Fuel Station Solar 80 kWp in ZA — Total Cost of Ownership (12-Year Horizon)
Headline verdict (mid scenario, 8% annual tariff escalation, 12-year horizon, discount rate 6.00% real): GO. Simple payback 6.24 yr; discounted payback 7.67 yr; NPV ZAR 758,814; IRR 14.62%; LCOE ZAR 1.39/kWh. Equipment: 188 × Jinko Solar Tiger Neo JKM425N-54HL4R-V monocrystalline modules (80 kWp DC) with one Sungrow SG50CX three-phase string inverter (50 kW AC). Location: Gauteng Highveld, South Africa. Evidence date: 2026-09-22. Limitation: SARS customs duties on the imported BoS are PENDING lookup (no duty rate applied).
| Item | Value |
|---|---|
| Equipment | 80 kWp DC rooftop PV (188 × Jinko Tiger Neo 425 W) + 1 × Sungrow SG50CX (50 kW AC) |
| Location | Gauteng Highveld, South Africa |
| Horizon | 12 years |
| Discount rate | 6.00% real |
| Tariff escalation (mid) | 8% / yr (Megaflex reference) |
| Simple payback | 6.24 yr |
| Discounted payback | 7.67 yr |
| NPV | ZAR 758,813.89 |
| IRR | 14.62% |
| LCOE | ZAR 1.39 / kWh |
| Verdict | GO |
| Evidence date | 2026-09-22 |
| Limitation | SARS import duty PENDING; no load-shedding derate applied |
1. Site and Equipment Inputs
| Input | Value | Unit | Source / note |
|---|---|---|---|
| PV peak capacity (DC) | 80.0 | kWp | System spec (188 modules × 425 Wp) |
| Module family | Jinko Solar Tiger Neo JKM425N-54HL4R-V | — | JinkoSolar product index — datasheet PDF confirmed at RFQ |
| Module certifications | IEC 61215:2021; IEC 61730-1:2016 | — | IEC Webstore catalogue — certificate holder, scope and validity to be requested at RFQ |
| Inverter | Sungrow SG50CX (50 kW AC, three-phase string) | — | Sungrow product index — datasheet PDF confirmed at RFQ |
| Inverter certifications | IEC 62109-1:2010; IEC 62109-2:2011 | — | IEC Webstore catalogue — certificate holder, scope and validity to be requested at RFQ |
| Mounting (assumed) | K2 Systems pitched-roof rail kit (model confirmed at RFQ) | — | K2 Systems product index |
| Annual specific yield | 1,560 | kWh / kWp / yr | SANEA South African Solar PV Map 2023 — Gauteng Highveld zone |
| Annual generation Year 1 | 124,800 | kWh / yr | = 80 × 1,560 |
| Self-consumed share | 0.92 | — | Model assumption — bounded default for forecourt load profile |
| Module degradation | 0.005 | / yr | Model assumption — linear, per Jinko Tiger Neo datasheet family convention |
| Capex (modules, inverter, mounting, BoS, install) | 1,200,000 | ZAR | TradVolt ZA rooftop indicative range, 2024 — see RFQ |
| Annual O&M (insurance, cleaning, inverter reserve) | 24,000 | ZAR / yr | TradVolt ZA rooftop indicative range, 2024 |
| Eskom tariff Year-1 (Megaflex, capacity+energy) | 1.55 | ZAR / kWh | Eskom tariffs hub (2024/25 Charge Book schedule; historic PDF superseded) (Megaflex reference) |
| Tariff escalation (mid scenario) | 0.08 | / yr | Model assumption — bounded default |
| Discount rate (post-tax real) | 0.06 | — | Model assumption — indicative ZA corporate hurdle rate |
| Horizon | 12 | years | Typical rooftop PV economic life to first inverter replacement |
| Residual value | PENDING | ZAR | Model assumption — bounded default; not applied to NPV (terminal value excluded) |
| Residual value year | PENDING | year | Model assumption — bounded default |
| PV export tariff | PENDING | ZAR / kWh | Model assumption — bounded default; surplus export not credited in the run below |
| Self-consumed export share | 0.08 | — | Model assumption (1 − self-consumed share) |
2. TCO Summary (scenario model — computed)
| Metric | Value |
|---|---|
| Currency | ZAR |
| Horizon (years) | 12 |
| Discount rate | 6.00 % |
| Total undiscounted cost (ZAR) | 1,521,890.15 |
| Total discounted cost / PV of costs (ZAR) | 1,421,833.61 |
| Total undiscounted benefit (ZAR) | 3,280,212.37 |
| Total discounted benefit (ZAR) | 2,180,647.50 |
| NPV (ZAR) | 758,813.89 |
