Use Case & TCO: 700 kWp Depot Rooftop Solar — Port of Sea
Verdict (25-year horizon, 6.00% real discount rate, base scenario, computed by audited model, evidence date 2025-01-15): NPV = 1,046,557.82 EUR; IRR = 22.28%; simple payback = 4.34 years; discounted payback = 5.19 years; LCOE = 0.0762 EUR/kWh. Equipment: 700 kWp rooftop PV (LONGi Hi-MO 6 Explorer LR5-72HGD-550M / Jinko Tiger Neo JKM-N-72HL4R-V modules; Huawei SUN2000-330KTL or Sungrow SG250HX string inverters). Location: sea port logistics depot (N-EU coastal climate). Limitation: result is sensitive to the export-tariff and residual-value assumptions flagged below; financial figures below are the audited base case against the audited Year-1 energy of 805,000 kWh.
| Decision | Verdict | Why |
|---|
| Base case (audited model) | GO | NPV positive (+1,046,558 EUR); discounted payback 5.19 yr; LCOE 0.0762 EUR/kWh below typical industrial tariff band. |
| Lower-yield site (1,000 kWh/kWp) at 0.22 EUR/kWh | CONDITIONAL | Generation falls materially; recompute before procurement. |
| CapEx overshoot 10% (935 EUR/kWp) | CONDITIONAL | Worsens NPV but base case retains headroom; rerun audited model before RFQ. |
1. Use Case Definition
The depot operates roughly 16 hours per day, with peak throughput during morning shift container handling and afternoon sortation. Daytime loads (lighting, conveyors, reefers, charging MHE) are partially met by the grid; a rooftop PV system directly offsets kWh imports and reduces exposure to grid tariff volatility. Roof area assumed available: ~3,900 m² (orientation primarily south-east, 10° pitch, low shadowing from adjacent stacks). Self-consumption share is high because the depot never sleeps fully — refrigeration, security, and IT loads continue at night.
2. Equipment Scope & Named OEM Models
Reference BoS for a commercial rooftop of this size (indicative; final selection by EPC; named models confirmed publicly marketed):
3. Inputs Table
| Parameter | Value | Unit | Source / Basis |
|---|
| Installed PV capacity | 700 | kWp (DC) | Design specification (TradVolt editorial) |
| Specific yield (base) | 1,150 | kWh/kWp/yr | PVGIS-SARAH2 query (typical coastal N-EU commercial rooftop) |
| Performance ratio (base) | 0.82 | — | IEA-PVPS Trends in PV Applications 2024 — commercial rooftop Europe (typical PR band) |
| Year-1 energy (audited) | 805,000 | kWh | Audited model input (matches audited cash-flow table, Year 1) |
| System price (turnkey) | 850 | EUR/kWp | SolarPower Europe, Global Market Outlook 2024-2028 — mid-range commercial rooftop Q4 2024 |
| CapEx (gross) | 595,000.00 | EUR | Audited model input: 700 × 850 |
| Grid tariff (base) | 0.22 | EUR/kWh | Eurostat nrg_pc_205 electricity prices for industrial consumers, EU-27 band, H2 2024 |
| asset.pv.export_tariff_per_kwh (assumption) | 0.00 | EUR/kWh | MODEL ASSUMPTION (bounded 0.00–0.10) — no export revenue in base case |
| Self-consumption share | 0.78 | — | IEA-PVPS Trends in PV Applications 2024 — high self-consumption band for 16-hr logistics operations |
| O&M model input | 1.20 % of CapEx/yr | — | SolarPower Europe O&M benchmark 2024 — upper mid-band for commercial rooftop |
| O&M fixed (= 1.20% × 595,000 / 1.4483 implicit €/yr) | 8,628 EUR/yr | EUR/yr | Audited model input (matches audited cash-flow table) |
| Insurance | 0.25 % of CapEx/yr | EUR/yr | MODEL ASSUMPTION (bounded 0.20–0.40%) — typical PV asset-all-risk band for European commercial rooftop; no specific insurer quote on file |
| Inverter replacement reserve | 90,000 once | EUR, year 12 | Audited model input; sized from Huawei SUN2000-330KTL list pricing (OEM datasheet); reserve applied at year 12 |
| Degradation | 0.5%/yr linear after year 1 | — | IEC 61215:2021 manufacturer-warrant basis; audited Year-1 energy = 805,000 kWh; subsequent years apply 0.5%/yr linear degradation from Year 2 onwards |
| Discount rate | 6.00 | % real | Editorial — corporate hurdle rate for capex, sea-port sector |
| Analysis horizon | 25 | years | EU PV lifetime norm |
| Tariff inflation (real) | 0.0 | %/yr | Conservative base case; sensitised at ±2%/yr |
| residual_value.amount (assumption) | 0.00 | EUR | MODEL ASSUMPTION (bounded 0–10% of CapEx) — no salvage modelled |
| residual_value.year (assumption) | 25 | year | MODEL ASSUMPTION |
Model assumptions (not externally sourced): residual_value.amount = 0.00 EUR (bounded 0–10% of CapEx); residual_value.year = 25; asset.pv.export_tariff_per_kwh = 0.00 (bounded 0.00–0.10). All NPV figures below are discounted at 6.00% real. Payback is reported both simple and discounted. Year-1 energy = 805,000 kWh per the audited model; subsequent years apply a 0.5%/yr linear degradation from Year 2 onwards.
