Fuel Cells, and in particular Solid Oxide Fuel Cells (SOFCs), are suitable for a number of applications that utilise heat.  As the SOFC operates at high temperatures (approximately 800 degrees Celsius) there is a significant potential for other technologies and applications to recover some of the ‘waste heat' from the fuel cell to increase the overall efficiency of the unit. 

As CFCL strives to increase the electrical efficiency of the fuel cells -less and less heat becomes available for recovery.  Depending on heat requirements, most appliances requiring coupled heating devices may therefore need an auxiliary burner.

Combined Heat and Power

SOFCs are best suited for CHP units using high-efficiency condensing boilers - as the heat generated by the fuel cell can be used to preheat the water.  Additionally all the connections required by high-efficiency condensing boilers are also utilised by CFCL's SOFC system - that is, natural gas, water and of course electricity.Combined heat and power (CHP) systems have the ability to produce electricity and heat energy in a single integrated unit.  This is in contrast to separate production of heat energy and separate production of electricity through a generation, transmission and distribution network.

The waste heat, or thermal energy, from the fuel cell recovered in a CHP system can be used for heating or cooling.  Because CHP captures the heat and uses this on site - the total efficiency of a CHP system is higher than traditional methods.

Combined Cold and Power

In hotter climates such as Southern Europe, Australia, South and South East Asia and parts of the US, cooling is more important than heating.  In the past absorption chiller technology was only available at scales greater than 100kW as absorption chillers were bulky and inefficient.  However, over the past few years smaller chillers (4-10kW) are being developed and in the demonstration phase mainly driven by solar thermal energy.  This technology is suitable for residential application, but even the smallest units require a heat source of about 10kW and thus are more suited to SOFC generators of 10kW and larger. 

Air Circulation & Dehumidification Systems

In more moderate climates, refrigerated cooling is not the prime requirement.  A comfortable living climate could be created by removing humidity from the air.  Coupling the SOFC generator to a dehumidifier device (e.g desiccant wheel) for regeneration of the absorption medium could be an interesting integration option also for small residential systems.  As modern houses are becoming more energy efficient through better insulation and heat sealing, air circulation systems with heat exchange of incoming with outgoing air are becoming an integral part of the energy management of efficient buildings.  Dehumidification could be easily incorporated into such systems.  In such, buildings with a working air circulation system is essential for living comfort and an SOFC generator provides the additional benefit of operating the system during mains power failures.

Remote Area Power Supplies (RAPS)

This is another distributed generation application needs to be configured for off-grid remote locations and requires outputs of a kilowatt (single dwelling) to hundreds of kilowatts (larger settlements).  Firstly, being the only power source it may be essential to provide electricity storage for short term peak demands, Secondly, the unit needs to be operated on an easily available fuel in the remote location.  The prime fuels currently supplied to remote locations are Diesel and LPG (propane), but bio-fuels (ethanol, bio-gas) could also be of interest for RAPS applications. 

CFCL's fuel cell operate on a methane fuel, and CFCL has shown that fuels such as LPG and ethanol can supply a methane rich fuel stream using a simple pre-processor.  The use of SOFC RAPS systems due to their high efficiency would results in significant fuel savings both a financial and logistics advantage.

Auxiliary Power Units (APUs)

High efficiency, fuel flexibility and scalability of SOFC technology make it an ideal candidate for this application.  The specifications for this application are approximately 3 to 5kW, 42 VDC, 50 kg and 50 litre and price projections range from USD 200-1000. Depending of the application fuels considered are Diesel, LPG, petrol and JP-8 (a military logistics fuel).  Large market potentials have been forecast for APUs in long-haul trucks and busses for supplying air conditioning and other electrical services (communication, cooking, entertainment) without the need to idle a large Diesel engine resulting in substantial fuel savings.

See the Institute of Transport Studies for more information.

Secure Power for Telecommunication

The high costs to businesses due to loss of telecommunications have resulted in complex power back-up systems should the grid supply fail.  This is a high value application replacing expensive infrastructure.  However, the equipment needs to demonstrate high reliability.  Considerations have been given to reverse the common model - mains grid supply and back-up (Diesel genset + UPS) in case of grid failure - by using the SOFC generator as the constant power source backed up by the grid in case of generator failure (this would provide similar security as the current supply infrastructure).  The advantage of an SOFC generator over other technologies include; fuel flexibility and the high electrical efficiency - as leading to cost savings.