Monitoring power use in irrigation systems

Although water is the number one key input into an irrigation system, energy also plays an obvious role. This is so much the case that it is becoming an increasingly expensive input in running irrigation systems, both in agricultural and municipal applications.

Energy is so important that Queensland Farmers Federation and Cotton Australia chaired a forum of stakeholders in Brisbane in August last year examining the issue of electricity costs, which some believe will make irrigation unsustainable. One solution proposed at the forum was a “special” food and fibre tariff at a reduced rate.

The sentiment hasn’t diminished this year. In January, Allan Dingle, chairman of Bundaberg District Canegrowers, stated that: “Current prices are unsustainable and relief is paramount for our industry and indeed all other irrigators to remain viable.”

One inescapable fact is that there will be electricity tariffs into the future. Another is that tariffs are reviewed each year and they only go in one direction, which is up. This being the case, it makes sense that using less electricity is the only way to reduce its cost. In this situation, it is crucial to ensure that irrigation systems are correctly designed and selected and efficient; this will reduce the amount of power being consumed and the size of its contribution to the balance sheet.

Water meters are now commonly used in irrigation systems to monitor water use and performance, so why not meters to monitor for energy use and performance?

“Measurement is the first step that leads to control and eventually to improvement. If you can’t measure something, you can’t understand it. If you can’t understand it, you can’t control it. If you can’t control it, you can’t improve it.”

H James Harrington

When you measure your irrigation system’s energy consumption, you can track use over a 24-hour, weekly and monthly cycle, get reports on high-consuming equipment and receive alarms when equipment is operating out of set thresholds. That way you will be able to identify issues such as whether that old pump you use is costing you thousands in running costs and water flow delivery.

Monitoring energy use as a way of managing costs is a relatively simple and cost-effective option with many of the more sophisticated control systems that are commonly used today. Control systems with input capability can interface with sensors to provide this valuable information and management tool.

There are many projects around the world today where energy use in irrigation systems is being monitored and managed - in countries such as Israel, Italy, Peru and Australia.

As an example, Highway No. 6 in Israel has a system controlling irrigation and water canals along the highway. This system is monitored using 60 power meters. The meters monitor electricity consumption of lights in 60 road segments and also of traffic lights in several intersections. Current, consumption and faults data are wirelessly transferred and displayed on the ICC central, located in eastern Tel Aviv.

All this goes to show that managing an efficient irrigation system is not simply about how much water is being applied. Increasingly, efficiency involves many factors, such as energy use, that smart managers are aware of and are responding to by improving their skills and adopting technology that is already available.

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