Stephentown is a town in Rensselaer County, New York, United States.

[3] The town, which was originally Jericho Hallow in the Massachusetts Bay Colony, was renamed for Stephen Van Rensselaer.

The town is located in the southeastern corner of the county, and has a sign proclaiming it to be the only Stephentown on Earth.

Pursuant to Section 68 of the Public Service Law, Stephentown Regulating Services LLC (SRS) (now operating as Stephentown Spindle LLC (SS)) was granted a Certificate of Public Convenience and Necessity for a 20-megawatt (MW) flywheel-based energy storage facility in 2009.

The flywheels are energized by and discharge their energy into the New York State transmission system.

The stakeholder-driven policy at the NYISO excludes the facility from providing power into the NYISO's wholesale electric and capacity markets because it does not meet minimum criteria - a minimum of 5 minutes or 1 hour - for sustained energy delivery.

[14][15][16][17][18] It is the first commercial flywheel project in the United States to provide frequency regulation service.

For a power comparison, the capital region's peak summer demand was 2,032 MW in 2017.