Three bridges to a world energy future – nuclear, coal and oil

'Bridge to the future' is a phrase that is often used in discussing the energy and power needs decades ahead. Some advocates suggest that renewables such as solar and wind are that bridge to a time when the planet will use less energy overall and with fewer environmental consequences. Others have proposed conservation, either voluntary or imposed by governments. Based on present knowledge, it is unlikely that such panaceas will contribute more than a small fraction of the energy needs of the mid- or late 21st century. Rather, the bridge to the future will almost certainly be made of three major components – nuclear, oil and coal – in proportions yet to be determined. Based on previous attempts, one major conclusion can be drawn: the changes in energy supply move more slowly than the public believes. Each month, the public is told about new and allegedly better sources of energy or more efficient ways to use energy. These may include hybrid automobiles, all-electric vehicles, power from the ocean, heat from burning kelp and so on. But energy sources change much more slowly than the public anticipates. For example, the only major new source of energy in the last half century has been nuclear. Power from coal and oil has, of course, been around much longer than that. The public wants reliability and reasonably low costs for its power and electricity supply. The first requirement casts a shadow on many renewables.