Through the detailed design of the passive design of the geometric parameters of the atrium, it is beneficial to achieve the design goal of a nearly zero-energy building. In the architectural design stage, the geometric design parameters of the atrium are verified and evaluated with different objectives such as energy consumption, carbon emissions, and costs, and then the most appropriate solution according to different design requirements is selected, which can reduce energy consumption and save costs. This paper proposes a method to optimize the energy consumption of a building’s atrium. Taking Jinan City as an example, this paper conducted 1260 energy consumption simulations for buildings with different geometric parameters of the atrium, based on the investigation of the geometric scale and energy consumption of the multi-story office buildings with near-zero energy consumption in cold areas with atriums. The degree of influence of each parameter on building energy consumption was determined. Finally, the parameter selection combination with the best effect is proposed. The results show that the selected four parameters are significantly related to energy consumption, and a new atrium design parameter was found through the combined analysis of the parameters: the body shape coefficient of the atrium. It was found that the importance of atrium design parameters on building energy consumption is as follows: the body shape coefficient of the atrium, the height-span ratio of the atrium (DSR), the atrium building volume ratio (VR), the skylight area ratio (SR), the atrium width-to-depth ratio (FDR). Seven groups of optimal design parameters were obtained by analyzing the design decisions with energy consumption as the target. Taking carbon emission and cost as the targets, three groups of optimal design parameters were obtained according to the Pareto frontier solution set, such as DSR = 2, VR = 0.13, SR = 0.1, and FDR = 2.5. It provides some references and ideas for the optimization of the energy consumption of the atrium of multi-story nearly zero-energy office buildings in the cold regions of China.

Conventional photovoltaic systems suffer from heat accumulation due to low-conductivity polymer back sheets, which reduces efficiency and limits waste heat recovery. This study proposes a hybrid system integrating a photovoltaic (PV) cell with a micro-channel heat pipe (MCHP) array, a phase change material (PCM) plate, and a thermoelectric generator (TEG). The polymer back sheet is replaced by an aluminum alloy to minimize interfacial thermal resistance. A four-day outdoor winter experiment was conducted in Kunming, China, and a one-dimensional transient numerical model was developed. The model is validated against measured data with root mean square errors of 1.6 °C for PV temperature, 2.2 °C for PCM temperature, 1.1 W for PV power, and 0.06 W for TEG power. Results show that the hybrid system reduces PV temperature by 11.1 °C, increasing PV conversion efficiency from 12.1% (standalone) to 17.8% (hybrid), with peak efficiencies of 21.0% and 23.9%, respectively. Over three days, the hybrid system generates 261.0 Wh of electricity, a 16.7% increase over the standalone PV cell (217.0 Wh) for the same active area of 0.12 m². Notably, latent heat release from the PCM enables sustained TEG output for 55 minutes after sunset, creating a nocturnal long‑tail generation effect. Sensitivity analysis identifies an optimal PCM mass of 0.5 kg and a melting range of 25-37 °C for high‑altitude winter conditions. These findings demonstrate that the proposed architecture offers improved efficiency, passive thermal management, and waste heat recovery, making it suitable for all‑season solar energy harvesting.

Light-driven air dehumidification technology using photo-thermal materials capable of absorbing solar light to excite photo-induced drying process will be next-generation air dehumidification technology to implement near-zero carbon building air conditioning. To fulfil this goal, a bespoke natural light harvesting configuration to deliver high-intensity solar light radiation is promising. This research proposes a novel sun tracking, light concentration and transmission system for high-intensity solar light delivery. The system includes a dual-axis sun tracking unit coupled with a double-Fresnel lenses for sun tracking, light concentration and collimation to maximize solar light collection and a tubular light transmission system with a thoroughly assessed internal surface coating material, micro-silver, having excellent transmission efficiency throughout whole solar spectrum, especially infrared spectral region-a major spectrum for moist desorption. A numerical model was developed to characterize solar light transmission through the system; a prototype was constructed and installed on a mobile lab through roof and tested under real outdoor conditions. The experiment showed in the investigated incidence angle range of 53o-67o the transmission efficiency maintained 0.94–0.97 for straight section of tubular transmission system, but it decreased to 0.52–0.70 for a 90o curved section, identifying geometric curve as a major source of transmission loss; the light concentration achieves up to 2.83 times higher output light intensity. The model was validated by experimental data and a case study showed for monthly global horizontal irradiance of 150×103 -160×103 Wh/m2 in summer at Hull, the delivered solar energy exceeds 200 × 10³ Wh/m². The seasonal solar light delivery capability of the system is governed by both the solar irradiance and solar geometry.