A turbine-generator device for use in electricity generation using heat from industrial processes, renewable energy sources and other sources. The generator may be cooled by introducing into the gap between the rotor and stator liquid that is vaporized or atomized prior to introduction, which liquid is condensed from gases exhausted from the turbine. The turbine has a universal design and so may be relatively easily modified for use in connection with generators having a rated power output in the range of 50 KW to 5 MW. Such modifications are achieved, in part, through use of a modular turbine cartridge built up of discrete rotor and stator plates sized for the desired application with turbine brush seals chosen to accommodate radial rotor movements from the supported generator. The cartridge may be installed and removed from the turbine relatively easily for maintenance or rebuilding. The rotor housing is designed to be relatively easily machined to dimensions that meet desired operating parameters.