The technique for optimization of parameters of a power unit of a gas-turbine small-size heat and power plant was developed with regard for seasonable nature of heat and electric energy loads; the approach uses linear versions of dependency of outlet parameters on the inlet parameters. A mathematical model of the energy unit of a mini-HPP was developed. Optimization calculations for a coal gas-turbine mini-HPP were carried out for several optimization criteria: minimal revenue from the produced heat and electric energy (at different levels of fuel price), minimum of fuel consumption during year, and minimal investment at a given internal return rate.