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Abstract In this article, we investigate the intergenerational transmission of sustainable consumption practices. Whereas previous studies have used self-reported attitudes and behaviour, this study uses data on actual energy consumption for space-heating and hot water combined with extensive panel data from Danish administrative registers. The paper shows significant intergenerational correlations between the energy consumption patterns of adults and their mothers, also when controlling for the energy consumption of the mother-in-law, where possible. Furthermore, it shows that the intergenerational correlation is slightly stronger for adults with lower income levels. These results suggest that energy consumption practices are shared and reproduced within the family. Following theories of practice, the intergenerational similarities in energy consumption practices refer to bodily learned practices that are indirectly transmitted and negotiated through family relations. In this way, these findings also contribute to a better understanding of how practical understanding regarding how to perform practices is transmitted within more ordinary aspects of consumption that play a less obvious role in distinction. To ensure more sustainable consumption practices in the future, this paper points to the importance of the role of family relations and the transmission of embodied practices.

The present paper exhibits a real time assessment of a robust Energy Management Strategy (EMS) for battery-super capacitor (SC) Hybrid Energy Storage System (HESS). The proposed algorithm, dedicated to an electric vehicular application, is based on a self-gain scheduled controller, which guarantees the H∞ performance for a class of linear parameter varying (LPV) systems. Assuming that the duty cycle of the involved DC-DC converters are considered as the variable parameters, that can be captured in real time, and forwarded to the controller to ensure both; the performance and robustness of the closed-loop system. The subsequent controller is therefore time-varying and it is automatically scheduled according to each parameter variation. This algorithm has been validated through experimental results provided by a tailor-made test bench including both the HESS and the vehicle traction emulation system. The experimental results demonstrate the overall stability of the system, where the proposed LPV supervisor successfully accomplishes a power frequency splitting in an adequate way, respecting the dynamic of the sources. The proposed solution provides significant performances for different speed levels.

Abstract The east German energy system is in a process of being completely rebuilt. Unfortunately, the huge investments are not used for implementing a technical and institutional restructuring, which is needed in order to achieve energy efficiency. The energy system will, among others, maintain its inefficient structure with separate production of heat and power. The ongoing changes are limited to improvements of power plant efficiency in combination with a change from a system based on brown coal for both heat and power into a system in which the electricity production is still based on brown coal and heating is produced on oil and natural gas. This rebuilding will bring the CO 2 -emission down from 20 t/inhabitant in 1989 to 13 t/inhabitant in year 2010, which is still much higher than the EU average on 8 t/inhabitant. This article describes how a restructuring could bring the figure below 7 t/inhabitant. The lack of ability to implement this restructuring of the energy system is, among others, due to an ownership structure, where networks of companies own the entire production and distribution chain from oil and coal to electricity. In this ownership structure, energy restructuring strategies which decrease the consumption of oil and coal will reduce the profits. At the same time the potential regulator, the parliamentary system, is politically and economically interlinked with and dependent upon the established energy companies. Consequently, it is difficult to establish the regulation reforms which are necessary for restructuring of the energy sector. There is still a lot to be gained from a restructuring of the east German energy sector. This restructuring requires institutional reforms, where the public regulation processes become independent of the industry which should be regulated.

In this communication, pretreatment of the anaerobically digested (AD) manure and the application of the pretreated AD manure as liquid medium for the simultaneous saccharification and fermentation (SSF) were described. Furthermore, fermentation of pretreated maize silage and wheat straw was investigated using 2l bioreactors. Wet oxidation performed for 20 min at 121 degrees C was found as the most suitable pretreatment conditions for AD manure. High ammonia concentration and significant amount of macro- and micro-nutrients in the AD manure had a positive influence on the ethanol fermentation. No extra nitrogen source was needed in the fermentation broth. It was shown that the AD manure could successfully substitute process water in SSF of pretreated lignocellulosic fibres. Theoretical ethanol yields of 82% were achieved, giving 30.8 kg ethanol per 100 kg dry mass of maize silage.

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

The anaerobic digestion of outdoor cultivated Rhizoclonium biomass was investigated in this study. The influence of applying mechanical and biological pre-treatment methods prior to the biomass digestion on the overall methane yields was examined. The results show that the application of a combined biomass blending ( 20% compared to use of a mechanical size reduction method alone. The methane yields from Rhizoclonium biomass were however observed to be considerably lower than those of other algae species from the literature.

A nonlinear dynamic model of the buoyancy system in a wave energy power plant is presented. The plant (“Wave Dragon”) is a floating device using the potential energy in overtopping waves to produce power. A water reservoir is placed on top of the WD, and hydro turbines lead the water to the sea producing electrical power. Through air chambers it is possible to control the level of the WD. It is important to control the level in order to maximize the power production in proportion to the wave height, here the amount of overtopping water and the amount of potential energy is conflicting. The pressures in the air chambers may be individually controlled by an air fan through an array of valves. The paper presents a model describing the dynamics from the air inlet to the level. Results from validation of the model against plant data are presented.

How quickly large biomass particles can ignite and burn out when transported into a pulverized-fuel (pf) furnace and suddenly exposed to a hot gas flow containing oxygen is very important in biomass cofiring design and optimization. In this paper, the ignition and burnout of the largest possible biomass (pine wood) particles in a pf furnace (a few millimeters in diameter) are studied experimentally in a single particle combustion reactor rig, in which the ambient gas temperature and oxygen concentration can vary in the ranges 1473–1873 K and 5–20%, respectively. A one dimensional (1D) transient model is also developed to predict their conversion, in which the key processes inside the particle and in the boundary layer outside the particle are properly considered. For the pine wood particles in which large temperature gradients exist, the primary heterogeneous ignition is always detected for all the test conditions. As the particle is further heated and the volume-weighted average temperature reaches the o...

Abstract This paper defines two electric grids for the area of Jutland in Denmark, namely the existing grid versus a “nature protection grid”, in which all 400 kV AC overhead lines are replaced by 150 kV lines. According to official Danish policies for laying underground cables, such a replacement makes it economically feasible on a long-term basis to replace all overhead lines with underground cables. The two grids are then tested against different energy demand and supply systems in a load-flow analysis. It is found that the “nature protection grid” is well suited for the implementation of sustainable energy systems exploiting both CHP and renewable energy sources such as wind power if certain strategies for the technical regulation of decentralised CHP units are used.