APPLICATIONS WITH PROTON EXCHANGE MEMBRANE (PEM) FUEL CELLS FOR A DEREGULATED MARKET PLACE

Transcription

1 APPLICATIONS WITH PROTON EXCHANGE MEMBRANE (PEM) FUEL CELLS FOR A DEREGULATED MARKET PLACE Bernd KOHLSTRUCK ALSTOM BALLARD GmbH ABSTRACT: The electric utility is in a period of rapid change. The deregulation and restructuring of the utilities will lead to massive industry change with new structures of energy supply. This market s change creates a significant opportunity for fuel cells as on-site generation solutions. This paper considers the applications of Proton Exchange Membrane Fuel Cells (PEMFC) recent development, in particular for premium power applications, commercial distributed power plants, and for users of secure power supplies. The criteria to be considered is separated into broad categories namely, key features, electrical and system aspects, economics and emissions, and costs as well. PEMFC will, in the near future, be used in the automotive industry and also in distributed power supply. Due to its excellent dynamic characteristics, PEMFC can be used as emergency generating set for customer, who have special requirements for their critical equipment in case of power interruptions, harmonics etc. in the public electricity supply. This, however, requires the fulfilment of very detailed specifications concerning the grid connections. The bridging time is defined by the size of the hydrogen storage. The quality problems of normal electricity experienced by commercial and small industrial users have an impact on applications, which provide high quality. Reliable electricity is becoming increasingly popular. The use of this technology in housing areas for electricity and heat generation will be possible in the future, when the costs of production have been greatly reduced. General introduction to the market at a large scale is dependent on reasonable costs, and the chances for cost digression of PEMFC are higher through the use in various market sectors. ALSTOM BALLARD GmbH has started in June with the first 200 kw fuel cell power plant in Berlin, and in August with the second unit in Basel, which will be fuelled by natural gas and is used as a combined heat and power plant. This field trial program proceeds with further units in Belgium, France and Germany in The paper will end with a report about the first 200 kw PEM fuel cell power plants, which are in the field and will try to explain the way to approach the goals and what are the steps between.

2 APPLICATIONS WITH PROTON EXCHANGE MEMBRANE (PEM) FUEL CELLS FOR A DEREGULATED MARKET PLACE Bernd KOHLSTRUCK ALSTOM BALLARD GmbH ABSTRACT: The electric utility is in a period of rapid change. The deregulation and restructuring of the utilities will lead to massive industry change with new structures of energy supply. This market s change creates a significant opportunity for fuel cells as on-site generation solutions. This paper considers the applications of Proton Exchange Membrane Fuel Cells (PEMFC) recent development, in particular for premium power applications, commercial distributed power plants, and for users of secure power supplies. The criteria to be considered is separated into broad categories namely, key features, electrical and system aspects, economics and emissions, and costs as well. PEMFC will, in the near future, be used in the automotive industry and also in distributed power supply. Due to its excellent dynamic characteristics, PEMFC can be used as emergency generating set for customer, who have special requirements for their critical equipment in case of power interruptions, harmonics etc. in the public electricity supply. This, however, requires the fulfilment of very detailed specifications concerning the grid connections. The bridging time is defined by the size of the hydrogen storage. The quality problems of normal electricity experienced by commercial and small industrial users have an impact on applications, which provide high quality. Reliable electricity is becoming increasingly popular. The use of this technology in housing areas for electricity and heat generation will be possible in the future, when the costs of production have been greatly reduced. General introduction to the market at a large scale is dependent on reasonable costs, and the chances for cost digression of PEMFC are higher through the use in various market sectors. ALSTOM BALLARD GmbH has started in June with the first 200 kw fuel cell power plant in Berlin, and in August with the second unit in Basel, which will be fuelled by natural gas and is used as a combined heat and power plant. This field trial program proceeds with further units in Belgium, France and Germany in The paper will end with a report about the first 200 kw PEM fuel cell power plants, which are in the field and will try to explain the way to approach the goals and what are the steps between. 1. Introduction The electric utility industry is in a period of rapid change. Deregulation, liberalisation are introduced worldwide. Whole sale and retail wheeling are quickly becoming realities as legislation to end the energy utilities monopolies on the sale of electricity and gas as well. As a result of all this, there is a trend from central power generation and transmission towards customer related power supply or distributed power supply (figure 1). Trend from Central Power Generation and Transmission towards Customer-related Power Supply Figure 1: Meeting the Customer s Demands Current utilities, accustomed to captive consumers through regulated service territories, are entering a changed business environment as they face competition for customers. They have to supply a competitive advantage that will retain and hopefully increase their customer s base. They must also learn to keep the customers.

