Comparison of control strategies for efficient thermal energy storage to decarbonize residential buildings in cold climates: A focus on solar and biomass sources

Abstract

This work presents novel energy production/storage/usage systems to reduce energy use and environmental effects, in order to address concerns about excessive heating demand/emissions in buildings. This focus is the design, control, and comparison of a biomass-fired model with a novel heater type and a solar-driven system integrated with photovoltaic thermal (PVT) panels and a heat pump. The heater has an external boiler and shell and tube heat exchanger, providing enhanced control over the combustion process and increased efficiency. Another feature of the present work is establishing a rule-based automation framework to manage the energy storage/flow among the components/grid/building. This smart integration reduces the size of the components, eliminates the need for a battery, and allows the system to interact in both directions with the electricity grid. The practicality of both systems is assessed and compared via a code developed in TRNSYS-MATLAB, considering the specific conditions of Toronto, Canada, characterized by high heat demand in winter. According to the results, the proposed solar-based system has an acceptable energy cost (78.9 USD per MWh of heating and electricity) attributable to the developed controllers applied to thermal energy storage. The results show that the PVT-based system integrated with a heat pump is environmentally superior, with a reduction in CO2 emission of 7.2 tonnes over a year. However, the biomass-fired system is an excellent option from the aspect of efficiency, with a relatively high energy efficiency of 69 %. Also, it is observed that the night set-back of the supply temperature can reduce the annual primary energy use and emission up to 60.3 MWh and 21.1 t, respectively. While the system relies more on the heat pump in cold months, the solar energy system supplies the entire demand in summer, demonstrating the significance of PVT and heat pump integration to increase energy reliability throughout the year.