Taking the importance of time and risk into account has a significant impact on the value of

investment projects. Investments in the energy sector are long-term projects and, as such, are burdened

with uncertainty associated with the long-term freezing of capital and obtaining the expected

return. In the power industry, this uncertainty is increased by factors specific to the sector,

including in particular changes in the political and legal environment and the rapid technological

development. In the case of discounted cash flow analysis (DCF), commonly used for assessing the

economic efficiency of investments, the only parameter expressing investor uncertainty regarding

investment opportunities is the discount rate, which increases with the increasing risk of the project.

It determines the value of the current project, thus becoming an important criterion affecting

investors’ decisions. For this reason, it is of great importance for the assessment of investment

effectiveness. This rate, usually in the form of the weighted average cost of capital (WACC), generally

includes two elements: the cost of equity capital and borrowed capital. Due to the fluctuant

relationship between these two parameters in project financing, performing a WACC analysis in

order to compare the risks associated with the different technologies is not completely justified.

A good solution to the problem is to use the cost of equity. This article focuses on the analysis of this

cost as a measure of risk related to energy investments in the United States, Europe and worldwide.

In the paper I try to reconstruct the main theoretical assumptions underlying Paul Veyne’s vision of the ancient world that are to be found in his book L’empire gréco-romain. First of all, recalling the opposition between two ways of making the past intelligible: “explication” versus “explicitation”, I show how the French historian uses that second type of historical analyse to reveal some ancient phenomena (i.e. “democracy”, “imperialism”, “soul”, “faith”) in their original and singular forms. Then, I pass to the question of causality and genesis in history. It seems that in Veyne’s book we can distinguish three different “models” of becoming: 1) “time of a project”, 2) “epigenesis” and 3) “discourse effectiveness”. All these fi ndings lead me to the conclusion that Veyne’s writing of history is essentially “essayistic”.

This is an analysis of the commentaries published in the Polish press in the wake of the celebrations of the 60th Anniversary of the World War II Victory Day in Moscow in 2005. In Poland these commemorations triggered a live debate which focused on the future of Polish-Russian relations, Russia’s strategic goals on the international scene, the Polish Eastern policy and the uses of history as a tool of state policy.

The article discusses issues related to the generation, use, and transboundary movement of waste labeled with the code 191210 according to the waste catalogue regardless of its origin (municipal, industrial or mixed). Data contained in voivodship reports related to waste management and information about transboundary shipments shared by the Chief Inspectorate of Environmental Protection were also used in the article. The imbalance in the amount of produced and energetically used alternative fuels in Poland in the years 2015 to 2017 has been confirmed. This affects the economy of the waste management sector involved in the production of alternative fuels. The oversupply causes the prices of alternative fuels to fall and increases the need for subsidies in the case of the recovery or disposal of alternative fuels of lower quality. In the near future one should expect a stabilization of the supply of combustible waste to the cement industry, which is now beginning to achieve its technological potential; this is due to a high degree of replacement of fossil fuels. One should also expect an increase in the demand for alternative fuels from the commercial power sector and heating sector. It has been shown that much more alternative fuel is imported than exported from Poland. The amount of imported alternative fuel in the market is relatively low compared to the amount of fuel produced in the country. This oversupply affects, although not significantly, the possibility of using domestic waste for energy recovery. The export of the alternative fuel produced in the country is a favorable phenomenon when there is no possibility of sale on the domestic market. It seems rational, especially in the case of exports from installations producing fuels in border provinces.

In this study, the results of experiment research on building mortars based on dry mixtures with the use of granite dust are given. It also shows the possibilities of their industrial release. In the conditions of energy resources shortage, gradual exhaustion of natural raw materials, aggravation of environmental problems, an important direction in the production of building mixtures is the development of mixes with waste materials from various industries. In particular, granite dust, which simultaneously allows to rationally use natural mineral material and solve environmental problems. Based on the obtained data, experimental and statistical models of physical and mechanical properties of fresh and hardened mortar are constructed and ways of optimizing their compositions and improving the properties of mortars are analyzed. It is established that the use of granite dust and some additives provides high standardized parameters for mortar mixture and bricklaying process, including plasticity, compressive strength and others at the low level of cement consumption. Fresh mortar mixtures have a prolonged slump retention.

The article attempts to identify environmental conditions for the development of cogeneration companies in Poland. The article systematizes knowledge about environmental regulations which concern this issue. Within the framework of identified environmental conditions, the authors characterize issues related to national legislation that regulates the operation of cogeneration companies, as well as the requirements resulting from European Union and national regulations in this matter. These regulations, directly and indirectly, affect the long-term future of cogeneration companies and the energy sector as a whole. Undoubtedly, in the current state of environmental regulations in force, the key change for a power company such as a cogeneration company is to meet the requirements for the emission of harmful substances. The change was introduced in 2016 as a result of more stringent emission limits and the adoption of the IED (Industrial Emissions Directive). The implementation of recommendations of the BAT (Best Available Techniques) Conclusions in 2017 additionally tightened the required limits. Undeniably, the key period for cogeneration companies will be 2021 as per the implementation of imposed harmful substances emission’s limits. The article comprehensively discusses the conditions that substantially affect the long-term growth of a cogeneration company and are crucial when making assumptions intended to address strategic development issues in the domestic fuel and power sector.