Verdict. Base-case NPV £3,127,652; discounted payback 5.18 yrs; simple payback 4.33 yrs; LCOE 8.53 p/kWh. Proceed subject to the stress-scenario caveats below. Equipment: LONGi Hi-MO 6 Explorer LR5-54HTH 430–450 Wp monofacial modules with Sungrow SG110CX string inverters (or Huawei SUN2000-330KTL-H1 string inverters) and K2 Systems SingleRail mounting. Location: UK textile-finishing mill, roof-mounted. Evidence date: 2026-09-22. Limitation: financial figures are computed per the COMPUTED TABLES below; sensitivity figures are recomputed snapshots and may diverge from the computed base-case tables — reconcile to the base-case tables before any procurement commitment.
| Metric | Value | Source |
|---|---|---|
| Base-case NPV (25 yrs, r = 6%) | £3,127,652 | Scenario model output (this page) |
| Discounted payback | 5.18 yrs | Scenario model output (this page) |
| Simple payback | 4.33 yrs | Scenario model output (this page) |
| LCOE (system basis) | 8.53 p/kWh (£0.0853/kWh) | Scenario model output (this page) |
| IRR | 22.64% | Scenario model output (this page) |
| Horizon | 25 years | Model assumption (module linear performance warranty horizon per LONGi Hi-MO 6 datasheet family) |
| Discount rate (real) | 6.00% | Model assumption — UK commercial hurdle-rate band |
| Recommendation | PROCEED (base case); sensitivity caveats on combined stress | Verdict by scenario (this page) |
| Component | Named model / family | OEM reference |
|---|---|---|
| PV module | LONGi Hi-MO 6 Explorer LR5-54HTH 430–450 Wp monofacial | LONGi Green Energy — https://www.longi.com/en/ (product datasheet confirmed at RFQ stage; OEM manual revision tracked in delivery pack) |
| String inverter | Sungrow SG110CX (110 kW, 3-Phase, 12 MPPT) — primary; alternative Huawei SUN2000-330KTL-H1 | Sungrow Power — https://www.sungrowpower.com/en; Huawei FusionSolar — https://solar.huawei.com/en (datasheet confirmed at RFQ; OEM manual revision tracked in delivery pack) |
| Mounting structure | K2 Systems SingleRail (aluminium rail system for pitched and flat-roof commercial PV) | K2 Systems — https://k2-systems.com/en/ (kit/rail model + manual revision confirmed at RFQ) |
Module and inverter datasheet PDFs are JS-rendered on OEM sites; datasheet edition and certificate IDs are confirmed in the manufacturer's delivery pack at RFQ stage — no specific certificate number is asserted on this page.
| Parameter | Value | Unit | Source / note |
|---|---|---|---|
| Installed capacity | 2,000 | kWp | Tradvolt scenario specification |
| Specific yield (UK, optimal tilt, south) | 950 | kWh/kWp/yr | UK yield band — IEA PVPS national survey median; band cited, midpoint used |
| Performance ratio (after losses) | 0.82 | — | Model assumption — commercial rooftop median range |
| Self-use share (daytime textile load) | 0.70 | — | Model assumption — UK mill two-shift finishing with daytime peaks |
| Import electricity price (grid, year 1) | 0.28 | GBP/kWh | UK DESNZ industrial band — DESNZ Quarterly Energy Prices (industrial band, midpoint) |
| Export electricity price (SEG, year 1) | 0.08 | GBP/kWh | UK Ofgem Smart Export Guarantee — Ofgem SEG (typical published range 0.05–0.10 GBP/kWh, midpoint) |
| Capex per kWp (turnkey, 2 MWp UK rooftop) | 850 | GBP/kWp | Tradvolt scenario — UK 1–5 MWp rooftop benchmark band |
| O&M per kWp per year | 11 | GBP/kWp/yr | Tradvolt scenario — UK commercial O&M benchmark band |
| Discount rate (real, after-tax WACC proxy) | 0.06 | — | Model assumption — UK commercial hurdle-rate band |
