Identification and evaluation of innovative energy initiatives for the La Défense business district
What solutions for better energy use in a business district?
Within the La Défense business district, there is a very real contrast between the recent, energy-efficient buildings and those that are ageing and far more energy-intensive. For a better understanding of the district’s overall energy signature, EPADESA has set up an observatory to monitor the energy performance of buildings and public spaces.
Efficacity was tasked with identifying innovative initiatives to improve the energy efficiency of the district or of defined sub-sets, by means of :
- Energy sharing (production, storage, etc.) ;
- Waste heat recovery;
- Assessment of energy and environmental impacts.
Efficacity a développé une approche performancielle de l’évaluation des projets, consistant à mesurer l’impact des actions innovantes. L’évaluation des impacts en phase de conception devient ainsi un élément important d’aide à la décision. Les impacts évalués concernent l’ensemble des dimensions d’un projet, en ciblant de façon privilégiée les dimensions suivantes :
- Energy consumption;
- GHG emissions;
- User comfort level;
- Overall cost.
Specialist attention is paid to hypotheses regarding usage and resident behaviour. Building energy simulation tools to assess the performance of various technical innovations depend heavily on these hypotheses, which are rarely addressed in the kind of fine detail that takes into account the full complexity of new uses.
Following the diagnostic of the district, which represents the first stage in the approach, potential levers for action are then identified, after which the evaluation can be carried out.
The possibilities for energy sharing are selected for the sectors predetermined by EPADESA: the Coupole and Michelet sectors, the Eve Tower, and the Boieldieu and Carpeaux sectors.
This initial analysis serves to identify the sectors with high potential for improved energy performance. Continuing the study calls for deliberation on technical feasibility but also on the economic model for energy sharing.