High-temperature superconductor (HTS) dynamic synchronous condensers have a small footprint, are readily transportable, and are expected to be an economic option for providing peak and dynamic reactive compensation to a power system. HTS dynamic synchronous condensers are also inherently stable to close-in faults and can provide up to twice their nominal rating for about one minute (peak rating) during depressed voltage events. These machines also use less than half of the energy of conventional synchronous condensers because the HTS field windings operate at a constant cryogenic temperature. They are expected to be highly reliable. In October 2004, the first HTS dynamic synchronous condenser was installed on the Tennessee Valley Authority (TVA) grid serving an arc furnace where it is being exposed to a large number of transients, providing an excellent accelerated age test of the device. TVA has ordered five HTS dynamic synchronous condensers rated at 12 MVAR, and successful operation of the first prototype machine is expected to lead to release of these orders to production by TVA, making HTS dynamic synchronous condensers the first HTS commercial product for enhancing power grid reliability