PROSPECTS FOR APPLICATION OF COGENERATION TECHNOLOGIES IN MUNICIPAL ENERGY

Abstract

The article considers conditions and possibilities for installing cogeneration units (CUs) in district heating boiler houses. The main requirement to do it is the equality of the CUs’ heat capacity and the heat capacity of the boilers that are going to be replaced.
 Because the fuel (natural gas) consumption increases due to such replacement, it is necessary to determine the conditions, taking into account the constant growth of energy carriers’ prices, under which the transition to cogeneration technologies in the heat supply system will be feasible, i.е. the project will make a profit and ensure the reasonable payback period. For this purpose, the relationships between the profitability of the project, the economic indicators of the equipment included in the cogeneration unit, and the price of energy carriers are suggested. An analysis performed with the help of these relationships showed that the cogeneration unit of the same thermal capacity as the boiler (or boilers), which is going to be replaced, in comparison with CU installed on the basis of a generating unit definitely requires an increase in fuel consumption, and the profit, determined as the difference between income from generated electricity sales and fuel purchase costs, becomes dependent on the prices of natural gas and electricity, as well as the cost-effectiveness of the equipment for cogeneration. With certain combinations of these parameters, the cogeneration unit, installed on the basis of heat generation, may not be profitable, but unprofitable. Moreover, as natural gas price increases and electricity tariff remains fixed, CUs, designed as profitable, may become unprofitable. These conditions are considered in the article. Relationships between the CU’s parameters and tariffs for the natural gas and electricity, which determine the area of profitable work of the cogeneration unit, are obtained. Given the current prices for energy carriers, the design of the CU based on the communal heat supply comes to the selection of the equipment that ensures the profitability of the installation that is sufficient for the recoupment of capital investments within 2-3 years. At the same time, the acceptable limits of the possible increase in the gas/electricity tariffs ratio should be determined.
 The main conclusion: the cogeneration unit based on district heat supply with a positive economic effect can be installed only if certain economic and technological conditions, which must be taken into account when designing it, are observed.