Development of a soft sensor for thermal inertia-based building electrical demand flexibility
João Carlos Simões, Marta J.N. Oliveira Panão, Guilherme Carrilho da Graça
Abstract
To stabilize the grid and reduce the need for grid level energy storage, due to the ongoing increased in the use of renewables for electricity production, building owners are incentivized to adjust their energy needs in demand response programs (DR). A common DR approach in service buildings is to temporarily turn off the HVAC system, triggering thermal inertia-based building electrical demand flexibility (TEF). TEF varies depending on internal loads and weather conditions. Currently the amount of TEF that can be provided to the grid is generally unknown to building managers and grid operators. This paper fills this gap by presenting a new soft sensor approach for estimation of TEF in cooling dominated service buildings. The proposed sensor was tested in three rooms with different thermal inertia and internal gains. The TEF potential was assessed in a typical modern office by simulating several DR events with different setpoint temperature variations, outdoor air temperatures and internal gains. Results show that the minimum duration of the HVAC off event (DHO) is 9 minutes for a 1.1°C operative temperature increase, with typical durations of 15 to 60 minutes. The TEF values vary between 5 Wh/m2 and 25 Wh/m2.