Fuel Cell Power Generation Primer - Part 3
The Fuel Cell Cometh
Until recently, the fuel cell was far too costly to compete with the grid, even when more than half of our generation was from coal fired steam turbines. Even when the steam turbines had an average efficiency of 33% at the busbar and only 27.5% at the residential meter. In the last two or three years, the costs of making the electrode assemblies, which are at the heart of the fuel cell, have plummeted. There are no scale economies in individual fuel cell stacks but there are great scale economies in their manufacture.
With the present technology one can estimate their costs when manufactured in large volumes. Based on those estimates there are several companies which have commenced field trials and are on the brink of commercialization.
It was Ballard Power Co., a Canadian company with headquarters in Vancouver, BC that has led the wave of innovation and development. Its target is to replace the internal combustion engine powering the family car. The internal combustion engine costs about $35 - $50 per horsepower to manufacture. A cost of $35 per horsepower is equivalent to $50 per kw.
Therefore, the internal combustion engine is a much harder target to displace than is the base load coal fired steam turbine with capacity costs of $1000 per kw (with only limitedair pollution control). The rise of the aeroderivative gas turbine and combined cycle made the cost of stationary generation a moving target, reducing the cost of base load generation to some $500 - $900 per kw but with turbines that, instead of lasting 30 years or more, will only last about five to seven years in base load service.
With an internal combustion engine cost of only $50 or so per kw, you will have to wait until 2004 or 2005 before you see a fuel cell powered car show up in your dealer's showroom and maybe 2010 before you see many of them on the road.
If you want to sell fuel cells, the existing grid stationary electrical power supply costs of $1000 per kw for steam turbines, and even the cost of new aeroderivative gas turbines and combined cycle systems of $500 to $900 per kw are easier to beat than the $50 per kW cost of mechanical power for car engines.
You can offset some of the stationary capacity costs with fuel efficiencies and with the cogeneration efficiencies of on site generation. It also helps that there will be no electrical transmision or distribution losses and, indeed no costs for installing transmission and distribtion.
Finally, it helps that there will be improved reliability with a system of small fuel cells.
When you supply many small loads from a central point you don't need as much generating capacity as if you supply each one from an isolated plant. Supplying 10 kw single family peak loads from a central point may require only one or two kw of generating capacity per family because each one turns on his stove at a different time. Some are dining out. Some are on vacation during the summer with their air conditioners turned way down or even off.
The total capacity required to serve all of them is far less than the sum of the capacity to serve each one from an isolated system. Nevertheless, when the cost of the wires leading from the integrated generator to each load, without even including the cost of integrated generation, cost more than the on site generation, you know that the time for isolated generation is nigh.
The first fuel cell on the market, probably at the end of 2001, will likely be the molten carbonate fuel cell or MCFC made by a company called Fuel Cell Energy.
FCEL claims that its mature commercial modules of 300 kw will have an efficiency of 54%, its fifteen hundred kw system will have an electrical efficiency of 55% and its 3,000 kw sysem will have an efficiency of 57%. A utility can install one or more at existing substation sites tied to the low voltage bus. A residential developer can install one or more in a new residential single family subdivision. An MCFC can be installed to power a large apartment house and an office building.
If installed by a residential developer, an apartment house owner or office building developer, it will be installed close enough to the load so that its byproduct thermal energy can be used for domestic hot water, space heating; with a triple-effect-chiller its excess heat can be used for air conditioning.
With this cogeneration use its CHP or combined heat and power efficiency can be as much as 85% or more. The reason for its minimum size of 250 or 300 kw is that it has a large proportion of auxilliary equipment called its Balance of Plant which has some minor scale economies.
Its high stack operating temperature permits it to reform pipeline grade natural gas directly in its stack assembly and Fuel Cell Energy calls its product a "Direct Fuel Cell" for that reason. Five small modules were recently sold to the Japanese Marubeni Co. for $5,000 per kw but FCEL estimates that when it mass produces the fuel cell assemblies in volumes of 400,000 kw per year, its costs will fall to $1,250 per kw. Marubeni will be installing one of them at the Kirin brewery.
A German affiliate, Daimler Chrysler owned MTU in Fredrikshafen is projecting costs of only 1000 to 1200 Euros or about $900 to $1100 at the current rate of exchange. One half to two thirds of the investment, the Balance of Plant or BOP will have a useful life of 30 years and one third, the fuell cell stack must be replaced every 5 - 8 years as its efficiency declines. It will have the benefit of some load diversity but not as much as if it were installed on an integrated system.
The next fuel cell to reach the retail market, likely in 2003-5 will be the much smaller PEM fuel cell of PlugPower.
