Greenhouse Production of Vegetables: Implications for the Region

By Fidel Maureira, Ph.D. Candidate, Department of Biological Systems Engineering, Washington State University

Dense rows of pepper plants in a greenhouse, on either side of a set of rails

Figure 1. Greenhouse production facility for bell peppers. Photo: Fidel Maureira.

Greenhouse agricultural production currently accounts for 1 to 2% of the agricultural production in the Unites States, but is rapidly growing. The value of this greenhouse production has increased 44% in the last years, and the number of operators has gone up by 71%. Large retailers have a significant interest in this technology, given the benefits of consistency in quality, flavor, and production volume, the potential for year-round supply, consumer preferences for local supply, and the perception that greenhouse production can be more sustainable than traditional production, with more efficient use of resources. New, larger, commercial operations tend to be concentrated around bigger cities to satisfy those local needs. This trend is true in other parts of the world as well, including neighboring Canada. What would greenhouses mean in the Pacific Northwest, if they are broadly adopted?

Greenhouses provide a tightly controlled environment, where computer systems allow strict management of ventilation, lighting, irrigation, humidity, temperature, and carbon dioxide concentration, with higher yields and resource use efficiency. These factors are all energy intensive, and therefore energy requirements can be large. Most of the technology is imported from the Netherlands, where it has been fine tuned in the last few decades to help achieve their national goal of “producing twice as much food with half the resources.” Adoption of this technology has helped the Netherlands become a global leader in the export of tomatoes, potatoes, onions and other vegetables, in spite of a lack of access to a massive land area, considered necessary for large-scale agriculture.

While greenhouse production of vegetables is not currently prevalent in the Pacific Northwest, given the national and global trend, and given the fact that it has been successfully incorporated just across the border in Canada (Figure 1) and in California (Figure 2), we plan to explore the impacts of this innovation on food production, energy production and the water system in Washington State. To get a better sense of the technology, production practices, and challenges, part of our team visited a bell pepper greenhouse production facility in British Columbia in 2018 (Figure 3). We also invited American Ag Energy—a company based on the U.S. East Coast, that is focused on integrating greenhouse production with power plants—to visit our team and discuss their operations. For example, we learned that the technologies prevalent in British Columbia were developed for milder summers and might not apply directly to hotter areas such as central Washington State.  Another factor that came up was the importance of having clean rainwater available, which brought up questions around whether rain water collection would be permitted under current water laws in Washington State.

Diagram showing key components and flows in an example greenhouse in California.

Figure 2. Example of tomato production in a greenhouse system in California, including water reservoirs and generation of electricity. This greenhouse system can produce in 125 acres the tomatoes that in open field production would take 3000 acres. The combined energy production from natural gas and photovoltaic systems meets the demand for electricity and heat used in the greenhouse system. The excess electricity generated is sold to the grid.

We plan to use a modeling system for greenhouse production to explore the potential to produce more food without exacerbating existing competition between different water uses in Washington State. Greenhouse production may even have the potential to alleviate some of those friction points due to higher resource use efficiencies (though it could lead to other issues, given their higher energy use). We will apply our simulation model to:

  1. Characterize the impacts of introducing greenhouse vegetable production on the food-energy-water system of Washington State,

    Nine people in a greenhouse, clustered in front of a trellis system, with tall vegetable plants in the background.

    Figure 3. Team visiting greenhouse production facilities in British Columbia, Canada. Photo: Mengqi Zhao.

  2. Evaluate the potential to capitalize on opportunities unique to the region, such as access to clean skies for solar energy,
  3. Compare the production per unit land and water, as well as the environmental footprint, of greenhouse and open-field vegetable production, and
  4. Obtain a list of the elements and conditions that would make the greenhouse feasible under future conditions expected in the region.

This work should inform the decisions of those in the food sector who are considering adopting greenhouses, policy-makers considering incentives to produce more food with less resources, as well as planning agencies who need to be cognizant of the impacts of large-scale adoption of greenhouses on the water and energy sectors.

 

This article was revised from the original version, titled “Greenhouse Production of Vegetables: Implications for the Regional Food-Energy-Water System,” published in November 2019 as part of the following report: Hall, S.A., Yorgey, G.G., Padowski, J.C., Adam, J.C. 2019. Food-Energy-Water: Innovations in Storage for Resilience in the Columbia River Basin. Progress Report for the Columbia River FEW Project. Available online at www.fewstorage.wsu.edu.

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