Agir em comum / agir o comum

Agir em comum / agir o comu

Hydrodynamic Interaction between an Accretion Flow and a Strong Wind around a Black Hole

In 2015, space heating and domestic hot water production accounted for around 40% of the Swiss final energy consumption. Reaching the goals of the 2050 energy strategy will require significantly reducing this share despite the growing building stock. Renewables are numerous but subject to spatial–temporal constraints. Territorial planning of energy distribution systems enabling the integration of renewables requires having a spatial–temporal characterization of the energy demand. This paper presents two bottom-up statistical extrapolation models for the estimation of the geo-dependent heat and electricity demand of the Swiss building stock. The heat demand is estimated by means of a statistical bottom-up model applied at the building level. At the municipality level, the electricity load curve is estimated by combining socio-economic indicators with average consumption per activity and/or electric device. This approach also allows to break down the estimated electricity demand according to activity type (e.g., households, various industry, and service activities) and appliance type (e.g., lighting, motor force, fridges). The total estimated aggregated demand is 94 TWh for heat and 58 TWh for electricity, which represent a deviation of 2.9 and 0.5%, respectively compared to the national energy consumption statistics. In addition, comparisons between estimated and measured electric load curves are done to validate the proposed approach. Finally, these models are used to build a geo-referred database of heat and electricity demand for the entire Swiss territory. As an application of the heat demand model, a realistic saving potential is estimated for the existing building stock; this potential could be achieved through by a deep retrofit program. One advantage of the statistical bottom-up model approach is that it allows to simulate a building stock that replicates the diversity of building demand. This point is important in order to correctly account for the mismatch between gross and net energy saving potential, often called performance gap. The impact of this performance gap is substantial since the estimated net saving potential is only half of the gross one

Electro What: A platform for territorial analysis of electricity consumption

In the canton of Geneva, the per capita electricity consumption of private households increased by 12.1% between 2000 and 2010. The electricity efficiency program ECO21 conducted by the Services Industriels de Genève (SIG) was initiated with the goal of reducing the demand. A territorial characterization of electricity demand permits designing such programs and making ex-ante estimations of savings potentials. To extend this approach to the whole Swiss territory, a collaboration was initiated with SIG to develop the ElectroWhat platform that decomposes the yearly electricity consumption of every Swiss municipality into estimated load curves per activity and per electric appliance

Energy efficiency indicators for high electric-load buildings

Energy per unit of floor area is not an adequate indicator for energy efficiency in high electric-load buildings. For two activities, restaurants and computer centres, alternative indicators for energy efficiency are discussed

Evaluation du développement des PAC dans le canton de Genève

La présente étude a été menée à la demande de l'Office Cantonal de l'Energie (actuellement ScanE). Dans le cadre de sa politique énergétique, le canton de Genève cherche à réduire ses importations d'électricité afin d'en diminuer la part non renouvelable et tout particulièrement celle issue du nucléaire. Dans ce contexte, la technologie de la pompe à chaleur (PAC), qui utilise de l'électricité, semble peu adéquate aux yeux des représentants politiques et pour cette raison, la conception générale de l'énergie ne fait pas figurer la promotion de la PAC, alors qu'au niveau suisse, cette technologie est soutenue par l'OFEN (Office Fédéral de l'Energie) ainsi que par la majorité des cantons. Le développement des PAC dépend de nombreux paramètres. La modification des standards de construction (nouvelle norme SIA 380/1, label Minergie) annonce une réduction des besoins en énergie de chauffage et de production d'eau chaude des nouvelles constructions avec pour conséquence une forte réduction des puissances en jeu. Les coefficients de performance (COP) des PAC progressent chaque année, rendant cette technologie toujours plus fiable et performante. Ce rapport doit permettre d'évaluer l'évolution de la part de la demande d'électricité imputable aux PAC en tenant compte des évolutions précédemment énoncées ainsi que de la conversion des chauffages électriques fixes, de la conversion de production d'eau chaude sanitaire par chauffe-eau électrique et de la compensation possible de ces besoins par une production locale et/ou renouvelable d'électricité. L'impact global de ce développement sera évalué au travers d'écobilans