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The installation of heat pumps in district heating (DH) systems is one of the most promising technologies to increase the efficiency of heat supply by using renewable energy sources and reducing heat carrier temperatures in the networks. The possibilities of installing heat pumps in DH systems are very wide, but most often the main purpose of their application is to increase the temperature of the supplied heat carrier at the heat substations of individual consumers or their groups. This paper describes a study that analyzed the possibilities of integrating an individual heat pump at a heat substation in a building to reduce the temperature of the heat carrier in the return line. The results of the study revealed the dependences of the reduction of the heat demand of the building from the DH network, the power of the heat pump, the coefficient of per [ABSTRACT FROM AUTHOR]

Combating climate change and reducing greenhouse gas emissions are among the European Union's priorities today. Direct implementation of these priorities is sustainable buildings. This paper analyzes the energy supply of a health resort building with renewable energy sources in the context of the "BREEAM In-Use" sustainability assessment system. The criteria for the "BREEAM In-Use" scoring system are grouped according to the 3E criteria and recommendations are made for the weights of the 3E assessment system criteria. In accordance with the criteria grouping methodology in the article, in the context of 3E criteria, the maximum weight should reach the energy indicator (about 50%), the second most important one is the ecological criterion, and about 16% should only meet the economic criterion. [ABSTRACT FROM AUTHOR]

The paper deals with the issue of the small business in the renewable energy field. The experience of the renewable energy leaders shows that the exploitation of the potential of renewable energy sources allows to overcome the dependence on the energy import, stimulates economic growth, and enables the creation of new workplaces as well as opening the prospects for the scientific and technological progress. A very healthy solution would be a promotion of "green and small" business. Therefore there is given an analysis of the main political, economic, social, and technological assumptions of "green and small" business development and its evaluation in the paper. [ABSTRACT FROM AUTHOR]

Construction of small distributed generators close to consumers is one of important features of the power systems development in many countries. This paper describes the current status of distributed generation generation in the EU countries, the advantages and disadvantages of small generators as well as the problems of their connection to a distribution network. The most important factors stimulating the development of distributed generation in many European countries are the following: the growing contribution into electricity production balance of power plants using renewable energy sources which are originally decentralised; development of small (with capacity less than 50 MW) combined heat and power production (cogeneration) power plants; implementation of energy policy directed to promotion of renewable energy sources and cogeneration. The paper focuses on a comparative analysis of distributed generation in the EU countries and its role in the balance of electricity generation. An analysis of the legal and economic environment, as well as principles of regulation of distributed generation and barriers for its penetration is presented. The analysis is based on the methodology of the European research project SOLID-DER financed by the 6th Framework Programme; 17 research institutions, universities and companies are involved into the preparation of this project. [ABSTRACT FROM AUTHOR]

Dealing with information systems of wind farms, promoters and designers encounter a problem of choosing the most appropriate communication variant. The information systems of CORBA and COM types still in use do not respond to the new challenges. The paper deals with the distinctive characteristics of communication variants of information systems developed in accordance with the concept of the standard IEC 61400-25 Wind Turbine Generator Systems -- Part 25: Communications for monitoring and control of wind power plants. Three communication variants are subjected to comparison: centralised topology, mixed topology and seamless topology. To evaluate an information system, the relevant criteria have been proposed (such as design cost, investment cost, outage timescale, etc). The evaluation of utility of communication variants is formulated as a multi-criteria problem. The problem is solved by the deterministic method. Seeking to specify the deterministic estimates received, a new probabilistic-statistical multi-criteria method based on normal distribution is proposed. It allows for the "measurement" of uncertainty of expert's input estimates. The application of the method is demonstrated for the problem in question. The results of solution -- the estimates of multi-criteria utility of each communication variants -- are discussed. The paper concludes that the method proposed might be a good instrument for comparison of competing projects, strategies or alternatives. [ABSTRACT FROM AUTHOR]

