Integrated PV/T coupled PEM system for low-carbon office buildings: Dynamic simulation, multi-energy synergy, and economic analysis

Aiming at the key demand of renewable energy consumption and low-carbon building energy transition, this paper constructs a PV/T-PEM office building energy system using electrolytic hydrogen as energy consumption. Different from the traditional single energy supply mode, the system realizes the spatio-temporal collaborative conversion of building cold-heat-electric-hydrogen four-dimensional energy through the deep coupling of PEM electrolytic cell and PV/T module. Its core innovation lies in the development of the hydrogen and electricity co-generation mechanism of "photovoltaic power generation - waste heat recovery - electrolytic hydrogen production - thermal energy step utilization". Based on the TRNSYS platform, the regulation value of PEM electrolysis device in calming PV fluctuations and improving system self-absorption rate was verified in the office building scene. The study shows that the PV/T supplies 71 % of the power consumption of the system, the hydrogen capacity is 6468.63 m3, and the carbon emission intensity is reduced by 42.7 % compared with the traditional building energy system, and the effect of the Electrolyzers as a flexible load on the photovoltaic volatility of 25 % is verified. The economic analysis reveals that when the hydrogen price is higher than $8/kg, the payback period can be shortened to 1/3 of the project life, which provides a feasible path for the transformation of building energy system from single energy saving to production and storage cooperation.