The Energy Department of the Agglomeration community of Le Havre and the Jules Siegfried High School (Le Havre) are implementing an experiment with cheap and easy monitoring system based on free and open source hardware enhanced with self-developed software. This project started in mid-2016.

Electricity consumption increases every year in public buildings despite energy efficiency efforts (lights, exhaust system, regulated systems…). In order to foster electricity savings - and save money, the first step is to know exactly which equipment consumes (and when) in the building. DIY monitoring systems are cheap, easy to modify, upgrade and share.

For on-the-spot datalogging (2 or 3 weeks), an Arduino Uno [+SD card and RTC shield] is used to collect data from the ENEDIS (French electricity network manager) electricity meter already installed on all sites. Old and new electricity meters can easily deliver data for power, consumption and intensity. On a simple request (and low price : 30 EUR), ENEDIS open the data flow port of their meters. With simple and low-cost electronical materials (resistances, wires, optocoupler…) and few lines of code, signal is received by Arduino, converted and saved on a SD card each minute during 2 or 3 weeks.

For long-term datalogging installation, a Raspberry Pi - with Python3, is used with a more complex architecture still in development: network connection is needed to store data on a remote server.

At the moment, only few prototypes with three Arduino and one with Raspberry Pi are used to collect electricity data on four sites of the Agglomeration community.

After a year, results are great and several buildings have been optimized with cheap but specific improvements: decreasing and optimized subscribed power (kW), new heating and water production regulation or improvement, decreased consumption during high cost period. New electricity meters (Linky) with new code will probably increase and improve data monitoring.