Dual production of solar energy and important plant-derived active pharmaceutical ingredients: Artemisinin, a pilot study

Abstract

• An simulated agrivoltaic system for the dual production of renewable energy and medicinal plants was investigated. • Artemisia annua plants that were shaded produced 20% more artemisinin than plants that were not shaded. • It seems possible to grow important high-value crops while also producing renewable photovoltaic energy. Agrophotovoltaics is a relatively new field of research where land is used for the production of both solar energy and various suitable (food) crops. Due to persistent rolling blackouts in South Africa, and a dire need to invest in renewable energy, a pilot study was conducted to test the feasibility to produce high value active pharmaceutical ingredient (API) yielding plants in combination with solar energy. In this study, solar panels were simulated by removing direct sunlight from Artemisia annua plants, and the concentration of the API, artemisinin, was determined and compared to control plants exposed to full sunlight. The impact of a low light regime on the biosynthesis of artemisinin was therefore investigated. Samples were collected from the shaded plants as well as from the control plants and artemisinin content quantified with liquid chromatography mass spectrometry. In addition, scanning electron microscopy analysis was conducted to determine the influence on the number and morphology of glandular trichomes which are believed to be the site of artemisinin production and/or storage. The shaded plants were found to contain roughly 20% more artemisinin as compared to the control plants. Scanning electron microscopy analysis could not establish a clear indication of the impact on the glandular trichomes due to a dense layer of filamentous trichomes obscuring the glandular trichomes in the sun exposed leave material. This pilot study indicates in principle that low maintenance solar panels may be used for energy generation and in practical enhancement of artemisinin content.