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Advanced Wind
Contemporary wind turbines use technology that is more efficiently harnessing wind power and converting it to energy than earlier versions did. Advances made in the last 10 years in rotor, gearbox and generator design and configuration have dramatically increased the energy-generating capability and reliability of wind turbines. Large-scale wind farms could be connected to the local power transmission network, while small turbines may be used to power isolated locations or areas where there is no centralized electricity grid. Engineers are developing new blade designs so that blades can be retracted to prevent damage during storms and are experimenting with airborne turbines that float in the sky, like kites, constantly harnessing the wind.
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Solar Thermal
Conventional solar energy uses photovoltaic panels to chemically convert sunlight directly into electricity. Solar thermal technology uses mirrors to focus sunlight onto pipes, heating the fluid inside. The hot fluid can be used to heat water, generating steam that can produce electricity. One advantage of the newer solar thermal is that the heat can be stored and used to generate electricity later — unlike electricity from photovoltaic panels, which must be used immediately or dumped. Engineers are improving mirror design to concentrate the sun’s rays and identifying efficient methods to store heat. Based on cost and heat storage capabilities, solar thermal could replace natural gas and generate electricity during times of peak demand.
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Combined Heat and Power
Also known as cogeneration, combined heat and power systems generate electricity and heat in a single, integrated system. This developing technology contrasts with today’s methods, where electricity is carried in from a central power plant but heat is generated locally. Generating electricity produces heat, which conventional power plants release unused into the environment. But cogeneration technology allows power plants to make use of that excess heat for other applications. One specific idea combines power generation with ethanol distillation in a single plant. The excess heat from electricity generation is used to produce steam, which then is used to distill ethanol, a biofuel alternative to gasoline.
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Power from Trash
Cities look at waste as a problem, but utilities look at it as an alternative source of electricity. There are many methods to convert waste to energy — ranging from using heat to bacteria. So far, converting waste into energy often has been considered impractical or environmentally dubious because it used more energy than it yielded. Ottawa-based Plasco Energy Group solved this problem by developing electric plasma torches that operate at a lower temperature than traditional incinerators. The company plans to apply the torches in a new plant it will build in its hometown. Atlanta-based GeoPlasma applies a similar approach in a plant it plans to build in Florida — plasma torches vaporize garbage, and gas produced in the process is used to generate electricity. The leftover waste will be sold as building aggregate.
