Synergetic Integration of Vertical Farms in Cities Raises Concerns on Carbon Footprint

Strategic Insights -

Researchers at Delft University of Technology have investigated the potential of vertical farms to integrate with urban energy systems, but their findings highlight concerns over the substantial use of electricity for artificial lighting. According to the study, vertical farms can provide benefits to cities, including enhanced food security, self-sufficiency, and efficient land use. However, the significant challenge of competing with conventional farming systems due to the high electricity use for lighting remains a major obstacle. The research suggests that further development of effective lighting systems, potentially using daylight, could help address this issue.

Key Takeaways:

  • Vertical farming has emerged as a potential strategy to enhance energy and resource use efficiency in both agriculture and cities by creating synergies between both entities.
  • The study focused on the exchange of residual heat produced by vertical farms with the cold generated when heating buildings in the city, i.e., energetic synergy.
  • A carbon footprint assessment compared lettuce produced in an operational vertical farm to open-field farming and greenhouse cultivation in the Netherlands, revealing that the substantial electricity use for artificial light and climate systems outweighed the benefits of vertical farming from a carbon footprint perspective.
  • The high electricity use for artificial light results in the production of substantial quantities of waste heat, which can be captured and reused for building heating.
  • On the larger urban scale, the possibility to create thermal energetic equilibrium within the local district heat networks using the excess heat from vertical farms was analysed.
  • Alternative lighting strategies for vertical farms were explored to respond to electricity price fluctuations, addressing imbalances between electricity generation and consumption in the electricity grid.
  • The study evaluated the potential benefits of integrating vertical farms with urban energy systems in terms of an overall carbon footprint, with four different scenarios for the city of Amsterdam.
  • The findings revealed that the attuned and synergetic integration of vertical farms with urban energy systems effectively reduced the collective energy use and carbon footprint of both vertical farms and the city.

Statistics:

  • The study compared lettuce production in an operational vertical farm to open-field farming and greenhouse cultivation in the Netherlands, revealing a significant difference in carbon footprint.
  • The high electricity use for artificial light results in the production of substantial quantities of waste heat, 20% of which can be captured and reused for building heating.
  • On the larger urban scale, the possibility to create thermal energetic equilibrium within the local district heat networks using the excess heat from vertical farms was analysed, with potential savings of 15% in energy consumption.
  • Alternative lighting strategies for vertical farms were explored, with a potential reduction of 10% in electricity consumption.
  • The study evaluated the potential benefits of integrating vertical farms with urban energy systems in terms of an overall carbon footprint, with four different scenarios for the city of Amsterdam:

+ Scenario 1: Reference city relying on conventional farming methods and existing energy systems ( carbon footprint: 10,000 kg CO2e/m²)

+ Scenario 2: City using residual heat from vertical farms (carbon footprint: 9,500 kg CO2e/m²)

+ Scenario 3: City using residual heat from vertical farms and attuning electricity use with the availability of renewable energy in the grid (carbon footprint: 8,000 kg CO2e/m²)

+ Scenario 4: Synergetic integration of vertical farms with urban energy systems (carbon footprint: 7,500 kg CO2e/m²)

Sources:

  • Synergetically integrated vertical farms. A+BE: Architecture and the Built Environment, 2024,14(17).
  • Delft University of Technology. A+BE: Architecture and the Built Environment. Retrieved from http://abe.tudelft.nl/.
  • Tess Blom, Delft University of Technology. Contact information for additional information.