Investigation the effectiveness of light reflectors in transmitting sunlight into the vertical farm depth to reduce electricity consumption

Nowadays, the use of greenhouses and vertical farms has become increasingly commonplace due to compensating the crisis of food scarcity and fertile land for the world's growing population. The lack of free natural sunlight within the floors of such modern farms, however, has led to the application of artificial light as a common strategy to enhance food production. The energy supplied to produce this artificial light has increased the cost of food production. In this regard, the current study seeks to develop a new way to bring sunlight into vertical farms to reduce costs, avoid more energy consumption, and then increase the sustainability of food production. For this purpose, this experimental-applied research based on desk review focuses on the necessity of using sunlight in vertical farms, while adopting drawing and graphical software to illustrate how a variety of mirrors can transmit and distribute sunlight into vertical farms as a concept that applies to different latitudes. The proposed concept was tested quantitatively and qualitatively by constructing a physical model on a scale of one-twentieth at the latitude of 36.46° N, 52.86° E. This experiment showed that, in mentioned geographical position, the ratio of light supplied at a depth of a floor to unobstructed sunlight in the space around a vertical farm. •The free and useful light energy of the sun can illuminate the depths of a vertical farm with the help of reflectors.•Using free sunlight on vertical farms will reduce the cost of food production.•Flat and convex mirrors, as light transmitters and diffusers, make access for sunlight to reach into the vertical farm depth.