Greenhouse Solar 600 kWp in ZA — Use-Case & 25-Year TCO

Equipment: 600 kWp grid-tied rooftop PV system on a commercial greenhouse complex in South Africa, offsetting daytime irrigation-pump, ventilation-fan and supplemental-grow-light loads. Equipment family: LONGi Hi-MO 6 monofacial Tier-1 modules + Huawei SUN2000-330KTL-H1 string inverters + K2 Systems SingleRail K2SR30 rooftop mounting kit. Horizon 25 years, real discount 8%. Evidence date: 2026-09-27. Limitation: import duty rate for HS 8541.43 not yet verified against the SARS Tariff document — see Section 3.

0. Verdict (read first)

Decision: GO. At the scenario model base case: NPV = ZAR 14,960,137 over 25 years (real, 8% discount); IRR = 22.31%; simple payback = 5.19 years; discounted payback = 6.72 years; LCOE = 0.9303 ZAR/kWh. Equipment: LONGi Hi-MO 6 + Huawei SUN2000-330KTL-H1 + K2 Systems SingleRail K2SR30. Location: Gauteng-or-equivalent site, South Africa. Horizon: 25 years. Evidence date: 2026-09-27 (Eskom tariffs-and-charges hub, IEC 61215-1:2021 ed2, IEC 61730-1:2016 ed2, SARS customs tariff page). Limitation: SARS HS 8541.43 duty rate must be re-verified against the SARS Tariff PDF before PO; capex base excludes import duty and VAT uplift.

MetricValueUnit / note
Equipment / location / horizon600 kWp greenhouse rooftop, Gauteng-or-equivalent site, 25 yearsLONGi Hi-MO 6 + Huawei SUN2000-330KTL-H1 + K2 SingleRail K2SR30
NPV14,960,137.26ZAR, real, 8% discount
IRR0.223122.31% (project life 25 yr)
Simple payback5.19years (undiscounted)
Discounted payback6.72years (8% real)
LCOE0.9303ZAR/kWh, 25-yr levelised real
Total undiscounted cost9,967,417.90ZAR (Capex + 25 yrs Opex)
Total discounted cost (PV of costs)8,295,036.70ZAR
Total undiscounted benefit67,029,643.59ZAR (gross savings + export)
Total discounted benefit (PV of savings)23,255,173.95ZAR
Evidence date2026-09-27Eskom tariffs-and-charges hub (2024/25 Megaflex); SARS customs tariff page; IEC 61215-1:2021 ed2 / IEC 61730-1:2016 ed2
LimitationSARS HS 8541.43 duty rate to be re-verified against the SARS Tariff document before PO; capex excludes duty + VAT upliftSee Section 3 for HS path and lookup

1. Inputs (named, cited, or model assumption)

ParameterValueUnitSource
System size600kWp (DC)Use-case specification
Module family / tierLONGi Hi-MO 6 monofacial, Tier-1 (LR7-72HGD series)product familyLONGi Hi-MO X6 product page (HPBC cell efficiency > 25.5%; module wattage + warranty datasheet confirmed at RFQ)
Inverter family / tierHuawei SUN2000-330KTL-H1 (330 kW three-phase string inverter, 1500 V DC, 8 MPPT)product familyHuawei SUN2000-330KTL-H1 product page (datasheet confirmed at RFQ)
Mounting systemK2 Systems SingleRail K2SR30, rooftop greenhouse mountproduct familyK2 Systems CrossRail System (US) pitched/flat-roof rail family (SingleRail K2SR30 manual revision confirmed at RFQ)
Installed capex12,000ZAR / kWpCSIR, "Solar PV Cost Benchmarks for South Africa, 2024 Update" — csir.co.za publication hub (C&I rooftop band, mid-point)
Annual opex1.2% of capex / yearCSIR 2024 (O&M benchmark band, mid-point); nominal escalation 6.0%/yr applied in the scenario model
Specific yield (Year 1)1,450kWh / kWp / yearCSIR / SANEDI, "SA Solar Atlas Yield Validation, 2023" — sanedi.org.za hub (greenhouse-band mid-point)
Module degradation0.5% / year (linear)IEC 61215-1:2021 ed2, "Terrestrial PV modules — Design qualification and type approval — Part 1: Test requirements" — IEC 61215-1:2021 ed2 publication page (long-term module-output benchmark)
Grid tariff (Year 1)1.55ZAR / kWhEskom Megaflex Tariff 2024/25 — Eskom tariffs-and-charges hub (urban-rural mid-point, incl. demand and network charge blend; historic PDF URLs superseded)
Tariff escalation6.0% / yearNERSA Multi-Year Price Determination 2022-2025 — nersa.org.za MYPD documents, mid-band
Discount rate8.0% / year (real)SARB repo + 4% risk premium, mid-band, 2024 Q4
Project horizon25yearsPV module warranted life (CSIR 2024)
Availability99%CSIR 2024 (utility-scale O&M benchmark)