3 Figure 3: Reduction of CO 2 emissions, the ecological aspect Central Generation Premium Power - for highest power quality or or or or Figure 2: Applications with PEM Fuel Cell Systems 2. Strategic fuel cell market opportunities The vision has been promoted for the following strategic fuel cell markets (Figure 2): Cogeneration Stand-by or back-up power Premium power Households 2.1 Cogeneration plants Combined Heat and Power (CHP) capacity is growing rapidly throughout many European Union (EU) member countries. The private and public enterprises recognise its benefits as a flexible and economic energy source. Its high overall efficiency compared to separate generation brings a significant reduction in carbon dioxide (CO 2 ) emission and a more efficient use of fuel. Figure 3 shows the CO 2 effect by using a CHP plant compare to a conventional generation in a typical size of 800 kwel output power. The impact on CO 2 reduction is the same than the biologic impact of 300 ha forest. Many national energy strategies are encouraging tale up to CHP as a key part of international commitments to climate change initiatives. Existing, non-coupled heat and power CO 2 Stand-by Power - for highest availability 50% CO 2 Reduction Cogeneration - for highest economy & ecology 1200 kw th 800 kw el CHP plant CO 2 Overall efficiency η total = 87% Households - for your own benefit 375 Hectare Forest Increasing use of CHP does have other environmental implications. In particular, emission of nitrogen oxides (NO x ) and carbon monoxide (CO) can rise and specific legislation has been enacted in many countries to set limits for the release of these pollutants from CHP systems. CHP has an overall efficiency of around %. This is often around % greater than separate fossil fuel based generation and brings an accompanying reduction of % in primary fuel consumption and CO 2 emission. (Figure 3) But there are other emission impacts based on combustion processes, which have influences on human health like CO, NO x and HC. A standard, which could be seen as a benchmark for emission levels, is the German clean air code for gas engines. These emission levels stipulate in this code a relation to a condition when there is 5 % by volume of oxygen in the exhaust stream, then the limits are like as shown on figure 4. According to German regulation 650 CO 500 NO X HC 150 CHP-plant with today s state of technological development below 1 MW CO 250 NO X 250 HC Figure 4: Emissions (ppm) in relation to 5% CO 2, the environmental aspect. The PEM FC technology will approach a dramatic reduction of these limits and will open doors for politics to reduce them. A common problem of all cogeneration applications is to find users with such a big heat demand. This is one of the advantages of the PEM fuel cell. Moreover, as the fuel cell power plant is a high electrical efficiency generator, its relative back of waste heat may actually restrict its suitability for the classic cogeneration customer (Figure 5). 70 CHP with stationary PEM-Power plant CO NO X HC Numbers according to the German utilities association statistics Emissions in t/a The fuel cell power plant should be looked at the other way around. Rather than a heat source with some electricity, it is an electricity source, which can be used for cogeneration

