Challenges to grid interconnectivity
"If you asked wind developers to identify the top challenges they face, access to transmission would be at or near the top of everyone’s list, said Hewitt, the Portland, Maine-based attorney. "This is particularly true in New England, where there has not been significant transmission built during the past 20 years. Unfortunately, the premium sites for locating wind projects in New England usually do not coincide with convenient access to the grid." (See the feature on p. 80 for more about this issue.)
He points out that although transmission utilities and merchant transmission companies are moving forward with new proposals to accommodate the increased need for transmission capacity throughout the U.S., wind developers are becoming increasingly more willing to assume the risk of building out their own transmission to get their power to market.
According to Lowe, transmission constraints are an emerging issue with his company’s customers. GE is engaged at the federal and regional levels in advocating for transmission policy reforms. Specifically, the company supports:
-
Proactive transmission planning initiatives such as ERCOT’s Competitive Renewable Energy Zone program, which is now being copied in Colorado and by the Western and Midwestern Governors’ Associations.
-
Interconnection queue reform to speed the processing of project applications, which is especially important in the Midwest.
-
FERC’s authority to intervene in and resolve interstate transmission planning disputes.
-
The development of a "Clean Energy Superhighway" that knits together the nation’s three interconnections (East, West, and ERCOT).
-
Support from grid planners to facilitate higher levels of wind penetration through the use of grid reliability and wind forecasting technology.
To help customers meet new and emerging standards for increased grid reliability, GE has developed several products offering improved methods of integrating wind power into electrical grids, Lowe said.
Not surprisingly, AWEA advocates a high-voltage transmission superhighway to carry electricity generated in rural, windy areas to urban load centers around the country. Regional transmission planning and cost-allocation policies are the most important components of future transmission policy and development.
According to Anthony, an upgraded and expanded transmission grid will lower energy costs for consumers. For example, the Midwest Independent System Operator (MISO) recently studied the costs of developing 16,000 MW of wind in the MISO system, along with 5,000 miles of new 765-kV transmission lines to deliver wind from the Dakotas to the New York City area. Although overall generation and transmission costs reached an estimated investment of $13 billion, if implemented, the project is projected to produce annual savings of $600 million over its costs.
Dealing with wind energy’s variability
During his interview, Anthony stressed that a major area of misunderstanding is the characterization of wind as an intermittent energy source for electrical generation.
"First of all, wind energy output is ‘variable,’ not ‘intermittent.’ This is an area where education is needed," he said. "The term ‘intermittent’ is not only inaccurate; it is also used in a negative, derogatory way by anti-wind activists. Intermittent implies that wind energy output can suddenly and inexplicably change; nothing could be further from the truth. In fact, wind energy output from a single wind turbine or a wind project containing hundreds of turbines is variable in that the output will change slowly over time and is very predictable, given that modern day wind forecasting techniques exist to allow system operators to anticipate changes in wind energy output in ‘day-ahead’ and ‘hour-ahead’ timeframes."
Conventional resources occasionally shut down with no notice, and these "forced outages" require operating reserves. In contrast, changes in wind energy output are not instantaneous, Anthony said. Because of the geographic diversity inherent with large numbers of wind turbine installations, it typically takes over an hour for even a rapid change in wind speeds to shut down a large amount of wind generation. Wind forecasting tools that warn system operators of upcoming wind output variations are becoming widely used and better integrated into system operations.
According to the DOE report 20% Wind Energy by 2030, factors that facilitate the integration of wind power into the electric system and further improve overall reliability and cost-effectiveness include the following:
-
Wind forecasting enhances system operation.
-
Flexible, dispatchable generators, such as natural gas plants, facilitate wind integration.
-
Aggregation and geographical spread of wind projects reduces variability; the more wind farms, the smoother the overall output can be.
-
Large balancing areas reduce impacts, for wind and for all technologies.
-
Changing load patterns, such as those enabled by a smart grid and plug-in electric vehicles, can complement wind power generation.
Email
Comments
Print
Reuse