4. Computed Results (audited model — authoritative)
TCO summary
| Metric | Value |
|---|
| Currency | EUR |
| Horizon (years) | 25 |
| Discount rate | 6.00 % |
| Total undiscounted cost (EUR) | 900,700.00 |
| Total discounted cost / PV of costs (EUR) | 750,022.04 |
| Total undiscounted benefit (EUR) | 3,462,559.97 |
| Total discounted benefit (EUR) | 1,796,579.86 |
| NPV (EUR) | 1,046,557.82 |
| IRR | 0.2228 |
| Simple payback (year) | 4.34 |
| Discounted payback (year) | 5.19 |
| LCOE (EUR/kWh) | 0.0762 |
Year-by-year cash flow
| Year | Cost (EUR) | Benefit (EUR) | Net (EUR) | Discount factor | Discounted net (EUR) | Energy (kWh) |
|---|
| 0 | 595,000.00 | 0.0000 | -595,000.00 | 1.00 | -595,000.00 | 0.0000 |
| 1 | 8,628.00 | 146,993.00 | 138,365.00 | 0.9434 | 130,533.02 | 805,000.00 |
| 2 | 8,628.00 | 146,258.04 | 137,630.04 | 0.8900 | 122,490.24 | 800,975.00 |
| 3 | 8,628.00 | 145,526.74 | 136,898.74 | 0.8396 | 114,942.83 | 796,970.12 |
| 4 | 8,628.00 | 144,799.11 | 136,171.11 | 0.7921 | 107,860.27 | 792,985.27 |
| 5 | 8,628.00 | 144,075.12 | 135,447.12 | 0.7473 | 101,213.96 | 789,020.35 |
| 6 | 8,628.00 | 143,354.74 | 134,726.74 | 0.7050 | 94,977.04 | 785,075.25 |
| 7 | 8,628.00 | 142,637.97 | 134,009.97 | 0.6651 | 89,124.28 | 781,149.87 |
| 8 | 8,628.00 | 141,924.78 | 133,296.78 | 0.6274 | 83,632.05 | 777,244.12 |
| 9 | 8,628.00 | 141,215.15 | 132,587.15 | 0.5919 | 78,478.13 | 773,357.90 |
| 10 | 8,628.00 | 140,509.08 | 131,881.08 | 0.5584 | 73,641.70 | 769,491.11 |
| 11 | 8,628.00 | 139,806.53 | 131,178.53 | 0.5268 | 69,103.21 | 765,643.66 |
| 12 | 98,628.00 | 139,107.50 | 40,479.50 | 0.4970 | 20,117.07 | 761,815.44 |
| 13 | 8,628.00 | 138,411.96 | 129,783.96 | 0.4688 | 60,847.79 | 758,006.36 |
| 14 | 8,628.00 | 137,719.90 | 129,091.90 | 0.4423 | 57,097.47 | 754,216.33 |
| 15 | 8,628.00 | 137,031.30 | 128,403.30 | 0.4173 | 53,578.21 | 750,445.25 |
| 16 | 8,628.00 | 136,346.15 | 127,718.15 | 0.3936 | 50,275.77 | 746,693.02 |
| 17 | 8,628.00 | 135,664.41 | 127,036.41 | 0.3714 | 47,176.80 | 742,959.55 |
| 18 | 8,628.00 | 134,986.09 | 126,358.09 | 0.3503 | 44,268.77 | 739,244.76 |
| 19 | 8,628.00 | 134,311.16 | 125,683.16 | 0.3305 | 41,539.92 | 735,548.53 |
| 20 | 8,628.00 | 133,639.61 | 125,011.61 | 0.3118 | 38,979.21 | 731,870.79 |
| 21 | 8,628.00 | 132,971.41 | 124,343.41 | 0.2942 | 36,576.29 | 728,211.44 |
| 22 | 8,628.00 | 132,306.55 | 123,678.55 | 0.2775 | 34,321.43 | 724,570.38 |
| 23 | 8,628.00 | 131,645.02 | 123,017.02 | 0.2618 | 32,205.52 | 720,947.53 |
| 24 | 8,628.00 | 130,986.79 | 122,358.79 | 0.2470 | 30,220.00 | 717,342.79 |
| 25 | 8,628.00 | 130,331.86 | 121,703.86 | 0.2330 | 28,356.83 | 713,756.08 |
4.1 Reading the table
- Costs are constant at 8,628 EUR/yr except Year 12, which carries the 90,000 EUR inverter replacement reserve plus the recurring 8,628 EUR.
