Food scarcity in urban populations is a significant and growing problem that the world is beginning to address. Indoor farming is a solution that many are adopting. Growing food indoors allows food to be localized in densely populated areas, which can significantly decrease costs and increase quality and quantity. The largest obstacle to realizing these benefits is the prohibitive operating costs associated with traditional horticulture lights. The University of Washington is dealing with this same problem in the wide variety of greenhouses throughout campus. There is a clear need to retrofit these structures with energy efficient alternatives.
In partnership with the University of Washington (UW) Farm, as well as IUNU, a Seattle-based startup comprised of UW Alumni and graduate students, this project will increase the efficiency of the University’s indoor horticulture lighting systems. This project’s aims can be broken down into two separate phases; 1) to conduct a feasibility study to compare the energy usage and plant output of the High Pressure Sodium (HPS) indoor horticulture lighting systems currently used by UW Farm with the high-efficiency plasma lighting systems developed by IUNU; and 2) install the high-efficiency lighting systems in the newly constructed UW Farm greenhouse for supplemental lighting.
The feasibility study will aid the subsequent Education and Outreach of this project by collecting data over a twelve-week period on the energy usage and plant output of both the HPS and plasma systems. This data will be provided to the UW Farm so that they have evidence to justify retrofits and materials for education and outreach.
In order to conduct the feasibility study, lettuce, alliums, basil, and brassica will be grown as this is what the UW Farm intends to grow with the lights once they are installed in Phase Two. These varieties of vegetation were also chosen under the guidance of Liz Van Volkenburgh who is a professor in the Biology Department at the university and a specialist in plant physiology. In order to set metrics for the feasibility study, pounds per watt will be used to measure the energy efficiency of the two lighting systems. This metric uses the pounds of produce grown and compares it to the input-wattage used by each lighting system in order to display output in the context of efficiency. To test the quality of the produce grown, we will conduct a blind taste test and shelf life analysis.
Furthermore, plasma lighting is a relatively new technology and there is a demand for more research into its potential horticulture applications. Growing interest surrounding energy efficiency and indoor horticulture are driving these demands. Plasma light is estimated to be 30% more energy efficient than LEDs and 50% more efficient than high-pressure sodium systems. The UW’s ownership of plasma lighting fixtures will provide a resource for UW undergraduate and graduate students to have an opportunity to produce unique, marketable research in future endeavors.