According to Agricultural Resource Management (ARM), farm irrigation pumping takes up 70 to 80% of the total electricity usage on a farm. And today, the majority of irrigated agriculture farmers operate on diesel pumps – partly because many diesel engines that were installed years ago continue to work well today. However, over the past 15 years there has been a growing trend of many farmers switching from diesel to electric.
A Comparison of Energy Costs
When there is convenient access to the electricity network, operating an electric pump can be very cost-effective – however this is not the case when infrastructure like poles and wires are aren’t already in place (requiring you to dish out rather extreme network connection fees).
Generally speaking, the cost for electricity varies according to when it is consumed (higher during peak periods), as well as where – but there is also an uncertainty with regard to how expensive electricity will be in the future. All in all, when a connection to grid power is practicable and no line extensions are needed, swapping out a diesel pump with one that is electric can bring down operating costs drastically today – when the current cost of electricity averages around $150–$250/MWh. (aginnovations.org).
The high and fluctuating prices of fuel today can render diesel pumps as a rather costly option, especially when you factor in the size and horsepower of your pump specifically. There are also maintenance costs including the installation of controls, which are higher than that of electric pumps.
To put things into perspective: according to AgInnovators.org, if you consider that average electricity costs usually range between $150 and $250/MWh – this represents more than twice the running cost of an electric generator.
Comparing Maintenance and Reliability
Electric pumps win in the maintenance sector, with little labour requirements involved. These motors don’t need to be refueled, and don’t require the monitoring and replacement of oil and filters. They simply require some lubrication four times out of the year. Electric pumps also integrate quite easily with digital systems, with a simpler installation of pump and Variable Frequency Drives (VFD) controls when compared to diesel engines. Since they can be operated and programmed remotely, this can help reduce costs associated with power surges.
The Vacon 100 Flow VFD is a good choice for pumping and irrigation systems, and it's conveniently available for purchase online.
An interesting fact: According to: Meta Economics Consulting Group, studies have shown that farmers value the reliability of electricity supply more than most other large consumer groups, but, are also not willing to pay a higher price for higher reliability despite the particularly destructive impact an extensive power outage could have on farm operations. Luckily though, there are cost-effective options when it comes to ensuring your farm has reliable backup power through all seasons.
Needless to say, diesel pumps require a little more maintenance and attention. Depending on the system, a pump engine may need to run for long periods of time which would require constant refueling of the engine along with regular checking of oil levels/filters. However, the extensive power range/stamina as well as the water availability of diesel pumps makes it a worthwhile option for many farmers – not to mention the technology it employs is very user-friendly.
Comparing Environmental Impact and Efficiencies
The good news about electric pumps is that they can range from 50-85% efficiencies. An electric motor also requires much less carbon emission energy compared to a diesel engine, and also produces less noise.
Diesel pumps do produce a higher level of direct greenhouse gas emissions when compared to the other two options, with some pumps ranging from only 20-35% efficiencies. Aside from irrigation, consider that tractors are also generally diesel-powered; with alternators that are either direct-connected engine driven or tractor PTO driven – but unfortunately also contributes to air pollution, global warming, and even soil and groundwater pollution due to spills. That’s something to think about as far as tractors go.
At the end of the day, the right power solution for your farm irrigation system (and for all of your farming operations) will be highly dependent on a range of factors – and there will always be certain advantages and disadvantages unique to both sources.