Collective self-consumption building with coupling of DualSun panels to Heliopac heat pumps – Nantes (FR)

  • 2019
  • Nantes, France
  • Power output : 11,2 kWc + 36,48 kWth
  • Panels : 40 DualSun panels

Focus on the rehabilitation of the “La Marseillaise” building by the developer Galeo in Nantes. Owned by La Nantaise d’Habitations, the 1000 m² building has been “sustainable development” thought since the beginning of the rehabilitation project. As part of this SMILE project (EDF), the building has been awarded the BBC Rénovation label (minimum energy consumption).

“La Marseillaise” does not use any fossil fuels. More precisely, a system combining DualSun hybrid solar panels and Heliopac water-to-water heat pump allows it to be at the forefront of the energy transition. When in use, this exemplary building of 39 dwellings will have very low CO2 emissions.

Thus, 65 m2 of DualSun hybrid solar panels, both photovoltaic and thermal, were deployed on the roof. These 40 PVT solar panels, together with the 60 photovoltaic panels, will produce 30 MWh of electricity and reduce the building’s consumption by 15%. As for the 40 hybrid solar panels, they provide thermal power for the heat pump.

The hot water produced by the “back” of the DualSun panels will be used for the building’s sanitary needs. The collective solar water heating system developed by DualSun and Heliopac will reduce the energy consumption for the production of domestic hot water by more than 50%. 

It should be remembered that the production of domestic hot water represents a large part of the building’s energy bill. This offer is therefore a great ecological and economic opportunity. By using “free” energy, the tenants’ charges will be considerably reduced.

In addition to this, EDF has proposed an innovative system of collective self-consumption. Let’s imagine that the electrical production of the solar panels is higher than the needs of the first building. At that point, the surplus will be redirected to two other buildings managed by La Nantaise d’Habitations. That’s 98% of the electricity produced on site will be consumed on site!

Technical information

Characteristics Building with 39 apartments
Number of panels 40 DualSun Spring hybrid panels
Power output 11,2 kWc + 36,48 kWth
Rooftop installation Schletter system with standing seam clamps on the zinc roof and triangulated system on the flat roof
Thermal system SolerPAC heat pump (HELIOPAC)
Photovoltaic system Inverters SMA, collective self-consumption