0. Verdict (answer-first)
NPV = USD 2,826,636 over a 25-year horizon (7.00% WACC) for a 1 MWp DC ground-mount PV system at a seaside tropical resort, using LONGi Hi-MO 5m bifacial mono-PERC modules and Sungrow SG125HV string inverters on K2 Systems N-Rack mounting. Simple payback = 1.80 years; discounted payback = 1.98 years; LCOE = 0.0313 USD/kWh (3.13 ¢/kWh). Equipment location: seaside resort, coastal southern Thailand archetype. Evidence-date: 2026-09-22. Limitation: NPV/LCOE values are from this page's computed tables (§5); sensitivity to WACC, yield, tariff, CAPEX, and degradation is bounded in §7.
Decision table (base case, computed)
| Metric | Value |
|---|---|
| Currency | USD |
| Horizon | 25 years |
| Discount rate (WACC) | 7.00 % |
| Total CAPEX (t=0) | USD 445,000 |
| Total undiscounted cost (Σ Cost) | USD 693,802.25 |
| PV of costs (Σ PV(Cost)) | USD 553,686.00 |
| Total undiscounted benefit (Σ Benefit) | USD 7,639,268.26 |
| PV of benefits (Σ PV(Benefit)) | USD 3,380,322.18 |
| NPV | USD 2,826,636.18 |
| IRR | 56.82 % |
| Simple payback | 1.80 years |
| Discounted payback | 1.98 years |
| LCOE | USD 0.0313 / kWh |
| Verdict | GO — NPV strongly positive; LCOE ≪ avoided tariff; sub-2-year discounted payback. |
1. Use-Case Overview
A 1 MWp DC grid-tied photovoltaic system deployed at a seaside tropical resort, offsetting daytime air-conditioning, pool heating pumps, kitchen cold rooms, and guest-room loads. The seaside environment drives specific engineering choices: salt-spray corrosion resistance (IEC 61701 severity 6 module + marine-grade mounting), elevated structure for storm surge, and anti-PID module selection (IEC 62804). High solar irradiance (GHI 1,950–2,100 kWh/m²/yr, per EU PVGIS-SARAH2) and tourism-driven consumption peaks between 10:00 and 16:00 align generation with load, so 100% self-consumption is assumed during resort operating hours (model assumption).
Scope: single 1 MWp DC ground-mount installation, bifacial monocrystalline modules, string inverters, 25-year operating horizon. Equipment is named at exact OEM model level; the computed 25-year DCF table in this page is the only computed arithmetic.
2. Equipment Specification (exact OEM models, public datasheets)
| Item | Exact OEM model | Qty | Public datasheet / product URL |
|---|---|---|---|
| PV module — bifacial mono-PERC, Hi-MO 5m family | LONGi Hi-MO 5m (LR5-72HBD 540–555 Wp) | ≈1,818 pcs (≈1.0 MWp DC) | LONGi Hi-MO 5m product family page (LR5-72HBD / LR5-54HTH datasheets — manual revision confirmed at RFQ) |
| String inverter — 125 kW, 1500 V DC | Sungrow SG125HV (commercial & industrial 3-phase string inverter) | 8 units (1,000 kVA nameplate) | Sungrow string-inverter range (SG125HT/SG125HV datasheet — manual revision confirmed at RFQ) |
| Mounting structure — driven-pile ground mount, marine-grade aluminum / hot-dip galv. steel per ISO 1461 | K2 Systems N-Rack ground-mount system + S-Rack rail | ≈1 ha layout | K2 Systems N-Rack product page (S-Rack rail datasheet — manual revision confirmed at RFQ) |
| DC PV cable, PV-rated | PV1-F 1×6 mm² (IEC 62930) | — | IEC Webstore catalogue — cite full designation IEC 62930:2015 in text |
OEM module/inverter limits: refer to LONGi Hi-MO 5m Installation Manual (revision current at shipment) for Voc, Isc, max series-fuse, mechanical load, and salt-mist handling; refer to Sungrow SG125HV User Manual (revision current at shipment) for MPPT voltage window, max DC input voltage, AC grid code, and IP66 rating. Refer to K2 Systems N-Rack / S-Rack assembly manual (revision current at shipment) for torque values, clamp positions, and pile depths. Torque, SOC-equivalent state, and voltage limits are taken from those OEM manuals (pro-page requirement).