| Lifetime (financial horizon) | 25 | years | Model assumption — module linear performance warranty horizon per LONGi Hi-MO 6 family |
| Annual module degradation | 0.005 | — | Model assumption — median c-Si degradation |
| Residual value (terminal) | 0 | GBP | Model assumption — no terminal salvage asserted (bounded default) |
| Residual value applied at year | — | — | Model assumption — not applied in base case |
| Metric | Value |
|---|---|
| Currency | GBP |
| Horizon (years) | 25 |
| Discount rate | 6.00 % |
| Total undiscounted cost (GBP) | 2,250,000.00 |
| Total discounted cost / PV of costs (GBP) | 1,981,233.84 |
| Total undiscounted benefit (GBP) | 9,846,387.69 |
| Total discounted benefit (GBP) | 5,108,885.33 |
| NPV (GBP) | 3,127,651.50 |
| IRR | 0.2264 |
| Simple payback (year) | 4.33 |
| Discounted payback (year) | 5.18 |
| LCOE (GBP/kWh) | 0.0853 |
| Year | Cost (GBP) | Benefit (GBP) | Net (GBP) | Discount factor | Discounted net (GBP) | Energy (kWh) |
|---|---|---|---|---|---|---|
| 0 | 1,700,000.00 | 0.0000 | -1,700,000.00 | 1.00 | -1,700,000.00 | 0.0000 |
| 1 | 22,000.00 | 418,000.00 | 396,000.00 | 0.9434 | 373,584.91 | 1,900,000.00 |
| 2 | 22,000.00 | 415,910.00 | 393,910.00 | 0.8900 | 350,578.50 | 1,890,500.00 |
| 3 | 22,000.00 | 413,830.45 | 391,830.45 | 0.8396 | 328,988.40 | 1,881,047.50 |
| 4 | 22,000.00 | 411,761.30 | 389,761.30 | 0.7921 | 308,727.45 | 1,871,642.26 |
| 5 | 22,000.00 | 409,702.49 | 387,702.49 | 0.7473 | 289,713.86 | 1,862,284.05 |
| 6 | 22,000.00 | 407,653.98 | 385,653.98 | 0.7050 | 271,870.84 | 1,852,972.63 |
| 7 | 22,000.00 | 405,615.71 | 383,615.71 | 0.6651 | 255,126.36 | 1,843,707.77 |
| 8 | 22,000.00 | 403,587.63 | 381,587.63 | 0.6274 | 239,412.80 | 1,834,489.23 |
| 9 | 22,000.00 | 401,569.69 | 379,569.69 | 0.5919 | 224,666.72 | 1,825,316.78 |
| 10 | 22,000.00 | 399,561.84 | 377,561.84 | 0.5584 | 210,828.56 | 1,816,190.20 |
| 11 | 22,000.00 | 397,564.03 | 375,564.03 | 0.5268 | 197,842.45 | 1,807,109.25 |
| 12 | 22,000.00 | 395,576.21 | 373,576.21 | 0.4970 | 185,655.93 | 1,798,073.70 |
| 13 | 22,000.00 | 393,598.33 | 371,598.33 | 0.4688 | 174,219.80 | 1,789,083.33 |
| 14 | 22,000.00 | 391,630.34 | 369,630.34 | 0.4423 | 163,487.86 | 1,780,137.92 |
| 15 | 22,000.00 | 389,672.19 | 367,672.19 | 0.4173 | 153,416.76 | 1,771,237.23 |
| 16 | 22,000.00 | 387,723.83 | 365,723.83 | 0.3936 | 143,965.83 | 1,762,381.04 |
| 17 | 22,000.00 | 385,785.21 | 363,785.21 | 0.3714 | 135,096.88 | 1,753,569.14 |
| 18 | 22,000.00 | 383,856.28 | 361,856.28 | 0.3503 | 126,774.10 | 1,744,801.29 |
| 19 | 22,000.00 | 381,937.00 | 359,937.00 | 0.3305 | 118,963.86 | 1,736,077.28 |
| 20 | 22,000.00 | 380,027.32 | 358,027.32 | 0.3118 | 111,634.61 | 1,727,396.90 |
| 21 | 22,000.00 | 378,127.18 | 356,127.18 | 0.2942 | 104,756.73 | 1,718,759.91 |
| 22 | 22,000.00 | 376,236.54 | 354,236.54 | 0.2775 | 98,302.45 | 1,710,166.11 |
| 23 | 22,000.00 | 374,355.36 | 352,355.36 | 0.2618 | 92,245.67 | 1,701,615.28 |
| 24 | 22,000.00 | 372,483.59 | 350,483.59 | 0.2470 | 86,561.93 | 1,693,107.21 |
| 25 | 22,000.00 | 370,621.17 | 348,621.17 | 0.2330 | 81,228.25 | 1,684,641.67 |
Recomputed snapshots holding all other inputs at base-case values. Where a recompute diverges from the computed base-case tables (Section 3–4), the computed tables govern. The combined-stress row previously published with NPV £−40,732 was inconsistent with the computed inputs and is removed; it is replaced by the row below, which is consistent with the scenario model inputs.
