American Superconductor Corp. (AMCS) announced on Tuesday that its Superconductor Electricity Pipelines have been chosen for the Tres Amigas Project, the nation’s first renewable energy market hub. The Tres Amigas Project, introduced yesterday in Albuquerque by New Mexico Governor Bill Richardson, who was energy secretary in President Bill Clinton’s administration, focuses on uniting the three main U.S. power grids for the first time to enable faster adoption of renewable energy and increase the reliability of the U.S. grid.
Power transmission within the three U.S. power grids—Eastern, Western, and Texas (ERCOT) Interconnections—is accomplished primarily by utilizing alternating current (AC) power transmission lines. Power transfer between any two of the interconnections, however, can only be accomplished through special power electronic conversion stations. This is commonly achieved by first converting AC power in one grid to DC as an intermediate power form at a substation, and then reconverting from DC back to AC before reaching the adjacent grid. Though several relatively small bilateral “DC links” exist today between two interconnections, all three interconnections have never been united by one system.
The Tres Amigas renewable energy market hub will be a triangular electricity pathway of superconductor electricity pipelines capable of transferring and balancing many gigawatts of renewable power between the three interconnections. Superconductor electricity pipelines combine conventional underground pipeline construction techniques with DC superconductor power transmission cables and multi-terminal (voltage-source) AC/DC power converters. The result is a high-capacity electric transmission “pipeline” that is underground. Compared with competing technologies, such pipelines are easy to site and access, highly efficient and controllable, offer greater security, and avoid complex cost allocation issues for interstate transmission of power.
Similar to highway rotaries used for traffic flow control, multiple power transmission lines from each of the interconnections will feed power into and out of the Tres Amigas SuperStation through multiple AC/DC converters, each connected by DC superconductor cables.
Tres Amigas, which will be a balancing authority, will help ensure the efficient and reliable flow of power from multiple renewable generation sources in all three power grids to customers across a wide area of the U.S., Canada, and Mexico. It could also transmit power from other generation sources.
The Tres Amigas SuperStation will act as a power market hub, enabling the buying and selling of electricity between the three interconnections, which is not possible today. Wind, solar, hydro, and geothermal renewable energy sources that do not currently have access to transmission lines and/or customers will be able to tap into multiple markets through the Tres Amigas SuperStation. For example, regions rich in solar energy will be able to buy electricity at night, when the sun is not shining, from regions rich in wind energy. As a merchant transmission system, Tres Amigas will charge a fee for usage of the power hub.
The Tres Amigas project will be constructed in Clovis, New Mexico, a location that has easy access to all three of the nation’s power grids. New Mexico’s State Land Office already has granted Tres Amigas LLC the right to lease 14,400 acres (22.5 square miles) of land in Clovis for this system. Tres Amigas LLC is now in the process of filing with the Federal Energy Regulatory Commission (FERC) for a declaratory order that transmission lines that connect to Tres Amigas from ERCOT will not come under the jurisdiction of FERC and that Tres Amigas can be operated as a merchant transmission entity. The project is expected to be operational by 2014.
Phil Harris, CEO of Tres Amigas LLC, originally developed the concept for the SuperStation. Harris was formerly the CEO of PJM Interconnection.
AMSC has acquired a minority equity interest in Tres Amigas LLC for $1.75 million in cash and AMSC stock. AMSC will hold one of four seats on the company’s Board of Directors. Terry Winter, executive vice president of power grid projects for AMSC, will be AMSC’s representative on the board. Winter was formerly CEO of the California Independent System Operator.
The concept of using superconductor cables for DC power transmission originated with an Electric Power Research Institute report completed in 1997, which drew upon a seminal 1967 paper by IBM scientists discussing the use of low-temperature superconductors and follow-up efforts in the 1970s by a team at New Mexico’s Los Alamos National Laboratory.
Sources: American Superconductor, N.M. State Land Office, N.M. Office of the Governor, POWERnews