We know of some people in the cold Canandian town of Saskatoon who are paying about a tenth as much for heat as their neighbors. They are expected to continue to do so as everybody's heating costs rise ten times by the end of the century. They will then be paying $28 a month to heat their three-bedroom bungalows, $2 less than their neighbors are paying now. The reason for the savings is that these government showcase bungalows have today's energy-saving features, only more so - very heavy insulation, for example, and quadruple glazing of windows.
Why are we telling you this?
Because the energy problem is far from over. Projections of the world's energy supply and demand over the next half century should be enough to spur all users of energy in any form to consider whether they are using it as efficiently as they can.
According to one of these projections it will take highly optimistic conservation achievements - a 30 percent saving through technological developments, for example - to make supply match demand by the year 2020. Another projection suggests that ''extreme'' energy conservation will be required simply to keep the globe's average per capita consumption constant as population increases until the year 2030. Without strong conservation measures, supply from all sources is projected to meet only half of the demand.
The only scenario resulting in an actual decreased demand for energy after the turn of the century is the so-called ''soft path'' of energy development - through decentralized solar sources, for instance, and altered life styles.
But this scenario is seen by most prognosticators as impossibly idealistic, at least in the short term. The consensus of recent international studies is a growth in energy demand by perhaps three times over the next 50 years - with major reliance still on oil and coal, and with greatly increased development of the latter.
Yet the challenge remains to develop the alternative sources of energy (hydro , solar, wood, alcohol) to ensure that they maintain at least their present 15 percent of the world's annual energy supply.
The need to get on with synthetics and other possibilities for the post-oil-coal years is dictated by the long lead times required to bring forward new energy sources. This is dramatized by the three decades it has taken for nuclear power to meet 3 percent of world energy demand - and by the political, economic, environmental, and technological restraints on nuclear expansion now.
Moreover, even those benign sources of energy such as the sun, water power, and windmills entail environmental risks. This month came a report from the National Audubon Society which publicizes the notion that there is no free lunch even in solar energy and conservation.
The manufacture of solar electrical cells, for example, could cause shortages of some substances such as cadmium. Large tracts of land could be used up for the arrays of solar cells needed to produce electricity.
As for conservation, the insulation and tight seams that help to save heat could be carried to an extreme resulting in indoor air pollution. This potential problem has been taken account of in the showcase energy-saving houses in Saskatoon. The need is for balanced design that both saves heat and provides sufficient ventilation.
We can imagine people in developing nations saying, ''If only we had such problems!'' They are starting from far behind in many ways. These countries have been particularly hard hit by high oil prices. And it is calculated that their energy supplies will have to grow at a rate higher than their economic growth in order to make up for lost time. Whereas the industrialized nations can achieve economic growth with energy growth at only half the same rate.
Rather ponderous thoughts, perhaps. But a world that doesn't think them now may find itself out in the cold before it knows it.