Efficient integration of alkaline water electrolyzer-A model predictive control approach for a sustainable low-carbon district heating system

District heating systems can utilize renewable energy sources and waste heat from industrial processes, making them a cost-effective heating solution. This paper integrates an electrolyzer technology into district heating system to improve energy efficiency and reduce greenhouse gas emissions by a power to hydrogen and heat model. To accurately predict the electrolyzer's electrochemical and thermal dynamic behavior, an advanced electrolyzer model is developed. The proposed model presents a dynamic approach implemented in model predictive control to optimize electrolyzer performance and reduce power fluctuations. By managing on-off cycles, degradation costs, temperature, and efficiency of the electrolyzer, the proposed model aims to harness waste heat generated during electrolysis, and store hydrogen in a hydrogen storage tank to manage renewable fluctuations. The district heating system utilizes electric, natural gas, and hydrogen boilers along with waste heat recovered from the electrolyzer to meet energy demands. The proposed model promotes sustainability and efficiency of district heating systems by utilizing renewable energy sources and effectively managing the electrolyzer. Case studies demonstrate the model's advantages and effectiveness, with results indicating that the optimal strategy utilizes recovered waste heat to satisfy approximately 10% of the heat demand, achieving an average electrolyzer efficiency of 90% and further enhancing sustainability.