Energy is again a national issue, and the Bush administration’s energy policy, while emphasizing increased production, includes interest in conservation, efficiency, and innovation. The century’s first decade will likely see increased research related to nuclear power and ways to store electricity in large quantities, but the technologies most likely to have significant impact in the energy area exist today. One can predict with near-certainty that no magic bullet will emerge to cure the nation’s energy ills.
Discovered in 1839, fuel cells long remained little more than a potential source of clean and efficient energy. Today, they are poised to become a commercial commodity. The 1990s saw a resurgent interest in fuel-cell technology, largely in proton-exchange membrane (PEM) fuel cells for use as nonpolluting vehicle power plants. PEM fuel cells split hydrogen atoms into electrons and protons and produce water and heat. The first production-model fuel-cell cars should be available in 2004, and some automakers expect to be selling 100,000 fuel-cell-equipped vehicles a year by 2010. The viability of fuel cells for vehicles resulted from a number of technological advances that improved fuel processing at lower costs, and further improvements will come. Current automotive fuel cells convert the hydrogen in fossil fuels such as methanol to electrical energy. Ultimately, the makers of PEM fuel cells expect to replace hydrocarbons with pure hydrogen. Two potential energy sources for producing the needed hydrogen from water are high-efficiency solar cells and nuclear power plants.
Solid oxide fuel cells (SOFCs) are in development as sources of electric power, and at least one company expects to market a model for home use later this year. SOFCs essentially work in the reverse manner of PEMs. They add electrons to oxygen, and the oxygen ions then react with a hydrocarbon to produce electricity, water, and carbon dioxide. Their potential applications include supplying electricity to individual buildings, groups of buildings, or entire neighborhoods. Conventional SOFCs operate at about 1000 °C, which causes materials stress and poor stability. Efforts are under way to find ways to improve material reliability and reduce operating temperatures.
Although solar cells have a small niche in today’s energy production, their low conversion rate of sunlight to electricity—about 20 percent at best—remains a stumbling block to their greater use. Significant advances in solar-cell materials are urgently needed. One company, Advanced Research Development, has combined two polymers, polyvinyl alcohol and polyacetylene, to produce solar cells