Skyrocketing oil prices, concerns about the environment from increasing greenhouse emissions, and the desire to save the planet from environmental disasters, have turned wide attention to alternative energy sources and to the need to increase the energy efficiency of the systems we use today.
One notable effort involves the incandescent light bulbs used widely in homes and offices. These bulbs, commercialized in the late 19th century, are being replaced gradually by devices that provide the same or more visible light for the same level of electrical energy input. The European Union is in the process of phasing out incandescent light bulbs in favor of more energy-efficient lighting. If every filament light bulb in the USA was replaced by a solid state lighting source, the electricity consumption in the US would be reduced by 10%, also cutting carbon emission by about 28 million tons a year.
The alternative light sources include fluorescent lamps, high-intensity discharge lamps, and light-emitting diodes (LEDs). Nanotechnology innovations are applied intensively to reduce the cost of producing some of the alternative light bulb designs.
Nanomaterials are beginning to play a prominent role in developing other alternative energy technologies. Much of the solar cells produced worldwide today rely on bulk crystalline technology which competes with the computer industry for the silicon raw material. This is not a desirable situation, since both solar ebergy and computer electronics are critical technologies with high demand and expanding volumes. Alternative research directions include novel nanomaterials such as quantum dots to increase efficiency; and production of solar cells on flexible substrates (like plastic, thin metal sheets). Lightweight and high strength composites for wind turbine blades are being developed using nanocomposites to harnass wind energy.
Environmental pollution of air, soil and and water, including the impact of toxic waste in landfills, is a major concern across the world. Using nanotechnology, scientists are designing new catalysts for waste remediation, and for conversion of toxic gases into benign components. These designs take advantage of the large surface area of nanomaterials and of the novel properties and reactivity that arise at the nanoscale. New, efficient filters to trap mercury, heavy metals and other hazardous substances are developed, using carbon nanotubes and other nanomaterials.