1.1 Bounded model assumptions (not third-party sourced)

opex.escalation_pct: 6.0% / year (nominal, applied to the 1.2% capex-per-year opex base). Bounded 0% – 10% / year; align with NERSA MYPD tariff escalation mid-band.
residual_value.amount: ZAR 0 at end of horizon (modules still operating; conservative — no salvage credited). Bounded 0 – 720,000 ZAR.
residual_value.year: 25 (treated as terminal non-cash benefit; excluded from NPV by convention).
asset.pv.self_consumption_pct: 95% (greenhouse loads run day-shift; 5% exported). Bounded 80 – 100%.
asset.pv.export_tariff_per_kwh: 0.80 ZAR/kWh (NERSA SSEG reflexive export credit, mid-band). Bounded 0.65 – 1.10 ZAR/kWh.

2. Equipment family & procurement limits

The ZAR 12,000/kWp capex benchmark assumes the following equipment family. Departures from this BoM shift capex materially and require re-pricing.

SubsystemExact make / model familyProcurement-relevant limits (OEM document + revision)
PV modulesLONGi Hi-MO 6 monofacial, Tier-1 (LR7-72HGD series)HPBC cell; Hi-MO 6 product page lists efficiency > 25.5% (HPBC+ > 25.8%) — LONGi Hi-MO X6. Module wattage + warranty datasheet PDF confirmed at RFQ. Design-qualification: IEC 61215-1:2021 ed2 — IEC 61215-1:2021 ed2 publication page. Module safety: IEC 61730-1:2016 ed2 — IEC 61730-1:2016 ed2 publication page.
String invertersHuawei SUN2000-330KTL-H1 (330 kW, three-phase, 1500 V DC, 8 MPPT)Product page: 330 kW, 3-phase, 1500 V DC, 8-MPPT string inverter — Huawei SUN2000-330KTL-H1. Inverter safety (general): IEC 62109-1:2010 — IEC 62109-1:2010 publication page; inverter safety (particular): IEC 62109-2:2011 — IEC 62109-2:2011 publication page. Specific MPPT range, IP66 rating and AFCI parameters: datasheet PDF confirmed at RFQ.
Rooftop mountingK2 Systems SingleRail K2SR30 + K2 SolarClamp kitCrossRail System pitched/flat-roof rail family — K2 CrossRail System (US). Roof-attach spacing, ballast / mechanical-fix verification, wind-load to SANS 10160-3 latest revision: K2SR30 manual PDF + revision number confirmed at RFQ.
DC cabling & protectionH1Z2Z2-K 1.5 kV DC PV cable, DC-rated SPD Class IIPer IEC 62930:2017 (designation cited; IEC Webstore catalogue — webstore.iec.ch — for full publication lookup).
AC switchgearMoulded-case circuit breaker + SSEG-compliant interface per NRS 097-2-1Anti-islanding required. Low-voltage switchgear reference: IEC 60947-3:2020 ed4 — IEC 60947-3:2020 ed4 publication page.

3. Import duty & HS classification

Status: duty rate to be verified against the SARS Tariff document before PO. The scenario model capex above excludes import duty and VAT uplift; landed-cost uplift must be added at PO stage. Lookup path: SARS Customs and Excise Tariff hub — sars.gov.za/customs-and-excise/tariff/.

HS classification: 8541.43 — Photovoltaic cells, whether or not assembled in modules or made up into panels (assembled module falls under 8541.43; sub-heading 8541.40 covers individual cells). Inverters typically classified under 8504.40 (static converters). Mounting structures under 7308.90. Import-control permits where applicable: ITAC — itac.org.za/import-control/.

4. Computed TCO summary (verbatim from scenario model)

TCO summary
MetricValue
CurrencyZAR
Horizon (years)25
Discount rate8.00 %
Total undiscounted cost (ZAR)9,967,417.90
Total discounted cost / PV of costs (ZAR)8,295,036.70
Total undiscounted benefit (ZAR)67,029,643.59
Total discounted benefit (ZAR)23,255,173.95
NPV (ZAR)14,960,137.26
IRR0.2231
Simple payback (year)5.19
Discounted payback (year)6.72
LCOE (ZAR/kWh)0.9303

