Integration of Solar Energy, Second-Life Lithium-Ion Batteries, and Plasma-Activated Water for Reduced-Nitrogen Greenhouse Cultivation

Abstract

The research demonstrates a national project combining solar photovoltaics with second-life automotive lithium batteries for local-scale agricultural irrigation and greenhouse climate control. The auto-opening greenhouse system can adapt to various climate conditions in resource-limited areas. Applying in-house battery management system (BMS) based on adaptive control algorithm, it allows real-time monitoring and prediction of critical parameters such as effective capacity and safety, ensuring safe operation and longer battery life. Results show that, with optimized management, the lifespan of second-life batteries can be extended by an additional 7.8–9.3 years, achieving a maximum discharge power of 3.3 kW while keeping thermal control deviations within 0.3%. Both grid-connected and stand-alone microgrid setups have been successfully tested in the field, improving local energy independence and reducing reliance on external power sources. In addition, to avoid the harm of chemical fertilizers to the environment, air nitrogen fixation technology is employed to extract nitrogen fertilizer from the air to irrigate crops such as tomatoes and cucumbers. The control system uses solar power to store electricity in batteries daily to provide nitrogen fixation and basic greenhouse needs, and can maintain greenhouse operations without relying on power grid. This work offers a practical, scalable model for low-carbon agricultural energy solutions, reducing carbon emissions by about 1.28 metric tons of CO2 per system each year. It provides a framework to guide policies, promote low-carbon transitions, and support global sustainable development goals in underserved areas.