types of chlorophyll, one preferring red light
and the other blue. Nuvege produces 6 million
lettuce heads a year.
CHALLENGES
Economics
Opponents question the potential profitability
of vertical farming. Its economic and
environmental benefits rest partly on the
concept of minimizing food miles, the distance
that food travels from farm to consumer.
However, a recent analysis suggests that
transportation is only a minor contributor
to the economic and environmental costs
of supplying food to urban populations. The
analysis concluded that “food miles are, at
best, a marketing fad”. Thus, the facility would
have to lower costs or charge higher prices to
justify remaining in a city.
Similarly, if power needs are met by fossil
fuels, the environmental effect may be a net
loss; even building low-carbon capacity to
power the farms may not make as much sense
as simply leaving traditional farms in place,
while burning less coal.
The initial building costs would exceed $100
million, for a 60-hectare vertical farm. Office
occupancy costs can be high in major cities,
with office space in cities such as Tokyo,
Moscow, Mumbai, Dubai, Milan, Zurich, and
Sao Paulo ranging from $1850 to $880 per
square meter.
The developers of the TerraFarm system
produced from second hand, 40-foot shipping
containers claimed that their system “has
achieved cost parity with traditional, outdoor
farming”.
Energy use
During the growing season, the sun shines on
a vertical surface at an extreme angle such
that much less light is available to crops than
when they are planted on flat land. Therefore,
supplemental light would be required. Bruce
Bugbee claimed that the power demands
of vertical farming would be uncompetitive
with traditional farms using only natural
light. Environmental writer George Monbiot
calculated that the cost of providing enough
supplementary light to grow the grain for a
single loaf would be about $15. An article in
the Economist argued that “even though crops
growing in a glass skyscraper will get some
natural sunlight during the day, it won’t be
enough,” and “the cost of powering artificial
lights will make indoor farming prohibitively
expensive”.
AgriKultuur |AgriCulture
“A vertical farm design modelled after the
Capitol Records building in Los Angeles
features a prominent renewable energy
source: a rotating solar panel that, like a
sunflower, gyrates to face the sun.” — NYT
Photo: Chris Jacobs courtesy the New York Times https://www.
flickr.com/photos/23023265@N02/2671028309
As “The Vertical Farm” proposes a controlled
environment, heating and cooling costs will
resemble those of any other tower. Plumbing
and elevator systems are necessary to
distribute nutrients and water. In the northern
continental United States, fossil fuel heating
cost can be over $200,000 per hectare.
Pollution
Depending on the method of electricity
generation used, greenhouse produce can
create more greenhouse gases than field
produce, largely due to higher energy use
per kilogram. Vertical farms require much
greater energy per kilogram versus regular
greenhouses, mainly through increased
lighting. The amount of pollution produced is
dependent on how the energy is generated.
Greenhouses commonly supplement CO2
levels to 3–4 times the atmospheric rate. This
increase in CO2 increases photosynthesis
rates by 50%, contributing to higher yields.
Some greenhouses burn fossil fuels purely
for this purpose, as other CO2 sources, such
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