ENERGY efficiency is the only sure route to energy sufficiency in the future, but nations are unlikely to achieve it without some hard political decisions. A brisk and informative series being aired on BBC, called Where on Earth Are We Going?, began with a programme called Energy Without End. It took a quick look at what is happening around the world on the energy use front and concluded that the key to a sustainable energy policy in many countries was using fossil fuels more efficiently.

But efficiencies of power plants vary considerably -- from 35 per cent at some places in England to 90 per cent in Sweden. Some Swedish plants fully utilise the steam generated in the conversion so that two energies are derived from one source. Sweden is also a society that takes energy conservation more seriously than some others, with the highest standards of energy insulation in buildings. Triple-glazing and quadruple-glazing are common in new buildings to minimise heat loss, says this film. But surely, only a rich society can achieve such standards.

The key to how much can be achieved seems to depend on political will. Radical use of taxation is one method, according to this documentary. Sweden has a fairly steep energy tax on gas and electricity, which forces people to use less. California has generous tax incentives to encourage industry to use alternative sources of energy. There are other methods, too. Holland has tough energy standards for new buildings. Massachusetts hands out energy-efficient light bulbs free so that it does not have to build new power stations. In the US in general, electrical appliances that fail to meet minimum energy efficiency standards are forced off the market.

The future of the Third World depends on greater use of solar energy and photovoltaic technology. Wind power is another source that has to be developed to its greatest potential. Without these, says Energy Without End, people on this earth face some pretty tough choices in the foreseeable future.