Powering CEA: Power Supply Solutions for CEA Facilities

Controlled agriculture facilities are unique and have generally higher power demands than what a utility may be used to seeing. It is important to understand the power that your facility’s process requires as it drives your utility rate structure and your power costs. Navigating and evaluating alternative energy options can help reduce your rates and improve your overall emissions impact and environmental, social, and governance (ESG) performance. Evaluating initial system costs and production of all power options and combinations are key to determining the best solution. Your power rates, grid capacity, and timing can make or break the viability of a new location or upgrade of an existing facility. A firm understanding of how you plan to use your facility, what power options are available, and strong partners to guide you to the best solution are critical to your bottom line.

Understanding Your Power Needs

Whether new construction or retrofit, understanding how your facility runs is critical. The process that your facility uses to produce its yield involves many steps. Each of those steps has a power need. Water pumps require power and operate at a rate based on your facility. Your plants require temperature and humidity levels that must be maintained. Your heating, ventilation, and air conditioning (HVAC) system is reacting to these set points and working to keep your system in balance. Lighting levels must be maintained at specific thresholds. It is well worth the time to think through your current process, your future plans for refinement or increased production, or goals for a new or enhanced facility.

Modeling the operations outlined above can be extensive. The equipment and processes all interrelate and react to growth and harvest schedules, solar gain, temperature, humidity, and many other factors. This interrelation requires that you view your facility’s needs on an hourly basis in what is called an 8760 load profile. This profile summarizes the complexity of how your facility behaves and communicates information to relevant parties. The 8760 is a blend of electrical and mechanical engineering, process design, energy modeling, solar evaluation, and equipment performance. Having the right partners with the experience and capability to perform this analysis properly is a critical step in finding your optimal power solution. As a designer and builder, ARCO/Murray Power Solutions (AMPS) develops these profiles in-house with their multidiscipline engineering team (see Figure 1).

While developing an 8760 is a sophisticated process, it is still a model approximating your needs. Backfilling this with performance data will yield a more refined prediction. Monitoring systems can be integrated into new or existing construction to empower your process with real-time information of how your facility functions.

Understanding Your Grid

Investigating your local grid and its potential strengths and weaknesses will set your project up for success. Communicate your energy needs with the utility company early so that you can plan for the timing of possible infrastructure upgrades or even consider alternative sites if building a new facility.

Work to understand the resiliency and quality of the local grid and any special considerations for your location. It is important to understand the power that you will receive because bad power quality can damage equipment. Prepare for potential outages by knowing common regional causes and seasonality. In larger outage events, the downtime difference could be days if your location is on the same distribution line as an essential service. These outages will drive your backup needs and you must account for the necessary infrastructure to keep operating when grid power may be down.

As a conscientious cultivator, you want to understand the emissions impact of your facility and product. While using power from the grid may look the same on the surface, there are significant differences in emissions impact between a grid with clean energy sources and dirty ones. Understanding the energy makeup of your local grid and its source of power is vital for ESG reporting, which has impacts in both consumer and investor spaces. Investigate your available electric suppliers and consider green sourcing opportunities, as well (see Figure 2).

Utility rates are not constant and can have large fluctuations in prices, especially related to peak demand. Each utility is different in their rate structure. Your peak usage defines your rate group, which sets your rate structure. Applying the rate structure to the 8760 will result in an accurate estimate of your electrical bill and will be a great start for exploring energy procurement options (see Figure 3).

Alternative Power Sources

Your local utility is not the only source of power available to you. By using alternative sources, you can reduce your carbon footprint and improve ESG performance. It can also mean energy independence, reduced risk of future grid utility escalations, and resiliency and consistency of supply that may not be available through your local grid. If grid power needs at your facility requires utility infrastructure upgrades that could have long lead times and construction durations, on-site alternative power options will be valuable
to consider.

These on-site systems are typically in the form of:

• Combined heat and power (CHP) or co-gen
• Solar arrays
• Battery
• Microgrid

Navigating through the appropriate size and potential combination of multiple sources requires expert guidance. Alternative source production is overlaid atop the 8760 to help understand the impacts and benefits to you. In some cases, there are additions or reductions to your facility’s infrastructure with the implementation of an alternative source that needs to be understood and accounted for. Additionally, with today’s supply chain volatility, understanding equipment availability, lead times, and current pricing is another vital aspect of your power choice. Work with a partner who has an extensive supplier network that is in tune with the current state of the market. While performance and pricing play a crucial role, time must also be considered and weighed in your determination. For example, AMPS is in constant communication with their supplier network to add this layer of information to the process.

