The constant increase in the popularity of renewable energy systems allows residential building users to apply solutions leading to the diversification of the energy supply. The use of RES systems in residential buildings not only contributes to a higher level of environmental care, but also significantly and measurably improves the energy efficiency of the facility. Using hybrid systems allows the supply to be reduced or eliminated from conventional energy sources. The article presents common layouts of renewable energy systems, which are successfully used in residential buildings. It also shows the impact of such systems on the amount of savings achieved in the use of energy from external or conventional sources. In residential buildings, the possibility of energy generation in the form of electricity and heat is dependent on many factors that determine the type and size of the systems used to obtain energy from renewable sources. We should assume the further and continuous development of RES, which will increase the share of electricity and heat produced in households. Technological development, decreasing prices of equipment and components used for the installation of green electricity generation systems will be a conducive factor for increasing the popularity of RES systems, not only for residential buildings but also for other types of buildings. The article also points out the economic aspect of the RES systems application. It presents the positive impact of RES installations on the environment and estimates the average time of financial reimbursement. The economic analysis concerns individual systems of renewable energy systems used in residential buildings.

The condition of the Polish energy sector does not inspire any trust of its customers. Outdated machinery and the lack of investment in new technologies make it necessary to take action to ensure the stability and continuity of electricity supplies to the end-user. In Poland, the industrial power sector is based on the use of coal and despite the Government’s announcements to resign from this raw material, more and more power investments are being made to generate energy from coal (Ostrołęka power plant). The solution which compensates for the current state of the Polish power industry is the development of distributed generation. The article presents a description of dispersed sources, power market, its organization and problems arising from its implementation. Distributed energy sources in the form of micro installations, energy clusters and virtual power plants have been described and characterized as well. It also assesses the impact of power market introduction on the development of distributed energy sources. The impact of the power market on the development of distributed sources is very hard to predict and determine. The functioning and further development of the energy sector, including the capacity market, strongly depends on the laws, regulations, as well as the economic and political situation in Poland and Europe. The social factor will also play an important role as the introduction of the capacity market will burden the financial side of each energy consumer. On the basis of the data presented on particular sources and distributed systems, one can only make predictions related to the possible effects of introducing the capacity market for the development of distributed sources.

The paper presents an analysis of the influence of the energy generated from renewable sources on an improvement in the energy efficiency of public utility building and households. It also presents the current state of the technologies for the production of electricity from renewable sources, as well as their share in the national power supply system. The conducted analysis concerns both micro, as well as large systems generating electricity. Systems generating power from renewable sources are gaining in popularity. With an increasing awareness in the society of the beneficial influence that renewable power generating systems have on the environment, as well as the support in form of various programs offering subsidies for the construction of new systems, power generation from renewable sources is becoming increasingly popular and common. Although the renewable energy systems are still not widely considered to be a profitable solution, systems using renewable sources of energy are positively perceived and treated as a new trend in the construction of multi or single-family residential buildings. The increasing share of the renewable energy in the national power supply system significantly reduces the demand for energy produced from conventional sources. This obviously translates into a reduced consumption of primary energy, for example, fossil fuels, and, in turn, leads to the reduced exploitation of natural resources, thus contributing to the protection of the natural environment. A reduced consumption of fossil fuels also means a significant reduction in environmental pollution during their processing into electricity or heat. Actions aiming at improving energy efficiency and reducing final energy consumption are being undertaken by many countries all over the world, and by the European Union. In 2012, the European Parliament and the Council issued Directive 2012/27/EU obliging the Member States to initiate actions aiming at a reduction in the consumption of final energy by 1.5% a year. The paper presents the current status of generation of energy from renewable sources during the last 13 years. The ways for using energy from the renewable sources to improve the energy efficiency of facilities were also discussed.