Based on the operating principle of certain hydroelectric power stations, a real estate complex in Pas-de-Calais has succeeded in making its common areas autonomous from an energy point of view. A curious installation that explores an alternative to batteries for residential electricity storage.
The concept is identical to that of reversible hydroelectric power stations or pumped storage, those hydroelectric plants that move water from reservoirs located at different heights to accumulate it or generate electricity.
Composed of three 11-storey buildings, the Goudemand residence in Arras, built in 1975, has undergone frequent renovations. But this time, the social landlord Pas-de-Calais Habitat speaks of “revolution”.
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Water to store electricity.
In this development, the principle is applied on a very small scale. The 11-storey, 30 m high building replaces the mountain. Its roof acts as an upper reservoir: it accumulates up to 60 cubic meters of water in 200 square meters and 30 cm deep. The lower tank consists of 5 underground plastic tanks with a total capacity of 10 cubic meters. The two tanks are connected by a pump and a turbine.
When the system needs to be charged, the first is turned on. This 1500W multistage pump draws water from basement reservoirs and delivers it to the rooftop swimming pool to store electricity as gravitational potential energy. Instead, to evacuate, the water from the roof falls into the tanks through a small 450 W Pelton turbine, which generates electricity.
Efficiency compared to batteries.
The pump is powered by two mini vertical axis wind turbines with a power of 500 W and a photovoltaic system of 2200 Wp, also installed on the roof.
Its variable power is first stored in a small bank of lead-acid batteries with a capacity of 24 kWh. It only pumps when the batteries are 100% charged. Then, once the batteries are discharged, the hydroelectric system switches to turbine mode to recharge them.
According to research by engineer Guilherme de Oliveira e Silva, published in Water Power Magazine, the useful storage capacity of the system is only 3,500 Wh. Its efficiency is said to be between 25-35%, very poor compared to the 70-80% claimed by large mountain pumping installations and 90% for batteries.
The system as a whole guarantees that the common areas of the residential, with the exception of the elevators, are 100% autonomous.
Via lemoniteur.fr
Pictures: Pas-de-Calais habitat – Home (pasdecalais-habitat.fr)
