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Accounting for around 40% of the total final energy consumption, the building stock is an important area of focus on the way to reaching the energy goals set for the European Union. The relatively small share of new buildings makes renovation of existing buildings possibly the most feasible way of improving the overall energy performance of the building stock. This of course involves improvements on the climate shell, for example by additional insulation or change of window glazing, but also installation of new heating systems, to increase the energy efficiency and to fit the new heat load after renovation. In the choice of systems for heating, ventilation and air conditioning (HVAC), it is important to consider their performance for space heating as well as for domestic hot water (DHW), especially for a renovated house where the DHW share of the total heating consumption is larger. The present study treats the retrofitting of a generic single family house, which was defined as a reference building in a European energy renovation project. Three HVAC retrofitting options were compared from a techno-economic point of view: A) Air-to-water heat pump (AWHP) and mechanical ventilation with heat recovery (MVHR), B) Exhaust air heat pump (EAHP) with low-temperature ventilation radiators, and C) Gas boiler and ventilation with MVHR. The systems were simulated for houses with two levels of heating demand and four different locations: Stockholm, Gdansk, Stuttgart and London. They were then evaluated by means of life cycle cost (LCC) and primary energy consumption. Dynamic simulations were done in TRNSYS 17. In most cases, system C with gas boiler and MVHR was found to be the cheapest retrofitting option from a life cycle perspective. The advantage over the heat pump systems was particularly clear for a house in Germany, due to the large discrepancy between national prices of natural gas and electricity. In Sweden, where the price difference is much smaller, the heat pump systems had almost as low or even lower life cycle costs than the gas boiler system. Considering the limited availability of natural gas in Sweden, systems A and B would be the better options. From a primary energy point of view system A was the best option throughout, while system B often had the highest primary energy consumption. The limited capacity of the EAHP forced it to use more auxiliary heating than the other systems did, which lowered its COP. The AWHP managed the DHW load better due to a higher capacity, but had a lower COP than the EAHP in space heating mode. Systems A and C were notably favoured by the air heat recovery, which significantly reduced the heating demand. It was also seen that the DHW share of the total heating consumption was, as expected, larger for the house with the lower space heating demand. This confirms the supposition that it is important to include DHW in the study of HVAC systems for retrofitting. ; iNSPiRe

Like many countries around the world, Sweden is experiencing an exponential growth in PV installations, driven largely by building mounted systems. As prosumers become significant actors in the electricity market, questions about how to integrate them technically, economically, and politically are becoming more critical. A recently concluded, three-year research effort dedicated to the techno-economic analysis of PV prosumers has identified some of the major challenges for multi-family housing owners in designing PV systems in light of uncertainty in the market and policies. This paper highlights the primary results and conclusions from the project, including; PV system sizing, strategies for electricity metering to maximize revenues, a Monte Carlo analysis to understand market and policy risks, and several case studies. The overall conclusion is that PV installations can be a profitable investment in Swedish multi-family houses, however it is important to have a roof with good solar resources, a well designed and installed system, and to capture as many available economic support programs as possible. While primarily focused on multi-family houses, much of this work can be used as a practical guide for many Swedish prosumers towards developing practical systems integration solutions and increasing renewable energy usage in buildings. ; QC 20190208

Analytical study of solar photovoltaic water pumping system can be performed on the basis of technical, economical and environmental phenomenon. Use of solar energy to generate off grid electric power has been enhanced in these days and it is continuously increasing day to day due to the active interest of government and people. Numbers of applications are available in the solar energy field and amongst its various applications solar photovoltaic water pumping system is best utilized for agriculture and community water supply. It has increased agriculture productivity due to the power availability when needed for irrigation. This technology has improved the living standard of farmers and villagers who have not proper electrical supply as per their requirement for water pumping. This technology is helping to complete the mission of government and helps farmers to get water pumping system without any need of grid connection. The use of fossil fuels was common earlier for the pumping system and mostly diesel generator based systems are used which causes emission of CO2 and other harmful gases. Fossil fuels increase pollution and causes global warming, health problems and many more while solar energy based applications are helping to reduce CO2 emission and making a step toward green environment. This manuscript presents study of technical and economic analysis of solar water pumping system useful for various water supply applications especially in agriculture sector.

The need to integrate the rapidly growing share of variable renewable energy sources in the power sector requires solutions that are capable of mitigating the intermittent nature of these sources. They are expected to constitute the backbone of the electricity generation system in the coming years in order to reach ambitious goals in terms of energy security and reduction of environmental impact. Energy storage appears a promising solution to improve the capability of variable renewable plants to meet the energy demand at all times, mainly through the re-allocation of the generation surplus. Among the several options that can favor the integration of variable renewables, electrochemical storage technologies - batteries and electrolysis cells - constitute the focus of this dissertation. These approaches can be used to defer substantial quantities of energy for medium to long time intervals, are largely location independent, and are considered a strategic part of the decarbonization pathway in the European Union, which represents the geo-political framework under investigation. Battery storage systems are analyzed in both small- and large-scale settings to quantify the energetic and economic benefits deriving from a more efficient use of renewable energy. A small-scale battery system connected to a residential PV plant is analyzed and the results are compared to a demand response strategy for load shifting. The integration of a large-scale battery facility in the energy system of an island is also simulated and the results show a much lower level of renewable energy curtailment. In both the situations the projected costs of the battery technologies are used to assess their techno-economic performance. Solid oxide electrolysis cells (SOECs) as employed in power-to-gas upgrading of biogas constitute the second electrochemical energy storage pathway that was studied. The upgrading process sought to increase the methane content in the biogas by directly converting the embedded carbon dioxide through high-temperature ...

The authors want to thank the collaboration of the "Empresa Municipal de Aguas de Gijón (EMA)". This work has been carried out in the framework of the Research Grants 2018-2020 (reference FC-GRUPIN-IDI/2018-000205), funded by the Government of the Principality of Asturias (Spain) and co-funded by ERDF.

Recent United Nations high-level dialogue on energy, which had emphasized on energy usage and environmental protection, has renewed commitments by different countries on the adoption of electric vehicle (EVs). This paper aims to analyze the economic feasibility of establishing electrical charging stations, which is an important factor for the wide adoption of EVs, using life cycle cost analysis. Although local data have been used, the method can be easily adopted to analyze economic feasibility at different markets. The findings have revealed that an electrical charging station is only feasible when the acquisition cost is kept to a minimum to return 1.47 times the initial investment in terms of life cycle cost. An acquisition cost of BND 29,725 on the electrical charging station represents the threshold below which an electrical charging station is more attractive. In order to promote these charging stations, the government needs to provide multiple incentives, including a subsidy to reduce the acquisition cost, relaxing control on the electric selling price, taxing the establishment of conventional filling stations, and minimally reducing the profit margin on the selling price of fossil fuel. It has been shown that a 40% initial subsidy on the purchase of electrical charging stations, coupled with a slight subsidy of BND 0.018/kWh on electricity, would make electrical charging stations economically competitive. To reach its target of 60% electrification of the transportation sector, Brunei would need to implement a structure program to establish between 646 and 3300 electrical charging stations by the year 2035, to cater for its expected number of EVs.