Energy recycling

The use of a heat pump to heat up a building “produces cold” where the heat is “pumped” to put it in the building. In the same way we cool down a building by “pumping” its heat that we have to put somewhere, and that somewhere will see its temperature rise, inevitably. If there is no need to heat up that place, this energy will be wasted, hence the technical lingo of waste heat recovery to describe the recycling process.

We know that:

• the substations produce heat or cold to control the buildings temperature;
• the water loop carries the heat or the cold transfered in the water by the operating heat pumps;
• the pumping station is used to put the network water back to a mean temparature if it has been too heated or too cooled by the several network substations, thanks to the sea water usage.

So, if the heat injected in the network water by a substation refreshing a building is recovered, even in part, by another substation heating another building, we have effectively recycled that energy that otherwise have been wasted in the air.

What’s described here is an ideal case not occurring in the real world: there never are to adjacent buildings where the first is heated while the second is cooled in the same time, with the same proportions, night and day, all year long… But when we consider the whole network, with all its building with different consumption profiles, we are aproaching that situation, and it is the purpose of these facilities.