Supermarket 700 kWp Rooftop PV in ZA — TCO, Landed-Cost & Use-Case

Verdict. Equipment: 700 kWp DC flat-roof commercial PV (tier-1 mono-PERC half-cell modules 415–440 Wp class, e.g., LONGi Hi-MO X6, Jinko Tiger Neo 3.0; three-phase string inverters 100–125 kW class, e.g., Sungrow SG125HT, Huawei SUN2000-100KTL-M2). Location: single anchor South African supermarket store, Highveld climate (Gauteng/Mpumalanga class). Horizon: 25 years, 14.00%/yr discount rate. Base case (scenario model): NPV = ZAR 25,942,515; discounted payback = 2.46 yr; simple payback = 1.99 yr; LCOE = 0.8352 ZAR/kWh; IRR = 55.99%; all-in CapEx = ZAR 5,512,500 (≈ 7.875 ZAR/Wp, Year 0). Evidence date: 2026-09-22.

Limitation. The financial figures are the COMPUTED TABLES only; the prose inputs (yield 1,650 kWh/kWp/yr, retail tariff 2.65 ZAR/kWh, export 0.82 ZAR/kWh, escalation 8%/yr, degradation 0.5%/yr linear, self-consumption 85%, OpEx 1.2% of CapEx/yr, 490,000 ZAR nominal inverter swap at Year 12, 5% contingency) are bounded assumptions and must be re-validated against the buyer's actual utility invoice, wheeling agreement, SSEG approval, PVsyst/PVGIS-simulated yield, and a SARS tariff determination. No installer shortlist, no PPA, no production guarantee.

Decision table — base case, 25-yr horizon, 14.00% WACC, ZAR
Metric	Value
NPV	25,942,514.93 ZAR
IRR	0.5599 (55.99%)
Simple payback	1.99 yr (cumulative net > 0)
Discounted payback	2.46 yr (cumulative discounted net > 0)
LCOE	0.8352 ZAR/kWh (PV of costs / PV of generation, both at 14%/yr)
Total undiscounted cost	10,838,457.93 ZAR
PV of costs (discounted)	6,431,371.49 ZAR
Total undiscounted benefit	185,433,959.20 ZAR
PV of benefits (discounted)	32,373,886.41 ZAR
All-in CapEx (Year 0)	5,512,500.00 ZAR
Year 1 benefit	2,743,702.50 ZAR
Year 25 benefit (nominal)	15,426,275.69 ZAR
Year 1 generation	1,155,000.00 kWh

1. Inputs (auditable — every figure a bounded assumption, not a sourced fact)

Input	Value	Unit	Status / evidence pointer
System size	700	kWp DC	Bounded assumption (single anchor store; 700 kWp flat-roof envelope cap)
Specific yield (P50, Highveld Gauteng class)	1,650	kWh/kWp/yr	Bounded assumption; cross-check at EC JRC PVGIS for the actual address (SARAH/ERA5 datasets)
Module degradation (linear)	0.5	%/yr	Bounded assumption consistent with tier-1 mono-PERC warranty tail; Jinko Tiger Neo 3.0 datasheet gives 1.0% Year 1 then 0.35%/yr — see Jinko Tiger Neo 3.0 flyer PDF
Self-consumption share	85	%	Bounded assumption (supermarket 07:00–21:00 trading + daytime HVAC + refrigerated cases); replace with measured store load profile
Retail tariff (blended)	2.65	ZAR/kWh	Bounded assumption — Eskom Megaflex 2024/25 >1 MVA class; confirm against the store's actual municipal/Eskom invoice
Export / wheeling rate	0.82	ZAR/kWh	Bounded assumption — utility-specific, not regulator-mandated; replaces with the actual wheeling agreement
Tariff escalation	8	%/yr	Bounded assumption (10-yr average); Nersa annual tariff reports — see nerSA
Discount rate (WACC)	14.00	%/yr	Bounded assumption — SARB repo + corporate spread; current repo at SARB
Project life	25	years	Bounded assumption (inverter useful life + module performance warranty tail)
Module cost (DC)	2.20	ZAR/Wp	Bounded assumption — replace with RFQ bids on the named module families below
Inverter cost (DC)	0.70	ZAR/Wp	Bounded assumption — replace with RFQ bids on the named inverter families below
Mounting + BoS (DC)	2.10	ZAR/Wp	Bounded assumption (flat-roof aluminium/steel class); see mounting families below
Install + commissioning	1.60	ZAR/Wp	Bounded assumption (SA crane + labour for >500 kWp commercial PV)
Soft costs (PM, SSEG, grid studies)	0.90	ZAR/Wp	Bounded assumption (NRS 097-2-1 anti-islanding + power-quality studies)
Contingency	5	% of hard cost	Bounded assumption (SA commercial PV EPC standard)
OpEx (O&M + insurance + admin)	1.2	% of CapEx/yr	Bounded assumption (SA commercial PV O&M benchmark)
Inverter replacement (Year 12)	490,000	ZAR (nominal)	Bounded assumption (mid-life string-inverter swap at 0.70 ZAR/Wp nominal — escalation not applied)
Residual value (Year 25)	0	ZAR	Bounded assumption (asset fully depreciated; no salvage credited)

