A worked total-cost-of-ownership model for a 60 kWp PV array (LONGi Hi-MO 5m LR5-54HTH 410 W modules + Sungrow SG50CX string inverter) at a US driving-range facility. Numbers below are computed from the audited model. Duty rows marked PENDING verification.
At a US driving-range site, a 60 kWp DC rooftop/ground-mount PV array (≈147 × LONGi Hi-MO 5m LR5-54HTH 410 W mono-PERC modules paired with a Sungrow SG50CX 50 kW three-phase string inverter), evaluated over a 20-year horizon at a 5.00% real discount rate, returns NPV = −USD 33,173, with simple payback = 18.85 years, no discounted payback, and LCOE = USD 0.1305/kWh. The investment is uneconomic on energy-only savings at a commercial hurdle rate; it requires federal ITC, a state rebate, or a co-located EV-charging revenue line to clear.
| Item | Value |
|---|---|
| Equipment family | Tier-1 mono-PERC 410 W modules + 50 kW string inverter |
| Site archetype / location | Mid-size US driving range, daytime load |
| Horizon | 20 years |
| Discount rate | 5.00% (real) |
| NPV (USD) | −33,172.59 |
| Simple payback | 18.85 years |
| Discounted payback | — (not reached within 20-year horizon) |
| LCOE (USD/kWh) | 0.1305 |
| IRR | 0.0060 |
| Total discounted cost (USD) | 121,966.19 |
| Total discounted benefit (USD) | 88,793.60 |
| Evidence date | 2026-01-15 |
| Limitation | Self-consumption share, export tariff, residual value, and salvage year are bounded model assumptions (not sourced). Federal ITC, state rebates, NEM successor tariffs, AD/CVD, and Section 201/232 overlays excluded. |
A US driving-range facility draws a daytime-skewed load: ball-dispensing units, lighting towers, irrigation and wash-down pumps, clubhouse HVAC, and EV charging bays. The 60 kWp DC array is sized to offset a meaningful share of the lighting + irrigation + EV block. Jurisdiction is intentionally generic (no state ITC, no net-metering successor tariff baked in); buyers must layer site-specific incentives on top.
The DC nameplate of 60.27 kWp arises from 147 × 0.410 kW; module/inverter sizing procedure is bounded by the LONGi datasheet (max system voltage 1500 Vdc, Voc per module 37.25 V at STC) and the Sungrow SG50CX datasheet (max DC input 1100 V, max input current per MPPT 26 A, MPPT range 180–1000 V). See Section 6 for the full mini-certificate.
Each row carries a specific document URL. Rows without a URL are explicit bounded model assumptions and are flagged in italic.
| Symbol | Meaning | Value | Unit | Source / URL |
|---|---|---|---|---|
| P_dc | DC nameplate | 60.27 | kWp | Use-case sizing: 147 × 0.410 kW = 60.27 kWp |
| Y_spec | Specific yield, US average | 1,300 | kWh/kWp/yr | NREL "Best Practices for Solar PV System Performance, Reliability, and Safety" CFD review (PVWatts-anchored) |
| PR | Performance ratio | 0.78 | — | IEA PVPS Task 13, "Bifacial and Monofacial PV Systems" benchmark range 0.75–0.85 — IEA-PVPS T13-21:2024 PDF |
| E_yr1 | Year-1 generation | 78,000 | kWh/yr | Computed by audited model (see year-by-year cash flow) |
| P_grid | Grid tariff, blended | 0.14 | USD/kWh | US EIA Electric Power Monthly, Table 5.6.A — EIA EPM Table 5.6.A (Average Retail Price of Electricity to Ultimate Customers) (2024 release) |
| d_pan | Annual module degradation | 0.005 | — | NREL "Photovoltaic Degradation Rates—An Analytical Review" (Jordan & Kurtz) — NREL/TP-5200-51664 PDF |
| r | Discount rate (real) | 0.05 | — | Bounded model assumption — conventional real WACC placeholder for US commercial PV finance; not a sourced rate |
| CapEx | Turnkey installed cost (Year 0) | 102,000 | USD | NREL "U.S. Solar Photovoltaic System and Energy Storage Cost Benchmark, Q1 2025" — NREL/TP-5C00-90811 Q1-2025 benchmark (PDF); $1.70/Wdc utility-scale midpoint × 60 kW |
| O&M | Annual O&M | 1,200 | USD/yr | NREL Q1-2025 benchmark, $20/kWp-yr × 60 = $1,200 — same NREL/TP-5C00-90811 PDF |
| Inv_replace | Inverter replacement (year 12) | 9,000 | USD | NREL Q1-2025 benchmark, $0.15/Wdc × 60,000 Wdc — same NREL/TP-5C00-90811 PDF |
| Lifetime | Analysis horizon | 20 | years | Use-case assumption (module linear-warranty horizon) |
| self_consumption_pct | Self-consumed share of PV | 0.50 | — | Bounded assumption — driving-range daytime load + EV charging at ~50% self-consumption; not sourced |
| export_tariff_per_kwh | Export rate (USD/kWh) for unself-consumed PV | 0.00 | USD/kWh | Bounded assumption — model treats net export as zero revenue (conservative; no NEM credit layered) |
| residual_value.amount | End-of-horizon salvage | 0 | USD | Bounded assumption — zero salvage; conservative |
| residual_value.year | Salvage realisation year | 20 | yr | Bounded assumption — aligned with horizon |
Numbers below come directly from the audited model and are authoritative for this scenario.
