Information About the Sheffield-Highgate Export Interface
This page has been created to provide equal access for all stakeholders to information about the Sheffield-Highgate Export Interface or SHEI. This information resource is intended to facilitate compliance by VELCO with FERC Standards of Conduct.
BACKGROUND ON THE SHEI
Following the addition of the Kingdom Community Wind plant, the Sheffield-Highgate Export Interface (SHEI) was created to monitor system flows in relation to system capacity in real time. The SHEI is an area of Vermont’s electric grid in the northern tier of the state. Generation resources inside that interface are limited in real time to ensure that system capacity is not exceeded in the event of a potential future transmission outage. The practical effect of the SHEI is that, from time to time, generation resources in the northern tier are required to curtail their output due to the lack of capacity to export power. Utilities, clean energy advocates, regulators and other stakeholders are currently discussing ways that the SHEI limitations can be addressed to reduce or eliminate curtailments of generation located within the interface.