According to the Solar Energy Industries Association (SEIA), America’s solar industry continues to expand at a record pace. California leads the way, with more than 25 GW of installed capacity. According to the SEIA, “the cost to install solar has dropped by more than 70-percent in the past decade.”

As the price of solar component declines, more California farmers are looking to solar energy. The National Renewable Energy Laboratory (NREL) notes that solar costs continue to decrease for both “standalone photovoltaics and PV-plus-storage.” NREL graphs illustrate dramatic year-over-year cost reductions in solar equipment.

California farmers take advantage of these lower costs by embarking on various renewable energy projects. Some invest in large-scale solar installations. Others commit to the use of solar-powered irrigation systems.

Overview: Solar Energy and California Agriculture

A July 2019 article in the Los Angeles Times offers a detailed look at solar technology and California agriculture. The article profiles a Fresno-based grower of oranges and almonds that devoted 160 acres of unused land to a 20 MW solar project. Another 100 MW solar project will follow in the near future. Solar projects like these will help the state meet ambitious renewable energy goals. In 2018, the state set a 100-percent clean energy goal for 2045. 

California agriculture and solar development are a good match due to the amount of land with poor soil and/or inadequate access to water. At the height of California’s drought, NASA, in collaboration with the USDA, estimated that farmers in the Central Valley left 1.03 million acres idle throughout 2015. 

One report estimates that the San Joaquin Valley alone has almost a half-million acres of farmland that may be more suitable for renewable energy development than agriculture. Solar development is often easier on these lands than it is on ecologically sensitive inland deserts. In some areas, bighorn sheep roam the land as golden eagles soar above.

Many California growers oversee energy-intensive operations that benefit from on-site energy production. For example, Fruit Growers News profiled a grower who required more than $200,000 worth of electricity every year. Their operations include activities like hauling, shelling and processing almonds. The payback period for the grower’s solar installation was just six years.

Solar Applications in California Irrigation

Irrigation is a big deal in California agriculture. It accounts for approximately 80 percent of all water used by the state’s homes and businesses. Every advancement has a positive ripple effect across the economy. This includes the innovative technology driving solar-powered irrigation.

From 2014 to 2019, the State Water Efficiency and Enhancement Program (SWEEP) funded irrigation system improvements. The program saved water and reduced GHG emissions. Initially, the program was a response to the state’s extreme drought conditions prevalent at the time. Altogether, it funded more than 600 projects, many of them solar. Together, these deployments will deliver annual water saving equivalent to 50,000 Olympic-sized swimming pools. The projects also yielded an annual reduction of 75,000 metric tons of carbon dioxide, an amount emitted by 16,000 cars.

Growers are prime beneficiaries of solar-assisted irrigation. California is the nation’s leading producer of fruits, nuts and berries. According to Fruit Growers News, 2017 California’s revenue from all crops totaled $33.4 billion. Of that, fruits, nuts and berries brought in $19.7 billion.

Drip irrigation is already popular in areas with high temperatures and scarce water supplies. California’s record drought drove interest in drip irrigation. It eliminates much of the evaporation that occurs with sprinkler systems. It uses a precise mix of pipes, valves and hoses to deliver water right to a plant’s roots. This saves water and reduces fertilizer loss. 

The California Climate & Agriculture Network (CalCAN) highlights various solar-powered irrigation opportunities:

  • Improved irrigation scheduling using soil, plant or weather-based sensors
  • Replace or convert fossil fuel pumps
  • Upgrade or convert to drip irrigation, micro-irrigation and low-pressure irrigation systems 

Today, solar-powered pumps are increasingly used to supply water. And, solar-powered sensors are increasingly used to deliver it with less fuss and more precision than ever.

Solar-powered Sensors

In May, 2019, Forbes profiled a California startup focused on soil moisture monitoring. It manufactures solar-powered irrigation sensors fitted with soil probes. In the past, growers spent many hours driving from field to field to monitor irrigation needs. Now, it’s possible to do it from one’s computer or smartphone.

Decreased solar costs, innovative sensor technology and cloud-based communications are a perfect trifecta. The new technology is ideal for growers who want to take their irrigation systems to the next level.

In one case study involving a 40-acre test plot, a California vegetable grower deployed the sensors. Water use declined six percent. Also, greenhouse gas emissions declined five percent. The grower also saved fuel ordinarily required to pump water and power trucks used to check the fields.  

The zero-maintenance, solar-powered sensors and soil probes are strategically placed at intervals across fields. There, they gather soil moisture data. The sensors’ ultra-low-power long-range radio (LoRa) signals use very little power. There’s a single small solar cell on each sensor. It powers the system, even in low light.

Data is securely beamed to a communications hub via a secure LTE wireless network. A cloud-based application automatically analyzes the information. The grower controls irrigation timing based on the information received. By stabilizing the moisture content of the soil, sensor-based irrigation systems can also increase yields.

Solar-powered Pumps

The Horticulture Innovation Lab at UC-Davis notes the advantages of solar-powered irrigation pumps. A solar-powered water delivery system cuts electricity costs and reduces labor requirements. .

A grower can create a cost-effective system comprised of photovoltaic (PV) panels, drip irrigation kits and 12-volt pumps. An effective filtration system is also essential for efficient operation. Solar pumps are particularly effective in both remote and hilly settings.

The Horticulture Innovation Lab says a simple 50-watt solar panel can power a 12-volt pump. Such a pump is capable of moving 350-700 gallons of water per hour to a water storage tank. From there, gravity feeds the water to the drip irrigation system. 

The system makes use of materials typically available from local suppliers. Examples include storage tanks, filters, irrigation tape/tubing, wiring, piping, valves and fittings. 

System pumping water for agriculture, with the control unit powered by solar energy

Future Prospects for Solar

Three important trends will drive further adoption of solar technology by California’s growers. First, the declining cost of solar components and installation. Second, California’s ambitious clean energy goals. Third, advances in solar-powered sensor technology and solar-powered pumps. 

A growing synergy of sensor technology, wireless communication, smartphone applications and cloud-based data storage bodes well for solar-assisted irrigation in the future. 

Also, the Horticulture Innovation Lab intends to continue to promote solar-powered drip irrigation. The team there will test new components that will drive further solar system efficiency and cost-effectiveness.

Final Thoughts

At Fruit Growers Supply, we’ve been devoted to meeting the needs of California’s growers since 1907. We offer commercial irrigation expertise that may benefit your operation. We design and install cutting-edge irrigation systems for growers. Once your system is in place, look to us for maintenance, parts and repairs.

Fruit Growers Supply maintains convenient locations in Santa Paula, Woodlake, Porterville and Orange Cove. We can also recommend sources for photovoltaic (PV) panels and other solar equipment. For further assistance, please call or contact us today.

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