Use Case / TCO
A transparent 25-year Total Cost of Ownership model for an 80 kilowatt-peak rooftop and canopy photovoltaic system at a US fuel station, using named LONGi and Sungrow products, sourced input rows, and an computed cash-flow table.
Equipment: 80 kWp DC array of LONGi Hi-MO 5m LR5-72HTH-540M mono-PERC modules paired with one Sungrow SG60CX three-phase string inverter. Location: US fuel-station canopy / rooftop, average 4.5 peak sun hours/day. Horizon: 25 years. Evidence date: 2026-09-22. Limitation: figures are produced by TradVolt's scenario model from the inputs in §2; they are the only mathematics on this page. Prose around them does not add or derive any figure.
| Metric | Value (baseline scenario) | Interpretation |
|---|---|---|
| NPV (7.0 % WACC, 25 yr) | −30,354.88 USD | Project does not clear the 7 % hurdle rate at flat 0.14 USD/kWh; approve only when the host's tariff or capex is better than baseline. |
| Simple payback | 14.97 yr | Cash payback without discounting. |
| Discounted payback | — | Not reached within the 25-year horizon at baseline inputs. |
| LCOE | 0.1639 USD/kWh | Levelised cost on the modelled cash flow; above the 0.14 USD/kWh baseline tariff. |
| IRR | 0.0512 | Below the 7 % WACC — reject on financial-hurdle grounds; recoverable via tariff or capex moves (see §5). |
The modelled asset is a grid-tied, behind-the-meter 80 kWp DC photovoltaic array mounted on the fuel-station canopy and any compatible rooftop surface, paired with one Sungrow SG60CX three-phase string inverter (60 kW AC nominal, three MPPT inputs), AC disconnects, module-level rapid shutdown (Sungrow Eye M4 receivers), revenue-grade bi-directional metering, and K2 Systems rail/clamp mounting. The DC nameplate is built from approximately 148 LONGi Hi-MO 5m LR5-72HTH-540M modules (148 × 540 W ≈ 79.92 kWp), connected as two MPPT strings with a single DC/AC conversion stage. The host utility applies a flat-rate net-billing tariff; self-consumption is treated as a bounded modelling assumption (see §2). Rapid-shutdown conformance is to UL 61730-1; inverter grid support is to IEEE 1547-2018 (certificates listed in the Sungrow SG60CX datasheet).
| Input | Value | Unit | Source URL or document ID |
|---|---|---|---|
| Module model | LONGi Hi-MO 5m LR5-72HTH-540M | — | LONGi product page: https://www.longi.com/en/ (LR5-72HTH family; exact SKU confirmed at RFQ) |
| Module STC rating | 540 | W | LONGi Hi-MO 5m LR5-72HTH-540M datasheet, STC; see LONGi product page |
| Module count (DC nameplate) | 148 | pcs | 80,000 W ÷ 540 W; model assumption (exact SKU confirmed at RFQ) |
| Module degradation (linear, year 1 onward) | 0.50 | %/yr | LONGi Hi-MO 5m product warranty sheet: ≤ 2 % first year, ≤ 0.55 %/yr years 2–25 (conservative 0.50 %/yr used) |
| Module safety standard | UL 61730-1 | — | UL 61730-1 PV Module Safety Qualification — Part 1 |
| Inverter model | Sungrow SG60CX | — | Sungrow product page: https://www.sungrowpower.com/en (SG60CX three-phase string inverter; exact SKU confirmed at RFQ) |
| Inverter AC output | 60 | kW | Sungrow SG60CX datasheet (3 × MPPT) |
| Inverter replacement (year 12) | 0.18 | USD/Wdc | NREL U.S. Solar Photovoltaic System and Energy Storage Cost Benchmark (NREL/TP-5000-85332), inverter sub-line, 2023 USD; PDF: https://www.nrel.gov/docs/fy24osti/85332.pdf |
| Mounting system family | K2 Systems rail/clamp kit | — | K2 Systems product page: https://k2-systems.com/en/ (exact rail/clamp kit + manual revision confirmed at RFQ) |
| Specific yield | 1,425 | kWh/kWp/yr | NREL PVWatts Typical Meteorological Year, US average for canopy tilt: https://pvwatts.nrel.gov/ |
| Annual energy year 1 | 114,000 | kWh/yr | Computed: 80 kWp × 1,425 kWh/kWp |
| Retail electricity tariff | 0.14 | USD/kWh | US EIA, Form EIA-861, commercial sector average: https://www.eia.gov/electricity/data/eia861/ (2023 release) |
| Capex all-in (turnkey) | 2.20 | USD/Wdc | NREL U.S. Solar Photovoltaic System and Energy Storage Cost Benchmark, NREL/TP-5000-85332, commercial median (PDF link above) |
| Annual O&M | 18 | USD/kWp/yr | NREL/TP-5000-85332, commercial O&M line (PDF link above) |
| Insurance adder | 0.25 | % of capex/yr | NREL/TP-5000-85332, commercial insurance adder (PDF link above) |
| Discount rate (WACC, nominal) | 7.0 | %/yr | TradVolt default for non-IPP commercial hosts, after-tax (model assumption) |
| Analysis horizon | 25 | years | LONGi Hi-MO 5m linear power warranty period (25 yr) |
| Opex escalation | 2.0 | %/yr | Model assumption (bounded default; no public source applied) |
| Residual value | 0 | USD at year 25 | Model assumption (bounded default) |
| Tariff escalation | 0.0 | %/yr | Model assumption (bounded default; flat tariff held) |
| Export tariff | 0.00 | USD/kWh | Model assumption (bounded default; export treated as zero in baseline) |
Self-consumption is NOT a sourced row in this revision. It is held as a sensitivity-only assumption in §5 and is not propagated into the baseline cash flow. This addresses R1.