5. Computed year-by-year cash flow (verbatim from scenario model)

Year-by-year cash flow
YearCost (ZAR)Benefit (ZAR)Net (ZAR)Discount factorDiscounted net (ZAR)Energy (kWh)
07,200,000.000.0000-7,200,000.001.00-7,200,000.000.0000
186,400.001,315,875.001,229,475.000.92591,138,402.78870,000.00
288,128.001,387,853.361,299,725.360.85731,114,305.01865,650.00
389,890.561,463,768.941,373,878.380.79381,090,628.95861,321.75
491,688.371,543,837.101,452,148.730.73501,067,372.67857,015.14
593,522.141,628,284.991,534,762.850.68061,044,533.81852,730.07
695,392.581,717,352.181,621,959.600.63021,022,109.68848,466.42
797,300.431,811,291.351,713,990.910.58351,000,097.23844,224.08
899,246.441,910,368.981,811,122.540.5403978,493.15840,002.96
9101,231.372,014,866.171,913,634.790.5002957,293.83835,802.95
10103,256.002,125,079.342,021,823.350.4632936,495.41831,623.93
11105,321.122,241,321.182,136,000.070.4289916,093.82827,465.81
12107,427.542,363,921.452,256,493.910.3971896,084.78823,328.48
13109,576.092,493,227.962,383,651.870.3677876,463.84819,211.84
14111,767.612,629,607.532,517,839.910.3405857,226.40815,115.78
15114,002.972,773,447.062,659,444.090.3152838,367.69811,040.20
16116,283.022,925,154.612,808,871.590.2919819,882.84806,985.00
17118,608.683,085,160.572,966,551.880.2703801,766.87802,950.08
18120,980.863,253,918.853,132,937.990.2502784,014.69798,935.33
19123,400.483,431,908.213,308,507.740.2317766,621.16794,940.65
20125,868.493,619,633.593,493,765.110.2145749,581.04790,965.95
21128,385.863,817,627.553,689,241.700.1987732,889.07787,011.12
22130,953.574,026,451.783,895,498.210.1839716,539.92783,076.06
23133,572.644,246,698.694,113,126.050.1703700,528.23779,160.68
24136,244.104,478,993.114,342,749.010.1577684,848.64775,264.88
25138,968.984,723,994.034,585,025.050.1460669,495.75771,388.55

6. Scenario verdicts

Scenario A — High-yield site (Limpopo / Northern Cape, ≥ 1,600 kWh/kWp), Megaflex ≥ 1.70 ZAR/kWh: GO. Yield and tariff scale factors lift the scenario model benefit stream above the tabled base case.
Scenario B — Base case as tabled (600 kWp, 1,450 kWh/kWp, Megaflex 1.55 ZAR/kWh): GO. NPV = ZAR 14,960,137, IRR = 22.31%, simple payback 5.19 yrs, discounted payback 6.72 yrs, LCOE 0.9303 ZAR/kWh. Proceed subject to (i) SSEG/Megaflex approval < 9 months, (ii) capex ≤ ZAR 12,000/kWp firm at PO, (iii) SARS duty-rate verification for HS 8541.43 before PO.
Scenario C — Low-yield OR low-tariff site (e.g. Highveld winter-shoulder, OR Ruraflex < 1.30 ZAR/kWh) with capex > ZAR 13,500/kWp: NO-GO. Discounted payback stretches beyond project horizon; LCOE approaches tariff parity; no margin for inverter replacement.

7. Use-Case Reference Datasheet

Use-Case Reference Datasheet — TradVolt / greenhouse-solar-600kwp-za / rev r9 System: 600 kWp DC, grid-tied, rooftop greenhouse mount Equipment family: LONGi Hi-MO 6 monofacial (LR7-72HGD) + Huawei SUN2000-330KTL-H1 + K2 Systems SingleRail K2SR30 Capex band: ZAR 7,200,000 (base, year 0) — sensitivity-bounded; excludes duty + VAT uplift Horizon: 25 years, real discount 8% NPV: 14,960,137 ZAR (base) IRR: 22.31% (project life 25 yr) Simple payback: 5.19 years; Discounted payback: 6.72 years LCOE: 0.9303 ZAR/kWh Duty rate: PENDING — verify via SARS Customs and Excise Tariff, HS 8541.43 Note: This is an internal use-case reference, not a third-party certification. No certificate number or issuer is implied. Validity: 12 months from datePublished, subject to Eskom Megaflex schedule revision.

8. Request a firm quotation

The figures above are use-case reference benchmarks. TradVolt routes verified RFQs to pre-computed South African EPCs with greenhouse-mount and SSEG/Megaflex licensing experience. Submit your site details for a binding offer.

Request a firm quotation — Greenhouse Solar 600 kWp (ZA)

9. Sources