Although it is difficult even today to store electric, solar or wind energy, it is possible to store water as potential energy. This is how Pumped Hydroelectric Energy Storage (PHES) works. PHES stations first appeared from the 1890s, in Switzerland or Italy. The system is composed of two reservoirs, one being higher than the other. The station is connected to the local electric network. During an energy consuming respite, the electric network powers the station: the energy pumps the water from the lower reservoir to the upper reservoir. On the contrary, during consumption peaks, turbines invert the circuit (from the upper reservoir to the lower reservoir) and renders kinetic energy. For that reason, pumped hydroelectric stations are said to be “reversible”. Nonetheless, the stations are dependent of a connection with an electric network. Besides, the whole process leads to 15% to 30% of energy loss (amongst the energy consumed by the pumps and the energy rendered by the turbines).
In 1980, a French inventor named Marcel Voisin registers a patent about a “constant hydroelectric energy production”… His idea is to place three reservoirs on different height and to use atmospheric pressure to make a drum rotate thanks to air pumps. The drum carries out a regular pumping, without needing any electric energy. As a consequence, the turbines are continuously working, overcoming the PHES’ disadvantages. Couldn’t we adapt it and develop it to make it a sustainable response for energy storing?