Along with a growth in the spread of renewable energy (RE) use, the demand of reliable and more detailed data about the disposable RE source is increasing. The paper presents the initial stage of processing meteorological data as baseline information for describing the RE potential. The analysis method of descriptive statistics has been applied for data processing. Research was performed to illustrate the benefit of the applied analysis. Using meteorological data collected in the Laboratory of Building Energy and Microclimate Systems of Civil Engineering Research Centre, the analysis of received findings and statistical processing was performed. The research showed that statistical characteristics gave additional valuable information about dominant RE streams in a particular location. It was determined that the chaotic nature of stream variation and occurred outliers of values influence the values of RE streams greatly when average magnitudes are calculated. Having the limits of values to RE stream variation and the weighted centre of distribution without outliers creates a possibility of selecting a RE transformer or their combination more objectively and choosing equipment operation parameters to use local conditions better. The evaluation of local meteorological conditions applying statistical methods may help both the energy user and the creator of a technological solution to developing sustainable RE expansion. [ABSTRACT FROM AUTHOR]

This paper analyzes the external costs of electricity generation technologies, which are highly important in order to create an effective policy to reduce the negative effects of energy supply and consumption. The described ExternE methodology allows us to accurately calculate the external energy cycle costs, considering the location of the power station and meteorological conditions. Based on this methodology and using the EcoSense model, the analysis of Lithuania and EU-27 external costs of pollutants emissions into the atmosphere is presented, as well as the external electrical power generation technology cost analysis in Lithuania. The conclusion was made that renewable energy-producing power plants have the lowest external costs, also the external cost comparison of the impact area and the technology life-cycle rate was made. [ABSTRACT FROM AUTHOR]

The paper deals with the sustainability assessment of electricity generation technologies in the EU, which was performed by applying the multi-criteria analysis approach. Integrated indicators for sustainability assessment of electricity generation technologies were calculated for specific technologies. These integrated indicators were obtained by summing up the normalized social, economic and environmental indicators for specific electricity generation technologies. The electricity generation technologies were ranked according to their positive impact on sustainable energy development in the EU, based on these integrated indicators. Sustainability assessment indicators for specific technologies were evaluated by applying results of empirical studies conducted in the EU. The sustainability assessment performed in the present study has indicated that the best technologies in terms of sustainability in the energy sector are technologies based on renewables. [ABSTRACT FROM AUTHOR]

The paper presents the current situation with the renewable energy sources in Lithuania. An overview of legislation promoting the production and usage of renewable energy in Lithuania is presented. Renewable energy production methods suitable for Lithuanian conditions, their advantages and disadvantages are discussed. It is shown that there is no any promotion from the state for usage of solar energy in private households. The potential of solar energy usage is determined. In order to show the effectiveness of solar thermal energy utilization under similar climatic conditions presented the example of promotion policy model and its results in Poland. [ABSTRACT FROM AUTHOR]

In many countries, including Lithuania, reliable wind power prediction is becoming necessary because of increasing wind power penetration. In this paper, a short review of wind power prediction models used in other countries is presented and possibilities of their application in Lithuania are discussed. Statistical and time-series models are based on wind speed or wind power measurements. Physical models take the output from numerical weather prediction models and downscale it to the wind farm's hub-height accounting for local terrain, roughness and atmospheric stability. Time-series models are accurate enough for the prediction period of 3-5 hours. For longer periods, physical and statistical models give better results. With a sufficient amount of data, the wind power prediction system in Lithuania can be implemented within a year. [ABSTRACT FROM AUTHOR]

Future alternatives must be developed for long-term and environment-friendly energy supply needed by the constantly growing world's population. Electrical-generation efficiencies of 70% are possible nowadays, along with heat recovery possibility. Fuel cells appear to be an important technology for the future. They can run on a variety of fuels, from solar hydrogen to methanol, from biomass to gasified coal. As the technology develops, and if the cost of fossil fuels continues to rise, this clean, efficient alternative will find more and more practical uses. The paper discusses stationary applications of the Solid Oxide Fuel Cells system. Fuel, oxygen and produced energy calculations are presented. [ABSTRACT FROM AUTHOR]