The energy consumption of buildings represents an important industrial expense and a determining impact on the sustainability of cities. Finding a model that allows the reduction of this consumption is one of the touchstones for the building industry. In the search for an adjusted model, in E22 we add our experience to GEOBATT, an energy hybridization project whose objective is the development of a new technology to supply the air conditioning systems of buildings. The project Hybridization of geothermal energy with flow batteries for the climatization of tertiary buildings of zero energy is based on the hybridization of the energetic use of the subsoil with the storage of electric energy by means of flow batteries, with the purpose of obtaining buildings of almost zero energetic consumption, with application both in developed and developing countries.

This objective responds to the Safe, Sustainable and Clean Energy Challenge, since it will allow to reduce the consumption of the buildings in a 80%, in addition to guaranteeing the security of the supply to critical facilities without need of generators. This is fundamental in developing countries, where the guarantee of supply is a pressing problem. The growing consumption of energy by humans is causing changes worldwide whose consequences are alarming and evident. The construction sector is responsible for 40% of energy consumption, so the European Commission is promoting measures and policies that lead to the development of new technologies to increase the efficiency of buildings to almost zero consumption.

In this context, SACYR Industrial, E22, UPM (Department of Fluid Mechanics and Aerospace Propulsion), UC3M (Fluid Mechanics Group) and IMDEA Energy, we have decided to join forces to develop a technology that hybridizes geothermal air conditioning with energy storage in flow batteries with the following benefits:

  • The geothermal use of the land will allow energy efficiencies much higher than those achieved with other energy sources, and will reduce the energy supply to a single type, the electrical, simplifying the energy management of the building.
  • The use of flow batteries will allow the electricity supply to be disconnected from subsequent consumption, ensuring uninterrupted operation of the building. In addition, it will make it possible to make effective use of energy from renewable sources, such as solar and wind power, given their intermittent nature.
    In addition, the synergy between the two technologies will make it possible to reduce investment and operating costs, revalue the thermal energy that would otherwise be lost in the flow battery and optimise its operation.

To achieve this objective, it will be necessary to develop advanced models of the geothermal air conditioning system, integrating non-linear parameters (COP or variable flow); a zero-dimensional model of the technical room; and flow and mixing models for flow batteries and electrolyte deposits. These models will allow both technologies to be optimized, which will crystallize in the development of a prototype and the implementation of a full-scale demonstrator pilot. In parallel, possible implementation scenarios will be analysed and an economic study will be carried out, which will be validated with pilot data.

The main objective of the GeoBATT project consists in the development of a new energy technology that supplies the air-conditioning systems of buildings based on the hybridization of underground thermal energy storage (low enthalpy geothermal energy) with the storage of electrical energy by means of flow batteries, in order to obtain buildings with almost zero energy consumption, with application in both developed and developing countries, contributing to a more sustainable building industry.