Better energy efficiency is imperative while finite energies are still predominant - which have to be conserved for higher-added-value purposes in the chemical industry - and to reduce pollution, but good efficiency is also economically desirable with the use of renewable energies, because some of them have relatively high production cost.
The waste of energy is still unbelievable, particularly in affluent societies, where energy cost represent only a relatively small share of total living expenses. Many efficient appliances are available on the markets, like compact fluorescent lamps, using up to 80 % less electricity than incandescent light bulbs, better insulated buildings and refrigerators, saving thermal energy, and leaner combustion engines, reducing fuel consumption by up to 50 %.
The main problem is often the human behavior, not buying such appliances, leaving the lights on in unoccupied rooms, overheating or overcooling offices, lighting streets and buildings during daytime, over-compensating better fuel efficiency by purchasing heavier vehicles, making short car rides instead of walking or biking over reasonable distances etc.
Energy efficiency is only part of the sustainable energy concept, complementing, but never replacing the transition to the clean, renewable energy age, which is the only long-term solution due to the rapidly depleting mineral resources.
Energy efficiency makes always sense over the life cycle time of an energy system, even if energy saving appliances or vehicles cost a bit more, but off-setting the extra cost by lower energy consumption. Returns on Investment from more efficient energy systems can exceed 1000 % in cases like the incandescent lamp substitution.
With the help of ISO standard 13602 efficiency ratios and LCA calculations can be made for any energy systems or chain of energy systems and thus making them economically and ecologically comparable.
Good energy efficiency programs can be found from many international and national energy efficiency NGOs, and under the UN-ECE website www.ee-21.net.
from the "Blueprint for the Clean, Sustainable Energy Age" - order
The ISEO working groups will add more information.