Article by Wynand Bezuidenhout
Grow Machines
Photos supplied
B
en van der Spuy and Gail
Beresford of Benoni are
the first people to have a
fully solar driven Grow
Machines NFT Trellis Crop System
in operation. With a carbon footprint generating potential of nearly
zero and using their plants to convert CO2 into oxygen they are most
definitely looking after our world’s
atmosphere and the welfare of
food security in South Africa. This
is certainly one of the most advanced hydroponic systems in existence and an example project for
the future.
Plants are produced in the soilless
Grow Machines Nutrient Film Technique Trellis Crop System, a South
African invention, powered by
eight 300 Watt Solar Panels
mounted on a sun tracking system.
The tracking system follow the sun
as the earth rotates ensuring a 90
degree sunlight contact angle that
optimizes the energy output from
the solar panels. It functions almost like a sunflower. The sun
tracking system improves the panel
efficiency with up to forty percent.
To get away with minimal energy
requirement and maximum efficiency, the solar system is combined with the variable speed tech-
nology and optimized flow control
system that comes standard with
the hydroponic system. Ben has
done some excellent research on
solar tracking. His efforts will save
them on energy requirements but
most importantly, it will ensure
that they have a reliable power
source, an important requirement
for Nutrient Film Technique production systems, available at all
times. This will ensure that they
don’t experience power related
production losses.
The hydroponic system was installed in December 2015. Ben and
Gail have since made remarkable
and “overwhelming” progress on
their production operating their
system like pro's...and pilots. Ben is
a retired SAL Pilot and Gail was a
SAL Flight attendant and manager.
The system was installed on their 4
hectare plot in Benoni – Johannesburg. If all goes well with marketing they intend to install another
system soon.
At the moment they are growing
multiple varieties in the system
including cucumbers, lettuce, brinjals, cabbage, pak choi, tah tai,
chinese cabbage, broccoli, peppers, chillies and some herb varie-
ties. Some of the best performers
include cucumbers, lettuce, pak
choi and tomato varieties. Surprising growth rates have been
achieved. Even seed suppliers were
astonished by the amounts and
quality of the fruits present on the
plants.
The hydroponic system was developed with special emphasis on
providing growers as much as possible flexibility in terms of varieties
that can be grown in the system.
Its unique, internationally patented
design allows all plants to receive
near optimal but equal amounts of
water, nutrients and dissolved oxygen providing an optimal root
zone environment to the plants.
The system was also designed in
such a way as to maximize energy
efficiency and minimize energy
losses for heating purposes during
winter times. Heat energy is only
applied where the plants need it
most…at the root zone. Optional
features are available to cool down
the roots zone during summer.
This aid in keeping dissolved oxygen levels high, sugar to energy
conversion for growth and transpiration high and pathogen levels
low. The hydroponic system is also
equipped with a unique nutrient