| IRR | 0.1462 |
| Simple payback (year) | 6.24 |
| Discounted payback (year) | 7.67 |
| LCOE (ZAR/kWh) | 1.39 |
3. Year-by-Year Cash Flow (scenario model — computed)
| Year | Cost (ZAR) | Benefit (ZAR) | Net (ZAR) | Discount factor | Discounted net (ZAR) | Energy (kWh) |
|---|---|---|---|---|---|---|
| 0 | 1,200,000.00 | 0.0000 | -1,200,000.00 | 1.00 | -1,200,000.00 | 0.0000 |
| 1 | 24,000.00 | 178,464.00 | 154,464.00 | 0.9434 | 145,720.75 | 124,800.00 |
| 2 | 24,480.00 | 191,777.41 | 167,297.41 | 0.8900 | 148,894.10 | 124,176.00 |
| 3 | 24,969.60 | 206,084.01 | 181,114.41 | 0.8396 | 152,067.15 | 123,555.12 |
| 4 | 25,468.99 | 221,457.88 | 195,988.88 | 0.7921 | 155,241.55 | 122,937.34 |
| 5 | 25,978.37 | 237,978.63 | 212,000.26 | 0.7473 | 158,418.93 | 122,322.66 |
| 6 | 26,497.94 | 255,731.84 | 229,233.90 | 0.7050 | 161,600.85 | 121,711.04 |
| 7 | 27,027.90 | 274,809.44 | 247,781.54 | 0.6651 | 164,788.87 | 121,102.49 |
| 8 | 27,568.46 | 295,310.22 | 267,741.76 | 0.6274 | 167,984.49 | 120,496.98 |
| 9 | 28,119.83 | 317,340.36 | 289,220.53 | 0.5919 | 171,189.19 | 119,894.49 |
| 10 | 28,682.22 | 341,013.95 | 312,331.73 | 0.5584 | 174,404.41 | 119,295.02 |
| 11 | 29,255.87 | 366,453.59 | 337,197.72 | 0.5268 | 177,631.56 | 118,698.54 |
| 12 | 29,840.98 | 393,791.03 | 363,950.05 | 0.4970 | 180,872.02 | 118,105.05 |
4. Assumptions, Scope and Limitations
- Equipment family: 188 × Jinko Solar Tiger Neo JKM425N-54HL4R-V (425 Wp monocrystalline, half-cut N-type) and 1 × Sungrow SG50CX three-phase string inverter. DC/AC ratio ≈ 1.60; AC output limited to 50 kW by inverter nameplate. Mounting assumed K2 Systems pitched-roof rail kit (exact rail/clamp model and torque values confirmed at RFQ).
- Module safety and performance: Jinko Tiger Neo family certified to IEC 61215:2021 (design qualification) and IEC 61730-1:2016 (PV module safety qualification, Part 1) — see IEC Webstore catalogue. Certificate holder, scope and validity to be requested at RFQ.
- Inverter safety: Sungrow SG50CX certified to IEC 62109-1:2010 and IEC 62109-2:2011 (safety of power converters for use in photovoltaic power systems) — see IEC Webstore catalogue. Certificate holder, scope and validity to be requested at RFQ.
- Tariff: Year-1 Megaflex capacity+energy reference price taken from the Eskom Tariff & Charge Book 2024/25 Schedule of Standard Prices — Eskom Tariff & Charge Book 2024/25 PDF.
- Irradiance: 1,560 kWh/kWp/yr for Gauteng Highveld, per SANEA South African Solar PV Map 2023 — SANEA. Coastal and Highveld Karoo sites deviate.
- Capex and O&M: indicative ZA rooftop range, 2024; firm quotes via /rfq/.
- Discount rate: 6.00% real, post-tax, indicative ZA corporate hurdle rate (model assumption).
- No load-shedding derate: savings assume the inverter is not curtailed during Stage 6+ outages. Actual delivery may be lower.
- Residual value, residual year, PV export tariff: PENDING bounded defaults; not applied to the NPV above (no terminal value credited; surplus export share assumed unremunerated in this run).
- HS codes and import duty: PENDING lookup. Use SARS customs & excise search to confirm duty rate, anti-dumping measures and VAT treatment before procurement.
5. Harmonised System (HS) Reference — PENDING
- PV modules (silicon crystalline): HS heading 8541.43 — duty rate PENDING. Confirm at SARS customs & excise.
- PV inverters: HS heading 8504.40 — duty rate PENDING. Confirm at SARS customs & excise.
- Mounting structures (aluminium/steel): HS headings 7610 / 7308 — duty rate PENDING. Confirm at SARS customs & excise.
- DC cabling (PV-rated): HS heading 8544.60 — duty rate PENDING. Confirm at SARS customs & excise.
6. Request a Firm Quote
For a capex and O&M offer tailored to canopy area, azimuth, roof-loading survey and SARS duty position, use the tradvolt.com RFQ form.
Reviewed by muse-ba · tradvolt.com green-tech desk.