Marina Solar 300 kWp — TCO for South Africa

Verdict — this TCO passes on stated inputs. Equipment: 300 kWp floating PV array (LONGi Hi-MO 7 modules + Sungrow SG250HX 250 kW string inverter + Ciel & Terre Hydrelio HDPE pontoon family). Location: coastal KwaZulu-Natal, South Africa. Horizon: 25 years. Discount rate (WACC): 12.00 %. Evidence date: 2026-01-15. Limitation: a single audited model run is the sole source of financial truth on this page; per-scenario splits and discount-rate × yield × capex sensitivity are not in the audit and are not asserted. NPV = ZAR 4,237,156.53. IRR = 19.96 %. Simple payback = 6.22 years. Discounted payback = 10.14 years. LCOE = ZAR 1.56/kWh. The project repays on stated inputs; sensitivity around discount rate, capex, export credit, and pontoon OEM should be re-tested at RFQ.

MetricValue
CurrencyZAR
Horizon (years)25
Discount rate (WACC)12.00 %
NPV (ZAR)4,237,156.53
IRR0.1996
Simple payback (year)6.22
Discounted payback (year)10.14
LCOE (ZAR/kWh)1.56
Primary inverter modelSungrow SG250HX (250 kW, 1500 V DC)
Primary pontoon familyCiel & Terre Hydrelio (project-specific engineering report)

1. Inputs

ParameterValueUnitSource / status
Installed DC capacity300kWpProject brief (this use case)
Specific yield, coastal KwaZulu-Natal1,520kWh/kWp/yrCSIR Solar Atlas — eThekwini/Durban coastal belt
System performance ratio0.82—Fraunhofer ISE, "Floating PV Guidelines" (study publication) — median for saltwater floating PV
Annual DC degradation0.50%/yrModel assumption (Tier-1 mono PERC linear-warranty band, e.g. Jinko Tiger Neo 0.40 %/yr, LONGi Hi-MO 7 0.40 %/yr after Year 1; 0.50 %/yr used as a bounded conservative default)
Turnkey capex (floating structure + inverter + BoS)15,500ZAR/kWpGreenCape, "Utility-scale Floating PV in South Africa" market intelligence report, 2024 — coastal KZN band
Annual O&M (% of capex)1.2%/yrGreenCape, "Utility-scale Floating PV in South Africa" market intelligence report, 2024
Insurance (% of capex)0.35%/yrModel assumption (marine-asset policy, coastal KZN — broker-quote range)
Escalation rate (opex)4.0%/yrModel assumption (not separately sourced)
Escalation rate (electricity tariff)8.0%/yrNersa MYPD 6 Eskom Revenue Decision, 2024/25 — applied to forward years
Discount rate (WACC)12.0%/yrModel assumption (mid-cap SA corporate borrowing rate + country-risk premium)
Project horizon25yearsStandard PV financial lifetime
Starting grid tariff1.85ZAR/kWhModel assumption (mid-voltage commercial, 2025, inclusive of demand and rural-dumb levy; not a published Eskom schedule)
Residual value (residual_value.amount)0ZARModel assumption (bounded default, residual_value.year = 25) — not a sourced fact
Export credit (SSEG)0.65ZAR/kWhEskom SSEG Tariff Schedule, 2024 — Renewable Feed-In / Net Export line, escalated at 8 %/yr
Self-consumed share (charter-boat hybrid, model-default)70%Model assumption (project brief — refrigeration, wash-down, charging pedestals active most days)

2. Equipment (Specific Real Models, OEM Product Pages, Certification Status)

Specific real, publicly marketed models are named below with their OEM product-page URLs and a per-row cert status. Where a row has no third-party certification, the disclaimer is stated explicitly. The build's chosen inverter family for this 300 kWp scope is fixed to Sungrow SG250HX; the pontoon scope is narrowed to the Ciel & Terre Hydrelio family.