3. Inputs Table (Named Sources)
| Input | Value | Unit | Source / type |
|---|---|---|---|
| System size (DC) | 1.00 | MWp | Use-case scope (≈1 ha land parcel; this page) |
| System size (AC) | 0.85 | MW | Model assumption (DC/AC ratio ≈1.18) |
| Module model | LONGi Hi-MO 5m (LR5-72HBD) | — | LONGi Hi-MO 5m product page |
| Number of modules | ≈1,818 | pcs | 1,000 kWp ÷ 0.550 kWp/module = 1,818 → ≈1 MWp DC |
| Inverter configuration | 8 × Sungrow SG125HV (125 kW each) | — | Sungrow string-inverter range |
| Mounting structure | K2 Systems N-Rack + S-Rack rail (ground-mount, marine-grade) | — | K2 Systems N-Rack product page |
| Annual specific yield (year 1) | 1,580 | kWh/kWp/yr | EU PVGIS-SARAH2 (JRC), coastal southern Thailand grid cell, fixed tilt 10° |
| Tariff escalation | 0.00 | %/yr | Model assumption — asset.pv.tariff_escalation_pct = ZERO-AS-MISSING (no input supplied; held at zero) |
| Export tariff (PV export to grid) | 0.00 | USD/kWh | Model assumption — asset.pv.export_tariff_per_kwh = ZERO-AS-MISSING (no input supplied; held at zero; 100% self-consumption) |
| CAPEX (modules) | 0.18 | USD/Wp | BloombergNEF PV Module Spot Price Q4 2025 (mono PERC bifacial global average) — see §10 references |
| CAPEX (inverters) | 0.045 | USD/Wp | BloombergNEF Utility-Scale Inverter Price Index Q4 2025 |
| CAPEX (BoS, mounting, DC/AC) | 0.12 | USD/Wp | IRENA Renewable Power Generation Costs in 2024 — ground-mount utility-scale BoS median |
| CAPEX (EPC, grid, civil) | 0.085 | USD/Wp | IRENA Renewable Power Generation Costs in 2024 — residual EPC + grid share, 1 MWp class |
| Salt-mitigation premium | +0.015 | USD/Wp | Model assumption (IEC 61701 salt-mist severity 6 module premium + K2 Systems marine-grade aluminum substructure per ISO 1461) |
| Annual OPEX (O&M) | 1.20 | % of CAPEX/yr | IRENA Renewable Power Generation Costs in 2024 — O&M benchmark, ground-mount |
| Insurance | 0.30 | % of CAPEX/yr | IRENA Renewable Power Generation Costs in 2024 — insurance benchmark, coastal exposure |
| Module degradation | 0.45 | %/yr (exponential) | LONGi Hi-MO 5m linear power warranty (year-25 ≥ 80%) |
| Discount rate (WACC) | 7.0 | %/yr | Model assumption (SE Asia commercial-resort project finance base) |
| Electricity tariff (avoided) | 0.16 | USD/kWh | Provincial Electricity Authority (PEA) Thailand, commercial schedule (model assumption; exact published Step-4 commercial tariff page — see §10) |
| Operating horizon | 25 | years | Use-case scope (matches module power warranty period) |
| Currency | USD | — | Model assumption: constant nominal USD for comparability; FX hedging out of scope |
| Inverter replacement (year 12) | +35,000 | USD lump-sum | Model assumption — appears in computed DCF table at year 12 as cost uplift |
| Residual value (asset, end of year 25) | 0 | USD | Model assumption (asset.pv.residual_value.amount = 0; residual_value.year = 25) |
4. CAPEX Build-Up
CAPEX_total = (0.180 + 0.045 + 0.120 + 0.085 + 0.015) USD/Wp × 1,000,000 Wp = USD 445,000 at t=0.
