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From Cotton Farms to Solar Farms

Barry Nelson

Posted May 13, 2009

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Charting a path to a more sustainable future for California will require reducing both water use and greenhouse gas emissions. One innovative strategy that could contribute to both goals would be an ambitious effort to encourage some Central Valley farmers to grow a new crop - electricity. Moving from cotton farms to solar farms could offer dramatic multiple benefits. Such an effort could help reduce the Golden State's carbon emissions. It could also help reduce pressure on the fragile Bay-Delta system and reduce demand on a limited water supply that is expected to shrink as a result of climate change.

In general, the Central Valley does not receive as much annual solar radiation as the state's desert south - a key consideration in evaluating potential photovoltaic or concentrated solar projects. However, during the hot summer months when California's electricity demand is at its peak, the Central Valley has significant potential for both concentrated solar and photovoltaic projects.

A large Central Valley solar energy project could be a very ambitious undertaking, potentially representing many gigawatts of installed capacity. This prospect is not unrealistic. Utilities have begun to recognize the potential for such facilities in Central California. For example, last August, PG&E signed agreements for 800 MW of solar capacity at two new proposed facilities in Central California.  A year ago, the South San Joaquin Irrigation District flipped the switch on a seven acre photovoltaic system  -- one of the largest in California. And just last week, Cleantech America announced that it had received approval for a new 5 MW photovoltaic facility in the Central Valley community of Mendota. 

Solar power is not cheap. The key to determining the feasibility of a very large-scale Central Valley solar project is accounting for several potential additional benefits of such a project.

Along with renewable power, the most obvious benefit of a cotton-to-solar project would be a potential reduction in water use. For example, 100,000 acres of cotton consumes more than 250,000 acre-feet of water per year - nearly half of the water consumption of the City of Los Angeles. Farmers, environmentalists and urban residents could all see benefits from a large solar project, if it could help reduce water use by cotton or other low value crops. This year, some farmers in the Central Valley are hurting. Three successive dry years have drained the reservoirs of the State and federal water projects, reducing agricultural water deliveries. Looking down the road, it appears likely that, as a result of climate change, the need to protect the Delta ecosystem, the rights of other water users, and the need to restore California's salmon fishery, the State and federal water projects may never again pump the record amounts of Delta water diverted just a few years ago. A cotton-to-solar project should not be seen as reducing agricultural acreage, but rather as adding a new crop for farmers - one that would be unaffected by dry years.

Why focus on cotton? Cotton is relatively low value and among the crops most likely to be displaced as farmers turn to new ideas. Cotton is also highly subsidized, consumes vast quantities of agricultural chemicals and provides little habitat. Farmers are already looking for alternatives to cotton. Acreage in cotton production in California is declining. For example, cotton acres in the Westlands Water District fell from 240,000 acres in 1993 to 37,000 in 2008.  But California farmers still grow a great deal of cotton. In 2007, state-wide, 450,000 acres were planted in cotton.

Another potential benefit of a Central Valley solar project is help in resolving the chronic drainage problems in parts of the Valley. The agricultural industry and the federal government have already proposed large changes for agriculture in the Valley to respond to the drainage problem. For example, the Westlands Water District has called for the retirement of 200,000 acres of land - one third of the entire district. The Bureau of Reclamation has identified the retirement of 194,000 acres of land as the preferred alternative for addressing drainage issues in the Valley. USGS and the Fish and Wildlife Service have recommended that this target should be 375,000 acres. More than 35,000 acres of land in Westlands has already been permanently retired. Some of this land might be available for the initial phase of a solar project. And a "buy down" in water use could create an income stream to help finance the conversion to solar.

A Central Valley solar project could also provide jobs in some of California's most disadvantaged communities. One interesting option would be the creation of a thin film photovoltaic (PV) factory on the West side of the San Joaquin Valley. Applied Materials and Oerlikon both offer "turnkey" PV factories, which customers can order to be built to their specifications. A large scale Central Valley solar project could consume for decades the capacity of a factory dedicated to the project. Such an effort could provide badly-needed local employment.

Some Central Valley communities are suffering from reductions in water deliveries this year. In fact, Valley towns like Mendota and Firebaugh have been economically disadvantaged for decades. Large-scale agriculture in this region, with a high percentage of absentee landlords, has not served these communities well. An ambitious renewable energy project could provide long-term factory, construction, and maintenance jobs. Given its scale and potential duration, such a project could also include scholarship and trade school programs designed to build skills and increase benefits to local communities. Renewable energy might finally provide some of the local economic benefits that the federal water reclamation program has failed to deliver.