Master Energy Plan

A master energy plan that summarizes your up-front capital expenditure and long-term system performance is the key to your decision-making process. You will likely have multiple options to consider and need all variables properly captured. Developing a full picture of all options requires an understanding of analysis and system design, procurement, utilities, financing, and other items. Guiding this process is complex—you need a strong partner to summarize options and help drive the right solution. You need an apples-to-apples comparison to make an informed decision.

Financing Systems

Production of alternative energy sources is financially attractive should you want to own and operate the equipment yourself. In many cases, extended warranties and user-friendly monitoring services help you understand system performance and keep the system operating at peak efficiency. Given the consistent production of alternative sources, outside investors are also interested in supporting your project and alternative power investment. To support this, the party receiving power agrees to buy at an established rate structure. These rates are typically better than those available from the utility provider and have defined escalations. The financier owns the system, operates, and maintains its performance. While the return on investment is not as attractive as a direct ownership scenario, it is an option to consider.

Federal, state, local governments, and utility companies encourage investing in efficient power producing systems. These incentives are generally in the form of tax benefits on the initial system investment and its depreciation. Additional incentives are available based on system performance. These need to be integrated into the financial model to give the full picture to help inform your decision-making process.

Monitoring and Tracking

Monitoring production and tracking results is important to understand and validate your actual usage and performance. It also helps you understand the correlation between your energy needs, operations, and yields. It can help identify underperforming systems for planned maintenance and investigation before they can cause unplanned downtime or expensive damage. Knowing your actual operational performance offers the opportunity to guide decision making based on real data.

Conclusion

Solving the power needs of your facility can be complex. Understanding your operations and facility demands require expert engineering. Driving the optimal solution means an understanding of design, construction, supply chain, timing, operations, and monitoring. Choosing the right partner to lay the course toward the best solution from the beginning is key to a successful project. Holding control on the power decisions puts you in the driver’s seat to mitigate costs, carbon impact, and increase financial benefit.

Acknowledgements

Resource Innovation Institute is a non-profit organization committed to cultivating a better future for all of humanity. Their consortium of members brings perspectives from across the field—uniting architects and engineers, growers and operators, researchers, and analysts. Together, they measure, verify, and celebrate the world’s most efficient agricultural ideas. In this article, RII’s Technical Director and members of the organization’s Technical Advisory Council working groups share perspectives on ways growers can make the most of technical and financial support from utility efficiency programs (2,3).

Download RII’s new free Best Practices Guide on Automation & Controls for Cannabis Cultivation (4). Access RII’s free Best Practices guides and trainings at: catalog.resourceinnovation.org.

References

1. https://catalog.resourceinnovation.org/item/controlled-environment-agriculture-market-transformation-strategy-implementation-plan-446270
2. https://resourceinnovation.org/tac/.
3. https://catalog.resourceinnovation.org/item/program-design-market-engagement-primer-407538.
4. https://catalog.resourceinnovation.org/item/best-practices-guide-automation-controls-cannabis-cultivation-435539.

About the Guest Columnist

As Project Engineer at RII, Carmen Azzaretti leads sprint cycles and design reviews for the PowerScore resource benchmarking platform, performs analysis for Producer Resource Efficiency Plans, facilitates the Data Working Group of the Technical Advisory Council, manages the RII catalog, and supports live workshops. Azzaretti works with producers to visualize trends in facility Performance Snapshots and create case studies to celebrate excellence in environmental performance. Azzaretti represents RII on industry committees developing standards for CEA including the ASHRAE Technical Committee 2.2 (Plant and Animal Environments) and Task Group 1 of the UL 3600 Scorecard for Measuring and Reporting Circular Economy Aspects of Products, Sites and Organizations.

About the Guest Columnist

As Director of Engineering for ARCO/Murray Power Solutions group (AMPS), Neal Benish leads an extensive in-house team of engineers and design/builders providing power solutions for clients. His team focuses on navigating and interrelating design, system performance, equipment supply-chain and lead times, utility rates, incentives, and monitoring to drive optimal solutions.

How to Cite this Article:

C. Azzaretti and N. Benish, Cannabis Science and Technology® Vol. 5(6), 18-22 (2022).