CO₂ refrigeration transition is reshaping cold chain solar sizing. Understanding R744 transcritical load profiles is essential for optimal PV specification.
F-gas phase-down status
R404A (GWP 3,922): banned for maintenance use since 2020. R410A: phased down through 2030. CO₂ (R744, GWP 1): future-proofed and essentially exempt from F-gas regulation.
CO₂ transcritical load profile
Below 10°C (UK winter): CO₂ as efficient or more efficient than HFC. Above 25°C (summer): CO₂ uses 15-25% more electricity than equivalent HFC. Annual average UK: 8-12% higher electricity consumption. This means: size PV slightly larger for CO₂ cold stores than equivalent HFC facilities.
Solar sizing guidance
For 500 kW cooling capacity CO₂ store: 300-350 kW PV → 92-95% self-consumption, 3.8-4.5yr payback. 400-500 kW PV → 86-90% self-consumption with higher export. Optimal: 350-400 kW PV + 250-500 kWh battery peak-shifting.
Heat recovery + battery
CO₂ gas cooler heat recovery (25-40°C lift): space heating, hot water, underfloor heating — reduces total site energy 15-25%. Battery for night setback (CO₂ runs harder at night): 250-500 kWh covers 4-6 hours evening pulldown; improves renewable contribution and reduces peak demand charges.
See more
CO₂ refrigeration guide: /guides/warehouse-solar-co2-refrigeration/. Cold storage guide: /guides/warehouse-cold-storage-solar/. Contact: /contact/.