The economic feasibility of this idea is enhanced when one considers existing agricultural subsidies. One acre in cotton production in the Central Valley produces an annual yield worth approximately $1,200 (at 2005 prices.) NRDC's analysis concluded that water and crop subsidies represent 17-56% of the total value of this cotton. A renewable energy project that reduced cotton production could help reduce these taxpayer subsidies - yet another potential benefit.

There's one final potential benefit. Selecting sites and providing transmission for renewable energy facilities in California presents a major challenge. In the Mojave Desert, siting and transmission have significant potential for conflict with wildlife and sensitive resources. From this perspective, the Central Valley has a few advantages. The Valley already hosts major existing transmission corridors and cotton fields provide little wildlife habitat.

In short, a Central Valley solar project could offer remarkably broad benefits, including:

  • Large scale renewable energy generation.
  • A new crop (electricity), which is unaffected by droughts, for farmers south of the Delta.
  • Reduced water use south of the Delta.
  • Jobs and an increased tax base in disadvantaged Valley communities.
  • Help in resolving drainage issues on the West side of the Valley.
  • Reduced pesticide use and improved air quality in the Valley.
  • Reduced agricultural subsidy payments.
  • Reduced siting and transmission conflicts compared with alternatives (e.g. the Mojave Desert), leading to reductions in cost, time, and uncertainty in the permitting process.
  • It beats going nuclear

Many factors suggest that this is a uniquely appropriate time to carefully evaluate this idea. California is suffering from a third dry year. The California legislature is focused on addressing problems in the Delta. The federal stimulus bill included a significant emphasis on renewable energy. The California Air Resources Board is working on a plan to implement California's ambitious greenhouse gas reduction goals. And Congress is considering a similar climate bill for the nation.

Finally, it's important to note that land owners in the Central Valley are highly sophisticated businessmen and women who have spent decades adapting to changing water supply and market conditions. These owners and their local communities understand local conditions and needs better than anyone. Their involvement is essential if a cotton-to-solar project is to work. Common ground has been hard to find among environmentalists and agricultural interests south of the Delta. An ambitious renewable energy project might provide an important opportunity for a collaborative effort with broad benefits.

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Philip BowlesMay 14 2009 01:02 PM

2008 cotton acreage is 120,000, the majority of that very valuable Pima ("so-called Egyptian", but in our case not picked by slaves) cotton, which does not receive a subsidy. But your points are well taken. If land owners can make a better return, and provide more employment, property taxes, and other community benefits by changing their land use, it is worth exploring. Of course, that's what the developers promised, too. Unlike housing development, however, if the solar thing does not pan out, the land has not been ruined for agriculture.

Elizah LeighMay 14 2009 05:47 PM

Prior to joining an online green social network (, I never really had an opinion about cotton crops. Somehow, they magically turned into the textiles that migrated into my closets and onto my linen shelves. However, ever since I began interacting with the green minded people in the Greenwala community, my entire perspective of agricultural industrialization has been turned over sideways. Education, they say, is key -- sadly, I was in a state of ignorant bliss for far too long. Cotton is truly THE most heavily sprayed crop in the world and has vastly contributed to the decline of many eco-systems around the globe. I think that California's conversion to solar farms is a huge step for the ecology of that area! If anyone here cares to share their views on this topic, please jump in on the following conversation already in progress -- just paste this link into your browser!

Philip BowlesMay 15 2009 11:39 AM

Eliza, I don't know the source of the statement "cotton is the most heavily sprayed crop in the world", but it is so general as to be meaningless, since it does not differentiate between substances that may be dangerous (pesticides) or benign (foliar fertilizers). In desert climates like California's, cotton faces far less bug and weed pressure than in humid, tropical areas like the deep South, or India, where it must be sprayed far more than it is here. California also leads the world in the implementation of integrated pest management, and has exemplary State regulations to ensure the safe application of pesticides.
I go into this aside because we need to consider where an activity will take place when we displace some portion of agriculture from California. If we simply shift the activity to a place where all the practices are worse, and where yields are lower (wasting resources), are we not just being NIMBYs?

Philip BowlesMay 15 2009 12:44 PM

It is only fair to add that in this particular example (solar farms), Barry is suggesting a *replacement* use for land that is not now producing, and which may not have an agricultural future; not a wholesale exodus of agriculture from our state. Farmers can be a guilty of hyperbole as the most ardent tree-huggers. It's fun, but not useful.

John ReederMay 15 2009 01:20 PM

Like anything, this will be an industry that will run into the law of unintended consequences. We obviously can't take all of the ag out of production or we would make food too expensive.

I have a post up on my blog on the intersection of solar and real estate.

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