CEA Site Selection Considerations to Maximize Efficiency and Sustainability
As greenhouse growers and indoor farmers strive to produce higher yields with fewer resources, the location of a CEA site becomes a pivotal factor in determining its overall efficiency and sustainability.
From leveraging natural climate advantages to optimizing water and energy use, the right site selection can drastically enhance a facility’s resource efficiency. Factors such as sunlight availability, local water sources, energy availability, and zoning permissions all play critical roles in shaping the resource efficiency of CEA operations.
Additionally, distribution logistics, renewable energy availability and co-location opportunities can significantly impact an operation’s carbon footprint. As carbon taxes and credit programs take root in North America–they are already in place at both the federal and provincial levels in Canada–reducing emissions is not just an ecological initiative but could determine long-term commercial sustainability.
Photo: Rob Eddy of Resource Innovation Institute
Resource-Efficiency Considerations
One of the first things to determine when judging a site’s viability for a CEA operation is whether the local community wants you there and has the infrastructure to support your business’s needs. Bradley Berg, a Project Developer with ARCO/Murray, an RII member, emphasizes that site selection “starts with knowing what your long-term strategy is on a property. This allows you to ask the right questions upfront instead of committing to a site with only short-term incentives, or in a community that doesn’t view your overall growth as beneficial.”
Without that community buy-in, “you’re going to have struggles down the road,” he adds. Whether in the form of a grassroots movements opposing your plans to implement innovative solutions such as combined heat and power (CHP) systems, solar panels, and geothermal wells, as well as potential challenges in navigating permitting and zoning changes with city councilors or county commissioners.
Local weather and climate will also inform a CEA operation’s energy use–although this is significantly more important for greenhouses than indoor farms. Choosing a site with a favorable climate can reduce the energy needed for heating, cooling, and humidity control, but there can be tradeoffs. For instance, locations with ample natural sunlight can reduce the dependency on artificial lighting– a significant energy consumer in CEA facilities–but could create greater heat loads. On the flip side, locating in valleys (like California’s Central Valley, or the Red River Valley in North Dakota) can bring cooler temps while making moisture tougher to handle and require supplemental lighting usage. Crop choices will greatly inform the best environmental setpoints to target.
On the topic of energy, a CEA operation that wants to make efficiency its backbone should consider if the site has opportunities to tap into renewable energy sources. Acquiring a bigger lot of land than what your facility will physically occupy can enable growers to use solar. That said, the facility’s scale could make solely relying on solar infeasible.
“The amount of land required for solar could be 10 times the size of the site itself,” Berg explains. “For instance, if you have a 2,000 square foot greenhouse, you might have enough land. But for large scale commercial facilities, the opportunities for solar are much more limited because the necessary land simply isn’t available.”
The potential for geothermal wells will largely depend on the site’s soil quality, according to Berg. “Do you have rock, or do you have the necessary soils that allow for deep excavation to install a geothermal system? If there’s a lot of rock to go through, the CapEx isn’t going to be feasible for utilizing that source.”
Water is another critical input to consider. Beyond the cost and energy intensity of remediating and purifying contaminated water sources, CEA facility operators should weigh whether zoning and local regulations allow them to tap into water-saving solutions such as rainwater catchment systems and reuse ponds, says Catherine Wilsbach, Director of Land Development at LIVIC Civil, another RII member.
“We do see reuse ponds where [growers’] ideal situation is to collect all the water from the roofs and direct it to a reuse basin. Some authorities are wary of this and require additional stormwater systems adding significant cost to the project with little benefit,” Wilsbach explains. Where these reuse pond systems are permitted, “we see less sediment laden runoff and the ability to leave more land undisturbed on the sites.”
Photo: IMEG Corp
Carbon Footprint Considerations
Other carbon footprint impacts, beyond energy and water use, can influence site selection for a sustainability-minded CEA facility. For example, distribution logistics could greatly reduce a site’s otherwise ideal conditions, Wilsbach notes.
“The distribution after harvest [can increase your operation’s carbon footprint],” she says. “Are you close to your customers? Whether you’re having to truck things like a further distance” ties directly to a CEA’s carbon footprint. Additionally, spoilage becomes an escalating issue the further away fresh products need to be transported, which can increase a facility’s overall biowaste.
Distance can also turn an otherwise carbon-cutting system into a carbon-neutral one or, in the worst cases, a carbon-emitting one. CHP systems often rely on natural gas as an energy source. These systems can be highly efficient as, in addition to the electricity generation, both heat and CO2 can be captured for use in the facility. However, “How are you getting that gas?” Berg asks. “Are you trucking it in, or do you have some other means of creating a feed store for that CHP unit?” The distance supplies must travel to reach your facility, whether natural gas, supplemental CO2, water, nutrients, or parts needed for system repairs, directly impacts your carbon footprint calculations.
“There’s an interesting dichotomy in site selection,” Berg notes. “Some sites have excellent utilities already in place, while others are ideal for renewable energy, but lack easy access to necessary supplies. However, progressive communities and utility providers are starting to make infrastructure upgrades in historically rural areas to help meet the needs of 21st century cultivation platforms.”
How the local utility sources its energy also will affect a CEA operation’s carbon accounting. Greenhouse growers in British Columbia, Canada, can rely on a grid that utilizes nearly 98% renewable energy, the vast majority of that being hydroelectric power. However, many parts of the United States still rely on fossil fuel-based grids. In those locations, it may be worthwhile to see if it is feasible to find a suitable site near that power generator to leverage co-location synergies. For example, in addition to utilizing electric energy from the utility, a CEA site could also capture waste heat for climate control.
Similar co-location opportunities may also exist with nearby manufacturing or industrial businesses. As an example, facilities producing different types of biomass could partner to tap into anaerobic digesters to reduce their reliance on less sustainable utility providers. Similarly, landfill gasses can be burned to generate heat and electricity, with some groups going so far as researching how to extract clean CO2 for use at nearby farms.
A thoughtful approach to site selection is critical for the success and sustainability of CEA facilities. Site selection is not just about site feasibility but also about how well the location aligns with the business’s overall sustainability goals. The right site for a grower prioritizing resource efficiency enables the integration of renewable energy solutions and innovative systems, enhancing sustainability.
Ultimately, a well-chosen site maximizes resource efficiency and supports the business’s sustainability goals, ensuring a competitive edge in the evolving agricultural landscape.