Useful thermal energy output
Useful thermal energy output of a topping-cycle cogeneration facility means the thermal energy:
(1) That is made available to an industrial or commercial process (net of any heat contained in condensate return and/or makeup water);
(2) That is used in a heating application (e.g., space heating, domestic hot water heating); or
(3) That is used in a space cooling application (i.e., thermal energy used by an absorption chiller).
(i) Total energy output of a topping-cycle cogeneration facility is the sum of the useful power output and useful thermal energy output;
(j) Total energy input means the total energy of all forms supplied from external sources;
(k) Natural gas means either natural gas unmixed, or any mixture of natural gas and artificial gas;
(l) Oil means crude oil, residual fuel oil, natural gas liquids, or any refined petroleum products; and
(m) Energy input in the case of energy in the form of natural gas or oil is to be measured by the lower heating value of the natural gas or oil.