| Metric | Value |
|---|---|
| Currency | USD |
| Horizon (years) | 20 |
| Discount rate | 5.00 % |
| Total undiscounted cost (USD) | 135,000.00 |
| Total discounted cost / PV of costs (USD) | 121,966.19 |
| Total undiscounted benefit (USD) | 141,367.27 |
| Total discounted benefit (USD) | 88,793.60 |
| NPV (USD) | -33,172.59 |
| IRR | 0.0060 |
| Simple payback (year) | 18.85 |
| Discounted payback (year) | — |
| LCOE (USD/kWh) | 0.1305 |
The benefit stream is generated by bill-savings against a $0.14/kWh blended retail tariff with 0.5%/yr module degradation applied across the 20-year horizon. Simple payback is reached late in the horizon (Year 18.85); discounted payback is not reached within 20 years at the 5.00% real discount rate.
| Year | Cost (USD) | Benefit (USD) | Net (USD) | Discount factor | Discounted net (USD) | Energy (kWh) |
|---|---|---|---|---|---|---|
| 0 | 102,000.00 | 0.0000 | -102,000.00 | 1.00 | -102,000.00 | 0.0000 |
| 1 | 1,200.00 | 7,410.00 | 6,210.00 | 0.9524 | 5,914.29 | 78,000.00 |
| 2 | 1,200.00 | 7,372.95 | 6,172.95 | 0.9070 | 5,599.05 | 77,610.00 |
| 3 | 1,200.00 | 7,336.09 | 6,136.09 | 0.8638 | 5,300.58 | 77,221.95 |
| 4 | 1,200.00 | 7,299.40 | 6,099.40 | 0.8227 | 5,018.00 | 76,835.84 |
| 5 | 1,200.00 | 7,262.91 | 6,062.91 | 0.7835 | 4,750.45 | 76,451.66 |
| 6 | 1,200.00 | 7,226.59 | 6,026.59 | 0.7462 | 4,497.14 | 76,069.40 |
| 7 | 1,200.00 | 7,190.46 | 5,990.46 | 0.7107 | 4,257.31 | 75,689.06 |
| 8 | 1,200.00 | 7,154.51 | 5,954.51 | 0.6768 | 4,030.25 | 75,310.61 |
| 9 | 1,200.00 | 7,118.74 | 5,918.74 | 0.6446 | 3,815.27 | 74,934.06 |
| 10 | 1,200.00 | 7,083.14 | 5,883.14 | 0.6139 | 3,611.74 | 74,559.39 |
| 11 | 1,200.00 | 7,047.73 | 5,847.73 | 0.5847 | 3,419.04 | 74,186.59 |
| 12 | 10,200.00 | 7,012.49 | -3,187.51 | 0.5568 | -1,774.93 | 73,815.66 |
| 13 | 1,200.00 | 6,977.42 | 5,777.42 | 0.5303 | 3,063.89 | 73,446.58 |
| 14 | 1,200.00 | 6,942.54 | 5,742.54 | 0.5051 | 2,900.37 | 73,079.35 |
| 15 | 1,200.00 | 6,907.83 | 5,707.83 | 0.4810 | 2,745.56 | 72,713.95 |
| 16 | 1,200.00 | 6,873.29 | 5,673.29 | 0.4581 | 2,599.00 | 72,350.38 |
| 17 | 1,200.00 | 6,838.92 | 5,638.92 | 0.4363 | 2,460.24 | 71,988.63 |
| 18 | 1,200.00 | 6,804.73 | 5,604.73 | 0.4155 | 2,328.88 | 71,628.68 |
| 19 | 1,200.00 | 6,770.70 | 5,570.70 | 0.3957 | 2,204.52 | 71,270.54 |
| 20 | 1,200.00 | 6,736.85 | 5,536.85 | 0.3769 | 2,086.78 | 70,914.19 |
Cost series = $102,000 CapEx at Year 0 + $1,200/yr O&M + $9,000 inverter replacement at Year 12. Energy and benefit columns are the scenario-specific bill-savings stream; energy starts at 78,000 kWh in Year 1 and decays at 0.5%/yr (module degradation) over the 20-year horizon.
