I've been trying to find some clarification in relation to the dumping of unused heat from fuel cells. The following links have info which indicate dumping is not allowed. If this is the case and a fuel cell is installed in a residential dwelling in regions where temperatures rise anywhere above 23 degrees at any point and time, then it can be assumed the only use for that heat would be for hot water systems coupled to the fuel cell unit(at this point and time). Many areas of Europe experience these temperatures during the year, and even a city like Paris, temperatures during summer would the negate the need for heating other than hot water. If dumping is not allowed as a result of energy wastage, and an energy service provider such as E.ON is installing fuel cells for the part reason of load lopping from the mains grid, then CFU's fuel cell with an electrical efficiency of between 50-60%, has a clear and distinct advantage over a PEM type cell which provides electrical efficiency of 30% (Clearedge) re; a PEM cell may need to be switched off in particular cases due to unnecessary heat dumping, or not installed at all. Again I am not 100% certain about the dumping regulation but if this is the case, seems advantageous to CFU
Links are from a UK board with Brendan Dow reply (2010) and a Denmark thesis on virtual power plants (page 57 heat dumping) 2010 aswell
