The department of the Pyrénées Atlantiques with the company Greengest. Implementation of an energy monitoring solution on the buildings of the department. The department's buildings correspond to 273 sites for 440,000 m2 with 2,500 employees.
Better manage its buildings, achieve financial savings and be part of Agenda 21, while involving and improving the comfort of users.
The first aspect of the approach consisted in carrying out an audit of the buildings. The objective of this step was to define the strategic orientations in terms of targeting of the actions on buildings and monitoring. The second aspect concerned the setting up of a steering committee to define and arbitrate the action scenarios. The scenario chosen consisted in carrying out work on the buildings and to establish an energy monitoring system. Knowing that we already had a construction team, the management of the operations was piloted internally. Works on buildings amounted to € 4 million for about sixty buildings, with an average time of return on investment of 11 years. The implementation of the monitoring system was entrusted to Greengest in the form of an energy performance contract (type: conception, realization, operation and maintenance contracts). The contract includes the installation of the monitoring system, its operation, the identification and implementation of energy performance actions, all over a period of 2 years with a target of 19% gain on energy performance. The performance obligation is governed by a system of bonuses and penalties, it is a form of co-engagement between Greengest and the department. So we bought an energy saving and not a technical solution. The monitoring solution covers 57 sites for an energy bill of € 1.2M per year. Approximately 1000 equipments have been deployed to form an architecture for collecting and transmitting energy data from buildings. The back-up architecture has been adapted on a case-by-case due to the heterogeneity of existing buildings. Systemes can be remote meter reading, radio and GPRS links , the repatriation of data from building management system (BMS) or communicating controllers. All data is collected and centralized in an SaaS software (software as a service) for energy management. Some grey areas are still monitored using flying probes and ponctual analyzes.
The return on investment is estimated at 3 years (excluding internal costs). The system has been in place for more than a year, and we are confident that the savings target set at 19% will be met. Among the very profitable actions, the monitoring made it possible to detect numerous anomalies setting of the equipment. For example, at a site, over-ventilation was maintained throughout the heating period while it is intended to chase heat in summer! Result: 600 € of savings each month. It is not uncommon to wait for 20% savings thanks to simple modifications of setpoints on the equipment: reduced at night, air … Finally, energy savings are not the only benefits gained, we have also gained in speed of interventions (internal and external), reduced waste due to water leakage, increased the quality control of archives and improved the continuous monitoring of photovoltaic production.
The energy monitoring allows us to have a better control our consumption and better understand the behavior of buildings. However, a period of 3 years of operation will certainly be necessary to obtain a complete results of the approach. We conduct studies in parallel to obtain the energy signatures of our main sites. Our objective is to renegotiate all operating contracts by the end of 2017 in order to switch to profit-sharing operating contracts.