Feasibility Study of Using Geothermal Heat-Pump Units for Substituting Small-Capacity Coal-Fired Boiler Houses (Taking the Baikal Natural Area as an Example)

Abstract

The economic feasibility of substituting small-capacity coal-fired boiler houses with geothermal heat-pump units in the central ecological zone of the Baikal natural area is analyzed. Three versions of a space-heating system equipped with heat-pump units are considered depending on the source of low-grade heat and the method for extracting it: a well, a horizontal ground collector, and a water basin (Lake Baikal). The study is carried out for the raions of the Irkutsk oblast and the Republic of Buryatia located in the most favorable natural and climatic conditions in the southern part of the Baikal natural area's central ecological zone, which have different economic conditions in terms of electricity tariffs and fuel cost. A conditional small-capacity coal-fired boiler house having averaged technical characteristics is taken as the base version for comparing it with heat-pump units. A monovalent mode of heat-pump unit operation is considered taking into account a shift for using a low-temperature space-heating system. The economic feasibility of substituting a coal-fired boiler house is estimated proceeding from the equality between the total discounted costs for implementing a space-heating system equipped with heat-pump units and costs for operation of the coalfired boiler house for the considered period of time. The dependences of the total discounted costs for the alternatives being compared have been obtained, using which it is possible to determine the level of electricity tariffs and coal prices at which the application of heat-pump units in the studied region becomes economically feasible. The influence of possible deviations of the conditions in a particular locality from the conditions typical for the analyzed regions that were adopted for consideration is taken into account. It can be concluded from the obtained results that, given the current prices for coal and electricity, it is not economically feasible to substitute small-capacity coal-fired boiler houses with heat-pump units under the natural and climatic conditions of the considered regions. The use of heat-pump units may become justified with a coal price equal to 5000-8000 rubles/t and electricity tariffs equal to 2-4 rubles/(kW h); in this case, the discounted payback period of investments will make approximately 30 years.

Directions for Transition to Low-Carbon Energy in the Baikal-Khuvsgul Transboundary Territory: Background, Conditions, Effects

“…An open loop with water intake from a reservoir is the most cost-effective method due to its relatively low cost [20]. However, a significant limitation is the Note -* at a rate of 82 rubles for 1 dollar.…”

“…The approach presented in [20] was used to assess the economic efficiency of heat pump unit to replace lowcapacity coal-fired boilers in the territory at issue. The characteristics of low-capacity boiler houses operating in the studied area are presented in Table 4.…”