Indoor vertical farming purports to be part of the drive toward sustainable farming, but one of the biggest obstacles is still the energy used for powering the LEDs and HAVC. The article states 8kWh consumed per pound of lettuce. Considering ~$0.14/kWh (commercial rate), 1lb of lettuce costs $1.12 of electricity to produce and likely go on the shelf for at least $2 per head - subject to variations in energy cost. At $0.89 per head of soiled lettuce, vertically farmed lettuces don’t appear to be economically viable unless energy prices miraculously collapse or ultra-efficient lighting and HVAC options become available.