Strategies for environmental friendly energy systems and the role of natural gas

The energy system is a complex chain of interlinked components that produce, transform and distribute energy form a mix of sources, and bring it to the end user in the correct form. There are several alternatives both in energy sources, energy carriers and technologies. What simplifies the situation is that the end user really needs only three things: mechanical work (often in the form of electricity), heating and cooling. This fact makes it possible to realize a simplified and clearer picture of the energy system, that may be applied both on a regianl, national and global level. By using this picture, we may easily formulate simple and robust main strategies on how to achieve more environmetally favorable and sustainable energy systems. The main strategies presented may be applied to advantage in integrated resource planning and in demand side management programs. This paper demonstrates that there are substantial opportunities for environmental improvements in the energy system by following these strategies, and especially by combining them and taking into account the important laws of thermodynamics. The few application examples presented deal mainly with the possibilities provided by natural gas on the production side, and on the potential improvements on the demand side in the residential and service sector. However, the main strategies may also be applied favorably in the industrial and transportation sector