When growers look to invest in new products or technology for their farming operation, they generally expect to get one of two things out of the investment. It will either increase their output (yield) or it will reduce their operating costs. Either one is a good thing. When growers invest in irrigation equipment they tend to be focused on the yield side of the equation. Adding center pivot irrigation will give a grower higher, more reliable yields, and he can expect that equipment to pay for itself in a reasonable amount of time.
However, irrigation is not just about increasing yield. The equipment and pumping stations have operational costs, so growers also look for ways to reduce those costs. A great way to do that is by using Variable Frequency Drives on your electric pumps. A Variable Frequency Drive (VFD) is an electronic device that can change the frequency of the supplied power to a pump or other electric motor. This means that the pump doesn’t always have to operate at the same speed, but can operate at different speeds depending on demand.
Let me use an example to illustrate. Corner machines are a great way to add additional irrigated acres to your investment in a center pivot. A typical corner machine on a quarter-mile pivot can pick up as much as 25 acres. However, corner machines can have a big effect on your pumping system. The difference in flow between when the corner machine is extended vs. retracted can be 35 percent or more. That’s significant! If your pump only operates at one speed, and is sized correctly to provide the right amount of water when the corner machine is extended, then it’s going too fast and providing more pressure and flow than necessary when the corner machine is retracted. The bottom line is the pump is using more energy than necessary, increasing your operating costs.
Here’s where the VFD comes in. If there is a VFD controlling the pump, it can reduce the speed of the pump as the corner machine retracts and continue to provide only the needed pressure and flow. The pump is then running at a slower speed and using less energy; therefore, saving money!
The corner machine example I used above strongly illustrates the benefit of using a VFD for your pumping system, but there are many other applications that can benefit just as much from a VFD, including rolling terrain, Benders, VRI, multiple pivots on a single pump, etc.
Valley® Water Management is focused on designing and building the best possible pumping solutions for growers. We have partnered with Yaskawa™ Electric America to make Yaskawa VFDs available on our custom-engineered pump stations, which are available to Valley dealers for all their pumping applications. Y
In a future post, I’ll tell you about another new product from Valley Water Management called Drive Connect.