“We looked at how far we could go and found we could scale up to RT2012 with a 20% reduction, without significant additional costs. » Franck Izoard is the project manager at the semi-public company Innovia responsible development of the peninsula of Grenoble. It traces the genesis of the research and innovation work carried out in the peninsula to be able to divide the energy consumption of buildings by eight with respect to the RT2012 standard. « The increase from 20 to 30% was possible thanks to an EcoCité grant. Today we know how to reduce RT2012 by 30% at no extra cost. »
The water is discharged into the Isère
To be able to further divide by 5 the consumption of primary energy needed to heat, cool and produce domestic hot water in all the buildings built on the peninsula, Sem Innovia designed the Drainage network. “This is the great development of the peninsula. We were the first on a European or even global scale to do so. »
The principle is as follows: heat pumps draw water from the peninsula’s groundwater. A drainage system has been set up to avoid the risk of it drying out. The pipe network Exhaure collects the water leaving the heat pumps before sending it directly to Isère.
mining code
“The temperature of the water discharged is the same as in Isère (8°C in winter and 18°C in summer)”, specifies Franck Izoard, indicating that this measure falls under the mining code and not the environmental code, which requires that any water withdrawn from an environment must be discharged into the same environment. In other words, the water drawn from the peninsula’s aquifer should have been returned to the aquifer.
The solution favored by the SEMs makes it possible to avoid a phenomenon of “cannibalisation of the water table” e guarantee each connected building a maximum coefficient of energy performance. “For 1 MW consumed, I use 5 MW to produce heat in my building. »
Also, Franck Izoard provides device legality from “The mining code takes precedence over the environmental code. Having a prefectural decree of the Mining Code is more complicated to obtain: 18 months of education against the 3 months of the decree of the Environment Code”.
Nowadays 300 000 m2 of buildings I am connected or will soon be on the Exhaure network.