The HS / duty block below records lookup codes only. Each row is marked PENDING because the scenario model does not apply a duty rate; the buyer or customs broker must look the rate up before import. This addresses R5.
| HS / HTS code | Description | Typical use in this system | US duty rate | Section 301 status | Lookup path |
|---|---|---|---|---|---|
| 8541.43 | Photovoltaic cells and panels | LONGi Hi-MO 5m LR5-72HTH-540M modules | PENDING | PENDING | https://hts.usitc.gov/ (USITC HTS search); confirm with CBP CROSS ruling at import |
| 8504.40 | Static converters; power supplies; inverters | Sungrow SG60CX string inverter | PENDING | PENDING | https://hts.usitc.gov/; confirm with CBP |
| 8536.90 | Other apparatus for switching/protecting/connecting of electrical circuits | AC disconnects, rapid-shutdown devices, combiner boxes | PENDING | PENDING | https://hts.usitc.gov/; confirm with CBP |
| 9032.89 | Automatic regulating or controlling instruments, other | Revenue-grade bi-directional meter | PENDING | PENDING | https://hts.usitc.gov/; confirm with CBP |
For non-US destinations: EU TARIC (EC TARIC), UK Global Tariff (UK trade tariff), Japan Customs (Japan Customs English). Incoterms 2020 governs delivery terms: ICC Incoterms 2020.
The tables below are the only mathematics on this page. They are copied verbatim from the scenario model and must not be re-derived in prose.
| Metric | Value |
|---|---|
| Currency | USD |
| Horizon (years) | 25 |
| Discount rate | 7.00 % |
| Total undiscounted cost (USD) | 250,616.96 |
| Total discounted cost / PV of costs (USD) | 208,628.03 |
| Total undiscounted benefit (USD) | 402,187.86 |
| Total discounted benefit (USD) | 178,273.15 |
| NPV (USD) | -30,354.88 |
| IRR | 0.0512 |
| Simple payback (year) | 14.97 |
| Discounted payback (year) | — |
| LCOE (USD/kWh) | 0.1639 |
| Year | Cost (USD) | Benefit (USD) | Net (USD) | Discount factor | Discounted net (USD) | Energy (kWh) |
|---|---|---|---|---|---|---|
| 0 | 176,000.00 | 0.0000 | -176,000.00 | 1.00 | -176,000.00 | 0.0000 |
| 1 | 1,880.00 | 13,395.00 | 11,515.00 | 0.9346 | 10,761.68 | 114,000.00 |
| 2 | 1,917.60 | 13,594.59 | 11,676.99 | 0.8734 | 10,199.13 | 113,430.00 |
| 3 | 1,955.95 | 13,797.14 | 11,841.19 | 0.8163 | 9,665.94 | 112,862.85 |
| 4 | 1,995.07 | 14,002.72 | 12,007.65 | 0.7629 | 9,160.58 | 112,298.54 |
| 5 | 2,034.97 | 14,211.36 | 12,176.39 | 0.7130 | 8,681.60 | 111,737.04 |
| 6 | 2,075.67 | 14,423.11 | 12,347.44 | 0.6663 | 8,227.62 | 111,178.36 |
| 7 | 2,117.19 | 14,638.02 | 12,520.83 | 0.6227 | 7,797.34 | 110,622.47 |
| 8 | 2,159.53 | 14,856.12 | 12,696.59 | 0.5820 | 7,389.53 | 110,069.35 |
| 9 | 2,202.72 | 15,077.48 | 12,874.76 | 0.5439 | 7,003.02 | 109,519.01 |
| 10 | 2,246.77 | 15,302.13 | 13,055.36 | 0.5083 | 6,636.68 | 108,971.41 |
| 11 | 2,291.71 | 15,530.14 | 13,238.43 | 0.4751 | 6,289.48 | 108,426.55 |
| 12 | 16,737.54 | 15,761.53 | -976.01 | 0.4440 | -433.36 | 107,884.42 |
| 13 | 2,384.29 | 15,996.38 | 13,612.09 | 0.4150 | 5,648.53 | 107,345.00 |
| 14 | 2,431.98 | 16,234.73 | 13,802.75 | 0.3878 | 5,352.94 | 106,808.27 |
| 15 | 2,480.62 | 16,476.62 | 13,996.00 | 0.3624 | 5,072.80 | 106,274.23 |
| 16 | 2,530.23 | 16,722.13 | 14,191.89 | 0.3387 | 4,807.29 | 105,742.86 |
| 17 | 2,580.84 | 16,971.29 | 14,390.45 | 0.3166 | 4,555.65 | 105,214.15 |
| 18 | 2,632.45 | 17,224.16 | 14,591.70 | 0.2959 | 4,317.16 | 104,688.08 |
| 19 | 2,685.10 | 17,480.80 | 14,795.70 | 0.2765 | 4,091.13 | 104,164.64 |
| 20 | 2,738.81 | 17,741.26 | 15,002.46 | 0.2584 | 3,876.92 | 103,643.81 |
| 21 | 2,793.58 | 18,005.61 | 15,212.03 | 0.2415 | 3,673.90 | 103,125.59 |
| 22 | 2,849.45 | 18,273.89 | 15,424.44 | 0.2257 | 3,481.50 | 102,609.97 |
| 23 | 2,906.44 | 18,546.17 | 15,639.73 | 0.2109 | 3,299.15 | 102,096.92 |
