  Relationship among efficiency and output power of heat-electric energy
converters as well as of any converters for transforming of heat energy into
any other kind of energy is considered. It is shown, that the parameter
efficiency does not determine univocally the output power of a converter. It is
proposed to use another parameter for determination of working ability of heat
energy converters. It is shown, that high output power can not be achieved by
any kind of Stirling-type converters in spite of their high efficiency.