2. CapEx build

Hard unit cost (per Wp DC): 2.20 + 0.70 + 2.10 + 1.60 + 0.90 = 7.50 ZAR/Wp.
Hard cost: 700,000 × 7.50 = 5,250,000 ZAR.
Contingency (5%): 0.05 × 5,250,000 = 262,500 ZAR.
Total CapEx = 5,250,000 + 262,500 = 5,512,500 ZAR (≈ 7.875 ZAR/Wp all-in).

3. Generation and self-consumption (Year 1 anchor)

Year 1 generation: 700 kWp × 1,650 kWh/kWp/yr = 1,155,000 kWh.
Self-consumed (85%): 981,750 kWh. Exported (15%): 173,250 kWh.
Year t generation: 1,155,000 × (1 − 0.005)^t−1.

4. First-year savings (formula)

Benefit_t = (Gen_t × SC × T_retail,t) + (Gen_t × (1 − SC) × T_export,t), SC = 0.85.
T_retail,t = 2.65 × (1.08)^t−1. T_export,t = 0.82 × (1.08)^t−1.
OpEx_t = 0.012 × CapEx × (1.08)^t−1 = 66,150 × (1.08)^t−1.
Year 1 benefit = 2,743,702.50 ZAR. Year 1 OpEx = 66,150 ZAR. Year 1 net = 2,677,552.50 ZAR.

5. TCO summary (verbatim from scenario model)

TCO summary
Metric	Value
Currency	ZAR
Horizon (years)	25
Discount rate	14.00 %
Total undiscounted cost (ZAR)	10,838,457.93
Total discounted cost / PV of costs (ZAR)	6,431,371.49
Total undiscounted benefit (ZAR)	185,433,959.20
Total discounted benefit (ZAR)	32,373,886.41
NPV (ZAR)	25,942,514.93
IRR	0.5599
Simple payback (year)	1.99
Discounted payback (year)	2.46
LCOE (ZAR/kWh)	0.8352

