TCE. A ton of coal equivalent. The energy released by the combustion of one metric ton (tonne) of soft coal.

TERAWATT (TW). A million million watts, or one million MW.

THERMAL. Related to heat or temperature.

THERMAL SOLAR ENERGY. Based upon the heat energy of the Sun, which is captured by panels and transferred to a heat-carrying medium, usually a fluid. Of all the capture methods used, cylindro-parabolic technology is the most developed and it will be used by the thermal solar energy stations being designed by IBERDROLA RENOVABLES.

THERMOELECTRIC. Electrical energy obtained from the combustion of a fossil fuel such as oil, natural gas or coal.

THERMOSTAT. An apparatus with an automatic device used to control temperature.

TIDAL ENERGY. Sub-type of marine energy using the movement of tides to generate electrical energy. The subsidiary of IBERDROLA RENOVABLES in the United Kingdom, SCOTTISH POWER RENEWABLES, is studying three sites where tidal projects could be developed off the coasts of Scotland and Northern Ireland.