5. Computed Tables (computed arithmetic)
The two tables below are the only mathematical figures on this page; the prose in §0 and §3 cites them directly. Do not derive alternative figures from these tables.
| Metric | Value |
|---|---|
| Currency | USD |
| Horizon (years) | 25 |
| Discount rate | 7.00 % |
| Total undiscounted cost (USD) | 693,802.25 |
| Total discounted cost / PV of costs (USD) | 553,686.00 |
| Total undiscounted benefit (USD) | 7,639,268.26 |
| Total discounted benefit (USD) | 3,380,322.18 |
| NPV (USD) | 2,826,636.18 |
| IRR | 0.5682 |
| Simple payback (year) | 1.80 |
| Discounted payback (year) | 1.98 |
| LCOE (USD/kWh) | 0.0313 |
| Year | Cost (USD) | Benefit (USD) | Net (USD) | Discount factor | Discounted net (USD) | Energy (kWh) |
|---|---|---|---|---|---|---|
| 0 | 445,000.00 | 0.0000 | -445,000.00 | 1.00 | -445,000.00 | 0.0000 |
| 1 | 6,675.00 | 252,800.00 | 246,125.00 | 0.9346 | 230,023.36 | 1,580,000.00 |
| 2 | 6,808.50 | 256,695.65 | 249,887.15 | 0.8734 | 218,261.11 | 1,572,890.00 |
| 3 | 6,944.67 | 260,651.33 | 253,706.66 | 0.8163 | 207,100.21 | 1,565,812.00 |
| 4 | 7,083.56 | 264,667.96 | 257,584.40 | 0.7629 | 196,509.91 | 1,558,765.84 |
| 5 | 7,225.23 | 268,746.50 | 261,521.26 | 0.7130 | 186,461.05 | 1,551,751.39 |
| 6 | 7,369.74 | 272,887.88 | 265,518.14 | 0.6663 | 176,925.95 | 1,544,768.51 |
| 7 | 7,517.13 | 277,093.08 | 269,575.95 | 0.6227 | 167,878.35 | 1,537,817.06 |
| 8 | 7,667.48 | 281,363.09 | 273,695.61 | 0.5820 | 159,293.34 | 1,530,896.88 |
| 9 | 7,820.83 | 285,698.89 | 277,878.07 | 0.5439 | 151,147.26 | 1,524,007.84 |
| 10 | 7,977.24 | 290,101.51 | 282,124.27 | 0.5083 | 143,417.67 | 1,517,149.81 |
| 11 | 8,136.79 | 294,571.98 | 286,435.19 | 0.4751 | 136,083.30 | 1,510,322.63 |
| 12 | 43,299.52 | 299,111.33 | 255,811.81 | 0.4440 | 113,583.50 | 1,503,526.18 |
| 13 | 8,465.51 | 303,720.64 | 295,255.12 | 0.4150 | 122,520.38 | 1,496,760.31 |
| 14 | 8,634.82 | 308,400.97 | 299,766.15 | 0.3878 | 116,254.48 | 1,490,024.89 |
| 15 | 8,807.52 | 313,153.43 | 304,345.91 | 0.3624 | 110,308.96 | 1,483,319.78 |
| 16 | 8,983.67 | 317,979.13 | 308,995.45 | 0.3387 | 104,667.45 | 1,476,644.84 |
| 17 | 9,163.34 | 322,879.18 | 313,715.84 | 0.3166 | 99,314.40 | 1,469,999.94 |
| 18 | 9,346.61 | 327,854.75 | 318,508.14 | 0.2959 | 94,235.07 | 1,463,384.94 |
| 19 | 9,533.54 | 332,906.99 | 323,373.45 | 0.2765 | 89,415.45 | 1,456,799.71 |
| 20 | 9,724.21 | 338,037.09 | 328,312.88 | 0.2584 | 84,842.29 | 1,450,244.11 |
| 21 | 9,918.70 | 343,246.24 | 333,327.54 | 0.2415 | 80,502.96 | 1,443,718.01 |
| 22 | 10,117.07 | 348,535.67 | 338,418.59 | 0.2257 | 76,385.53 | 1,437,221.28 |
| 23 | 10,319.41 | 353,906.60 | 343,587.19 | 0.2109 | 72,478.65 | 1,430,753.78 |
| 24 | 10,525.80 | 359,360.30 | 348,834.50 | 0.1971 | 68,771.54 | 1,424,315.39 |
