High energy performance districts

The aim of this research programme is to study the various energy solutions available at district scale, based on evaluation of local energy resources and of the energy needs in the short and medium term, and also to assist urban agencies in choosing the best investment in technical, economic and environmental terms. The work of the programme addresses the energy system holistically, including the infrastructure and networks for all energy vectors, building morphology and envelopes, as well as usage.


Energy circulates around a city in a variety of forms (electricity, gas, heat, etc.). Energy demand (both electrical and thermal) varies considerably over time and space, depending on type of activity, time of day, season. Similarly, local renewable and recovered energy (R&REN) production capacity is subject to cycles and to a wide variety of external factors.

Urban energy is currently managed in silos by vector (supplier of electricity, gas, heat, etc.), with no coordination. This management approach makes it impossible to take advantage of possible energy sharing between different urban activities. It implies oversizing of infrastructure and networks and makes the use of renewable and recovered energy difficult. These “free, clean” energies are not always available at the precise moment and in the precise form they are needed.

Our vision: a convergence of local energy networks

A very high energy efficiency city must rely heavily on the intermediate scales ranging from the urban island to the district. Such a city is designed as an integrated system along the entire urban design and management value chain. Each decision takes account of usage and, systematically, of the entire range of technological possibilities. The systems of the future will gather together all the renewable and recovered energy sources available and will significantly increase output by combining energy vectors and maximising the synergies between urban functions and components.

In this new deal for district energy, the new district managers contract for and run full-scale energy communities within which the parties exchange energy and services with significantly enhanced overall efficiency.

Our general R&D method

Efficacity is developing a robust conceptual data model to describe and model the operations of a district and all the systems serving it in a Geographic Information System (GIS). This model incorporates the buildings, with all their diversity of form and usage, the energy systems and local production sources.

Efficacity is also developing dynamic multi-energy simulation tools capable of simulating energy flows at every point in the district for each vector, and of tracing the source of local production, in order to qualify the energy mix minute by minute and establish the overall dynamic efficiency of the district.

For the built environment, Efficacity is developing complementary dynamic tools for the exploration of morphologies, programming and constructive orientations at urban island scale allowing for refined modelling of their intrinsic energy performance and their effects on quality of use.

Through in-depth studies of generic urban fabrics, Efficacity is creating virtual test beds at the district-wide scale to define, analyse and validate the performances achievable by the latest generation multi-energy architectures.


Division into projects

This theme is divided into three research projects: