Low-GWP Strategies for Achieving CARB Compliance
|Andre Patenaude | Director, Food Retail Marketing & Growth Strategy, Cold Chain
Emerson Commercial & Residential Solutions
Emerson was recently invited to participate in a webinar series hosted by the North American Sustainable Refrigeration Council (NASRC) aimed at helping retailers prepare for California’s refrigerant regulations and incentives. In the webinar, Diego Marafon, refrigeration scroll product manager at Emerson, and I discussed emerging refrigeration strategies for supporting low-GWP (global warming potential) compliance and hydrofluorocarbon (HFC) reductions while uncovering opportunities to lower operating costs.
In the U.S., the California Air Resources Board (CARB) is leading the charge for regulations impacting commercial refrigeration. For large centralized refrigeration systems — which today make up the majority of retail refrigeration — CARB’s current proposal would require new systems with more than 50 pounds of refrigerant to use refrigerants below 150 GWP. As a result, CO2 is a primary refrigerant choice for operators seeking to stay with a large centralized system and meet CARB’s proposed regulation.
But as retailers evaluate new system architectures, they also have an expanding variety of decentralized and distributed options to consider. What’s more, CARB’s latest proposals provide new approaches for achieving HFC reductions that are giving retailers the option to remodel, rather than invest in all-new refrigeration systems for their fleet of stores. These proposals include:
- Greenhouse gas emission potential (GHGp) reduction by 55% — Requires the total GHGp of all refrigeration systems in all stores to be 55% below the 2018 baseline by 2030, where GHGp equals the sum of the refrigerant charge times GWP — or GHGp = ∑(charge X GWP). This is a per-company target which gives retailers some flexibility in achieving compliance. As retailers retrofit their stores, they’ll receive credits for refrigerant charge and GWP reductions. But retailers must have the abilities to track, report each store’s GHGp baselines as well as document and verify any equipment changes.
- Weighted average GWP (WAGWP) reduction < 1,400 — Requires the WAGWP of each retailer to be less than 1,400 by 2030. It’s calculated by finding the sum of the charge times GWP in every system in every store, divided by the total charge — or weighted average GWP = ∑(charge X GWP) / ∑ This approach allows retailers to aim for a fixed target — without the need for tracking a company baseline — while giving them the option to only retrofit the stores needed to meet the 1,400 GWP target. Retailers may need to apply this equation to multiple retrofit scenarios to successfully deploy this strategy. Simply put, they’ll need to do the math and figure out how to best reach this target.
Weighing your retrofit options
In the webinar, we discussed each of these approaches and ran the numbers to show how retailers could take a long-term view of their store fleet strategies and make modifications to achieve their goals — utilizing refrigerant changes, system retrofits or installing new refrigeration systems. Using a WAGWP calculator developed by Emerson, we demonstrated different strategies for achieving CARB compliance, providing cost projections for each option. If you’re interested in learning more about the WAGWP calculator, you can contact your salesperson, or visit the contact us page.
For this exercise, we looked at a hypothetical scenario of a California retailer with 25 stores, 66 total refrigeration systems and a WAGWP of 2,715. Then we evaluated three different retrofit options and calculated their impacts:
- Refrigerant change from R-404A to R-448A — By changing out the refrigerant in all 25 stores, the retailer could achieve a WAGWP of 1,383 (nearly a 50% GHGp reduction). The total CapEx for the changes were $3M, with a cost per WAGWP reduction of $2.2k.
- Convert half the stores to a new CO2 system — By installing new CO2 systems in 12 of the stores and leaving the other 13 untouched, the retailer could achieve a WAGWP of 1,277 (or a 54% GHGp reduction). The total CapEx for the changes were $27.3M, with a cost per WAGWP reduction of $19k.
- Hybrid approach — By converting 20 systems to R-448A and installing 28 new scroll booster systems (with R-513A) — leaving 18 systems as is — the retailer could achieve a WAGWP of 1,520 (or 55% GHGp reduction). The total CapEx for the changes were $15M, with a cost per WAGWP reduction of $13k.
These scenarios demonstrated how to calculate system retrofit and remodel impacts while showing the multiple alternatives for implementing lower-GWP remodel strategies. It’s important to realize that in California, CARB has incentive programs to help retailers offset the cost of making these system changes.
But CARB is just one piece of a dynamic regulatory landscape — which includes energy, environmental and food safety regulations within varying regional, national and global jurisdictions — that continues to drive changes in refrigeration equipment and architectures. In response, Emerson is committed to developing a full spectrum of low-GWP refrigerant technologies, including CO2, R-290 and hydrofluoroolefins (HFOs), as well as lower-GWP HFC A1 refrigerants that are still in use. Most recently, we’ve expanded our offerings to support the industry’s need for more flexible, distributed architectures which deliver both high energy efficiencies and low-GWP ratings.
To learn more about using Emerson’s tools for calculating the impacts that system retrofits or remodels would have on your store fleet’s environmental footprint, view this NASRC webinar with the title of, “Emerson Technology Solutions.”