Search

Due to an increase of intermittent renewable energy sources in power systems nowadays, there is a need for greater amount of regulation energy for power system balancing. Power system is mostly balanced by increasing or decreasing generation of conventional power plants, but a higher level of energy storage in the system would contribute to the grid stability, as well as grid flexibility. Energy storage can be integrated at various levels of electricity system (generation, transmission, distribution, customers) and in various forms of storage (hydro, thermal, chemical, etc.). However, each power system should be adequately analysed in order to find the best technical and economical solution. Within this research authors had intention to investigate the potential of power to heat options in large scale district heating systems. Power to Heat (PtH) represents a novel approach in balancing power system. In order to compare PtH with traditional sources of flexibility, three different technologies are analysed – pumped storage hydro power plant, cogeneration combined cycle gas turbine and electric boiler. The analysis was carried out by the means of PLEXOS Integrated Energy Model. The research has shown in which way and to what extend PtH concept can be competitive to traditional way of flexibility procurement. Moreover, a comprehensive economic analysis was conducted. Results have shown that electric boilers have the best economic indicators, while from the technical point of view, it is most desirable to combine electric boilers and cogeneration units. Namely, in that generation set-up the best techno-economic outcome is achieved. Economic analysis took into account capital and operation expenditures, while electricity price was modelled detailly on an hourly basis. Moreover, technical performances of observed technologies were load dependent which contributed to the reliability and accuracy of the results obtained.

Ambient conditions have significant effect on combined cycle power plants (CCPPs). Parameters-like efficiencies, fuel consumption, power production and even operation cost differ according to the ambient conditions that depend on the climate that cannot be changed. Therefore, deciding the location of the plant wisely would bring more efficient and profitable. In this paper, exergy analysis based on the second law of thermodynamics, considering environmental temperature variations, are performed for a cogeneration power plant. Mathematical model of analyse is introduced. Magnitudes of the variation of irreversibility, reversible power, power production and specific fuel consumption (SFC) are evaluated for the combined cycle. The results indicated that, decrease of environmental temperature augments the energy performance of the combined cycle form about 53% to 56% and improves the exergetic performance from about 51% to 56%. However, the augmentation via temperature decrease is not continuous. It is shown that the environmental temperature decrease causes a reduction about 5% in the SFC.