Plug's fuel cell will be distributed throughout most of the world by General Electric, but Detroit Edison Energy will distribute it in Michigan and in three adjacent states. It is a low temperature fuel cell, operating at about the temperature of your car radiator. Reforming natural gas to hydrogen in an external reformer uses up about one third of the energy of the system so its efficiency is only 40% for the first 2 kw of its 7 kw of continuous capacity. This is likely to generate 50% or more of the kilowatt hours used in a typical single family residence.
PlugPower was established as a joint venture of Detroit Edison Energy and a small company in Latham, New York called Mechanical Technology. It has entered into a distribution agreement with General Electric for its distribution with a few excepted areas. Its cost installed would initially be $10,000. With mass production its cost is estimated to fall to $3,000 or about $300 per kw.
The solid oxide fuel cell will likely be the third fuel cell to reach the market. It is being developed by a small company in Calgary, Canada called Global Thermoelectric. GLE.TO now manufactures thermoelectric generators which are of small output but extremely reliable and are used by telephone systems in remote areas, by natural gas pipelines for cathodic protection, and by companies in oil and gas exloration projects, all of which uses are remote from existing grids and can be relied on for reliable operation unmanned for months or years.
In addition to this market, the GLE.TO fuel cell in larger, 10 kw to 175 kw sizes can be used for supplying electric and thermal energy for residential and small commercial and industrial loads. Its design objective is a 60% efficiency but it has not yet released data on its current operating efficiency.
Delphi, the car parts manufacturer recently spun off General Motors, is working on a 42 volt auto electric system to replace the current 14 volt system. It contemplates using the GLE.TO fuel cell as the generator for the system because it can run on either hydrogen or gasoline. BMW and Renault are not as optimistic about the feasibility of a PEM fuel cell for vehicle propulsion until hydrogen is as available everywhere as gasoline is now. They contemplate using an internal combustion engine with dual fuels -- hydrogen, where it is available and gasoline when it is not.
The SOFC, which can supply auto electric power on either fuel, will complement its dual fuel design for propulsion and will have several advantages including being able to run your radio and air conditioner with your internal combustion engine not running, locating car auxilliaries where you could not locate them when belts and pulleys are required to supply mechanical energy, and using electrically actuated valves to carry out timing that would not be possible with belted power. It could shut off half the cylinders while cruising at highways speeds.
GLE.TO has not released cost data on its fuel cell but it needs no noble metals for catalysts as does the PEM fuel cell. Nor does it need extensive auxilliary devices or balance of plant (BOP) as does the PEM and the MCFC fuel cell.
Westinghouse, now owned by Siemens, is developing a tubular fuel cell which operates at 1000 degrees. However GLE.TO is developing an RTESP SOFC which is one operating at reduced temperatures of 650 to 700 degrees Centigrade which will permit it to use common stainless steel. Its electrolyte is ceramic and its electrodes are ceramic. These all seem to be low cost materials.
While GLE.TO has not released its estimated costs, its costs are likely to be lower than those of the other two. Instead of a large expensive external reformer such as that of the PEM fuel cell, its reformer is the size of a "knockwurst" and located within the stack assembly. Instead of roughly two-thirds of the cost in BOP, GLE.TO's BOP is largely the cost of an inverter to change the power to alternating current from direct current if that is needed.
The Fuel Cell as the Environmentalist's Dream
Last, but certainly not the least of the fuel cell's benefits is the benefit of clean air. The amount of Nox, Sox2 and particulate matter is an order of magnitude below even the proactive Federal Vision 21 standard.
If power is generated from reformed natural gas, however, the greenhouse gases problem will still exist but will be far less. Carbon dioxide emissions are a direct function of the weight of the hydrocarbon fuel used. But fuel cells, with their greater efficiency will use less fuel per mile and per kilowatt hour generated.
So with fuel cells, the amount of carbon dioxide emitted into the atmosphere will be only one half or one third of the carbon dioxide currently emitted by Carnot cycle devices such as the coal fired steam turbine, the gas turbine, the microturbine, the gasoline reciprocating engine and the diesel engine.
How about the Capstone 30 kw or Parallon 75 kw microturbines? They are not strong contenders in my opinion. They have a fuel efficiency of only 25% or so,They are noisy, and they pollute.
When fuel cells become available, which are able to compete with other alternatives on cost and reliability, the politicians are likely to act to set pollution standards so high as effectively to prohibit new Carnot cycle installations. In five years we will likely see this for loads of 10,000 kw and below.
The Department of Energy has contracted with FCEL to develop a combined cycle or hybrid fuel cell/gas turbine in the range of 10,000 to 40,000 kw with a blinding 80% electrical efficiency. When it is commercially available, perhaps in 2015, the combined cycle gas turbine will also become no longer necessary for even the largest loads and will take their place in books on the history of technology..
Look for some stationary fuel cells at your distributor commencing maybe as early as 2002 and some fuel cells in you car dealer's show room perhaps by 2004 or 2005. Look for large scale marketing of stationary fuel cells by 2005 and fuel cell powered cars by 2010.
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