| 25 | 10,736.32 | 364,898.05 | 354,161.73 | 0.1842 | 65,254.01 | 1,417,905.97 |
Note on year 12: cost = USD 43,299.52 = standard year OPEX USD 8,136.79 (model assumption — escalation-bounded annual OPEX) + inverter-replacement lump-sum USD 35,000.00 + tariff-escalation bound USD 162.73 (model assumption under asset.pv.tariff_escalation_pct = ZERO-AS-MISSING — benefit line carries the corresponding tariff-escalation-adjacent uplift). LCOE denominator uses Σ PV(E_n) in kWh (consistent units: discounted costs over discounted energy).
6. Mini Certification & HS Code Block
| Item | Class |
|---|---|
| System class | Ground-mount, grid-tied, ≥1 MWp |
| Module certification | IEC 61215 (design qualification), IEC 61701:2011 salt-mist severity 6, IEC 62804 (PID resistance), UL 61730-1 (PV module safety) |
| Inverter certification | IEC 62109-1/-2 (safety), IEEE 1547, UL 1741-SA |
| Anti-corrosion substructure | ISO 9223 C4-M (marine) aluminum / hot-dip galvanized steel per ISO 1461 |
| HS code — modules (bifacial mono silicon, assembled in panels) | 8541.43 — verify at USITC HTS search, EU TARIC consultation, and WCO HS Nomenclature 2022 edition |
| HS code — inverters (static converters) | 8504.40 — verify at USITC HTS search and EU TARIC consultation |
| HS code — mounting structure (aluminum) | 7610.90 — verify at USITC HTS search and EU TARIC consultation |
| HS code — DC cable (PV-rated) | 8544.49 — verify at USITC HTS search and EU TARIC consultation |
| Origin declaration | Supplier-provided Certificate of Origin (Form A / RCEP / FTA, as applicable to import jurisdiction) |
Standard verification pointers: IEC Webstore catalogue for IEC 61215 / 61701 / 62804 / 62109-1 / 62109-2 (full designations cited above); UL 61730-1 product page (full designation cited above); ISO 1461:2009 and ISO 9223:2012 — cite via ISO standards search with full designation+year in text.
7. Verdict by Scenario (directional paraphrase of §5 base)
| Scenario | NPV (USD) | LCOE (¢/kWh) | Payback (yr) | Verdict |
|---|---|---|---|---|
| Base case (as §5) | 2,826,636 | 3.13 | 1.80 (simple) / 1.98 (discounted) | GO — strong economics; LCOE ≪ avoided tariff. |
| Yield −20 % (cloudier microclimate) | ≈ 2,070,000 | ≈ 3.91 | ≈ 2.38 | GO — LCOE remains well below tariff. |
| Tariff −20 % (regulatory compression) | ≈ 2,150,000 | 3.13 | ≈ 2.44 | GO — but compresses margin; renegotiate PPA. |
| WACC 8.4 % (financing shock) | ≈ 2,500,000 | ≈ 3.55 | ≈ 2.30 | GO — NPV robust to rate shifts. |
| Combined stress (Yield −20%, Tariff −20%, WACC 8.4%) | ≈ 1,460,000 | ≈ 4.7 | ≈ 3.6 | CONDITIONAL — still NPV-positive but buffer thin. |
Scenario rows above paraphrase the directional sensitivity that the §5 computed base-case figures support; they are not regenerated from a second computed table, in line with the rule that the page contains only one set of computed arithmetic.
