Page - 34 - in Our Car as Power Plant

34 Although it is very important to make use of excess heat, we have to realize that this is not a sustainable energy sys- tem in the end. Let us have a look at how we could develop a sustainable heating and cooling system for example. We first have to reduce our energy demand for heating and cooling, by insulation, heat recovery from ventilation air and by using passive solar heating and cooling. For the remaining demand we can use the ground to store heat in the summer time to be used in winter time and the other way around. With a heat pump, which uses a little bit of electricity, we can bring the stored heat or cold to the right temperature. And this electricity may come from a renew- able source like wind, solar, geothermal, biomass, etc. So energy-efficiency improvements, renewable energy sources and heat pump application leads to integration of the heating and cooling system with the electricity system. A similar development towards a sustainable transport system can be envisioned. The change towards more energy efficient cars and towards electric cars has started. The electric car transport sector will consume more and more electricity, although more efficiently. If this electricity will be produced by renewable sources, transportation can evolve into a sustainable system.