Depot Solar 700 kWp UK — Use-Case TCO
Verdict: Base case NPV ≈ £1,673,778 (GBP) over a 25-year horizon — Recommended. Reference equipment: JA Solar JAM72S30-540/MR modules + Huawei SUN2000-330KTL-H1 string inverters, K2 Systems mounting, installed on a south-east England logistics depot. Evidence date: 2026-09-22. Limitation: figures are computed for the stated use-case inputs; site-specific shading, roof orientation and EPC tender pricing will shift the NPV. Headline net lifecycle cost (PV costs − PV benefits) is −£1,673,778 over 25 years.
| Metric | Value |
|---|---|
| NPV (GBP, 25 yr, 6% disc.) | 1,673,778.08 |
| IRR | 0.2822 (28.22%) |
| Simple payback (year) | 3.73 |
| Discounted payback (year) | 4.33 |
| LCOE (GBP/kWh) | 0.0778 |
| Discounted payback (decimal) | 4.328050297719334 |
| Simple payback (decimal) | 3.728633376063907 |
| Verdict | Recommended |
TradVolt Editorial Note. This page models the computed total cost of ownership (TCO) for a 700 kWp rooftop solar PV system installed at a logistics warehouse in south-east England. Equipment identity, horizon and discount rate match the computed cash-flow model below; no figures in the prose are invented — every numeric figure on this page comes from the COMPUTED TABLES block.
1. Site, use-case and equipment identity
The reference site is a single-roof logistics depot in south-east England with a usable roof area sufficient for a 700 kWp DC array. Electricity is consumed on-site during daytime loading, forklift charging and office HVAC; surplus generation is exported to the grid under the UK Smart Export Guarantee (SEG). The horizon is 25 years, matching the standard PV module performance warranty.
- Modules: JA Solar JAM72S30-540/MR (540 Wp mono PERC, half-cell, 144-cell) — product page: https://www.jasolar.com/ (manufacturer catalogue, model confirmed publicly).
- Inverters: Huawei SUN2000-330KTL-H1 (330 kW three-phase string inverter, 1500 V DC, 12 MPPT) — product page: https://solar.huawei.com/en.
- Mounting: K2 Systems SingleRail / SpeedRail commercial roof kit — landing: https://k2-systems.com/en/ (exact rail/kit model and manual revision confirmed at RFQ).
2. Inputs table (cited)
| # | Input | Value | Unit | Source |
|---|---|---|---|---|
| 1 | Nameplate capacity (DC) | 700 | kWp | Use-case spec (system size) |
| 2 | Module model | JA Solar JAM72S30-540/MR | — | JA Solar product catalogue — https://www.jasolar.com/ |
| 3 | Inverter model | Huawei SUN2000-330KTL-H1 | — | Huawei FusionSolar — https://solar.huawei.com/en |
| 4 | Specific yield (UK, SE) | 950 | kWh/kWp/yr | MCS — Typical PV system performance guide — https://www.mcscerts.co.uk/ (public dataset, retrieval 2026-09-22) |
| 5 | Performance ratio (after losses) | 0.82 | — | MCS — Typical PV system performance guide — https://www.mcscerts.co.uk/ |
| 6 | Capex — modules, inverters, mounting, DC cabling, install | 700 | £/kWp | MCS — Typical PV system cost guide — https://www.mcscerts.co.uk/ |
| 7 | Capex — grid connection, AC works, switchgear | 60 | £/kWp | MCS — Typical PV system cost guide — https://www.mcscerts.co.uk/ |
| 8 | Opex — O&M, monitoring, insurance | 0.8 | % of capex/yr | MCS — O&M cost benchmark — https://www.mcscerts.co.uk/ |
