Vertical Farming Questions

Hi Leonie, thanks for your interesting questions.

Vertical farming has some perceived benefits over conventional farming primarily because of its highly controlled and controllable nature. So, for instance, your question about disease and insect infestation in vertical farming environments could be less of an issue because the environment is tightly monitored and not exposed to the outside where insects could gain easy access to crops. Also, in theory in terms of disease, by controlling air quality through various air flush measures the vertical farm could be less disease prone than, say, one that is not regularly flushed or farmed by hand.

RE: question 2, according to this article on vertical farming, vertical farming is not a good strategy for growing corn. I do not know (or can't imagine) a world where vertical farming is a total replacement for conventional farming. Industrial feedstocks such as pork, cattle and poultry largely use corn from conventional farming and to me I can't see the need for vertical farming to exist separately from conventional farming, or it being a zero-sum-game where one scenario can exist only when the other does not exist.

Your question about the sun being free, compared to the cost of electricity, is a good one and brings us to solar photovoltaics and grid parity... I can speak about the United States in that the cost of solar has reached grid parity (equal to the cost of conventional energy sources such as fossil fuels, which you can see in this chart) in many states in the U.S. and is expected to reach more states in 2016.

The concept of grid parity is even more interesting when considered along with energy storage (large batteries) that can store renewable energy from PV that is produced at cost or less than the cost of conventional fuels, for use at night or when the sun isn't shining. The cost of solar is expected to fall 50% further in the next decade, while battery technologies will continue to improve.

When LED lighting, which is highly efficient, is combined with solar electricity from PV the cost of solar for vertical farming versus exposed sunlight in conventional farming may be less on the whole. This study suggests that using LED lighting increased yields of tomatoes when compared to less efficient high pressure sodium lighting, which to me suggests that LED lighting in vertical farming growing environments could be MORE productive than conventional farming with sunlight. Though, I am not sure.

Labor costs of conventional farming can be reduced by as much as 50% in vertical farming environments, and water usage can be dramatically reduced because the environment is highly controlled. Water may be recycled and treated to 98% efficiency, which also reduces costs on the whole.

Let us know if you have more questions, Rob