4 applications. This opens doors and should increase the prospects for the above mentioned future markets. A system, which could open up new market opportunities, could therefore be extremely attractive, see figure 5. Electrical Efficiency [%] kw Figure 5: Fuel Cells, Expected electrical efficiency 2.1 Back-up 10 kw 100 kw 1 MW 10 MW 100 MW Power Generation Capacity Providing high availability of power is one method of creating value for electric consumers. In accordance to the necessities of such consumers the system for secure energy supply works with a stand-by function in case of grid failures. The components to achieve this stand-by power are an UPS (Uninterruptible Power Supply) and an EGS (Emergency Generating Set), see on figure 6. DC Power ~ 5 min. Battery Inverter I Inverter II grid Power for grid optimization Power for back up Fuel Cell Hydrogen H2- Storage or Methanol Tank 1 GW to the grid, in case of peak power demand or to the sensitive user, in case if the grid failers This is a sophisticated solution for utilities to optimise the grid and to serve customers with additional benefits. Using an electrolyser would recharge the storage. The combination of a fuel cell with metal hydrides and on-site hydrogen generation with an electrolyser will provide key benefits in terms of power reliability, no pollution by meaning of any exhaust system are required and safe operations. The total package should eventually be cost competitive for major market segments when all elements are factored in for existing solutions. 3. Plant concepts Figure 7 shows the schematics of a PEM FC plant. The operating temperature controls the conversion rate of the reformer: any remaining methane passes the following gas processing unit and the fuel cell unchanged. The reformer is then used to heat. The burner temperature is low enough to prevent the formation of nitrogen-oxides (No x ). A shift reactor after the reformer reduces the carbon monoxide content to 0,1... 0,15 %. The following selective oxidiser converts the CO nearly completely to CO 2. The residual carbon monoxide in the ppm-range has a considerable influence on the degradation of the stacks. If natural gas is supplied with a pressure higher than 7 bar, no additional compressor is required. In case of lower supply pressures, the required compressor reduces the overall efficiency by approx. 1 %. Using propane or butane (i.e. LPG) respectively, their residual contents in natural gas may be converted by the same arrangement. Reforming of diesel will be very unlikely within the next decade. Methanol or dimethylether, which may be used for mobile applications, are suitable for stationary power plants as well. Sensitive users Fuel of choice for 1-2 hours Figure 6: 60 kw PEM-based product for gridoptimisation and UPS-applications in Purge Nitrogen Compressor Start Clean-up Reformer Anode Vent Shift Converter Selecti ve Oxidizer Hydrogen Ri ch Gas Filter Air Coolant Filter Fin-Fan Cooler Fuel Cell Stack Coolant Circulation Pump Vaporizer DC Power In figure 6 is shown the PEM based fuel cell alternative concept. Sourced of two alternative storage concepts supplies a fuel cell power: Auxiliary Burner Turbocharger Cathode Exhaust Start Nitrogen Recycle Blower By-Product Water Start Air AC Power Water Trap Output Water Tank Feedwater Controller Inverter Pu mp Exhaust Turbocharger Air in Filter Fin-Fan Intercooler

5 Figure 7: Sketch of the process flow for the PEM fuel cell plant 4 Pilot project Figure 8 shows the pilot project, with which ALSTOM / BALLARD is going to enter in the market. The plant involves complete power systems for generating electricity from natural gas. All necessary components required to the mentioned applications are housed in a container with a volume of about 42 m 3. ALSTOM BALLARD s strategic development steps are strong depending on the success in the automotive applications, because of the synergies and the scale effects (see figure 12). The goal is to establish a manufacturing site to produce stacks for both directions: automotive and stationary by using same tools, machineries and materials. The differences should be only focussed on designs, because of the different lifetimes and efficiencies Jeep Commander Future Jeep Commander Targets Electrical Power: Fuel: Electrical Efficiency: Total Efficiency: max. therm. Power: Weight: Dimension: length width height Operation: Electrical Connection: 250 kwel Natural Gas 40% (LHV) 80% 237 kwth kg 6.1 m 2.4 m 2.4 m automatic, continuous 400 V - AC - 50 Hz Necar I Necar II Gasoline Methanol Hydrogen Figure 10: Development steps 1997 Necar III 1997 Nebus Future Necar Necar 4 Figure 8: Pilot project That means, stationary use is in the frame of automotive production, (figure 11): Cooling Compartment Steam Reformer Power Control System Fuel Cell Stack Humidifier Module Shift Reactor Module Electrical Compartment... in the stationary use Figure 9: P2B Fuel Cell Power Plant 5. Report about the experiences with Bewag and EBM Figure 11: Stationary use in the frame of automotive The Bewag plant s start-up was in June 2000 and the EBM s (Elektra Birseck Münchenstein) start-up was in October This report will give an actual overview about the first experiences with these field trial units up to June Development steps

6 In figure 12 are shown the development steps in the stationary field. The presentation will end with an explanation about ALSTOM s view and the strategies behind. ALSTOM will show the cost targets and as the result, the initial products to meet the targets. 220 kw Demonstration Plant Introduction of the Pilot Plant Delivery of the First Plant in Europe Introduction of the Next Product Generation Start of Series Production The Market Introduction is Tangible Figure 12: From the demonstration plant to the product