Seite - 88 - in Our Car as Power Plant

88 The main technological challenge is evident, and strikes the core of our system: the fuel cell. In our concept, the fuel cell will be used for a much wider operating time than for driving only. The lifetime of the current generation Proton Exchange Membrane fuel cell is about 150,000 km or 4,000 operating hours, sufficient for a transportation-only car. However for the Car as Power Plant, this needs to be improved by at least a factor 5, while at the same time the cost for the fuel cell needs to come down to about $30/ kW (34). Using the car for electricity production, requires maintaining a heat balance in a stationary operational fuel cell in the car. This is a next big challenge: to extract the heat and make use of it, and to generate high power production efficiency but also achieve a high combined system effi- ciency (power, heat, water). With heat recovery, combined fuel-cell energy efficiencies can be increased considerably. And using the exhaust of the water / steam at the tail pipe, both for water applications and for heating purposes is a parallel challenge. TECHNOLOGICAL CHALLENGES