Fuel cell systems and hydrogen have significant potential but also face challenges. Fuel cells can be highly efficient energy converters with no side emissions besides water. They come in a modular form and can be customized for different applications. However, widespread adoption faces uncertainties around fuel infrastructure and the need for lower costs. Different fuel cell types are being developed for applications such as transportation, portable power, and stationary power generation. Improvements in areas like membrane performance, catalyst loading, and manufacturing costs will help fuel cells reach broader commercialization.

1. Fuel Cell Systems and Hydrogen: Now and the Future Christopher Hebling, PhD Fraunhofer-Institut for Solar Energy Systems ISE Heidenhofstr. 2, 79110 Freiburg, Germany [email_address] Freiburg, 13 th June 2007 Local Renewables Freiburg 2007

2. Modularity of Fuel Cells 11 MW 250 mW 5 kW 100 kW 250 kW 250 W

3. No side products during energy conversion other than electricity, heat and humidified air Intrinsic features and desirable properties of fuel cell systems Uncertainties Fuel infrastructure not clear and thus, not installed yet High efficiency energy converters (conversion efficiency up to 50% el and 80% tot ) resulting in high power density systems Separation of power and energy enables customization of formfactor and energy capacity aimed for Competitiveness with existing converters (batteries, internal combustion engine, turbines, etc.) in terms of: cost, reliability, safety, conversion efficiency of total system, consumer acceptance, etc.

4. How fuel cells work © www.bigs.de

5. Functional Units of Polymer Electrolyte Membrane Fuel Cells, PEMFC Anode Cathode Membrane Electrode Assembly Flow Field / Bipolar Plate Diffusion layer

6. Design criteria for fuel cells systems - Point of Operation of stack and overall system - Pressure level and pressure drop in case of hydrogen - Hydrogen or reforming of hydrocarbons or alcohols - Water management, recycling of water in case of methanol - Heat management, cooling, co-generation of heat and power - System dynamics, quick-start, cold-start capability - BoP: valves, vents, compressors, pressure reducers, pumps, etc. - Power conditioning, high-efficiency DC/DC conversion, DSP proc. - Cost-effective production of stack, peripherals, system

7. Specific Energiy Density of Fuels (without container)

8. Fueling concepts Hydrogen best suited fuel in terms of perfomance Hydrogen is emission-free at the tail-pipe Hydrogen provides the opportunity of creating an energy hub Hydrogen is encumbered by production and storage Reforming enables fuel cell systems to fit into the existing fuel infrastructure Reforming is mandatory for auxiliary power units Requirements for system dynamic limit application for traction Desulfurization required Direct fuel cells qualify for smaller applications due to low power density Direct methanol or direct ethanol fuel cell are under investigation Simple systems and high storage density enable early market entrance Only make sense when neat alcohol is used

10. Linde AG Linde AG ISE ISE Battelle Scalability of reformers Hydrogen generation in Nm 3 /h Industrial reformer Decentralized H2-generator Industrial CHP Reformer for APU CHP Reformer for portable systems Reformer for micro systems 100.000 1.000 10 1,0 0,1 0,01 10.000 100 Fuel cell power in kW 1,0 0,1 0,01 10 100

11. Scalability of electrolyzers ELT Hydrogenics Hydro Accagen Largest units: Assuan-dam / Egypt 156 MW el (33000 Nm³/h), Cuzco / Peru: 22 MWel (4700 Nm³/h) Smallest unit: ISE 4l/h (gasochromic windows) ISE Kathode Anode 0,5 O 2 H 2 H 2 O H 2 O OH - KOH KOH

12. Fuel cells early markets Production and logistics Consumer - applications Automotive Small traction Building automation Medical technology Robotics

14. Summary Fuel cell systems are on their way Major issues: - improved membrane performance - reduced catalyst loading - compound bipolar plates - cost reduction of materials and production - availability and reliability of peripherals - standardization, customer acceptance Due to intrinsic advantages of fuel cell systems the market potential seems tremendous Different early markes such as off-grid and portable FC are being addressed in the US, Asia and Europe, long term goal is transport Hydrogen technology and fuel cells will play an important role in a decentralized solar energy economy