Highly efficient buildings ensuring flexibility for smart cities

Knauf Insulation Italia is part of the SATO project and since 2018 the company has been researching, in collaboration with Politecnico of Milan, the impact that highly efficient envelopes have on the reduction of buildings energy needs for heating and cooling, their capacity to store thermal energy and thus their contribution to the smart transformation of cities. In a decentralized energy system, Buildings as Battery (BaB) offer the flexibility to receive renewable energy when it is available, they mitigate peaks in demand for power on the grid (when all inefficient buildings demand power instead) and they properly exploit moments of overabundance and scarcity of energy supply from renewable sources.

Through simulations, confirmed by real measurements, the study by the end-use Efficiency Research Group (eERG) of the Politecnico di Milano shows that just one day of heating or cooling in highly efficient buildings is enough to keep a comfortable indoor temperature for up to three or four days. One of the main obstacles for progressing towards so-called “smart cities” and the integration of renewables in buildings is the excessively high energy need for heating and cooling of our present building stock due to inadequate thermal quality of the building fabric and to ventilation losses. Current buildings are similar to a (thermal) battery that is short-circuited to ground: energy that is fed into the building is quickly discharged and wasted. We would never do anything of the sort with an electric battery, and it is indeed irrational to do so for the thermal storage available in the thermal capacity of walls and floors of the European building stock.

Good quality renovations of existing building envelopes can achieve a reduction in energy need for heating and cooling of up to 80%. In a situation where the growth rate in the use of energy outpaces the rate of decarbonisation, the construction of new buildings and the execution of renovation projects that do not apply the best design strategies and the best materials and components would be a net divergence from the goal of decarbonisation. If this non-optimal path is taken, the building stock will be locked-in for many decades in a level of energy need for heating and cooling that is much higher than that which has been made possible thanks to innovation in the building sector. This excess amount would be wasted each year throughout the entire lifetime of those non-state of the art new or renovated buildings. In addition to directly reducing the use of energy and climate-altering emissions, the deep renovation of building fabrics also has the effect of allowing a more rapid and effective penetration of renewable sources into the energy system.

Knauf Insulation Italia’s work, including the collaboration with Politecnico of Milan and the SATO project, supports the Energy Efficiency First principle with very significant data and justifies rational energy transition strategies in which the reduction of energy demand in buildings is an indispensable prerequisite for a rapid transition to renewable energy and the urgently needed decarbonisation of urban areas.

Find out more:

·       Knauf Insulation Italia Innovation Section

·       Report (Part 1 in EN) – Highly insulated buildings as a crucial element for smart cities, grid balancing and energy storage for renewables

·       Report (Part 2 in IT) – Real measurement and simulation in summer (cooling).