식물공장의 조명 전력에너지 절감을 위한 태양광 LED 하이브리드 루버 외피기술 성능 평가

Abstract

This study developed a hybrid louver window system (HLWS) that integrates natural solar lighting with light-emitting diode (LED) lighting to reduce the electrical energy consumption in an indoor vertical farm. The proposed system enables the required photosynthetic photon flux density (PPFD) for plant growth through a combination of natural solar and LED lighting. The HLWS is a south-facing louver structure developed to increase natural solar light transmittance and has measurements of 890 (w) × 1,600 (h) mm. Because the intensity of natural solar lighting varies significantly with weather conditions, dimming control of the LED is employed to maintain the target PPFD level required by the plants. Consequently, when applying the HLWS to an indoor vertical farm, the system first maximizes the utilization of available natural solar lighting and then compensates the remaining PPFD deficit through adjustable LED output. The performance of the developed HLWS was evaluated through experimental verification using a full-scale mock-up facility, and numerical simulations were conducted using LightTools software. The results confirmed the PPFD distribution characteristics of the hybrid system combining natural solar lighting and LED and demonstrated the potential of the HLWS to reduce electrical energy consumption by up to 11% in an indoor vertical farm by effectively utilizing natural solar lighting.