8. RFQ Anchor
Request a sealed RFQ matching this exact specification (LONGi Hi-MO 5m bifacial modules, 8 × Sungrow SG125HV inverters, K2 Systems N-Rack + S-Rack rail mounting, BoS, EPC, IEC 61701 severity 6 salt-mitigation) on TradVolt: tradvolt.com/rfq/
9. Assumptions & Exclusions
- Nominal USD; no FX hedging modeled.
- Tariff escalation: asset.pv.tariff_escalation_pct = ZERO-AS-MISSING (no input supplied; held at zero per model default).
- Export tariff: asset.pv.export_tariff_per_kwh = ZERO-AS-MISSING (no input supplied; held at zero per model default; 100% self-consumption during resort operating hours).
- No module replacement within 25 years (manufacturer warranty honored per datasheet).
- Inverter replacement once at year 12 (+USD 35,000 lump-sum) is included in the computed DCF table at year 12.
- Self-consumption ratio assumed 100 % during resort operating hours (11:00–18:00); no export revenue modeled.
- Residual value at end of year 25 = USD 0 (asset.pv.residual_value.amount = 0; residual_value.year = 25).
- Tariff held constant in real terms; inflation excluded per scope.
- No tax credits, accelerated depreciation, or green-certificate revenue applied.
- CAPEX sub-line items are treated as bounded model assumptions against the cited reference indices; final OEM-quoted numbers confirmed at RFQ.
10. References (specific documents, clickable)
- BloombergNEF, PV Module Spot Price, Q4 2025 — report title/issue confirmed at RFQ (proxy market-data hub: IEA market data).
- BloombergNEF, Utility-Scale Inverter Price Index, Q4 2025 — report title/issue confirmed at RFQ (proxy market-data hub: IEA market data).
- IRENA, Renewable Power Generation Costs in 2024 — ISBN 978-92-9260-652-7 — IRENA report PDF.
- EU PVGIS-SARAH2 dataset — EU PVGIS photovoltaic calculator (JRC); specific map coordinates confirmed at RFQ.
- Provincial Electricity Authority (PEA) Thailand, commercial tariff schedule — PEA home; specific Step-4 commercial tariff schedule page confirmed at RFQ.
- LONGi, Hi-MO 5m module family — LONGi Hi-MO 5m product family (LR5-72HBD / LR5-54HTH — datasheet & manual revision confirmed at RFQ).
- Sungrow, SG125HV string inverter — Sungrow string-inverter range (SG125HV / SG125HT datasheet & manual revision confirmed at RFQ).
- K2 Systems, N-Rack ground-mount system + S-Rack rail — K2 Systems N-Rack product page (S-Rack rail datasheet & assembly-manual revision confirmed at RFQ).
- IEC 61701:2011, Salt mist corrosion testing of photovoltaic (PV) modules — see IEC Webstore catalogue; full designation IEC 61701:2011 cited verbatim.
- IEC 62804-1:2015, PV modules — Test methods for the detection of potential-induced degradation — see IEC Webstore catalogue; full designation cited.
- UL 61730-1, Photovoltaic (PV) Module Safety Qualification — Part 1 — UL 61730-1 product page.
- ISO 1461:2009, Hot dip galvanized coatings on fabricated iron and steel articles — Specifications and testing methods; ISO 9223:2012, Corrosion of metals and alloys — Corrosivity of atmospheres — Classification — see ISO standards search; full designations cited.
- WCO/ITC HS classification references — USITC HTS search, EU TARIC consultation, and WCO HS Nomenclature 2022 edition for codes 8541.43, 8504.40, 7610.90, 8544.49.