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Renewable energy has been prioritized in Danish energy policy since the early 1980s. This has led to the current situation where Denmark is one of the leading countries in the world in the field of wind energy utilization. The background for this success is a story about how a society can manage the development and diffusion of sustainable technologies so that they are simultaneously socially acceptable and environmentally benign. Consequently, this article describes the relationship between the organization of wind power and the protection of nature. The aim is to analyse which kinds of public planning and policy can promote wind power and nature protection in a situation where a conflict exists between these two issues. The discussion acknowledges that it has been a serious problem to balance these contrasting considerations. However, it also suggests that the problems seem solvable if technology development, the social organization relating to the use of the technology and proper planning are brought together to work in a spirit of local involvement. © 1998 John Wiley & Sons, Ltd. and ERP Environment

Abstract The Danish city Frederikshavn is aiming at becoming a 100% renewable energy city. The city has a number of energy resources including a potential for off-shore wind power, waste and low-temperature geothermal energy usable as heat source for heat pumps producing district heating. In this article, a technical scenario is described and developed for the transition of Frederikshavn’s energy supply from being predominantly fossil fuelled to being fuelled by locally available renewable energy sources. The scenario includes all aspects of energy demand in Frederikshavn i.e. electricity demand, heat demand, industrial demand as well as the energy demand for transportation. The locally available energy resources are deliberated and an energy system is designed and analysed with an energy systems analysis model on an aggregate annual level as well as on an hourly basis. Particular attention is given to the use of geothermal energy in the area. It is shown, that the use of geothermal energy in combination with an absorption heat pump shows promise in a situation where natural gas supply to conventional cogeneration of heat and power (CHP) plants decreases radically.

Abstract This article presents a model of natural ventilation of buildings at the stage of design and a consequence of the behaviour of the occupants. An evaluation is made by coupling multizone air modelling and thermal building simulation using a deterministic set of input factors comprising among others climate, local environment, building characteristics, building systems, behaviour of occupants and heat loads. Selected deterministic input factors are varied to generate additional information applied in an optimization loop. With that, it is found that the optimal solution depends to a great extent on the possibility of optimization of the behaviour of occupants, and to a lesser extent on the design of the building.

Abstract There is a variety of solar-based energy system designs for buildings. Although these systems are economically profitable, reducing the energy cost of the buildings over time, their penetration has not been that impressive yet due to their high initial cost. In this study, an energy system comprising a few PVT panels (without any batteries) and a heat storage tank is proposed and investigated for smart buildings with two-way interactions with both heat and electricity grids. Removing the battery from the system would result in a sharp reduction of the cost of the system and, thereby, will make incentives for the end-users to adopt the solution. This novel system will not only supply the buildings’ real-time electricity and domestic hot water needs but also will compensate for a significant portion of the buildings’ energy expenses by selling the surplus generations to the electricity and heat networks. The dynamic model of the proposed system is comprehensively analyzed from thermodynamic and economic points of view using TRNSYS software. Additionally, defining the overall annual exergy efficiency, and the total product cost as the objective functions, optimization of the design and size of the system employing the TRNOPT tool has been done. It is shown that the optimized system results in 16.7 €/MWh and 7.7 €/MWh lower energy costs for electricity and heat of the buildings compared to when the buildings’ demand is only supplied by heat and electricity grids.

Greenhouse gas mitigation strategies are generally considered costly with world leaders often engaging in debate concerning the costs of mitigation and the distribution of these costs between different countries. In this paper, the analyses and results of the design of a 100% renewable energy system by the year 2050 are presented for a complete energy system including transport. Two short-term transition target years in the process towards this goal are analysed for 2015 and 2030. The energy systems are analysed and designed with hour-by-hour energy system analyses. The analyses reveal that implementing energy savings, renewable energy and more efficient conversion technologies can have positive socio-economic effects, create employment and potentially lead to large earnings on exports. If externalities such as health effects are included, even more benefits can be expected. 100% Renewable energy systems will be technically possible in the future, and may even be economically beneficial compared to the business-as-usual energy system. Hence, the current debate between leaders should reflect a combination of these two main challenges.

