Energy Use in a Time of Drought

Source: Grist.org
Source: Grist.org

Amidst California’s ongoing drought, farms and ranches have taken a variety of steps to adjust their practices to cope with less water and sustained heat.

A new report commissioned by the California Public Utilities Commission (CPUC) finds that, as a result of these coping mechanisms, the agriculture sector consumes noticeably more electricity in drought years than in normal years. What’s more, the increase in electricity usage varies significantly by agricultural sub-sector.

A detailed look at this data reveals some of the opportunities to achieve even greater water and energy efficiencies so that agricultural producers can survive future droughts without suffering astronomical energy costs on top of all the other stresses a drought can bring.

Calculating ‘Drought Factors’

In the CPUC report, researchers tallied up electricity consumption in the agriculture sector during ‘normal’ years and in drought years, then calculated the difference between them.

Screen Shot 2015-07-16 at 11.59.28 AM
Source: CPUC and Navigant Consulting, Energy Efficiency and Goals Study for 2015 and Beyond

They found that, since 2007, California’s agriculture sector has on average consumed an additional 931 gigawatt-hours (GWh), or about 17.5% more electricity in drought years.

A closer look reveals differences depending on the type of operation, or sub-sector.

Agricultural processing operations are estimated to have only minor increases in electricity consumption. This is due to the need for slightly higher cooling loads to keep products and warehouses at the required temperatures.

Confined animal feeding operations (CAFOs) and dairies also have higher cooling loads that suck up more energy in order to keep the animals (and their output) in good shape. The CPUC report estimates that dairies and CAFOs each use 10-11% more electricity in the average drought year.

Meanwhile, vineyards and wineries – due in part to their large amounts of liquid that need to be kept within a specific temperature range – have considerable drought-year energy needs, on the order of about 30% higher than in a normal year.

Water Use the Greatest Factor

Perhaps unsurprisingly, irrigated agriculture has seen the greatest increase in electricity use in recent drought years.

According to the CPUC analysis, drought can be expected to boost electricity use on the average irrigated agriculture operation by a full one-third above normal year usage. This is due primarily to the need to pump groundwater from lower water tables.

The higher electricity use also stems from the need to rely more heavily on groundwater, as other sources of water become scarce or disappear entirely; farms reliant upon water deliveries from local irrigation districts have seen their supply greatly diminished or eliminated altogether, while those traditionally benefiting from rainfall, rivers, and streams have seen minimal precipitation and diminished flows.

Notably, this analysis does not capture drought-induced energy use increases in the form of gasoline or diesel burning, which many farms still use to power their pumps.

A Vicious Cycle

Unfortunately, with the length and severity of droughts anticipated to increase under a changing climate, we can expect future drought years to only exacerbate this problem.

And with higher agricultural energy use comes higher greenhouse gas emissions, feeding a vicious cycle wherein a climate-change-fueled drought leads to higher greenhouse gas emissions, which further destabilizes the climate, potentially leading to more severe droughts…

So how do we break the cycle?

One way is to shift to renewable energy resources such as solar, wind, and biomass. Growers around the state are already doing this, with an estimated 8-10% of operations already producing their own clean energy. Net Energy Metering Aggregation, which CalCAN helped pass into law in 2012, is one way to make renewables cost-effective in agricultural contexts. A variety of state and federal grants, rebates, and tax credits can also help with affordability, not to mention the long-term savings to be had—even outside of drought years.

Another way to tackle this challenge is to make farms even more water- and energy-efficient to begin with, so that when a drought year rolls around the stresses of water scarcity have less of an impact. We have previously discussed some of the many ways this can be achieved through soil management practices as well as through improved pump and irrigation technology and maintenance.

The USDA recently invested $21 million in on-farm conservation efforts through its Environmental Quality Incentives Program (EQIP). We blogged about that effort here.

Pacific Gas & Electric (PG&E) runs a suite of ratepayer-funded programs to help growers fund and implement energy-efficient technologies, and the company has stepped up its efforts in this arena as the drought continues. PG&E has put additional funding towards pump efficiency tests and scaled up its efforts to assist small and medium-scale growers transition away from high-pressure sprinkler systems. It is also seeking to improve informational materials that help growers make better-informed water use decisions, for example by using soil moisture sensor systems and automated pump monitoring software. As the drought drags on, there is still more that PG&E can do to spur innovative approaches to water and energy use reductions, including incentivizing innovative soil management practices that conserve water.

The State of California is also using the drought as an opportunity to aggressively promote on-farm water and energy efficiencies. Cap-and-trade funds have already been used to support 154 projects that simultaneously reduce water use and greenhouse gas emissions. That program, administered through the California Department of Food and Agriculture (CDFA), is likely to see its budget quadrupled in the coming year. CDFA is looking at ways to also encourage management practices that build soil organic matter to store water, something that CalCAN has suggested since the program’s inception.

Another new cap-and-trade-funded program, to be run by the California Energy Commission (CEC), is likely to receive significant investment as well. The Water-Energy Technology Program’s first phase will be reserved exclusively for agriculture-sector projects and will provide rebates for converting to low pressure drip irrigation systems, as well as support for emerging efficiency technologies. Although drip irrigation is not a one-size-fits-all solution, as it does not provide adequate groundwater recharge in some areas of the state, these incentives are a good start to what will hopefully become a more expansive program.

Additionally, Water Bond funds approved by voters last fall through Proposition 1 (2014) will soon become available for agricultural projects. CalCAN and CAFF worked to include agricultural water use efficiency efforts in the bond legislation, and we will be weighing in on the use of these funds as the process moves forward.

Finally, we need to improve our understanding of the ‘water-energy nexus’, and clarify the many ways that water and energy use intersect. A bill introduced by Senator Fran Pavley (D – Agoura Hills) would fill in some of the gaps by commissioning a comprehensive study to help guide future water-energy efficiency efforts across all sectors.

Room for Improvement

There is still much work to be done to support growers as they adjust to what may be a ‘new normal’ for California agriculture. Soil management practices need to be incentivized alongside technological solutions. Technical assistance through the Resource Conservation Districts and UC Cooperative Extension needs to be a focus of future outreach efforts.

Above all, we need to continue to support farmers’ efficiency efforts – whether it’s a drought year or not – to make sure that managing for water scarcity doesn’t translate to additional greenhouse gas emissions.

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