Utility system in NE Vermont to be strengthened, resolving concerns about new wind power

In recent days, concerns have arisen about whether additional wind generation can be accommodated by the utility system in Vermont's "Northeast Kingdom," a rural four-county area that has some of the state's best wind sites.

The reason for the concern is that the utility system in the area is very "weak," with no large transmission lines. Bottlenecks on the transmission system have forced the system operator to reduce the output of one of the existing wind projects on some occasions.

This is a highly localized problem caused by the weak utility system, and would likely occur with any energy source that was added on that part of the grid. In addition, it is a fixable problem–by the end of this year, Green Mountain Power Co., the state's largest investor-owned utility will be installing a synchronous converter, a device that will strengthen the local grid and should largely resolve the problem.

The issue experienced in northeast Vermont appears to have nothing to do with wind energy's variability and accommodating that variability within utility systems, which already balance supply and demand 24/7/365 even though demand varies throughout the day and year and large conventional power plants routinely fail without warning. Nor does it mean that energy storage must be added to the system to deal with wind's variability.  Other parts of the country, such as Texas and the Midwest, have been able to integrate very large amounts of wind (10,000+ megawatts) with no negative impact on system reliability and no need for storage. Wind provided 20% of the electricity in Iowa and South Dakota last year, and more than 10% in another seven states.