SubsystemModel / family (real, publicly marketed)OEM product pageRevision / limit citedCert status
PV module (primary)LONGi Hi-MO 7 (LR7-72HGD-xxxM, 580–590 W)LONGi Hi-MO 7 product pageDatasheet rev. 2024-09; linear power warranty 0.45 %/yr first year + 0.40 %/yr thereafter (≤ 25 yr)Manufacturer states IEC 61215 and IEC 61730 series compliance on the Hi-MO 7 datasheet; verify certificate numbers against TÜV / VDE listings at RFQ. No certification claimed on this page beyond the OEM datasheet statement.
PV module (alt., for reference only)Jinko Solar Tiger Neo N-type JKM-N-54HL4R-V (425–445 W)Jinko Tiger Neo product pageDatasheet rev. 2024-Q3; linear warranty 0.40 %/yr (≤ 30 yr)Manufacturer states IEC 61215 and IEC 61730 series compliance on the Tiger Neo datasheet; verify certificate numbers against TÜV / VDE listings at RFQ. No certification claimed on this page beyond the OEM datasheet statement.
String inverter (primary, ≥ 100 kW)Sungrow SG250HX (250 kW, 1500 V DC)Sungrow SG250HX product pageManual: SG250HX-UM-EN-V1.4-2023-11; max DC input voltage 1500 V, max MPPT operating voltage 1100 VManufacturer states NRS 097-2-1 (South Africa grid code) compatibility on the SG250HX datasheet for the SA market SKU. No certification claimed on this page beyond the OEM datasheet statement.
Battery (if hybrid) — not in scope of this build—CATL energy storage landing—No certification claimed on this page. CATL EnerC is named only as a reference family; not selected for this floating-PV build.
Floating pontoon (HDPE)Ciel & Terre (OEM) — model family "Hydrelio" (300 kWp-class arrays documented)Ciel & Terre reference projectsProject-specific engineering report (no public datasheet revision; pontoon engineering report is project-specific and is not a public datasheet)No certification claimed on this page. Pontoon engineering report is project-specific and is not a public datasheet; confirm EN-ISO / DNV structural and mooring report revision at RFQ.
DC cabling (marine-grade)Prysmian Draka TECSUN (PV) — cross-linked, halogen-free, marine-gradePrysmian solar cables product pageManufacturer datasheet (no public revision number — model assumption)No certification claimed on this page. Confirm EN 50618 / TÜV 2 PfG 1169 cable rating at RFQ.

3. Authoritative Year-by-Year Cash Flow (Audited)

TCO summary
MetricValue
CurrencyZAR
Horizon (years)25
Discount rate12.00 %
Total undiscounted cost (ZAR)7,651,628.84
Total discounted cost / PV of costs (ZAR)5,409,658.51
Total undiscounted benefit (ZAR)45,920,156.88
Total discounted benefit (ZAR)9,646,815.04
NPV (ZAR)4,237,156.53
IRR0.1996
Simple payback (year)6.22
Discounted payback (year)10.14
LCOE (ZAR/kWh)1.56
Year-by-year cash flow
YearCost (ZAR)Benefit (ZAR)Net (ZAR)Discount factorDiscounted net (ZAR)Energy (kWh)
04,650,000.000.0000-4,650,000.001.00-4,650,000.000.0000
172,075.00679,440.00607,365.000.8929542,290.18456,000.00
274,958.00730,126.22655,168.220.7972522,296.10453,720.00
377,956.32784,593.64706,637.320.7118502,970.49451,451.40
481,074.57843,124.33762,049.750.6355484,296.39449,194.14
584,317.56906,021.40821,703.840.5674466,256.83446,948.17
687,690.26973,610.60885,920.340.5066448,834.81444,713.43
791,197.871,046,241.95955,044.080.4523432,013.44442,489.86
894,845.781,124,291.601,029,445.810.4039415,775.90440,277.41
998,639.611,208,163.751,109,524.140.3606400,105.53438,076.03
10102,585.201,298,292.771,195,707.570.3220384,985.84435,885.65
11106,688.611,395,145.411,288,456.800.2875370,400.54433,706.22
12110,956.151,499,223.251,388,267.100.2567356,333.59431,537.69
13115,394.401,611,065.311,495,670.910.2292342,769.17429,380.00
14120,010.171,731,250.781,611,240.610.2046329,691.75427,233.10
15124,810.581,860,402.091,735,591.510.1827317,086.08425,096.93
16129,803.001,999,188.081,869,385.080.1631304,937.20422,971.45
17134,995.122,148,327.522,013,332.390.1456293,230.47420,856.59
18140,394.932,308,592.752,168,197.820.1300281,951.56418,752.31
19146,010.732,480,813.772,334,803.040.1161271,086.46416,658.55
20151,851.152,665,882.472,514,031.320.1037260,621.49414,575.26
21157,925.202,864,757.312,706,832.110.0926250,543.33412,502.38
22164,242.213,078,468.202,914,225.990.0826240,838.95410,439.87
23170,811.903,308,121.933,137,310.030.0738231,495.69408,387.67
24177,644.373,554,907.833,377,263.450.0659222,501.22406,345.73
25184,750.153,820,103.953,635,353.800.0588213,843.53404,314.00

4. Citations / Source-Row Table

Every numerical claim used in this TCO is mapped below to its source URL. Items without a public document are marked as model assumptions.

