Small Fuel Cells for Portable Applications
Fuel cells are used to produce electricity and are more advanced and energy-efficient technologies than combustion engines, which burn the fuel. Fuel cells operate according to the principle of electrochemical reactions and therefore they function completely different than combustion engines. Figure 1 shows the basic principle of the electrochemical reaction.
No customer reviews
The fuel cells generate the necessary electricity on board. In portable applications, such as laptops, Direct Methanol fuel cells DMFC provide the required electricity and avoid the need to plug the appliance to the electricity network for recharging. A key feature of the PEM fuel cell is its electrolyte, an organic polymer that is formed into a solid membrane.
The organic polymer is mostly based on perfluorocarbon sulfonate, with Nafion being the most common material for the membrane.
The main bottleneck for a widespread application of fuel cells are the high costs of the technology. Infrastructure availability is another important prerequisite for the use of PEM fuel cells in transport applications. PEM fuel cells require high purity hydrogen which is not available everywhere. High purity hydrogen can be produced directly by electrolysis, but at relatively high costs. Traditional processes for hydrogen production such as steam methane reforming SMR need to be complemented with a purification step in order to produce the required level of purity.
Delivering hydrogen to petrol stations would require a network of pipelines, which does not yet exist, although hydrogen is already transported in pipelines for industrial applications. Alternatively, hydrogen cylinders could be transported by trucks, or petrol stations could have small on-site hydrogen production and storage facilities.
For portable applications, liquid methanol can be transported or sold to end-users in small bottles. In that case, the fuel cell requires only a small recipient to store a certain amount of alcohol. Although some stationary applications exist for this technology, most PEM fuel cells are used to provide electricity to portable items and different types of vehicles. Figure 3 : Planned launch dates for fuel cell vehicles by manufacturer Crawley, Figure 4 : Share of DM fuel cell units installed by application and total number of installed units Crawley, PEM fuel cell systems are more efficient than internal combustion engines.
The overall CO2 balance, however, depends mostly on how the required hydrogen is produced.
Micro Fuel Cell Companies to Watch
Automotive manufacturers are interested in fuel cell technology because it is a "next-generation" technology that could have fuel reproduced from local sources and low or zero emissions. Fuel cell vehicles usually use compressed hydrogen as the fuel type, although several manufacturers have also demonstrated a fuel cell vehicle with methanol. Automotive fuel cells can have one or more of the following:.
Buses have successfully demonstrated the use of fuel cells for transportation purposes into the commercial vehicle market.
The difference between buses and automobiles are the power requirements, space availability, operating regimen, and refueling sites. Buses require more power than automobiles and get more wear due to constant stops and starts. Large quantities of hydrogen can also be stored on-board buses easily because of the available area of a bus.
Fuel cell buses have an advantage over diesel buses because they have zero emissions. This is critical in heavily populated and polluted cities. Many bus manufacturers began demonstrating their first fuel cell buses in the early s.
CORDIS | European Commission
Like the fuel cell automobiles, the fuel type most often used is compressed hydrogen, although methanol and zinc have been demonstrated. Utility vehicles have been a successful early adapter of fuel cell technology because the competing technology for these vehicles is often lead-acid batteries which require maintenance and charging.
Demonstrations of fuel cell utility vehicles show that they offer lower operating cost, reduced maintenance, lower downtime, and extended range. Fuel cell—powered utility vehicles can also be operated indoors because there are no emissions.
Products related to this article
Utility vehicles that can be powered by fuel cells are forklifts, golf carts, lawn maintenance vehicles, airport movers, wheelchairs, unmanned vehicles, boats, small planes, submarines, small military vehicles. The first fuel cell utility vehicles were demonstrated in the early s. Like the fuel cell automobiles, the fuel type most often used is compressed hydrogen, although methanol, metal hydrides, and sodium borohydride have also been demonstrated.
In countries with large populations, scooters, and bicycles are popular forms of transportation. Fuel cells have been positively demonstrated for these applications with compressed hydrogen and methanol.
Fuel cells for mobile applications
Hydrogen storage is still an issue for these vehicles; therefore, metal hydrides and electrolyzers have been researched during the last decade. Many manufacturers demonstrated their first fuel cell scooters and bicycles in the early s, which is later than many of the fuel cell automobile and bus demonstrations. Like the fuel cell automobiles, the fuel type most often used is compressed hydrogen, although methanol, metal hydrides, and zinc have also been demonstrated.
Fuel cells for stationary applications have been used commercially for over twenty years. The main difference in these fuel cell systems is the choice of a fuel cell and fuel and the heating and cooling of the stacks. Stationary fuel cells can be used as a primary power source.
It is often used to power houses that are not connected to the grid or to provide supplemental power. In hybrid power systems, fuel cells can be connected to photovoltaics, batteries, capacitors, or wind turbines, providing primary or secondary power. Fuel cells can also be used as a backup or energy power generator providing power when the grid is down. A standalone system may require another source of energy for peak periods. These can be batteries and supercapacitors, or a combination of both. Many manufacturers began demonstrating their stationary power stations in the s.
