Electricity + Control August 2016

A SENSE OF AFRICA

Farmers reap rewards from energy investments Information from Eskom

B efore any farmer spends money on improving operations there’s one crucial question they want to ask: what will the payback period be? Recently Jacobsdal crop farmer, Steven Squires, undertook a wide-ranging assessment of where he could make his business more efficient and where it could save money. An economist, Squires understood the importance of any investment to pay for itself – and that the bottom line of his business, AIS Farming, should reap the benefits as soon as possible. AIS Farming irrigates maize, wheat and ground nuts on 500 hectares near the Riet River in the western Free State. Production is in the order of 13,5 tons per hectare of maize, seven tons per hectare of wheat and 3,5 tons for groundnuts. Irrigation is fully mechanised with nuts being dried using axial fans, which use coal as the energy source. In 2013, acutely aware that energy was a key (and growing) cost to his business, Squires initiated a R1,5Menergy efficiency upgrade. Before deciding what to invest in, he obviously needed to know where AIS Farming was spending money and howmuch. Assisting him to determine his energy-cost baselinewas an EskomEnergy Advisor who not only visited Jacobsdal to help Squires with the number crunching but gave him detailed, practical advice on what the numbers meant. Working with the advisor, Squires decided on a number of interventions that would help AIS to cut its energy bills. Pumps and motors were replaced with newer and more efficient models. Pumps’ suction pipes were enlarged to lower water speeds, effectively eliminating cavitation (which impacts performance and reduces equipment life expectancy while adding to maintenance costs). Moreover, Variable speed drives (VSDs)

what has been Squires’ experience? “In total, we spent R1,5 M on the upgrade,” he explains. “That includes upgrading the pump station structures and equipment and replacing our main pipeline. On some centre pivots the payback has been less than one year, in line with what we were expecting and even better than what we were promised. “We took detailed readings of electric- ity consumption per pivot. While there were some variances between the plant- ing seasons we compared, the results were remarkable – as much as four times what we were expecting. In one case, for instance, energy consumption went down from 162 835 kWh to 89 311 kWh – we saved 45%. On the pivot where the pipe was replaced, the payback will be less than five years. Overall, yes, a great investment and very acceptable payback periods.” Conclusion So would he recommend that other crop farmers take a leaf out of AIS Farming’s book? “Definitely,” says Squires. “The whole process of deciding what to do, what changes to make and what invest- ments to make was challenging but defi- nitely not difficult. I would certainly advise every crop farmer using irrigation not to hesitate; investigate the possibilities, the potential up and down sides. You’ve got nothing to lose. And you get great advice and help from Eskom’s Energy Advisors”.

were installed to ensure that the motors were running at their optimal speeds and not wasting electricity. A small amount was invested in soil moisture probes, which would have the benefit of not only making sure that crops were getting the right amount of water but also testing the wisdom of Squires’ decision to implement no-till operations - no-till operations has had the effect of improving water absorption while reduc- ing the need for irrigation. (The Eskom Energy Advisor was ex- tremely helpful in making Squires aware of what equipment was available from whom at what cost and what likely energy savings could be achieved.) Payback on the investment Two years since making the energy- efficiency switch, AIS Farming is as au- tomated as it is ever likely to be. Thanks to the VSDs the business can afford to automatically start and stop its pumps using timer switches to irrigate outside of Eskom’s peak periods. “During the week irrigation is done at night when evapora- tion and wind speeds are lower while ad- ditional irrigation is done over weekends when electricity costs are lower,” says Squires, adding: “One of the benefits of the new set-up is that our eight employees are more productive; instead of being involved in the detail of irrigation, they can be used for other tasks on the farm.” But back to that all-important payback question. How much did AIS invest and

Enquiries:Tel. 08600 37566 or email advisoryservice@eskom.co.za

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