Abstract Sustainable infrastructures need technologies that do not cause climate or environmental degradation. The only long-term sustainable solution to global warming in terms of both environmental and economic mitigation is renewable energy generation for stationary and transportation infrastructures. The papers in this special issue review some of the major technology and economic approaches to sustainable infrastructures. They specifically address the issue of sustainable energy and transportation systems, i.e. energy generation for vehicles and the relation to the stationary supply of electricity and heating. In order for communities, regions, nations and international communities to become sustainable, they must make energy into integrated infrastructures that use hybrid technologies. This chapter reviews and summarizes many of the points made in the volume to that end: sustainable infrastructures for power generation and transportation. The key is to consider the true costs for energy in terms of well to wheels and how the developing technologies for renewable energy power generation can be leveraged or made into hybrid systems that are cost-effective and sustainable. The series of articles begin to get into such as an approach for sustainable energy systems.

Improper management of pig manure has resulted in environmental problems such as surface water eutrophication, ground water pollution, and greenhouse gas emissions. This study develops and compares 14 alternative manure management scenarios aiming at energy and nutrient extraction. The scenarios based on combinations of thermal pretreatment, anaerobic digestion, anaerobic co-digestion, liquid/solid separation, drying, incineration, and thermal gasification were compared with respect to their energy, nutrient and greenhouse gas balances. Both sole pig manure and pig manure mixed with other types of waste materials were considered. Data for the analyses were obtained from existing waste treatment facilities, experimental plants, laboratory measurements and literature. The assessment reveals that incineration combined with liquid/solid separation and drying of the solids is a promising management option yielding a high potential energy utilization rate and greenhouse gas savings. If maximum electricity production is desired, anaerobic digestion is advantageous as the biogas can be converted to electricity at high efficiency in a gas engine while allowing production of heat for operation of the digestion process. In conclusion, this study shows that the choice of technology has a strong influence on energy, nutrient and greenhouse gas balances. Thus, to get the most reliable results, it is important to consider the most representative (and up-to-date) technology combined with data representing the area or region in question.

Transport is one of the most challenge sectors when addressing energy security and climate change due to its high reliance on oil products and lack of the alternative fuels. This paper explores the ability of three transport strategies to contribute to the development of a sustainable transport in China. With this purpose in mind, a Chinese transport model has been created and three current transport strategies which are high speed railway (HSR), urban rail transit (URT) and electric vehicle (EV) were evaluated together with a reference transport system in 2020. As conservative results, 13% of the energy saving and 12% of the CO2 emission reduction can be attained by accomplishing three strategies compared with the reference transport system. However, the energy demand of transport in 2020 with the implementation of three strategies will be about 1.7 times as much as today. The three strategies show the potential of drawing the transport demand to the more energy efficient vehicles; however, more initiatives are needed if the sustainable transport is the long term objective, such as the solutions to stabilise the private vehicle demands, to continuously improve the vehicle efficiency and to boost the alternative fuels produced from the renewable energy sources.

This paper defines and compares two strategies for integrating intermittent renewables: SuperGrid and SmartGrid. While conventional energy policy suggests that these strategies may be implemented alongside each other, the paper identifies significant technological and socio-economic conflicts of interest between the two. The article identifies differences between a domestic strategy for the integration of intermittent renewables, vis-a-vis the SmartGrid, and a cross-system strategy, vis-a-vis the SuperGrid. Policy makers and transmission system operators must understand the need for both strategies to evolve in parallel, but in different territories, or with strategic integration, avoiding for one strategy to undermine the feasibility of the other. A strategic zoning strategy is introduced from which attentive societies as well as the global community stand to benefit. The analysis includes a paradigmatic case study from West Denmark which supports the hypothesis that these strategies are mutually exclusive. The case study shows that increasing cross-system transmission capacity jeopardizes the feasibility of SmartGrid technology investments. A political effort is required for establishing dedicated SmartGrid innovation zones, while also redefining infrastructure to avoid the narrow focus on grids and cables. SmartGrid Investment Trusts could be supported from reallocation of planned transmission grid investments to provide for the equitable development of SmartGrid strategies.