As a result, Eskom has been doing extensive research on energy efficient farming and how to best support South Africa’s farmers and all other types of agro-businesses with energy efficiency advice.
Farming operations plus the processing, packaging and other support industries comprising the sector, consumes 6,000GWh (gigawatt hours) of electricity per year, 4% of the national total. Although far less than the 148,000GWh consumed by the industrial sector, powering the agricultural sector is of strategic importance to the long-term socio-economic wellbeing of our country. Apart from the fact that millions of people are directly or indirectly dependent on agriculture for their livelihoods, the sector is key to our nation’s food security and foreign currency-generating food exports.
49M, the local movement that calls on all South Africans to switch to energy efficient business practices and lifestyles, encourages farmers to conduct energy use assessments as a starting point to improve the energy efficiency of their operations. Through this assessment process, data on a farm’s energy consumption and associated costs can be collected and analysed as a basis for change on four fronts:
• Changing energy use behaviour;
• Streamlining operations;
• Improving maintenance procedures; and
• Switching to energy efficient technologies, including renewable energy solutions.
Energy use assessments typically analyse electricity bills, usage data and all electric equipment and processes specific to the operation of a particular farm.
• Lighting – optimising inefficient lighting systems by fitting energy efficient component alternatives such as Compact Fluorescent Lamps (CFLs), Light Emitting Diodes (LEDs), T-5 systems, electronic control gear, lighting sensors and daylight harvesters.
• Motors – replacing outdated, inefficient or oversized motors with energy efficient alternatives and installing Variable Speed Drives (VSDs), where applicable.
• Pumps – replacing inefficient pumps with energy efficient alternatives and operating them in an optimal configuration with correctly sized motors and VSDs, where applicable.
• Renewable energy – utilising alternative energy sources such as solar water heating systems, micro-hydro schemes and photovoltaic installations.
Importantly, and as a starting point, farmers are advised to check which electricity tariff they are billed at; there could be an opportunity to reduce energy costs by moving to a more cost-effective structure. Moreover, shifting energy-intensive operations outside periods of peak demand for electricity could mean paying lower tariffs.
An Eskom Energy Advisor conducted an energy use assessment on the farm of Kosie and his son Manie Eloff outside Soekmekaar in Limpopo Province. The assessment showed that irrigation accounts for 61% of their electricity bill.
The Eloffs’ have 14 pumps of varying sizes, some of which could save electricity by using Variable Speed Drives. Costly, and a new technology in the eyes of many farmers, Kosie and Manie decided to go ahead and invest in a VSD.
• The VSD was installed on a 45kW motor; and
• The throttles that change the flow and pressure as the irrigation load changes were removed.
The installation reduced energy demand from 18,9kW to 13,2kW, a saving of almost 30%. Due to this improvement in energy efficiency, Kosie and Manie Eloff are now investigating the savings potential of the other 13 pumps on the farm as well.
Eskom's national Advisory Service can help locate technology suppliers. The team can also advise farms and any other business in the agricultural sector on:
• Reducing energy usage;
• Doing walk-through energy assessments to identify energy usage patterns, energy needs, areas of energy wastage and energy saving opportunities;
• Improving the energy efficiency of operations and electrical systems and processes;
• Prioritising maintenance as an important contributor to reducing energy usage; and
• Finding SANAS approved energy savings Measurement and Verification Authorities.
Advisors also help in identifying funding opportunities for energy efficiency projects.
