Introduction

Our primary needs for energy - heat and light to sustain life on earth - are obtained from the sun. With increasing dependence on acquired forms of energy, energy has become an important need in out life. Generation, transportation/transmission, distribution and usage in end use devices are the main components in the energy system. Energy is obtained from resources, which can be broadly categorised as renewable and non-renewable or depletable. These resources are converted in to a form desired by the end user. The conversion of energy from one form to another form results in a loss of some useful energy (law of entropy). In a complex system with a large number of conversions, the losses are considerable.

Renewable sources ^[1] are available all the time, while the depletable resources such as coal, oil, or uranium, were stored over a period of millions of years. Renewable energy can be obtained from the sun either directly (providing light and drying of grain and other materials, heating of earth), or indirectly (wind, hydro, biomass and firewood). Firewood is a renewable resource, only if our annual consumption equals or is less than the annual production. To cater for the needs of a growing population for cooking and rural industries it is necessary to:

• Use alternative sources such as solar devices or biogas.
• Improve efficiency of end use devices, e.g. improve stoves for cooking, improved boilers, driers and other machines which enable sustainable fuel wood production.

Thus the energy has been a dynamic force in accelerating the growth and development of human society. The demand for energy is not an end in itself but for the services such as heating, lighting, mechanical power and other services that satisfy human needs. This necessitates the need for proper energy management taking into consideration the satisfaction of basic human needs through economically feasible, energy efficient, environmentally sound and viable options. These include:

• Promoting energy efficient improvements.
• Beginning a transition to renewable energy sources.
• Optimising energy source - end use matching.

This highlights the need for integrated regional planning ^[2], based on a detailed look at how energy is used rather than the traditional preoccupation with energy supply and aggregate demand.

Maximum thermodynamic efficiency and maximum cost effectiveness in energy use are the two principles that govern energy conservation policies. The efficiency of energy use depends on thermodynamics, and the cost of energy use responds to the economics of resource allocation. In any region where the energy supply structure is vulnerable, the conservation of energy is a very effective way to alleviate energy constraints.