To accomodate strain on the coil, the ring must have some radial leeway. When the coil cools down, those nodes stay fixed while the radius between the ripples contracts. Page 2 Terry Walsh, Bechtel's project manager, finds fault with this rippled support design. Walsh is concerned that these high-stress points will cause strain on the conductor as well as dangerous hot spots from friction. He says that Bechtel is studying an alternative approach in which a telescoping support structure absorbs coil shrinkage and expansion.
Ring sharing The benefits associated with SMES are wide ranging.
Boom also says that SMES could make it simpler for utilities to buy power from intermittent alternate energy sources, such as cogenerators and wind and solar power plants. Otherwise, the savings from generating efficiency are lost to the costs of refrigerating the coil. This is because as the superconductor cools down it generates strong magnetic forces. The aluminum ring must also be buried in a bedrock trench to counterract these forces. Although the free-spending military has firm plans for SMES, the trick in persuading a frugal utility to build is to reduce operating costs.