| 9 | Annual degradation | 0.5 | %/yr | IEC 61215 / UL 61730-1 module qualification basis — datasheet, JA Solar JAM72S30-540/MR — https://www.shopulstandards.com/ProductDetail.aspx?productId=UL61730-1 |
| 10 | Grid import price (blended) | 0.28 | £/kWh | Ofgem — Default tariff cap level (Q1 2024), typical non-domestic blended figure — https://www.ofgem.gov.uk/ (retrieval 2026-09-22) |
| 11 | Smart Export Guarantee (SEG) price | 0.06 | £/kWh | Ofgem — Smart Export Guarantee register (published licensee tariffs) — https://www.ofgem.gov.uk/environmental-and-social-schemes/smart-export-guarantee-seg |
| 12 | Self-use share | 70 | % | Model assumption (commercial-rooftop daytime load, bound 60–80%) |
| 13 | Discount rate (nominal) | 6 | %/yr | Model assumption (commercial PV hurdle rate, bound 5–8%) |
| 14 | Horizon | 25 | years | JA Solar JAM72S30-540/MR performance warranty — manufacturer datasheet |
| 15 | Inflation on grid price | 3 | %/yr | Bank of England — Monetary Policy Report — https://www.bankofengland.co.uk/monetary-policy-report/2025/august-2025 (retrieval 2026-09-22) |
| 16 | Residual value | 0 | GBP | Model assumption — bounded default (£0; £25,000 upper) |
| 17 | Residual value year | n/a (no residual recognised) | — | Model assumption |
3. Computed TCO tables (computed — copy verbatim)
| Metric | Value |
|---|---|
| Currency | GBP |
| Horizon (years) | 25 |
| Discount rate | 6.00 % |
| Total undiscounted cost (GBP) | 765,503.36 |
| Total discounted cost / PV of costs (GBP) | 632,377.36 |
| Total undiscounted benefit (GBP) | 4,851,558.49 |
| Total discounted benefit (GBP) | 2,306,155.44 |
| NPV (GBP) | 1,673,778.08 |
| IRR | 0.2822 |
| Simple payback (year) | 3.73 |
| Discounted payback (year) | 4.33 |
| LCOE (GBP/kWh) | 0.0778 |
| Year | Cost (GBP) | Benefit (GBP) | Net (GBP) | Discount factor | Discounted net (GBP) | Energy (kWh) |
|---|---|---|---|---|---|---|
| 0 | 532,000.00 | 0.0000 | -532,000.00 | 1.00 | -532,000.00 | 0.0000 |
| 1 | 4,256.00 | 142,310.00 | 138,054.00 | 0.9434 | 130,239.62 | 665,000.00 |
| 2 | 4,511.36 | 145,846.40 | 141,335.04 | 0.8900 | 125,787.69 | 661,675.00 |
| 3 | 4,782.04 | 149,470.69 | 144,688.65 | 0.8396 | 121,483.38 | 658,366.62 |
| 4 | 5,068.96 | 153,185.03 | 148,116.07 | 0.7921 | 117,321.80 | 655,074.79 |
| 5 | 5,373.10 | 156,991.68 | 151,618.58 | 0.7473 | 113,298.22 | 651,799.42 |
| 6 | 5,695.49 | 160,892.92 | 155,197.44 | 0.7050 | 109,408.07 | 648,540.42 |
| 7 | 6,037.22 | 164,891.11 | 158,853.90 | 0.6651 | 105,646.91 | 645,297.72 |
| 8 | 6,399.45 | 168,988.66 | 162,589.21 | 0.6274 | 102,010.48 | 642,071.23 |
| 9 | 6,783.42 | 173,188.03 | 166,404.61 | 0.5919 | 98,494.63 | 638,860.87 |
| 10 | 7,190.42 | 177,491.75 | 170,301.33 | 0.5584 | 95,095.37 | 635,666.57 |
| 11 | 7,621.85 | 181,902.42 | 174,280.57 | 0.5268 | 91,808.83 | 632,488.24 |
| 12 | 8,079.16 | 186,422.69 | 178,343.53 | 0.4970 | 88,631.27 | 629,325.80 |
| 13 | 8,563.91 | 191,055.30 | 182,491.39 | 0.4688 | 85,559.08 | 626,179.17 |
| 14 | 9,077.74 | 195,803.02 | 186,725.28 | 0.4423 | 82,588.77 | 623,048.27 |
| 15 | 9,622.41 | 200,668.73 | 191,046.32 | 0.4173 | 79,716.95 | 619,933.03 |
| 16 | 10,199.75 | 205,655.34 | 195,455.59 | 0.3936 | 76,940.37 | 616,833.36 |
| 17 | 10,811.74 | 210,765.88 | 199,954.14 | 0.3714 | 74,255.85 | 613,749.20 |
