Pumps Can Save Energy, Money in Vineyards
Sonoma winegrowers learn about financial incentives and technical tips for how and when to use pumps
Sonoma County growers gathered at Francis Ford Coppola Winery on Wednesday to learn the ins and outs of irrigation pumps at a seminar sponsored by the Sonoma County Winegrowers, Sonoma County Vintners, Sonoma County Farm Bureau and Northern California utility supplier Pacific Gas & Electric (PG&E).
The chief attraction came from The California Water Institute’s Center for Irrigation Technology at California State University, Fresno. Bill Green, education manager of the Advanced Pumping Efficiency Program funded by PG&E, towed his fifth-wheel mobile unit to an oak-shaded clearing near the Geyserville winery. It resembles a food truck, but instead of a lunch counter, the unit opens to reveal a working pump system complete with electronic testing equipment and a video display.
“Water and energy are two major issues in this state,” Green said. “This drought is historic—there hasn’t been anything similar for hundreds, even thousands of years. California’s water systems were developed in the mid-1960s, when the population was less than 20 million.” Not only has the population nearly doubled that figure, the state’s agriculture industry also has ballooned during the past 50 years.
“We need a comprehensive new program, but that takes years and we haven’t even started yet,” Green noted.
In the meantime, while water conservation is essential, farmers can achieve more efficient delivery and monetary savings by monitoring and improving irrigation systems. “There are a lot of bad pumps out there,” Green said. “Many are never fixed until they break.”
PG&E sponsors subsidized testing for electric- or natural gas-powered pumps operating at least 25hp. Those with smaller pumps can pay for testing and receive energy rebates. Once pumps are tested, the program will take care of all the paperwork; growers can use any reputable pump tester. The subsidized pump-efficiency tests ($100 vs. $200-$300) are offered only for freshwater pumps—not for winery water-recycling systems, although these might be eligible under state-sponsored programs.
“All you have to do is call,” Green said. “We’ll help you through the process.
“The payback comes mostly from energy savings,” he explained. Improved pump systems can earn a 12-cent per kW hour reduction in power costs.
“We want to help get efficient hardware in the field,” Green said. Management is also important, but the hardware is “the low hanging fruit.”
A pump audit will include evaluations of pump and pipe size, lift (elevation increase from source to destination) and flow. As water levels drop, flow is reduced. Undersized pipes should be replaced to reduce friction and use less power. Replacement may also be subsidized through the USDA’s Natural Resources Conservation Service (NRCS), which also can help growers to replace inefficient drip-irrigation systems.
California residents are routinely alerted to “Spare the Air” days, when they are asked to limit energy consumption during peak hours. Green, who maintains a family farm near Fresno, said that he only irrigates during off-peak (nighttime) hours, saving about two-thirds in power costs.
In this drought year, Green has noticed one drawback to this watering system: “Coyotes are chewing through my drip irrigation lines,” he said.
Green fired up his demonstration system, which includes a variety of pumps, valves and pipe sizes to illustrate how each aspect affects performance. Submersible pumps, for instance, are less efficient than more accessible types, but they have less visible wiring. This makes them more attractive, but also less attractive to another agricultural pest: copper thieves.
Water pressure may vary from hour to hour. For a test, Green suggested, switch off different blocks. “Even your neighbors can affect your pump efficiency,” he cautioned.
Diminishing levels of groundwater can also mean that pumps are damaged by increased levels of sand or silt, which can quickly grind down pump impellers.
“We are overdrawing our groundwater in California by about 2 million acre-feet per year,” he said. With a conversion rate of 325,851.4 gallons per acre-foot, this amounts to more than 6 billion gallons of water per year.
When even the slightest change in water level creates less water flow, pressure and lift in pumps, pumps must operate at peak efficiency. Although most of the audience indicated they filtered their pumped water, few checked their filters regularly. “When filters clog up, you lose pressure,” Green warned.
Although PG&E’s rebate and subsidy programs do not apply to wastewater treatment, wineries can increase efficiency there as well. Improvements in technology offer more choices, said Dr. Ahmad Ganji, principal of BASE Energy Inc., which manage s PG&E’s Agriculture & Food Wastewater Energy Program.
In general, Ganji recommended anaerobic treatment for winery waste. These, he said, are more efficient than the most common vertical turbines and fine-pore diffusion aerators. Automatic systems are most efficient.
“Anaerobic treatment is more expensive but good for places with less space,” important where real estate is expensive, he said. And this non-aeration system has another significant advantage: It can self-generate power. Initial capital investment is higher, and temperature control is essential since the water needs to maintain a relatively constant, high temperature for the process to work.
Ganji addressed other water/energy conservation measures.
• Wineries should implement written procedures for water conservation.
• Brush or sweep winery floors before hosing them down.
• Use high-pressure, low-flow nozzles.
• Plan for sequential use of tanks so they don’t all need to be washed at the same time.
• For tank and bottle washing, use the last rinse water for the first rinse in the next vessel.
More from Sonoma County Winegrowers
The annual Grower Seminar, Tradeshow and BBQ will be June 6 at Shone Farm in Forestville. The program will address the county’s new biological assessment requirement, an industry trend report and public relations advice for “communicating during a crisis,” a trade show and casual lunch with Sonoma County wines and presentation of the Viticulture Award of Excellence. For trade show information, email email@example.com; for registration, email firstname.lastname@example.org.