integration of solid oxide fuel cells and ... - Ea Energianalyse

1. INTRODUCTION
1.4 SOFC
The fuel cell technology is a candidate for the future energy system.
Basically it is a converter of chemical to electrical energy and it has an
efficiency which is higher than the most of competing technologies of
today 4 . Additionally the efficiency is almost not affected by the size
of the system. Solid Oxide Fuel Cells (SOFC) are operated at high
temperature (700-800 ◦ C) which enable them to accept a lot of different
fuels e.g. diesel, natural gas or biogas. This is an advantage because it
makes the technology more flexible.
1.4.1 SOFC Waste heat
The high temperature at which the Solid Oxide Fuel Cells (SOFCs) are
operated gives them an important advantage compared to other (low
temperature) fuel cells: The waste heat is rejected at a much higher
temperature and that is an advantage if the waste heat is to be utilized
for certain purposes.
The waste heat can be turned into useful energy when it is used for
e.g. space heating or water heating. These are normally low temperature
applications. But in some cases this heating service is not needed.
So another options is to utilize the waste heat in a heat driven heat
pump/chiller which will reduce the consumption of primary energy 5 .
Especially heat driven chilling is interesting since the demand for
cooling (air conditioning) often increases when the outside temperature
is high while the demand for (space) heating decreases. It is also possible
to produce both cooling and heating simultaneously in a Combined
Cooling, Heating and Power (CCHP) unit.
Thus it would be interesting to investigate how a fuel cell could be
integrated with a heat driven chiller.
4 The electrical efficiency of a fuel cell system fueled with methane is about 55%
today [31].
5 Assuming that the produced heating/cooling replaces an energy services which
require primary energy.
6