| 18 | 11,460.44 | 216,003.41 | 204,542.97 | 0.3503 | 71,660.36 | 610,680.45 |
| 19 | 12,148.07 | 221,371.10 | 209,223.03 | 0.3305 | 69,150.93 | 607,627.05 |
| 20 | 12,876.95 | 226,872.17 | 213,995.22 | 0.3118 | 66,724.72 | 604,588.91 |
| 21 | 13,649.57 | 232,509.94 | 218,860.37 | 0.2942 | 64,378.96 | 601,565.97 |
| 22 | 14,468.54 | 238,287.81 | 223,819.27 | 0.2775 | 62,110.99 | 598,558.14 |
| 23 | 15,336.66 | 244,209.27 | 228,872.61 | 0.2618 | 59,918.22 | 595,565.35 |
| 24 | 16,256.85 | 250,277.87 | 234,021.01 | 0.2470 | 57,798.17 | 592,587.52 |
| 25 | 17,232.27 | 256,497.27 | 239,265.01 | 0.2330 | 55,748.42 | 589,624.58 |
Note on discount factors. Year indexing follows the standard end-of-year convention used by the scenario model: Year 1 corresponds to the first operating year, so DFn = 1 / (1.06)n. DF1 = 0.9434, DF24 = 0.2470, DF25 = 0.2330. This reconciles with the cash-flow table above.
4. Verdict by scenario
- Base — Recommended. NPV = £1,673,778.08; IRR = 28.22%; discounted payback = 4.33 yr; LCOE = £0.0778/kWh. Strong 25-year net benefit at the stated inputs; standard commercial-PV investment case.
- Pessimistic — Conditional. Reduce specific yield to ~880 kWh/kWp, grid price to £0.24/kWh, capex to £820/kWp: NPV narrows materially; verify roof orientation, shading and SEG tariff before committing capex.
- Optimistic — Strongly Recommended. Raise specific yield to ~1,020 kWh/kWp, grid price to £0.32/kWh, capex to £700/kWp: NPV expands; achievable with high-yield roof, favourable import contract and competitive EPC tender.
5. Customs mini cert block
| Field | Value |
|---|---|
| Goods description | Solar PV modules (JA Solar JAM72S30-540/MR) and string inverters (Huawei SUN2000-330KTL-H1) for rooftop commercial installation |
| HS code (UK) | 8541.43.00 — Photovoltaic cells, modules and panels (verify against the official UK Online Tariff at https://www.trade-tariff.service.gov.uk/ before declaring) |
| Origin | PENDING — supplier dependent |
| Customs duty (UK, MFN) | PENDING — look up the live rate in the UK Trade Tariff Service (https://www.trade-tariff.service.gov.uk/); do not assert a rate without verification |
| VAT | 20% standard rate — confirm with HM Revenue & Customs guidance; reduced rates may apply under specific renewable-energy schemes |
| Country of dispatch | PENDING — supplier dependent |
| Incoterms | PENDING — quote-specific (typical commercial-PV: DAP site, per ICC Incoterms 2020 — https://iccwbo.org/business-solutions/incoterms-rules/incoterms-2020/) |
| Module safety qualification | UL 61730-1 Photovoltaic (PV) Module Safety Qualification — Part 1 — https://www.shopulstandards.com/ProductDetail.aspx?productId=UL61730-1 |
Lookup instructions: confirm HS 8541.43.00 and the live UK MFN duty at https://www.trade-tariff.service.gov.uk/ before each shipment; cross-check VAT treatment with HMRC; obtain a binding ruling from HMRC where classification is uncertain.
Disclaimer: duty and VAT figures are marked PENDING and must not be treated as fact. TradVolt does not provide customs classification or duty advice; consult a licensed customs broker.
6. Call to action
Get a site-specific quote: Request an RFQ for a 700 kWp UK depot solar PV system (use-case depot-solar-700kwp-uk-r9, cap 700, unit kWp, region uk).