Exhibit 21 THERMO POWER CORPORATION SUBSIDIARIES OF THE REGISTRANT At December 4, 1995, Thermo Power Corporation owned the following companies: State or Registrant's Jurisdiction % of Name of Incorporation Ownership -------------------------------- ---------------- ------------ Takepine Limited United Kingdom 100% Tecogen Securities Corporation Massachusetts 100% NuTemp, Inc. Illinois 100% ThermoLyte Corporation Massachusetts 78%