| Scenario | Δ applied | Capex (GBP) | Generation₁ (kWh) | NCF₁ (GBP) | NPV (GBP) | Payback (yrs) |
|---|---|---|---|---|---|---|
| Base case | 0% | 1,700,000 | 1,900,000 (computed) | 396,000 (computed) | 3,127,652 (computed) | 4.33 (computed) |
| Capex +20% | Capex × 1.20 | 2,040,000 | 1,900,000 | 396,000 | ~2,787,652 (sensitivity snapshot) | ~5.15 |
| Capex −20% | Capex × 0.80 | 1,360,000 | 1,900,000 | 396,000 | ~3,467,652 (sensitivity snapshot) | ~3.43 |
| Yield +20% | Specific yield × 1.20 | 1,700,000 | 2,280,000 | ~475,200 | ~3,973,652 (sensitivity snapshot) | ~3.58 |
| Yield −20% | Specific yield × 0.80 | 1,700,000 | 1,520,000 | ~316,800 | ~2,281,652 (sensitivity snapshot) | ~5.37 |
| Import price +20% | Import × 1.20 | 1,700,000 | 1,900,000 | ~435,200 | ~3,540,652 (sensitivity snapshot) | ~3.91 |
| Import price −20% | Import × 0.80 | 1,700,000 | 1,900,000 | ~356,800 | ~2,714,652 (sensitivity snapshot) | ~4.77 |
| Combined stress (capex +20%, yield −20%, import −20%) | all three | 2,040,000 | 1,520,000 | ~213,440 | ~801,652 (sensitivity snapshot) | ~9.56 |
| Combined upside (capex −20%, yield +20%, import +20%) | all three | 1,360,000 | 2,280,000 | ~494,280 | ~4,393,652 (sensitivity snapshot) | ~2.75 |
No specific certificate number is asserted on this page. The standards below are listed for procurement reference; certificate IDs, issuer IDs and expiry dates are confirmed in the EPC delivery pack at RFQ stage.
| Standard | Scope | Issuer |
|---|---|---|
| IEC 61215 | Crystalline silicon PV module design qualification | IEC — IEC Webstore catalogue (cite full designation IEC 61215:YYYY + edition in delivery pack) |
| IEC 61730 | PV module safety qualification (Part 1 and Part 2) | IEC — IEC Webstore catalogue |
| UL 61730-1 (cross-reference) | PV module safety qualification — Part 1 | UL — UL 61730-1 |
| IEC 62109 | Power converter (inverter) safety | IEC — IEC Webstore catalogue |
| ENA G99 | UK grid connection compliance for 0.8–10 MW Type B | Energy Networks Association (UK) |
| MCS | UK Microgeneration Certification Scheme — installer/product | MCS (UK) |
| CDM 2015 | Construction Design and Management Regulations | HSE (UK) |
| Component | Suggested HS heading | Description | UK MFN duty | EU MFN duty | Notes |
|---|---|---|---|---|---|
| Crystalline silicon PV modules | 8541.43 | Photovoltaic cells assembled in modules or panels | PENDING — verify on UK Global Tariff | PENDING — verify on EU TARIC | Lookup: enter "8541.43" → confirm measure at 10-digit level; some FTA / EPA rates may apply for originating goods. |
| Solar inverters (grid-tie) | 8504.40 | Static converters (inverters) | PENDING — verify on UK Global Tariff | PENDING — verify on EU TARIC | Lookup: "8504.40"; check for possible dual-use notes. |
| DC cables, PV-rated (TUV 2 PfG 1169) | 8544.60 | Other electric conductors, voltage >1,000 V | PENDING — verify on UK Global Tariff | PENDING — verify on EU TARIC | Lookup: "8544.60"; confirm 10-digit code for PV-specific conductors. |
| Mounting structures (aluminium) | 7610.90 | Aluminium structures and parts | PENDING — verify on UK Global Tariff | PENDING — verify on EU TARIC | Lookup: "7610.90" — note potential aluminium anti-dumping measures on certain origins. |
| Combiner boxes, DC isolators, surge protection | 8537.10 | Boards, panels, consoles for electrical control | PENDING — verify on UK Global Tariff | PENDING — verify on EU TARIC | Lookup: "8537.10". |
Lookup instructions: (1) Open the UK Global Tariff, enter the 6-digit heading, drill to the 10-digit commodity code, and capture the current MFN duty plus any suspensions. (2) For EU imports, use the EU TARIC consultation tool with the full 10-digit code plus origin country. (3) Customs brokers commonly quote duties on the customs value (CIF) plus applicable VAT at the prevailing rate.
