Aquifers

Underground cold and heat storage

Underground storage of heat and cold in aquifers has become a tried and tested horticultural technique. Depending on requirements, water is either removed or added to the deeper soil layers. The aquifers must meet minimum requirements in terms of composition, flow rate and direction, and depth in order to guarantee efficient and effective application. Certhon works with specialised partners to determine whether and how aquifers can be rendered viable.

By drilling one or more wells and installing filters at the right depth, lots of deoxygenated water can be extracted and infiltrated. The temperature of well water is naturally 11 to 12 ℃. By infiltrating heated water with a maximum temperature of 25 to 30 ℃, warm wells are created. This heat remains close to the infiltration well, because groundwater hardly moves at all at a great depth.

Heat pump boosts energy
The heated water is pumped up from the warm aquifers during the winter months. The heat pump then derives energy from this warm water and boosts it to form high-grade energy, which is then used for greenhouse heating. Cooled groundwater is left over due to the heat pump having extracted the heat. This cold water, which generally has a temperature of 5 to 8 ℃, can then be infiltrated in the ground. And so cold wells are created. During the warm summer months, this cold water from the aquifer can be used for cooling the greenhouse soil and/or air, without the use of the heat pump.