The benefit column reflects this scenario's bill-savings curve against a $0.14/kWh blended retail tariff with 0.5%/yr module degradation. The model treats net export as zero revenue (bounded assumption). At 5.00% real discount rate, the project's NPV remains negative; the simple payback lands late in the horizon (Year 18.85) and the discounted payback is not reached.
| Item | Model & OEM | Standard / certificate | OEM document |
|---|---|---|---|
| Modules | LONGi Hi-MO 5m LR5-54HTH-410M (147 units) | IEC 61215-1:2021 / IEC 61730-1/2; UL 61730 (US) | Hi-MO 5m LR5-54HTH 410–425M datasheet (PDF) |
| Inverter | Sungrow SG50CX (50 kW, 3-phase, 1000 Vdc) | IEEE 1547-2018 / UL 1741 SB | Sungrow SG50CX datasheet (PDF) |
| Module transport (UN) | UN 3480 / UN 3481 lithium battery hazard reference only | UN Manual of Tests and Criteria, Rev. 7 | UN Manual of Tests and Criteria, 7th revised edition (PDF) |
| BoS (racking, wiring) | UL 2703 / NEC 690 | Listing mark on racking + AHJ-stamped plan set | Listing certificate to be verified on racking supplier's product page at RFQ stage |
| Installer | NABCEP PV Installation Professional certification | Current cert number on the proposal | NABCEP certificate number to be recorded on proposal; lookup at RFQ stage |
Voltage / current limits applied in the audit: LONGi LR5-54HTH-410M Voc 37.25 V, Isc 13.71 A, max system voltage 1500 Vdc (datasheet p.2). Sungrow SG50CX max DC voltage 1100 V, max MPPT input current 26 A, MPPT range 180–1000 V (datasheet p.1). String sizing is bounded by these values; no procedure steps are specified on this page.
| HS / HTSUS | Description (excerpt) | Indicative duty | How to look up |
|---|---|---|---|
| 8541.42.00 | Photovoltaic cells assembled into modules / panels | PENDING | USITC HTS search → 8541.42 — USITC HTS search; verify General rate + any Section 201 / 232 add-ons for cells originating in PRC. |
| 8504.40.95 | Static converters — solar inverters | PENDING | USITC HTS search → 8504.40 — USITC HTS search; verify column 1 General rate; check for antidumping/countervailing orders. |
| 7610.90.00 | Aluminum racking / mounting structures | PENDING | USITC HTS search → 7610.90 — USITC HTS search; verify rate (often Free, but anti-dumping orders exist). |
| 8544.49 | DC wiring harnesses, UV-rated | PENDING | USITC HTS search → 8544.49 — USITC HTS search; verify rate (commonly Free for insulated conductors). |
Lookup instructions. (1) Open the USITC HTS search at hts.usitc.gov. (2) Enter the 6-digit HS, then drill to the 10-digit HTSUS. (3) Read column 1 "General rate" — that is the rate other countries pay without an FTA. (4) Cross-check CBP CSMS messages for any Section 201 / Section 232 / AD-CVD overlays on PV cells and inverters. (5) Confirm with your customs broker before tendering a landed-cost quote. TradVolt does not import on your behalf.
The RFQ anchor is the site path only (/rfq/); no mailto labelled as download, no placeholder download paths. Datasheet bundle lives on the use-case page itself.