into the power cell. There it is catalyzed by air and exchanges electrons that generate electricity. The electricity is then used to power, for instance, the electric drive motor(s) of a vehicle. The spent fuel remains on board the vehicle.
At the refueling station, fresh fuel is pumped into the vehicle tank and the spent fuel automatically pumps back into the fuel station system. The station uses electric power to revitalize the spent fuel. This process makes the electric power cell a clean, environmentally friendly, re-usable electrical power storage technology.
Alchemy’s magnesium metal-air electric power storage is initially being built into buses. The technology is also intended to be used in cars — to provide power and range similar to vehicles with internal combustion engines.
Another application for Alchemy’s refuelable magnesium metal-air batteries is for stationary applications; including long term storage of electrical power for on demand or emergency use. Shelf life expectancy is tens of years, far exceeding any other energy storage system currently known.
US patent: publication application number 20050031938 for a rapidly rechargeable electric power system has some elements of the technology currently described by Alchemy Energy.
The future of transport is in alternatives to petroleum where the ‘fuel’ can be produced efficiently from a variety of energy sources. It’s about choosing energy carriers where the energy conversion — in and out of the carrier — is as efficient as possible.
Electrical power is a good energy carrier; as is methanol; and hopefully, so is Alchemy’s magnesium metal-air power cell.
Phil Jones
11/04/2006
Posts:2
jacklig
07/21/2009
Posts:2