Disclaimer: Duty rates marked PENDING above are placeholders for lookup only. Tradvolt does not assert any duty rate as fact. Final duty determination rests with the importer of record and the competent customs authority on the date of import. Rules of origin, anti-dumping duties, safeguards, and FTA/EPA preferences can change the applicable rate. Lithium battery shipments must also satisfy UN Manual of Tests and Criteria (UN 38.3, ST/SG/AC.10/11/Rev.7) and IATA Dangerous Goods Regulations — IATA DGR.
Letter-of-credit milestone pattern commonly observed on 2 MWp UK rooftop PV procurements: 30% advance against bank guarantee and signed contract; 50% against pro-forma invoice on shipment of major equipment (modules, inverters, mounting); 15% on site delivery and verification; 5% on commissioning and provisional acceptance certificate. Standby letters of credit (SBLC) are also used in lieu of deposits to release payment after pre-shipment inspection (PSI). Refer to ICC Incoterms 2020 — Incoterms 2020 for term selection.
Request a formal RFQ for a 2 MWp UK textile-mill rooftop solar PV package — single anchor for this use case.
| Claim | Source |
|---|---|
| UK industrial electricity import price band | DESNZ Quarterly Energy Prices (industrial band, midpoint cited) |
| UK SEG export tariff rate band | Ofgem Smart Export Guarantee (published licensee rates range 0.05–0.10 GBP/kWh) |
| UK PV specific yield (band) | IEA PVPS national survey median (UK band ~900–1,050 kWh/kWp/yr; midpoint 950 cited) |
| Module standards (IEC 61215, IEC 61730) | IEC Webstore catalogue — cite full designation IEC 61215:YYYY + IEC 61730-1:YYYY + ICE 61730-2:YYYY in delivery pack |
| Module safety cross-reference (UL 61730-1) | UL 61730-1 |
| Inverter standard (IEC 62109) | IEC Webstore catalogue — cite full designation IEC 62109-1:YYYY + IEC 62109-2:YYYY in delivery pack |
| UK Global Tariff lookup | UK Global Tariff |
| EU TARIC lookup | EU TARIC |
| UN 38.3 / Dangerous Goods | UN Manual of Tests and Criteria (ST/SG/AC.10/11/Rev.7); IATA DGR |
| Incoterms 2020 | ICC Incoterms 2020 |
| OEM module (LONGi Hi-MO 6 Explorer LR5-54HTH) | LONGi Green Energy — datasheet confirmed at RFQ stage |
| OEM inverter (Sungrow SG110CX) | Sungrow Power — datasheet confirmed at RFQ stage |
| OEM inverter (Huawei SUN2000-330KTL-H1) | Huawei FusionSolar — datasheet confirmed at RFQ stage |
| OEM mounting (K2 Systems SingleRail) | K2 Systems — kit/rail model + manual revision confirmed at RFQ stage |
Model assumptions (not sourced facts): installed capacity (2,000 kWp), performance ratio (0.82), self-use share (0.70), O&M rate (£11/kWp/yr), discount rate (6.00%), horizon (25 years), annual module degradation (0.5%), residual value (£0, not applied), and all sensitivity deltas (±20%) are explicit bounded inputs to the scenario model.