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• A new energy system is developed and examined using dynamic modelling to meet the needs of a two-story structure. • To decrease the size of the plant, including the PVT size and fuel consumption, the PCM is incorporated into the building. • Fuel consumption and prices are reduced by 17.24% and 8.57%, respectively, using the suggested approach. • Exergy efficiency, unit product cost, and CO 2 emission of 64.3 %, 0.26 $/kWh, and 0.21 kg/kWh are obtained respectively at optimum point. The buildings energy sector is expected to account for 40% of total world energy consumption and 40% participation on total carbon dioxide emissions, according to the International Energy Agency reports. The present study proposes a novel integrated system to meet all loads of the house's energy requirements. The system employs a heat storage tank rather than pricey batteries, which helps to keep the total cost of the system as low as feasible. Also, the system is developed for an on-grid operation, being capable to sell surplus energy to the grid helping to reduce the payback time. Dynamic modeling is conducted to analyze the system performance to provide heating, cooling and power demands of a case study building, for which two scenarios of with and without Phase Change Material (PCM) incorporation is considered. The influence of critical design factors is investigated, after which a tri-objective optimization is carried out. It was found that, the integration of PCM energy storage would reduce the annual heating and cooling demands of the building by 25.6%. As a result, the exergy efficiency of the proposed system increases by 13 % and the product cost is reduced by 8.57%. Based on the obtained yearly average results, the proposed building energy system yields exergy efficiency, unit product cost, and CO 2 emission of 64.3 %, 0.26 $/kWh, and 0.21 kg/kWh, respectively. [ABSTRACT FROM AUTHOR]

[Display omitted] • Biomass power plant model integrated with thermochemical heat storage was created. • Fluidized bed using Ca(OH) 2 /CaO stores surplus electricity from renewable energy. • Overall energy efficiency was 9.79% for the base case (output: 1 MW el). • Steam flow rate is most important parameter for flexible power generation. • Energy storage efficiency is dramatically improved by recycling steam. In this study, a biomass power plant integrated with thermochemical heat storage (TCS) using Ca(OH) 2 /CaO particles reacted in a fluidized bed reactor was proposed. In the strategy of power generation, organic Rankine cycle (ORC) was worked by the heat from biomass combustion in normal operation. In charging time, the electricity from the power grid was stored by dehydration reaction in the daytime although the turbine output was not changed, and the amount of biomass combustion decreased compared to normal operation time. In discharging time, the heat from hydration reaction was converted to electricity through the ORC in the evening and the turbine output increased to respond to the increase of the electricity demand. The designed process was evaluated from energy efficiencies and the flexibility of the power generation by dynamic simulation. Results show energy storage efficiency and overall energy efficiency equaled 58.5% and 9.79% (only ORC: 11.4%) for base case, respectively. The energy storage efficiency increased by increasing the heat recovery from steam after a reactor, and it led to the decrease of the biomass combustion in charging time. It was found that the inlet gas flow rate into the reactor had the largest influence on energy efficiencies by changing the parameters such as fluidized bed volume, inlet gas conditions into the reactor, and heat supply into the reactor. In addition, the increase of the turbine output and discharging time were flexibly changed in discharging time by changing operational parameters. Therefore, it is possible to add flexibility to biomass power plants by integrating TCS. [ABSTRACT FROM AUTHOR]