Synergetically integrated vertical farms: Reducing energy and resource use through synergies between vertical farms and cities

Over the past decades, various farming methods have evolved to address global challenges of increasing food demands, decreasing availability of arable land, and climate change. One such method is vertical farming, which uses active climate systems and artificial lighting in stacked systems, enabling year-round, stable yields with minimal land-use. Vertical farms (VFs) are often advocated as sustainable, offering benefits such as efficient land-use, high yields, minimal water and nutrient use, no pesticides, and proximity to urban food demands. However, substantial electricity use for lighting and climate control poses a major challenge.

This study assesses the potential to integrate VFs in cities to reduce energy and resource use, and carbon emissions of both entities collectively. It compares the carbon footprint of VFs and conventional farming in the Netherlands, revealing that the substantial electricity use in VFs outweighs their benefits from a carbon footprint perspective. Additionally, it explores reusing residual heat from VFs for building heating at both building and urban scales. It also examines synergies such as reusing water and nutrients outputs from buildings in VFs, and attuning lighting with grid electricity availability.

Findings indicate that synergetic integration of VFs in cities can reduce collective energy use and carbon footprints of both VFs and cities. However, the overall carbon footprint of these cities surpasses that of cities relying on fossil-based heating and conventional farming. These increased emissions should be weighed against the benefits VFs bring to cities, including enhanced food security, self-sufficiency, replacement of fossil-based heating, efficient land-use, and grid flexibility. In conclusion, while VFs offer significant urban benefits, their high carbon footprint due to artificial lighting remains a challenge.