The building sector accounts indicatively for 40% of the energy consumption and 36% of GHG in the EU. More specifically, energy consumption intended for heating and cooling represents around half the total of the final energy consumption. In EU households, heating and hot water alone account for 79% of the total final energy use (Heating and cooling: EU, 2020). Most of the thermal energy is produced from fossil fuels (66%), and only 13% comes from renewable energy (Heat Roadmap Europe, 2015). Also, it should be taken into consideration that over 35% of buildings in the EU are more than 50 years old, and around 75% of the EU’s building stock is considered inefficient (EU Buildings Database, 2020).
The CHESS SETUP project objective is to design, implement and promote a reliable, efficient and profitable system able to supply heating and hot water mainly from renewable sources to both new and existing buildings. The system is grounded in the optimal combination of solar energy production, heat storage and the use of a heat pump in a single system managed by an intelligent monitoring and control system.
The system operation is based on the use of solar panels (thermal, hybrid and photovoltaic) to transform solar radiation into heat and electricity, to be used for domestic hot water and heating. During the summer, there is high solar radiation and low heat demand. The unused share of the collected thermal energy is transferred to the seasonal storage tank to be stored, increasing the temperature of the storage medium—either liquid or solid. When the solar radiation is lower and the heat demand increases, a heat pump transfers the heat stored in the seasonal thermal storage at high efficiencies in order to satisfy the energy demand of the building. Part of the electricity produced by the solar panels is self-consumed by the system. If there is an electrical surplus, it can be stored in batteries or injected into the grid.
The operation is optimised according to some external factors, such as energy prices (electricity and gas), weather conditions or user requirements by using a smart control management system specifically developed for the project. This control system is customisable and easily adaptable as needed.
The combination of the high inertia of the seasonal storage system with the intelligent management system allows the energy to be supplied more efficiently and continuously, increasing the self-sufficiency of the system and reducing the peak demands.
The system not only provides a solution in terms of energy efficiency and primary energy consumption but, if implemented widely, could also have great benefits to the electrical grid by flattening the electric curve and allowing greater integration of renewable sources. This could be achieved through the control system, which can activate the heat pump during periods of low electricity demand, for example, or when the grid is not able to absorb the energy produced by renewable sources.
