Search

Abstract: The Energy Strategy of the Republic of Croatia was adopted by the Croatian Parliament in 2009 for the period until 2020 in order to harmonize national energy goals with goals and time framework of strategic documents of the European Union. The adoption of the Energy Strategy Implementation Program with associated measures is still in process. The goal of the Strategy was to create sustainable energy system that will make a balanced contribution to the security of energy supply, competitiveness and environmental protection in Croatia. In this paper an overview of the energy production, final energy consumption and planned development of energy infrastructure is given. The intention of the paper was to research and stress out the abilities and opportunities of Croatian energy system and to give recommendations for Energy Strategy implementation and practical realization of planned energy infrastructure projects for improvement of security of energy supply and competitiveness of energy system of the Republic of Croatia. [Copyright &y& Elsevier]

Given the self-declared energy and environmental protection objectives of many car manufacturers responsible companies must use energy-efficient production technologies. The running costs of production sites are a decisive factor in the overhead of automotive production. Therefore, it is important for many operators to reduce those costs in a sustainable way. For this purpose, they attempt to reduce both the energy consumption costs and CO 2 emissions of production systems. However, most components of the energy costs are determined during the very early phases of the product creation process. To achieve an estimation of the energy consumption in this early planning stage, a new suitable forecasting method is required. Therefore, this paper presents an approach for determining the prospective energy consumption by using Methods-Energy Measurement combined with defined energy reference cycles for manufacturing technologies. With this approach, key performance indicators are defined, and the production technologies are divided into basic energy consumers. The average energy values will be determined empirically by using the defined energy reference cycles. With these data, the energy demands for different scenarios are calculated. Thereby, it is possible to estimate the potential energy consumption of complex manufacturing cells. The designed method is validated within a case study of a modern automotive body shop. In summary, the approach contributes to identify and realize sustainable solutions in advance and thus increase the profitability of a factory. [ABSTRACT FROM AUTHOR]

Abstract: Nowadays, the importance of electrical generation based on renewable energies is increasing, due to its low emissions of greenhouse gases. At the same time, Distributed Generation and Microgrids (MG) are becoming an important research line because of their peculiar characteristics. MGs are composed of small power sources which can be renewable, placed near customer sites. Moreover, they have the inherent property of islanding: the disconnection of either the MG from the main grid or a portion of a MG from the rest of the MG. There are two kinds of islanding: intentional or planned (for maintenance purposes), and unintentional or unplanned. The latter is mainly due to disturbances and it is used to avoid damages in sources and loads. It is the most critical case because it must be detected as soon as possible to activate all the control systems which allow continuing the energy production and distribution despite the disconnection. In islanding, it is crucial to ensure the power and the electrical signal quality. In grid-connected mode, the inverters use the electrical signal of the main grid as reference. Once in islanding, the main grid reference is lost and new control techniques for the inverters are needed in order to obtain the correct values of voltage magnitude and frequency in the MG. The main objective of this paper is to make a survey on MGs focussed on two important features: unplanned islanding and control of inverters in that scenario. The idea is to present the basic architectures and regulation techniques of MGs and to study the islanding behaviour, mainly the different detection techniques and the inverters’ control once islanded. [Copyright &y& Elsevier]