Improvements in electrical efficiency of lighting may not soon be repeated. While major successes have been achieved in electric lighting, there are other uses of electricity for which finding big efficiency improvements will be more difficult. Converting electricity to motion through motors and actuators is still relatively inefficient, but could be greatly improved if room-temperature superconducting technology could produce a superconducting motor. While that might be achieved in the next couple of decades (if we’re lucky) heating ourselves and our local environments will be a far more difficult challenge, as that requires a lot of raw power and the fundamental laws of physics suggest little improvement may be possible.
You just can’t get something for nothing. The temperature in our surroundings is maintained by the application of energy. As energy sources have run out and costs have risen, big increases have been achieved in lighting efficiency, mostly by narrowing the frequency bandwidth of the emitting devices so they emit less heat, but heating devices like gas furnaces already have efficiencies above 95%, so there is little room for improvement there. Increased efficiency beyond the high nineties won’t be financially justifiable until fuel prices are a great deal higher.
Efficiency increases are possible, but not enough. Efficiency can be increased by limiting the energy expenditure to the areas where you need it. This means that applying the heat locally, as through electrically heated socks, for instance, reduces the total energy required to warm the wearer. Does that mean that in the future our homes may be kept, say, at a temperature just warm enough to ensure the water pipes don’t freeze, and our clothing will have to keep us warm when ambient temperatures are cool or cold? Quite possibly.
New heating technologies don’t show much promise. Insulation effectiveness and heat delivery methods can be improved, and perhaps heat emitters can even be optimized to radiate or beam heat energy in a narrower bandwidth, similar to the way LED lighting has made efficiency improvements. That might help in the direction and localization of heat energy, but since radiant energy tends to drop in frequency as it is absorbed and re-radiated, it could be said that all radiant energy tends to wind up as thermal energy, leaving little to be gained by narrowing the output bandwidth of the conversion device. In other words, a heat-radiating LED doesn’t make much improvement over a simple nichrome wire (as used in toasters, for example) and will undoubtedly cost more.
I am hoping to be surprised. There are a great many scientists at work around the world trying to solve these problems, quite aware that energy supplies are finite and that the exploding human population will absorb energy from any source at every higher rates. Some government funding still goes to basic research, though I fear there is a lot less of that going on than there was, say, three decades ago. Still, necessity being the mother of invention, I can hope that basic research will be increased significantly in the near future, and that the necessity won’t be manifested in too horrible a way.
As usual, the real problem is … us. It has become increasingly clear that our real problem is not the need for higher energy efficiencies, but to curb and then reverse our skyrocketing numbers. This fundamental demand-driver represents our biggest single problem, and the source of many symptom-problems such as energy cost/scarcity and pollution (as well as wars over energy sources). Not until we can intelligently manage our population will we be able to achieve a sustainable situation where energy cost and volatility are truly under control.
As always, I welcome your comments. — Tim