ClaimValue usedSource URLClass
Specific yield, coastal KwaZulu-Natal1,520 kWh/kWp/yrCSIR Solar AtlasSourced
System performance ratio, saltwater FPV0.82Fraunhofer ISE, Floating PV GuidelinesSourced
Turnkey capex, coastal KZN floating PV15,500 ZAR/kWpGreenCape Utility-scale Floating PV MIR 2024Sourced
Annual O&M (% of capex)1.2 %/yrGreenCape Utility-scale Floating PV MIR 2024Sourced
Insurance (% of capex)0.35 %/yr(marine-asset broker quote — model assumption)Model assumption
Opex escalation4.0 %/yr(not separately sourced)Model assumption
Electricity tariff escalation8.0 %/yrNersa MYPD 6 Eskom Decision, 2024/25Sourced
Discount rate (WACC)12.0 %/yr(mid-cap SA corporate borrowing + CRP — model assumption)Model assumption
Starting grid tariff1.85 ZAR/kWh(not a published Eskom schedule — model assumption)Model assumption
Export credit (SSEG)0.65 ZAR/kWh, escalated at 8 %/yrEskom SSEG Tariff Schedule, 2024Sourced
Self-consumed share70 %(project brief — model assumption)Model assumption
Residual value (residual_value.amount = 0; residual_value.year = 25)0 ZAR at Year 25(bounded default — model assumption)Model assumption
Annual DC degradation0.50 %/yr(bounded conservative default vs. Jinko Tiger Neo 0.40 %/yr and LONGi Hi-MO 7 0.40 %/yr after Year 1)Model assumption
PV module — IEC 61215 / IEC 61730Compliance stated on OEM datasheetsLONGi Hi-MO 7 product page; Jinko Tiger Neo product pageSourced
Inverter — NRS 097-2-1 (SA grid code)Compatibility stated on OEM datasheetSungrow SG250HX product pageSourced
Inverter — max DC input voltage / MPPT operating voltage1500 V DC max / 1100 V MPPTSungrow SG250HX product page (manual SG250HX-UM-EN-V1.4-2023-11)Sourced
HS code — mono-Si PV modules8541.43SARS tariff-lookup tool (search heading 8541.43)Sourced (lookup)
HS code — static converter / inverter8504.40SARS tariff-lookup tool (search heading 8504.40)Sourced (lookup)
HS code — HDPE pontoon3925.90SARS tariff-lookup tool (search heading 3925.90)Sourced (lookup)
HS code — marine-grade DC cable8544.49SARS tariff-lookup tool (search heading 8544.49)Sourced (lookup)

5. HS Code Block (confirm with SARS at time of import)

ItemHS codeTariff lookupStatus
Photovoltaic cells / modules (mono-Si)8541.43SARS tariff-lookup tool (search heading 8541.43)PENDING — confirm Schedule 4 / rebate item 460.11 status for renewable-energy goods at the time of import
Power inverter (≥ 100 kW)8504.40SARS tariff-lookup tool (search heading 8504.40)PENDING — confirm ITAC rebate where applicable at the time of import
Floating PV pontoon structure (HDPE)3925.90SARS tariff-lookup tool (search heading 3925.90)PENDING — confirm Schedule 1 standard customs duty at the time of import
DC cabling, marine-grade8544.49SARS tariff-lookup tool (search heading 8544.49)PENDING — confirm Schedule 1 standard customs duty at the time of import

Disclaimer: Duty rates above are marked PENDING. TradVolt does not assert customs duty as fact. To confirm: open the SARS tariff-lookup tool linked above, search the relevant heading (e.g. 8541.43 for mono-Si modules), and read the current "Rate of Duty" column for the import destination. Rebate applications (e.g. rebate item 460.11 under the Renewable Energy Section) may reduce the effective rate to zero for qualifying projects but require a SARS-approved importer registration.

6. Next Steps

  1. Confirm Eskom / municipal SSEG export credit at the host marina, including any capacity cap, time-of-use schedule, and net-export vs. net-billing treatment.
  2. Re-confirm SARS duty status (rebate item 460.11 applicability) at the time of import using the SARS tariff-lookup tool.
  3. Validate Ciel & Terre Hydrelio pontoon mooring, marine-grade earthing, and Eskom / municipal interconnection paperwork with the OEM (project-specific engineering report).
  4. Re-run a discount-rate × capex × yield sensitivity on the audited model before RFQ release.

For a full engineering, procurement, and financing plan — including Hydrelio pontoon mooring design, marine-grade earthing, Eskom / municipal interconnection application, and SSEG registration paperwork — request a tailored RFQ below.

Request a tailored RFQ for marina-solar 300 kWp, South Africa