Load frequency control (LFC) is one of the most important tools in power system control. LFC is an auxiliary service related to the short-term balance of energy and frequency of power systems. As such, it allows the acquisition of a central role in enabling electricity exchanges and providing better conditions. The classification of LFC can be carried out from different angles: we can enumerate, among others, the type of control used. The following types of control are presented in this review: classical, optimal, and robust control. More advanced controls can also be used for classification: fuzzy logic control, ANN control, genetic algorithms, PSO control, etc. The influence of renewables and power control tools like FACTS is also considered as a category to be analyzed. The last classifications are related to two important subjects—the influence of DC links on LFC efficiency and the dangers of cyberattacks on the LFC.

The aim of this paper is to present the state of development of renewable energy sources (RES) in Poland in accordance with the obligations of European Union energy policy. The EU Member States are obliged to adopt different support mechanisms for the development of renewable energy sources, and in consequence to achieve their Directive’s targets. Poland, being a Member State of the EU since 2004, has accepted a target of a 15% share of energy generated from renewable energy sources in final energy consumption, including 19.3% from renewable electricity until 2020. Due to the difficulties with target achievement, the authors found it reasonable to analyze the challenge of RES development in Poland. The article presents energy policy in the EU, as well as the review of measures implemented for renewable energy development. The current state of and perspectives on using renewable energy sources in Poland and in the EU are also depicted. In the article, the authors analyze the relation between reference prices at dedicated RES auctions in Poland and the levelized cost of electricity (LCOE). The paper also provides a description of the renewable energy sources’ development in three areas: electricity, heat and transport biofuels. Its main content, though, refers to the generation of electricity from renewable energy sources.

Vehicle-to-grid (V2G) technology is one of the advanced solutions that uses electric vehicles (EV) to balance electricity demand in the power system. It can be particularly useful in analyzing and then mitigating the risk of not delivering electricity to the end user. Therefore, it is necessary to analyze the possibility of operation of this technology in the legal framework. The article presents the analysis of the legal status in Poland, referring to the documents of the European Union and domestic legislation. Potential changes in Polish energy law that could facilitate the implementation of V2G technology are also proposed. In addition, the authors suggested the principles for the use of this technology, formulating a mechanism called the V2G Program. Within this Program, the V2G Service was defined and a business model of its implementation by a participant of the V2G Program (uEV) was presented. In addition, an uEV selection algorithm is provided so that the mathematical model of the V2G Service can be validated. Based on the performed simulations, it can be concluded that the implementation of the V2G Program requires significant changes in the Polish energy law, but it is feasible from the technical point of view.

Electric buses are increasingly appearing on the streets of cities around the world. Thus, it is necessary to consider the impact of their charging on the distribution system operation, especially near the charging point. This article presents the problems that may arise while new charging points are connected. Research was carried out on the existing charging point at Spartańska Street in Warsaw, which allowed to obtain daily bus charging profiles and voltage curves. The authors then proposed an exemplary model of a bus terminus with the designed infrastructure for charging buses, based on the assumptions of the public transport operator in Warsaw. The comparison of these two solutions was made and based on it, a methodology of calculating daily demand for any terminus was prepared. In addition, no problems with the power quality were found during the research. This allows us to state that the introduction of electric buses into the fleet of passenger carriers will have a minor impact on the operation of the power system in Warsaw.

One of the key aspects of vehicle-to-grid technology (V2G) is the analysis of uncertainty in electric vehicle user behavior. Correct estimation of the amount of available energy from electric vehicles that are expected to provide ancillary services to the electricity system operator or to secure the end user’s demand is essential to design these services in an appropriate way. Therefore, it is necessary to analyze the probabilities of V2G service performance for different scenarios. This paper presents the author’s approach to determining the values of V2G service provision probabilities using survey data. It was found that estimating these values using simulation and forecasting tools makes sense when the coefficients resulting from survey responses are used as initial data. Thus, the paper also presents the results of the surveys that were conducted. As the results from the simulations show, the values of the probabilities of V2G services are not high, which should induce future operators of V2G services to offer a beneficial product for the customer.

Thanks to the development of technology, the presence of electric vehicles (EVs) on the roads is no longer a purely theoretical issue. Also in Poland, electric cars are already visible on the streets, and charging stations (EVCS) are increasingly being installed near newly emerging buildings and housing estates. The article attempts to determine to what extent the use of electric cars will affect the demand for power and energy in the Polish electric power system (PEPS). The basis for PEPS modernization plans should be a detailed analysis of the technical adequacy of all its subsystems: generation, transmission and distribution, on the basis of which it will be possible to assess the potential impact of EVCS infrastructure operation on the Polish electric power system. This publication presents an example of such analysis for the distribution sub- sector, most exposed to potential negative interactions with the future, extensive infrastructure of EVCS.