• Energy Research

Abstract This literature review was built upon recently published articles on Life Cycle Assessments (LCAs) of agricultural biogas plants, to: enhance understanding of the relevant literature in the field and the related question by readers worldwide. It was designed to highlight methodological issues and impact indicators, which best represent this research field; consequently, they should be considered in performing environmental assessments of agro-biogas derived energy systems. The literature review highlighted the wide variability of environmental results due to the ways the feedstock mixtures were produced, managed, and supplied; and due to the regions in which the anaerobic digesters were located and operated. Differences were found to be related to the aim and function of the study and to the methodological approach used, especially for the development of the environmental impact assessments. Other differences resulted from the ways the energy produced was utilised, whether it was used as an input to the natural gas national grid, and/or if it was used within the production system. The authors of this review concluded that, although much progress has been made, many unsolved challenges and methodological choices must be addressed to further improve the robustness of LCA in relation to AD and to related approaches.

The paper presents the use of Life Assessment Analysis (LCA) to determine the environmental impact of produced electricity and heat for power plants and coal-fired plants in Poland. Moreover, the usefulness of this method of assessment for energy sector was demonstrated. The article also presents the comparative analysis of energy production from burning solid fuels with the use of Ecoindicator 99. The conducted LCA analyses aimed at undergoing a critical review of the objectives of Polish energetic policy. The difference was presented concerning the results of the environmental impact as well as the causes of the essential values of the impact were discussed. Furthermore, the authors identified the measures which will contribute to the reduction of the impact of electricity production on the environment during the production of electricity in the future.

The article proposes methods for determining the optimal thermal insulation thickness for economic and ecological reasons, depending on the number of degree days of the heating period. Life cycle assessment was used for the ecological analysis. Analyses were performed for selected variants typical of Polish conditions. The optimal thermal insulation thickness as well as the amount of economic and ecological benefits depends very much on the condition of the building without thermal insulation, but also on the heat source used and the thermal insulation material to be used. For each variant, the optimal thermal insulation thickness for ecological reasons is much greater than the optimal for economic reasons. Taking into consideration the climatic zone and the associated number of degree days of the heating period, the colder the zone, the greater the optimal insulation thickness, as well as economic and ecological benefits.

Abstract Sustainable construction is the only way to ensure the implementation of the principles of sustainable development. The paper presents the importance of the thermal insulating investment of the building in three areas: economic, environmental and social. It shows the influence of the existence of the building on the environment, with a particular focus on the investment process involving thermal insulating of external vertical walls of the building. The paper proposes a methodology for assessing the environmental and economic benefits. The analyses for various combinations were performed, including the condition of the building before thermal insulation, type of construction material of the building, the heat source used, type of thermal insulation and climate zone, in which the building is located. The obtained results indicate that the thermal insulation investment is, for all examined variants, beneficial for ecological reasons and for almost all economic reasons. The highest values of economic benefits were obtained for the variant of the coldest climate, and the variant in which the building before thermal insulation has the worst thermal performance, the most expensive type of heat source (i.e. the biggest costs of obtaining 1 kWh of thermal energy) and the least expensive material used for thermal insulation. The highest values of environmental benefits were obtained for the variant of the coldest climate, which is obvious, but also for the variant, in which the building before thermal insulation has the worst thermal insulation, the least environmentally friendly type of heat source and the most eco-friendly insulation material applied. The paper also articulates social benefits resulting from such an investment.

The problem of air pollution not only in Poland but also around the world has become an important topic of political, economic, scientific, and legal discourse. Its position is the result of international obligations and Poland's membership in the structures of the European Union. In Poland, air quality is very bad, which makes it one of the countries with the worst air quality indicators in the European Union. One of the methods to reduce this high level of air pollution is to intensify the development of renewable energy sources by introducing effective support mechanisms for investors of new user-friendly and environment-friendly energy. The aim of the article was to analyse the support system for the development of energy production from renewable sources using the so-called "green" certificates of origin mechanism, which in Poland already has a 14-year tradition. The article presents the model of the renewable energy production support system in force in Poland. It pointed to its strengths and weaknesses. The development trends of the RES support system were also presented.

Energy saving is at the heart of sustainable development in the context of climate change. Saving energy is not only the amount of energy that we save, but also reducing emissions of pollutants to the atmosphere, as well as reducing the consumption of energy resources that are used to produce energy. Reducing pollutant emissions and the use of energy resources can be achieved by increasing the use of renewable energy sources, but at present, this method of obtaining energy in the world is not representative. It should be noted that renewable energy devices throughout the life cycle generate environmental impact. Similar to this situation, the building’s thermo-modernization, which is focused on reducing the pressure on the environment of the building’s user, also has an impact on the environment throughout the building’s life cycle. Determining this environmental impact and ecological or economic benefits or costs is the purpose of the following article. Thermo-modernization of the building, for the purposes of the article, is understood as thermal insulation of walls and replacement of the heat source for heating the building and preparation of hot utility water. The need to replace the heat source with a much more ecological one results in Poland from provincial legal regulations announced by virtue of a resolution. In the study, data from the Ecoinvent data library included in the SimaPro computer program was used for the LCA (Life Cycle Assessment) analysis. As a result of thermo-modernization of the representative buildings, large ecological benefits were obtained, while economic costs remain at a high level.

The energy efficiency of the construction sector should be determined by the cleanliness of the environment and, thus, the health of society. The scientific aim of this article was to develop a methodology for determining the optimum thickness of thermal insulation, taking into account both economic and ecological aspects and considering both heating and cooling costs. The method takes into account the number of degree days of the heating period, as well as the number of degree days of the cooling period. Variants in terms of different types of thermal insulation, various types of construction materials for building walls, climatic zones and heat sources, were taken into consideration. In order to find the optimum thicknesses of thermal insulation, both in economic and ecological terms, a metacriterion was used. The optimum thicknesses of thermal insulation with the use of the metacriterion were obtained in the range of 0.11–0.55 m. It was observed that the values of the optimum heat transfer coefficients for economic and ecological reasons do not depend on the type of construction materials used for vertical walls. The type of applied heat source is of the greatest importance for the size of the economic and ecological benefits. The proposed mathematical model for determining the optimum thickness of thermal insulation with the use of a metacriterion is a kind of generalization of earlier models from the literature.

Improving product sustainability is becoming an increasingly significant challenge for modern enterprises. A growing number of manufacturers are interested in enhancing product sustainability throughout the product life cycle. This study is concerned with using case-based reasoning to identify ways of improving product sustainability and select variables for model specification. Parametric models are applied to search for opportunities to improve product sustainability. This can be achieved through changes introduced at the product design stage. Simulations are performed using constraint-satisfaction modeling to identify conditions for achieving the sustainability targets of new products. Constraint-satisfaction modeling provides a suitable framework for finding all possible sustainability-enhancing changes (if any) during the new product development process. These changes may support R&D specialists in identifying opportunities to improve the sustainability of new products. We demonstrate the usefulness of the proposed approach with an example in which our method enabled a reduction in the product failure rate and an increase of battery lifespan for a robot vacuum cleaner line. We analyzed several factors affecting two targets of product sustainability: minimizing the product failure rate and maximizing battery lifespan. Our findings indicate that R&D staff size is the biggest factor in reducing the product failure rate, and that battery capacity is the most significant factor in battery lifespan.