Though he may have lost the battle of the currents to George Westinghouse in the 19th century, it looks as though Thomas Edison's direct current (DC) standard may finally be making a comeback. In light of Europe's growing interest in wind power, scientists and entrepreneurs alike are giving DC transmission a second look and are considering using it as the basis for a continent-wide high voltage DC grid.
The reasoning is fairly straightforward: unlike AC transmission, DC suffers low voltage losses over long distances. Incorporating it into a continent-wide power distribution system would thus deal with two of wind power's main downsides: the fact that you can't always get it when you want it and where you want it. Since the wind is bound to always be blowing somewhere, the current generated by wind turbines could be stored and made to flow in one direction or another, depending on each country's energy needs. How then to store all this wind power? An important component to this continental grid would be the branch to Norway. Since it has a large number of hydroelectric plants, wind energy could be stored in grid-filling quantities and used to pump water up into the reservoirs that power the turbines. If there were to be a large wind drop across Europe — leading to a resulting drop in wind energy production — the water stored in the reservoirs could be unleashed to power the hydroelectric turbines and provide a large source of current that could be transmitted over the grids to sustain the continent's needs for up to 4 weeks. While other transient and long-term energy storage schemes are being considered, Norway's hydroelectric turbines — because of their huge capacity — will likely account for the brunt of it.
Jürgen Schmid, the head of ISET, an alternative energy institute at the University of Kassel in Germany, and one of the lead proponents of this continental grid, estimates that it could supply at least 30% of the power needed in Europe. He envisions them eventually replacing all base load power plants — conventional power plants that provide a continuous and constant flow of power regardless of demand — which would greatly help reduce carbon emissions and pollution.
Several companies in Norway have already begun building high voltage DC lines between Scandinavia, the Netherlands and Germany while Airtricity, an Irish wind power company, has plans to build what it calls a "Supergrid" — which would connect offshore wind farms in the Atlantic Ocean and Irish, North and Baltic seas with consumers in northern Europe. Others believe its potential could be carried over to solar, wind and geothermal power to create a global energy market gathering and transmitting current from one continent to another.
Though certainly promising, whether all these rosy scenarios come to fruition, however, remains yet to be seen.
Via ::The Economist: Where the wind blows (magazine, sub. required)
See also: ::Colossal Magnetic Levitation Wind Turbine Proposed, ::What did the Wind Say to Coal?, ::Innovative Wind Turbine From Australia
Image courtesy of scjody via flickr