No more over head power lines

                  Abundant solar and wind power lies across America’s vast plains and deserts, but getting that distant renewable energy to cities without wrecking vistas and raising lawsuits over transmission lines is a sizable hurdle for green-leaning utility companies. Thousands of miles of towering electrical lines will be needed before big alternative-energy projects can take hold. Yet such power lines portend years of legal snarls over the not-in-my-backyard problem.
Into this fray comes Phil Harris and his pioneering plan to use underground superconducting cables that will be both hidden from view and more efficient than traditional lines. Mr. Harris wants to build a virtually invisible network that would create a national renewable-energy hub located in the Southwest.
Today, the nation’s power grid is in three disconnected pieces – Eastern, Western, and Texas. Harris’s project, called Tres Amigas, would use superconducting cable to provide the first large-scale commercial trading link between those big grids – opening up new markets for renewable wind and solar power in the American East and West.
These superconducting cables contain special materials chilled to superlow temperatures, allowing electricity to flow efficiently, with no resistance. The only lost energy goes toward refrigerating the cables. While Harris’s “hub” would run in a loop, it would demonstrate the potential for superconducting power lines that could travel long distances and eliminate the 7 percent of electricity wasted by ugly, above-ground transmission lines.
In papers filed in early December with the Federal Energy Regulatory Commission, Tres Amigas outlined its plans for a $600 million, 15- to 20-mile triangular-shaped hub near Clovis, N.M., constructed using superconducting cable.
Such a trading hub could spur investment in wind and solar power development in many states around the region, say officials with Public Service Company of New Mexico (PNM). The company is weighing construction of a new “wind collector” transmission line to connect new wind farms in the east-central part of the state with Tres Amigas, if the new transmission hub is built.
Today, PNM has “no significant ability” to move power to the eastern US or to Texas, says Greg Miller, lead engineering and operations director for PNM. While power lines that run west to California remain congested, Tres Amigas would open up the other two markets – allowing development of New Mexico wind power.
“We have very rich potential for renewable-energy development, particularly with wind in the east-central part of our state,” Mr. Miller says. With at least 10,000 megawatts of wind power development currently waiting for transmission lines to be built, “we think [the hub] could be the trigger that will allow us to move forward.”
The supercooled cables from American Superconductor, the nation’s largest maker of superconducting cable, are already being used in small projects by the Long Island Power Authority, American Electric Power, and National Grid. Perhaps two dozen locations worldwide rely on superconducting cable, but often it is to connect key stations less than a mile from each other.
Tres Amigas would be a “game changer,” company officials say.
“What we’re starting to see is a new phase in commercialization of superconducting cable – not just in this country but globally,” says Daniel McGahn, president and chief operating officer of American Superconductor in Devens, Mass.
A tour of American Superconductor’s factory found the company creating flat metal tape out of “high-temperature superconducting” (HTS) oxide materials and costly silver, then slicing it into thin flat strips. The strips wrap around a pipe carrying liquid nitrogen, which cools the cable to minus 346 degrees Fahrenheit.
At that temperature, electrons that ordinarily move randomly, losing energy in bumper-car-like collisions that generate heat, shift to highway mode. Electrons then move in pairs in one direction, generating no heat and losing no energy.



An extract from Christian Science Monitor,