Environment has become a major concern for society, which awareness of the importance of an environmentally respectful development has been growing during the last decades. Economic reasons have encompassed this transition to a more planet friendly conception of human development. In fact, this transition has been parallel to the growing prices of fossil fuels, facing a clear perspective of a shortage on its availability, insufficient to cope with a growing demand in the near future. Within this context, the role of renewable energies in order to stop depending on fossil fuels and to reduce greenhouse gases emissions has become crucial.   Because of its climate, heating represents a major source of energy consumption in Sweden, accounting for almost 60% of the residential and services sector energy use. Maximizing the efficiency of heating systems and using renewable, environmentally friendly and economically sustainable sources of energy may have an enormous impact on both environment and economy.   In this thesis the use of district heating and ground heat pump for a multi-dwelling building is evaluated, both from the economic and environmental points of view. Both are recognized to be efficient heating systems, allowing important savings of other sources of energy, and respectful with the environment.   An installation combining both district heating and ground heat pump, for a multi-dwelling building in Gävle has been analyzed. Different scenarios have been considered, and results obtained show that when installing a ground heat pump, both economic savings and CO2 emissions reduction are obtained. Annual economic savings account for 16,8% when providing 60% of the thermal energy with the ground heat pump, and considering the investment associated to the recent installation of a new heat pump (in the case studied, boreholes were already drilled), the payback time is 7,4 years. CO2 emissions reduction for a normal year reaches 34%. However, if we look at the wider picture of electricity and heat production from a community (local, regional, national or even international) point of view, several considerations have to be taken into account, which are discussed in the report.

For a district heating company it is of importance to have an efficient and well performing system. A central part in the work to lower temperature levels in district heating networks is to acknowledge and improve cooling capability in substations. The aim of this thesis is to analyse substations in Polish district heating systems in order to identify reasons of poor cooling and to present suggestions of implementable measures. Furthermore, the economical saving potential from an improved cooling is evaluated. The analysis was carried out for two of the five Polish companies included in this report; Sydkraft EC Slupsk and MEC Koszalin. It was followed by two scenarios created for evaluation of improvement possibilities based on calculated financial savings from reduction of distribution heat losses and distribution pumping. The results show that there are significant improvement possibilities. From the carried out scenarios a saving potential between 15 000 to 20 000 PLN/substation is possible to achieve for selected worst substations, if their individual annual average cooling is set to 30°C. The analysis further shows that causes of poor cooling in substations are highly individual but points out that customer owned substations are represented in the majority of worst substations.

The municipality of Knivsta plans to expand from 15,000 to 25,000 inhabitants until the year 2025. In order to do so the municipality is planning to build a new residential area, Nydal. The purpose of this bachelor thesis is to estimate the heat demand for the new district and to investigate the advantages and disadvantages of using a common or an individual heat solution. The common solution consists of a pipe grid system connecting each building with a central heat source and in the individual solution each building has its own heat source. The heat units that have been used are combined heat and power and solar thermal heating. The total yearly heat demand for Nydal was calculated to total 21.6 GWh for the common solution and 19.4 GWh for the individual solution. This implies that the losses in the pipe grid are 2.2 GWh. The heat demand peaks are largest in January, about 7600 kW, and smallest in July, about 300 kW. To cover the heat demand for the common solution during summer, solar panels need to cover 6.5 per cent of the roof area. To be able to cover the heat demand for the larger buildings in the individual solution up to 45 per cent of the roof area needs to be covered with solar panels. Furthermore, the total installed heat power from CHP plants is 4320 kW in the common solution and 7375 kW in the individual solution. In conclusion, a common solution is to prefer because less CHP needs to be installed despite heat losses in the pipe grid.

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No description available.

Thesis (M.S.)--University of North Texas, Aug., 2007. / Title from title page display. Includes bibliographical references.

Thesis (Ph. D.)--Catholic University of America, 1931. / Vita. Bibliography: p. 157-160.

Thesis (MBus) -- AUT University, 2008. / Includes bibliographical references. Also held in print ( ix,143 leaves ; 30 cm.) in the Archive at the City Campus (T 338.47919313 ERU)

Zugl.: Clausthal, Techn. Univ., Diss., 2008

Thesis (Ph. D.)--Agra University, 1951. / Includes bibliographical references.