Use Case / TCO · Sea Freight Sector · Published 2026-01-15 · Evidence reference date: 2026-09-22 · Reviewed by TradVolt Editorial

Cold-Storage ESS 2 MWh — Sea Freight Use Case & TCO

Answer first — verdict for a 2 MWh / 1 MW BESS at a port-adjacent cold-storage / reefer yard, 10-year horizon, 8 % discount rate, computed TCO: the project is not economic. NPV = −634,096 USD; both simple and discounted payback are none within the 10-year horizon; levelised cost of storage = 0.3220 USD/kWh. The cash-flow table shows a single mid-life augmentation in year 7 (90,350.91 USD cost) that the annual savings stream never recovers from in undiscounted terms either (cumulative undiscounted net at year 10 is −522,289.47 USD, derived from total undiscounted cost 1,179,395.76 USD minus total undiscounted benefit 657,106.29 USD). Treat the inputs that drive savings (peak-shaving tariff, genset fuel offset) as the binding constraints: under the modelled savings level the asset loses money over ten years on both an undiscounted and a discounted basis.

Decision summary

1. Site Profile (Sea Freight, Cold Storage)

• Type: Port-adjacent refrigerated warehouse plus reefer container yard.
• Connection: MV grid (11 kV) with on-site diesel rotary UPS for reefer plugs.
• Driver: Peak demand charges from the port authority, plus reefer genset fuel burn during peak tariff windows.
• Operating hours: 24/7 (reefer demand is temperature-driven, not shift-driven).

2. Equipment & Input Assumptions

Every row cites a named source. Rows without a public source are labelled as a bounded model assumption.

3. Reference Equipment & Documentation

• BESS family: CATL EnerC containerised LFP system, referenced from the CATL energy storage landing page at catl.com/en/ess. The product page is JS-rendered; the exact cabinet variant (e.g. 306 kWh or 372 kWh per cabinet), DC-block configuration, and UL/IEC certificate IDs are confirmed at RFQ against the OEM customer datasheet.
• PCS class: Sungrow ST / SG-HV family (e.g. SG125HV, SG250HV), referenced from the Sungrow corporate landing page at sungrowpower.com/en. Specific PCS model, firmware revision, and torque/voltage/SO-C limits are taken from the OEM installation and operation manual supplied with the unit at RFQ.
• Compliance framework references: EU Battery Regulation Regulation (EU) 2023/1542; UN transport tests UN Manual of Tests and Criteria (UN 38.3, ST/SG/AC.10/11/Rev.7); stationary lithium standards IEC 62619:2022 (cited via IEC Webstore catalogue) and UL 1973; PCS EMC directive compliance per the EU CE/EMC framework referenced via EUR-Lex for the battery side and the relevant EMC Directive for the PCS.

4. Computed TCO — Summary

5. Computed TCO — Year-by-year Cash Flow

Read the year-7 row as the modelled mid-life augmentation event (cost 90,350.91 USD), not a separate capex line. Discount factors shown to four decimals are the year-by-year factors implied by the 8 % discount rate used in the summary table.

6. Verdict by Scenario (Consistent with the Tables Above)

• Base case (savings level implied by the cash-flow table, 8 % discount): NPV = −634,096 USD; simple and discounted payback are both — (none within the 10-year horizon); cumulative undiscounted net at year 10 is −522,289.47 USD. The project does not reach cash-positive operation in undiscounted terms either, and the earlier draft claim of "year 6–7 cash-positive" is contradicted by the computed cash flow: the only year with a negative net is year 7 (the augmentation event), and the cumulative net remains negative throughout. Verdict: do not proceed at the modelled savings level.
• Optimistic (annual benefit ≈ 134,000 USD/yr, holding other inputs): the cash-flow table sits below this level — re-quote the model with the higher tariff spread to find the break-even benefit. As a guide, simple payback requires annual benefit ≈ 184,000 USD/yr at constant cost; the reader should re-run the model's inputs rather than rely on a worked derivation here.
• Pessimistic (annual benefit at or below the modelled 71,843 → 59,899 USD/yr band): NPV worsens further; payback remains none within the horizon. Verdict: do not proceed; pursue ancillary services or demand-response stacking.

7. Sensitivity — Directional (Not a Computed Table)

The scenario model produces a single deterministic cash flow; a multi-cell sensitivity grid was not part of the computed output. The directional guidance below is consistent with the table inputs but is not itself a computed figure.

• Annual benefit level is the binding lever: the modelled 71,843 → 59,899 USD/yr band already fails; lifting it to roughly 184,000 USD/yr would move simple payback inside the horizon (re-run the model to verify).
• Discount rate movement between 6 % and 10 % changes the PV of benefits (446,533.94 USD at 8 %) by roughly ±15 %; it does not flip the verdict on its own.
• Capex reduction of ~30 % (≈ 270,000 USD) would close most of the NPV gap; capex is the second lever after tariff spread.

8. Certifications & Compliance — Target Framework, Not Held Certificates

9. HS Code & Duty — Lookup Path, Not Asserted Rates

Lookup the exact sub-heading (6-digit) and the national tariff line (8–10 digit) in the destination country's customs portal before shipping, then cross-check any anti-dumping or safeguard measures applicable to lithium-ion cells. Suggested lookup paths:

• EU: EU TARIC consultation.
• United States: USITC Harmonized Tariff Schedule, with US Customs and Border Protection for any trade-action overlay.
• United Kingdom: UK Global Tariff.
• Japan: Japan Customs.
• Australia: Australian Border Force.
• South Africa: SARS.
• Ghana: Ghana Revenue Authority.
• Uganda: Uganda Revenue Authority.

10. Engineering Caveats

• Sea-freight reefer yards typically have high harmonic distortion; specify PCS with low THDi (< 3 %).
• Salt-air corrosion: specify C4 / C5-M enclosure rating for the BoS shelter.
• Port tariff structures change annually; lock peak-shaving savings in a multi-year contract before sizing the BESS — the modelled 95,000 USD/yr figure is a representative placeholder, not a contracted tariff.
• BESS SOC operating window, DC and AC voltage limits, and torque settings for the PCS come from the OEM installation and operation manual supplied with the unit at RFQ; the figures in the computed tables above are not a substitute for the OEM manual revision.

All financial figures on this page are the output of TradVolt's scenario TCO model for the inputs in §2; only the computed tables (§4 and §5) carry numbers. Sensitivity commentary in §7 is directional and not a computed table. Sources in §2 are cited to the document URL or to the named report identifier; specific OEM model, certificate IDs, and customer tariff figures are confirmed at RFQ.