Where the Northwest
shapes energy efficiency


New Agricultural Efficiency Technologies

Created 6/30/2015 by Rob Penney
Updated 8/6/2015 by Mary Medeiros McEnroe
213 views • 1 comment
1 person likes this

Occasionally you hear about driverless GPS-driven tractors or see irrigators that don’t spray water high into the air, but in general what you see driving by a farm hasn’t changed much in many years. However, new agricultural efficiency technologies have come out recently, so your view from the road may change. 

One challenge in getting these technologies adopted widely is the understandably conservative nature of farmers, who may be reluctant to risk crop failure by relying on wireless controls, complex algorithms, and cutting-edge sensors. They fear that a field could turn brown because some blue-tooth wireless controls failed to pair. Furthermore, like some industries, energy may be a relatively small part of their operational expenses so they may feel that they have little to gain and much to lose by trying something new. However, the technologies described below are set to make farming more efficient and effective, and will hopefully be demonstrated and adopted soon.

Irrigation Optimizers

• Low-energy spray application (LESA) involves spraying water close to the ground or even dragging hoses or socks between rows to minimize water evaporation. I’ve seen irrigation systems where it looks like much of the water evaporates before it ever falls to the ground,

especially if there’s a breeze. With LESA, less water needs to be pumped, and the pressure can be 6-10 PSI rather than 40, so energy use can be cut by almost a third and save water, which is pretty important these days.  Note that this approach should only be used on flat terrain to avoid run-off.

• Irrigation VFD optimization is expected to save energy due to improvements in controlling existing irrigation pumps that are already controlled by a VFD. A network of pressure sensors provides feedback to VFD-controlled pumps to reduce the pump speed when pressure set-points are exceeded, resulting in energy saving of about 20% of energy use. This control approach is ideal for hilly or rolling terrain.

• Advanced sensors and controls can now tell farmers details of their irrigation operation, soil moisture, fertilizer status, and more – all funneled to their smart phone. These will facilitate Variable Speed Irrigation (VSI) and Variable Rate Irrigation (VRI), which show promise in terms of applying just enough water to satisfy crop requirements based upon life stage of the crop, soil water-holding capacity, and meteorological inputs.   One issue that needs to be worked out is getting all the manufacturers to agree to some common communication protocols (which is the same issue that has plagued HVAC and lighting control systems).

LEDs for Indoor Agriculture

This is one of the biggest advances in horticulture lighting in decades. Lights used in greenhouses and hydroponic systems are typically selected for general illumination rather than photosynthesis for a particular crop and, thus, are inefficient. Specialized spectrally-tuned LED lamps can cut energy costs by 40%.

An example of a farming enterprise that is utilizing these LEDs is AeroFarms in New Jersey, which will produce enough greens in an abandoned factory to feed up to 80,000 people. Produce is grown in vertical structures with no pesticides, herbicides, or fungicides, and using 97% less land and 95% less water than conventional farms. This approach is ideal to serve the local community. When the produce doesn't have to be trucked thousands of miles to consumers, it can be harvested at full ripeness and spoilage is minimized With optimized conditions, they can go from seeds to salad in as few as 16 days, so get 22 crops per year instead of three. Vertical farms are already popular in Japan, where cropland is limited. One vertical farm warehouse there produces 10,000 heads of lettuce daily! This all sounds good for business, food quality, and the environment, as long as the products retain the nutritional quality I enjoy from conventional organic farming.

Livestock Ventilation

Improved livestock ventilation can be provided with high-volume, low-speed (HVLS) fans up to 24 feet in diameter. A single HVLS fan is capable of displacing many smaller, constant speed fans, cutting energy use by 90%.

To learn more about these and 250 other emerging efficiency technologies, check out BPA’s E3TNW database(www.E3TNW.org).

Rob Penney

WSU Energy Program

Log in to comment, rate, and share.
Comments (1)
Mary Medeiros McEnroe on 08/06/15 on 01:26 PM (Pacific Time)



We have no agriculture here in our service territory, but this is very interesting.  I'm sharing it with some colleagues at utilities who do have agricultural customers and may be interested.