Unlike other fuel cell applications, the fuel type most often used is natural gas. Other common fuel types are propane, compressed hydrogen, bio-gas, methanol, oil-based fuels, town gas, synthesis gas, digestor gas, and land fill gas. The United States, Germany, and Japan have the greatest number of stationary fuel cell power stations. Fuel cells for portable, backup, automotive, or stationary power applications have been demonstrated, and there are some fuel cells commercially available in these categories.
The fuel cell design such as power output, heat balance, efficiency, size, weight, and fuel supply may be slightly different for each application, and must be customized to suit the required load. She previously owned Clean Fuel Cell Energy, LLC, which was a fuel cell organization that served scientists, engineers, and professors world-wide. Fuel cells are electrochemical devices that convert chemical energy from the reactants directly into electricity and heat.
The device consists of an electrolyte layer in contact with a porous anode and cathode on either side. Hydrogen has many unusual characteristics compared with other elements. Some of these interesting and unusual characteristics include This boost of human and financial investment has been beneficial to the development of other PEMFC applications, and not only transportation. This has made them of more than academic interest, and has provided financial resources for more extended testing and exploration of new markets.
Consequently, the use of PEMFC units for portable and small stationary applications has rapidly increased over the last few years as these sectors have begun to expand and are currently enjoying a strong period of growth cf. This has also helped contribute to development programmes as market pull starts to match technology push.
PEMFC applications and perspectives. Since its first commercial development in the s, the PEMFC technology has known a continuous evolution. Due to a short startup time, reduced material strain, and lower requirements on thermal insulation and security than high-temperature fuel cells, PEMFCs have found potential markets mostly in transportation including niche applications; light duty vehicles and buses, small and large stationary applications and portable sources cf. Application of fuel cells section. Today, about two-thirds of the installed PEMFC units are being used for portable applications, because this market is the most developed and the closest to reaching commercialization of all the sectors.
Moreover, the interest for portable applications is likely to grow in the near future as hydrogen storage solutions will become commercially available. Off-grid power generation, which promotes this technology, is currently enjoying a reasonable growth. The U. Department of Energy DoE is also leading a consortium involving industrial and academic research in the fuel cell and hybrid vehicle field for longer term operating, cost, weight, and efficiency targets.
The goals include the development of high-temperature PEMFCs, low cost stacks and manufacturing processes, improvement of performance, and the first commercialisation of combined heat and power CHP units.
The JTI is an industry led public-private partnership, which coordinates the implementation of industrial research, demonstration projects at an appropriate scale to validate research results and provide feedback. It also leads cross-cutting and socio-economic activities including infrastructure issues in order to get a rational basis for future policies and support the future broad market introduction of fuel cell and hydrogen technologies. The JTI is updated on an annual basis. A joint-agreement has been signed between Nippon Oil and 5 other Japanese firms at the beginning of in order to create a nationwide dealership network and launch the commercialization of the Ene Farm home-use fuel cell system to individual customers.
Other emerging countries, e. India , may undertake similar subsidy programmes thereby boosting the number of installed PEMFC units worldwide. However, whilst the automotive sector provides the most significant potential for PEMFC systems as the unchallenged technology for powertrains in future fuel cell vehicles FCVs , it will likely be the last one to reach full commercialization, and obviously not in the short term.
Development and demonstration programmes with car and bus fleets are ongoing but the actual number of FCVs on the roads is still quite low.
Many of the automakers, which manufacture their own stacks, are likely to be producing PEM units. In the timetables, today sounds a realistic date for FCVs, still with caution yet! The future of PEMFCs is really promising as the technology can be adapted to several key markets spanning growth opportunities over the short portable , medium stationary , and long term transportation timeframe. Current research shows that the main causes of short life and performance degradation are poor water management, fuel and oxidant starvation, corrosion and chemical reaction affecting cell components.
Operation under dehydrated conditions could damage the membrane, whereas flooding favors corrosion of the electrodes, the gas diffusion media and the membrane. Corrosion products and impurities from outside e. Thermal management is particularly important when the fuel cell is operated at sub-zero and elevated temperatures and is key at cold start-up and when subjected to freezing conditions cf.
However, challenges remain to make them competitive with traditional power sources. Cathode losses with current materials are too high to meet the targets of the U. Department of Energy. Insufficient stability due to platinum dissolution and carbon corrosion is of particular concern under dynamic operating conditions and must be addressed.
The current state of the technology is such that Nafion is an acceptable material for steady state operation and low duty cycle applications. For more demanding systems such as automotive applications, important membrane and electrode issues do exist. The water management due to high membrane humidification but no-flooding requirement is a central issue and significantly adds to the system complexity, weight, size and cost.
The overall goal is towards simplification, cost decrease and high reliability.