Alternative energy sources gain in favor


POSTED: Monday, December 01, 2008

A new paradigm is brewing for the power generation, and it is long overdue.

The technology for diversified energy has long been available, but the rising costs and decreasing supplies of fossil fuels and concerns about man's role in climate change have made them more economically viable.

Traditional power generation is centralized under the control of a public utility. Electricity is generated by de-localized power stations that pump the electrical energy into a grid at high voltage where it is regulated and distributed through a complex matrix. As cities expanded both in size and in area, auxiliary power stations were added to the grid wherever they could be built.

Thomas Edison's original plan for electricity distribution in New York City called for small power plants on every block. This soon proved to be logistically unmanageable, and his insistence on using DC current made long-distance transmission across a large area inviable.

The large-power-station model began when Nikola Tesla eventually won a bitter AC/DC battle with Edison and built the first hydroelectric plant at Niagara Falls.

The use of AC allows electricity to be transmitted more efficiently over long distance at high voltage that can be stepped down as needed. This model became the standard as new hydroelectric sources were tapped, fossil fuels became available and nuclear power came on line.

Now as fossil fuels become more expensive and less abundant, and as awareness and concern increase over the dangers of their oxidized products such as carbon dioxide and sulfur dioxide, alternative sources are more attractive and difficult to implement.

Much of the early thinking about alternative energy has continued the model of large power plants producing large quantities of electricity. The emerging model has many small sources spread over a large area instead.

In the diversified model, power companies could become more grid managers than power suppliers.

It is likely that existing power companies will own or share in these systems and continue to manage large power plants, but there will be many personal-sized solar and wind generators on rooftops as well.

Some of these systems are well under development or already in use.

A small town in Spain is using a graveyard as a solar collection site. The city placed small photovoltaic cells on and around gravestones, overriding protests of sacrilege and desecration of the graves in favor of the common good.

Several independent companies have developed small, cylindrical wind turbines with helical blades on a vertical axis that can catch the wind from any direction and are virtually noiseless. An array of these generators lining the streets like light posts can produce significant amounts of energy, and have the added benefit that different parts of a city have different wind speeds and directions, allowing for some areas to be actively producing electricity while others are idle.

Carbon-based hydroelectric power generation will continue, but it has significant limitations. New technologies will exploit renewable solar-based phenomena such as photovoltaic cells, oceanic thermal conversion, wind and waves, the gravitational energy of the tides, and the geothermal energy buried within the earth.

Opposition of various kinds will no doubt retard development of diversified technologies. But complaints about transmission lines spoiling the landscape did not stop us from having the miracle of electricity in our homes, businesses, schools and factories.