Łukasz Bartela

Economic and environmental evaluation of selected advanced power generation technologies

In this article, the economic and ecological benefits of selected advanced technologies for electricity production based on coal and natural gas are evaluated. Among the analysed technologies are integrated gasification combined cycle (IGCC) systems, supercritical coal-fired power plants, multi-fuel hybrid cycles, and natural gas combined cycles. In addition, as a complement to coal technologies, CO2 capture and storage installations are adopted. The main indicators evaluated are the unit carbon dioxide emission and the break-even price of electricity. The analysis took into account, among other factors, the existing support mechanisms for ecological technologies, primarily in the form of the European Union (EU) Emissions Trading Scheme. The analysis shows that the systems integrated with CO2 capture can be competitive compared to systems without capture. Especially interesting in this context are IGCC systems integrated with carbon capture installations. The results are, however, affected by many factors, such as the fuel price, operational reliability, and auxiliary power need. The influence of these factors is evaluated in this article both qualitatively and quantitatively.

Thermodynamic and economical analysis of the ORC module application to an existing combined heat and power unit with the backpressure turbine

This paper presents the results of the thermodynamic and economic analyses of two variants of integration of a CHP unit with ORC modules. The first variant consists in an integration of a CHP unit with a single ORC module. The module is installed on one of the steam outlets from the asymmetric part of a back-pressure steam turbine. The second variant assumes installation of modules on two outlets of this part of the steam turbine. An argument for the integration of a unit with ORC modules is the ability to obtain in the summer period additional electric power based on the use of heat, which in the period of lower demand for heat is dissipated in the environment. For these two variants, the thermodynamic analysis was carried out, which allowed to determine the electrical power that can be generated by ORC modules. Analyses were performed for various low-temperature boiling fluids. Economic analyses were also performed, which allowed to determine the net present value and the internal rate of return for the two variants of integration. Assumptions required to perform economic analyzes were adopted. As a part of the economic analysis, sensitivity analysis of the selected economic effectiveness indicators on the relative change of the investment cost and electricity prices was performed. The influence of changes of working time of the integrated unit within a year and the discount rate was also examined. The obtained results indicate a high potential of the proposed integrations. Supplying of ORC modules by steam leaving the backpressure steam turbine can allow for economically justified extension of the period of operation of many CHP units. Appropriate modernizations in the case of switched off post-industrial CHP units can contribute to the restoration of their ability to generate profit.