Pacific Northwest Refrigerated Produce Corridor

Case Study: Pacific Northwest Refrigerated Produce Corridor

Scenario A produce logistics provider in Yakima, WA, transports temperature-controlled apples to distribution centers in Southern California. Due to perishability and strict cold-chain compliance (maintaining 32–36°F), refrigerated trailers (reefers) are mandatory. The project evaluated retrofitting existing fleet with electric reefers versus continuing with diesel units. Key constraints included limited charging infrastructure along I-5, mandated 12-hour driver rest rules, and a state-mandated 2030 zero-emission freight target.

Given Data

• Distance: 1,150 miles (Yakima → Ontario, CA)
• Payload: 42,000 lbs = 21 tons (standard reefer load, accounting for refrigeration unit weight)
• Fuel consumption: 1.85 kWh/mile (verified field data for 2023 battery-electric reefer + prime mover)
• Emission factor: 345 g CO₂e/kWh (Western Electricity Coordinating Council 2023 grid-average, including hydro, wind, and natural gas backup)

Calculation Using the same formula:

Carbon Emissions per Ton-Mile = (Fuel Consumption × Emission Factor) ÷ Payload

Substituting values:

• Fuel Consumption × Emission Factor = 1.85 kWh/mi × 345 g CO₂e/kWh = 638.25 g CO₂e/mi
• Convert to kg: 638.25 g/mi = 0.63825 kg/mi
• Divide by payload: 0.63825 kg/mi ÷ 21 tons = 0.0304 kg CO₂e/ton-mile

Rounded to two decimal places: 0.03 kg CO₂e/ton-mile

Result and Decision Although the electric reefer’s ton-mile intensity (0.03) was 40% lower than the incumbent diesel fleet (0.05), the total trip energy demand (2,127 kWh) exceeded available depot fast-charging capacity during overnight stops. The team concluded that full electrification was premature without infrastructure investment. Instead, they piloted a blended strategy: deploying electric reefers on the first 300-mile leg (Yakima → Portland), where grid decarbonization is strongest and charging exists, while retaining diesel for the longer southern segment. This reduced corridor-wide emissions by 22% vs. baseline — validated using the calculator across sub-legs.

Lesson Emission factors are location- and time-sensitive — using a single regional grid average masks intra-corridor variability. Engineers must segment routes and apply spatially resolved emission factors (e.g., WECC sub-regional data) to avoid overestimating benefits of electrification in high-carbon grid zones.