Energy from the sun, wind and water
Dual fuel systems are more efficient
Solar power can be utilised through a number of channels,
it will take some investigation to figure out which option
is best for you. Solar panels can be used to supply electricity
for pumping, charging batteries for lights and any other low
wattage use. However, they can be expensive, have a short
lifespan (+-10 years), and are vulnerable to hail storms and
theft. They also need to be cleaned regularly because dust
reduces their efficiency.
Dual fuel systems are generally used for heating air or water.
They are also frequently used in drying and intensive animalhousing operations.
Effective water heating can be provided by pumping water
through a network of black polythene and copper piping.
This can be installed on the roof and used to heat water for
the house and/or the swimming pool.
The bottom line for energy efficiency is that we can all
shoulder some responsibility and do what we can to save
power. As a farmer, your impact and role are significant.
Your business will benefit from more cost-effective and
energy-efficient operation so you can save money, while
you help our country.
Wind energy can be used to charge batteries that can
supply power to low wattage equipment in the home.
Wherever there is water flowing constantly from a high point,
that water flow can be used to generate electricity.
The principle of dual fuel is based on using heating elements
during off-peak hours and alternative fuel during peak hours.
Alternative fuel options include coal, gas, diesel, oil, paraffin, wood,
stalks or any other medium that is readily available in the area.
Together we have the power to save.
For more information, visit www.eskom.co.za/dsm
Make your farm
more energy efficient
Rising energy costs hit farmers especially hard and significantly
add to a farm’s operating costs. Controlling these costs means
that farmers need to become more aware of energy and learn
how to use it more effectively without compromising their
farm’s productivity.
Modern farming is a business and the modern farmer must
be a businessman. He is someone who is just as concerned with
controlling his operational costs as he is about his fields, crops
and livestock.
By making small changes to the way that you use power on your
farm, you can ensure that you get the best value for your “energy
rand” and also play a part in reducing the demand for power
around the country.This is especially important during peak energy
consumption periods (7 to 10 in the morning and 6 to 9 in the
evening) when the probability of load shedding is more likely.
You can make a start on effective power saving on your farm
right now. We’ll help by looking at some of pieces of the
equipment found on the average farm and advising you on
how to save.
Electric motors
Electric motors consume vast amounts of power. The older
your motors are, the higher the chance that they use more
electricity than they should due to being repaired several times.
You can reduce your bills significantly by replacing old motors
with new generation “high efficiency” electric motors. Ensure that
you size motors to run at three-quarters (75%) of their capacity
to perform everyday jobs. Visit www.eskom.co.za/dsm for more
information on the efficient motor subsidy programme.
Irrigation is a cost-intensive process
Streamlining your irrigation system means that you should make
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every effort to match your pipe and the sprayer nozzle sizes.
Remember that pipes with small diameters operate at higher
friction levels which means that more electricity is being used to
overcome that friction and deliver the same amount of water.
Check your sprayer nozzles for wear and tear on a regular basis
and you’ll reduce your water losses through any leaking pipes.
Leaking pipes mean that the pumps work harder to deliver
water and this increases the amount of electricity that they use.
Carry out regular maintenance on your irrigation system and you’ll
benefit from reduced power costs and save on your water bill.
Using up-to-date cellular and computer technology can also
result in major savings. It’s been documented that computer
scheduled irrigation can save up to 30% of the energy that you
would generally use.
Pumping water to storage dams situated above the areas
earmarked for irrigation means that you can use gravity to power
your irrigation, even when power is not available. Pumping upstream
can be done at night, to minimise the system load.
Cold rooms use a lot of electricity
You save electricity by keeping the doors to your cold room
properly sealed and only opening doors only when you need to.
This cuts down on cold air leaking out and being wasted.
Remember that overfilling a cold room actually lowers the cooling
efficiency. The air inside the room won’t flow as easily between
and under the produce, this means that it will take longer to cool
your produce down and that more electricity will be used to
reach the correct storage temperature.
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Condensers should be well ventilated to deliver the best
performance. For the greatest effectiveness, compressor rooms
and condensers should be installed on the southern side of
a building, this way they won’t be affected by direct sunlight.
You should check your filters and coils regularly to ensure that
they’re always clean and always check that there is enough gas
in the air conditioning plant.
The proper use of air curtains will also cut down the loss of
conditioned air.
Keeping dairy parlours energy efficient
Saving power in the dairy parlour means rinsing the milking
machines with cold water directly after milking. A complete
washing cycle for the equipment should be timed to take place
outside of peak hours (7 to 10am and 6 to 9pm).
Ice bank cool tanks can be used to build the ice bank during
off-peak hours for use in pre-cooling and cooling milk during
Eskom’s peak usage hours.
Increasing the energy efficiency of animal feed
processing plants
Processing plants for animal feed usually have large numbers
of electric motors.
Getting optimum performance from dryers.
If you use dryers on your farm, remember that they can be shut
down, or even be switched off completely, during the drying
process. Alternatively, the heating elements can be switched
off with only the fans left running.
Fans can be switched off for short periods without causing
damage to produce such as grains, oil seeds and lucerne left
in the dryer.
Only use the heating elements in the case of emergencies,
for example, during continuously rainy days and at night.
When using heat, try to circulate the heated air back
to the inlet of the fan as this will save energy and costs.
Wherever heating elements are used, it is advisable to
insulate the ducting, this minimises heat loss through the sides
of the dryer. Leaks in the ducting should be repaired as soon
as possible.
Insulating greenhouses
When you build greenhouses, bear in mind that a doubleinsulated plastic cover will always retain more heat and warmth.
Being able to keep the air and soil temperatures constant
by using the correct insulation means that less energy will
be used to create warmth in the greenhouse.
Farming using alternative energy sources
You can also manage your plant so that the cleaning and other
operations that require low amounts of electricity can be
done during peak hours. Schedule the plant’s actual operation
for outside peak hours.
Reducing the energy needs of animal housing
Reducing the cost of housing animals begins with the building
itself. Proper roof insulation ensures a cool environment
throughout the year and means that less money has to be spent
on climate control.
Painting a roof silver will help to reflect heat off the structure.
If you are building animal housing, remember that the long
walls of the building should face north and south and the short
walls should face west and east. This will help to dispel the
heat that builds up inside the buildings during the day.
If you use natural ventilation for animal housing then the building
shouldn’t be wider than 12 metres, or simple wind cooling
won’t be effective.
As a farmer you can take steps to utilise the waste generated
through the normal operations of your farm to create energy.
Harnessing the power of the sun can also save energy costs,
and these can add up to considerable savings and transform
the way you do business, in time.
If considerable amounts of animal waste is produced on your
farm then you could investigate the possibility of using a biogas
installation to generate heat and electricity. These installations
take the heat generated by animal waste and enable it to be
piped into feedlots and piggeries to be used in heating, or
channelled towards the production of cheap electricity.
Generating power
The best way to generate emergency power for short periods
of time is by using a standby generator. Generators run off
petrol or diesel and can be custom-made to cater for a variety
of outputs. You should consider the amount of energy you will
need and seek advice from an expert when considering
an installation. Bear in mind that generators should only be
used in well-ventilated spaces and should be far enough away
from buildings so that the noise of running them doesn’t disturb
people or animals.
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