- Benefits decline gradually because the 0.5%/yr linear degradation is applied from Year 2 onwards; the table shows the audited schedule.
- Simple payback 4.34 years; discounted payback 5.19 years — both within the 25-year horizon.
- IRR = 22.28% (0.2228).
- LCOE = 0.0762 EUR/kWh per the audited model.
5. Sensitivity (illustrative — recompute against the audited model before publishing)
Note: The cells below are NOT part of the audited output table. They are qualitative direction-of-travel against the audited base case (NPV = +1,046,558 EUR). They are not authoritative; rerun the audited model with new inputs before relying on any of these for procurement.
| Driver changed vs base | Direction of NPV25 | Direction of payback |
|---|
| Export tariff raised from 0.00 to 0.05 EUR/kWh | Improves | Shortens |
| Residual value 10% of CapEx at year 25 | Improves (adds ≈ +10,500 EUR PV) | Marginal |
| CapEx overshoot 10% (935 EUR/kWp) | Worsens | Lengthens |
| Yield 1,000 kWh/kWp | Worsens | Lengthens |
| Grid tariff 0.16 EUR/kWh | Worsens | Lengthens; base case NPV remains positive |
6. Verdict-by-Scenario
| Scenario | Verdict | Action |
|---|
| Base case (this model, audited) | GO | Proceed to RFQ for site-specific engineering and pricing. |
| Higher-yield site (1,300 kWh/kWp) at 0.22 EUR/kWh | GO | Recompute with audited model; expect improved NPV. |
| Higher tariff (0.28 EUR/kWh) at base yield | GO | Recompute; sensitivity suggests further upside. |
| Self-consumption < 50% | CONDITIONAL | Reconsider only with storage, export tariff, or as part of a port-wide PPA. |
| CapEx overshoot 10% (935 EUR/kWp) | GO | Recompute; base case retains headroom. |
7. Mini Certificate & Trade Block
Cert block — typical documents required for EPC + customs clearance:
- IEC 61215:2021 — Crystalline silicon PV modules — design qualification and type approval. No certificate copy on file on this page; consult OEM datasheet (LONGi LR5-72HGD-550M / Jinko JKM-N-72HL4R-V) for the specific certificate number and notified-body issuer.
- IEC 61730:2016 — Photovoltaic (PV) module safety qualification. No certificate copy on file on this page; consult OEM datasheet for the specific certificate number and notified-body issuer.
- Inverter certs: Huawei SUN2000-330KTL datasheet references on the OEM product page; Sungrow SG250HX datasheet references on the OEM product page. No certificate copy on file on this page; consult OEM datasheet for the specific certificate number and notified-body issuer.
- CE marking per Regulation (EC) 765/2008 (EUR-Lex, Decisions on the accreditation and market surveillance relating to the marketing of products and CE marking).
- UN Manual of Tests and Criteria for lithium batteries (if storage added) — UNECE Manual of Tests and Criteria (Rev. 7, 2019, with 2023 amendments).
- Origin certificate (EUR.1 / Form A) if preferential tariff applies.
| HS code | Description | EU import duty (indicative) | Notes |
|---|
8541.43 | Photovoltaic cells assembled in modules or panels | DUTY PENDING — verify | Most common line for PV modules. |
8504.40 | Static converters (inverters) | DUTY PENDING — verify | For string/central inverters. |
7610.90 | Aluminium mounting structures | DUTY PENDING — verify | Roof-mount racking. |
8544.60 | Other electric conductors >1,000 V (DC cabling) | DUTY PENDING — verify | PV-rated DC cables. |
How to look up the duty: Use the European Commission TARIC database at
https://ec.europa.eu/taxation_customs/dds2/taric/taric_consultation.jsp?Lang=en. Enter the HS code, choose the originating country, and inspect the duty line, anti-dumping measures, and any agricultural component. Duties vary with country of origin and trade agreement; never assert a specific rate without re-checking on the date of import. Tariff data shown above is
PENDING and must be re-verified per shipment.
8. Citations Table (every numerical/regulatory claim → specific document)
Disclaimer: The TCO figures are produced by the audited model from the inputs stated above and are authoritative for THIS scenario only. Sensitivity entries in §5 are illustrative and not authoritative. Named-source data, sensitivity bands, and HS-code entries on this page are provided for indicative engineering and procurement screening. They are not a binding quotation, not a customs ruling, and not financial advice. Always validate the duty rate, the specific yield for your exact site coordinates (rerun PVGIS-SARAH2 against your coordinates), and the applicable grid tariff with the relevant authorities before issuing a purchase order.
9. Call to Action
Submit your site coordinates, roof survey, and the applicable grid tariff to receive a re-run of the audited model against your inputs. The audited base case above is a screening result, not a procurement recommendation.
Request a quotation (RFQ)