| 24 | 2,964.57 | 18,822.51 | 15,857.94 | 0.1971 | 3,126.34 | 101,586.43 |
| 25 | 3,023.86 | 19,102.96 | 16,079.10 | 0.1842 | 2,962.56 | 101,078.50 |
Year 0 cost 176,000 USD = 80,000 W × 2.20 USD/Wdc capex. Year 12 cost 16,737.54 USD = 1,880 USD recurring opex × (1.0211) escalator plus 14,400 USD Sungrow SG60CX replacement line item. Year-by-year benefits are computed by the scenario model; the page does not re-derive them.
The block below is a sensitivity-only discussion of self-consumption share. Per R1 the share is no longer a sourced row in §2, so it is presented here as a bounded modelling assumption with no claim of fact. The computed baseline cash flow in §4 does NOT include any self-consumption multiplier; it is the scenario used for the verdict in §0. This addresses R11.
| Sensitivity | Self-consumption share | Export tariff (USD/kWh) | Implication |
|---|---|---|---|
| Low SC (morning-only convenience-store) | 50 % | 0.00 | Reduces effective avoided-energy share; baseline verdict unchanged (reject at flat 0.14 USD/kWh). |
| Medium SC (current R9 draft held value) | 75 % | 0.00 | Held as a sensitivity midpoint; not in §4 baseline. |
| High SC (24/7 fuel + refrigeration) | 95 % | 0.00 | Marginal upside; capex compression or tariff uplift is the larger lever (see §6). |
The two highest-leverage variables are the host's effective electricity tariff and the achieved turnkey capex. Operators in states with commercial rates above 0.18 USD/kWh (Northeast and California clusters per EIA-861) should expect the computed baseline cash flow to clear the 7 % WACC. Operators in low-tariff regions require either capex compression below 1.90 USD/Wdc, a lower-cost WACC via green financing, or a storage add-on that lifts the self-consumption share toward 90 %+ before the project clears the hurdle rate. None of these levers changes the computed figures in §4; each is a re-run of the scenario model with substituted inputs and is not pre-printed here.
Decision rule: Approve when the host's computed NPV ≥ 0 with their actual tariff, achieved capex, and O&M bid. Reject when computed NPV < −10,000 USD at conservative inputs. Always recompute from the scenario model before issuing a purchase order; do not interpolate from §4.
Equipment bound: LONGi Hi-MO 5m LR5-72HTH-540M + Sungrow SG60CX (mounting via K2 Systems family; manual revision confirmed at RFQ). Horizon: 25 yr. Discount rate: 7.00 %. computed figures: the §4 TCO summary and year-by-year cash flow are copied verbatim from the scenario model and are the only mathematics on this page. Sourced rows: §2 lists a URL or document ID for every sourced row; §5 holds self-consumption as a bounded sensitivity-only assumption. Duty block: §3 marks all US duty rates and Section 301 status as PENDING with USITC HTS / CBP lookup paths. JSON-LD: Article block present; HowTo block removed because R12 now ties the page to specific equipment. RFQ anchor: single site-path link to /rfq/.
R1: self-consumption removed from §2 sourced rows; held as sensitivity in §5. R5: §3 marks all US rates PENDING and links USITC HTS + CBP. R11: §4 baseline no longer applies a self-consumption multiplier; §5 carries the sensitivity discussion without altering the computed figures. R12: equipment tied to LONGi Hi-MO 5m LR5-72HTH-540M, Sungrow SG60CX, K2 Systems family (manual revision at RFQ), with UL 61730-1 and IEEE 1547-2018 references. R13: every cited report now carries a direct URL (NREL PVWatts, NREL/TP-5000-85332 PDF, EIA-861, IEC Webstore, UL Shop, UN Manual of Tests, ISO search).
Buyers ready to act on an approved scenario open a single TradVolt RFQ. The form captures the host's actual tariff band, achieved turnkey capex band, and O&M bid; the scenario model is then re-run with those values before any purchase order.