http://www.unescap.org/esd/energy/publicat...andby-power.htm
or extract from the article below
2.4.1[/url] Introduction
Imagine you have ordered a glass of cool carbonated drink in a bar. What would your reaction be if the waiter returned with a glass filled mostly with frothy bubbles and very little liquid at the bottom? You will certainly feel cheated. Why should you pay for a practically empty glass? And yet this is what happens to most of us in our day-to-day life and we continue to pay for