The article presents a synthetic analysis of the crude oil market in Poland. As of today, this safety is provided mainly on the basis of native lignite and hard coal resources. However, the analysis of the hard coal market conducted by the authors indicates that the carried out mining restructuring (among others) led to an excessive reduction of mining volume and employment level in the hard coal mining sector. This led to a precedent situation when Poland became an importer of this energy carrier. In addition, the European Union’s requirements for greenhouse gas emissions must be taken into account. In connection with the above, it is necessary to search for new energy sources or technologies that enable hard coal to meet the requirements. It is possible to apply the so-called clean coal technologies that allow the greenhouse gas emissions generated during coal combustion to be reduced. As of today, they are not used on a mass scale, because the use of this type of technology involves additional financial expenses. However, taking into account that technologies have been growing faster and faster, are modernized in a shorter time, making a breakthrough discovery took hundreds of years, now it is often a few months, clean coal technologies can become the optimal solution in the near future. It is also necessary to diversify the sources of obtaining imported energy carriers.
The article describes coal and crude oil in terms of their mutual substitution. The article is a continuation of research conducted by the authors. Previous publications presented considerations on analogous topics related to natural gas and renewable energy sources. The crude oil market in Poland was analyzed and forecasts for oil extraction and the demand in the world and Poland by 2023 were presented. The SARIMA model was also created. The model made it possible to obtain oil an prices forecast.
The dynamic development of wind power in recent years has generated the demand for production forecasting tools in wind farms. The data obtained from mathematical models is useful both for wind farm owners and distribution and transmission system operators. The predictions of production allow the wind farm operator to control the operation of the turbine in real time or plan future repairs and maintenance work in the long run. In turn, the results of the forecasting model allow the transmission system operator to plan the operation of the power system and to decide whether to reduce the load of conventional power plants or to start the reserve units.
The presented article is a review of the currently applied methods of wind power generation forecasting. Due to the nature of the input data, physical and statistical methods are distinguished. The physical approach is based on the use of data related to atmospheric conditions, terrain, and wind farm characteristics. It is usually based on numerical weather prediction models (NWP). In turn, the statistical approach uses historical data sets to determine the dependence of output variables on input parameters. However, the most favorable, from the point of view of the quality of the results, are models that use hybrid approaches. Determining the best model turns out to be a complicated task, because its usefulness depends on many factors. The applied model may be highly accurate under given conditions, but it may be completely unsuitable for another wind farm.
In the constant pursue of the sustainability of socio-industrial systems, the definition of useful, reliable and informative, and at the same time simple and transparent, indicators is an important step for the evaluation of the circularity of the assessed systems. In the circular economy (CE) context, scientific literature has already identified the lack of overarching indicators (social, urban, prevention-oriented, etc.), pointing out that mono-dimensional indicators are not able to grasp the complexity of the systemic, closed-loop, feedback features of CE. In this respect, Emergy accounting is one of the approaches that have been identified as holding the potential to capture both resource generation and product delivery dimensions and therefore to provide an enhanced systems’ evaluation in a CE perspective.
Because of Emergy’s intrinsic definition and its calculation structure, Emergy-based indicators conceptually lend themselves very well to the evaluation and monitoring of circular processes. Additionally, Emergy has the unique feature of enabling the evaluation of systems that are not necessarily only technosphere systems, but also of technological systems which embed nature (techno-ecological systems).
The present paper gives a perspective on a set of Emergy-based indicators that we have identified as suitable to evaluate circular systems, and outlines the different perspective compared to the circularity indicators defined in the “Circularity Indicators Project” launched by the Ellen MacArthur Foundation.
Among the numerous modern, high-efficiency energy technologies allowing for the conversion of chemical energy of coal into electricity and heat, the Direct Carbon Fuel Cells (DCFC) deserve special attention. These are devices that allow, as the only one among all types of fuel cells, to directly convert the chemical energy contained in solid fuel (coal) into electricity. In addition, they are characterized by high efficiency and low emission of pollutants. The paper reviews and discusses previous research and development works, both around the world and in Poland, into the technology of direct carbon fuel cells with an alkaline (hydroxide) electrolyte.