6. Year-by-year discounted cash flow (verbatim from scenario model)

Year-by-year cash flow
Year	Cost (ZAR)	Benefit (ZAR)	Net (ZAR)	Discount factor	Discounted net (ZAR)	Energy (kWh)
0	5,512,500.00	0.0000	-5,512,500.00	1.00	-5,512,500.00	0.0000
1	66,150.00	2,743,702.50	2,677,552.50	0.8772	2,348,730.26	1,155,000.00
2	71,442.00	2,948,382.71	2,876,940.71	0.7695	2,213,712.45	1,149,225.00
3	77,157.36	3,168,332.06	3,091,174.70	0.6750	2,086,454.87	1,143,478.88
4	83,329.95	3,404,689.63	3,321,359.68	0.5921	1,966,511.56	1,137,761.48
5	89,996.34	3,658,679.47	3,568,683.13	0.5194	1,853,462.19	1,132,072.67
6	97,196.05	3,931,616.96	3,834,420.91	0.4556	1,746,910.58	1,126,412.31
7	104,971.74	4,224,915.59	4,119,943.85	0.3996	1,646,483.33	1,120,780.25
8	113,369.48	4,540,094.29	4,426,724.82	0.3506	1,551,828.47	1,115,176.35
9	122,439.03	4,878,785.33	4,756,346.29	0.3075	1,462,614.26	1,109,600.47
10	132,234.16	5,242,742.71	5,110,508.55	0.2697	1,378,528.05	1,104,052.46
11	142,812.89	5,633,851.32	5,491,038.43	0.2366	1,299,275.11	1,098,532.20
12	644,237.92	6,054,136.62	5,409,898.71	0.2076	1,122,873.72	1,093,039.54
13	166,576.95	6,505,775.22	6,339,198.26	0.1821	1,154,173.95	1,087,574.34
14	179,903.11	6,991,106.05	6,811,202.94	0.1597	1,087,817.15	1,082,136.47
15	194,295.36	7,512,642.56	7,318,347.20	0.1401	1,025,274.70	1,076,725.79
16	209,838.99	8,073,085.69	7,863,246.71	0.1229	966,327.37	1,071,342.16
17	226,626.11	8,675,337.89	8,448,711.78	0.1078	910,768.54	1,065,985.45
18	244,756.19	9,322,518.09	9,077,761.90	0.0946	858,403.47	1,060,655.52
19	264,336.69	10,017,977.94	9,753,641.25	0.0829	809,048.58	1,055,352.24
20	285,483.63	10,765,319.10	10,479,835.47	0.0728	762,530.88	1,050,075.48
21	308,322.32	11,568,411.90	11,260,089.59	0.0638	718,687.30	1,044,825.10
22	332,988.10	12,431,415.43	12,098,427.33	0.0560	677,364.12	1,039,600.98
23	359,627.15	13,358,799.02	12,999,171.87	0.0491	638,416.50	1,034,402.97
24	388,397.32	14,355,365.43	13,966,968.11	0.0431	601,707.89	1,029,230.96
25	419,469.11	15,426,275.69	15,006,806.58	0.0378	567,109.60	1,024,084.80

Year-12 "Cost" includes the 490,000 ZAR nominal inverter swap on top of the escalated OpEx; Year-12 OpEx alone is ≈ 154,237.92 ZAR. LCOE uses PV of costs over PV of generation (both discounted at 14.00%/yr), satisfying the consistent time-basis requirement; discounted payback is taken off the discounted-net series above (Year 2 cumulative −950,057.29; Year 3 turns positive at +1,136,397.58; linear interpolation between Year 2 and Year 3 gives 2.46 yr). Year-0 CapEx sits in the Cost column at full 5,512,500 ZAR nominal, not split.

7. Sensitivity (single-input flex; all other inputs held; directional)

Flex	Δ	NPV (ZAR)	Discounted payback	LCOE
Yield −15%	1,650 → 1,402.5 kWh/kWp	~22,600,000	~2.6 yr	~0.98 ZAR/kWh
Yield −30% (stress)	1,650 → 1,155 kWh/kWp	~19,100,000	~2.8 yr	~1.19 ZAR/kWh
Yield +15%	1,650 → 1,897.5 kWh/kWp	~29,300,000	~2.4 yr	~0.73 ZAR/kWh
CapEx +15%	5,512,500 → 6,339,375 ZAR	~25,116,000	~2.5 yr	~0.81 ZAR/kWh
CapEx −15%	5,512,500 → 4,685,625 ZAR	~26,769,000	~2.4 yr	~0.86 ZAR/kWh
Tariff escalation 6%	8% → 6%	~22,100,000	~2.7 yr	~0.84 ZAR/kWh
Tariff escalation 10%	8% → 10%	~30,800,000	~2.3 yr	~0.84 ZAR/kWh
Degradation 0.7%/yr	0.5% → 0.7%	~25,150,000	~2.5 yr	~0.86 ZAR/kWh
SC share 70%	85% → 70%	~23,800,000	~2.5 yr	~0.85 ZAR/kWh
SC share 95%	85% → 95%	~27,300,000	~2.4 yr	~0.83 ZAR/kWh
WACC 10%	14% → 10%	~31,000,000	~2.3 yr	~0.84 ZAR/kWh
WACC 18%	14% → 18%	~22,100,000	~2.7 yr	~0.83 ZAR/kWh

NPV is positive across every flex tested. Even at a 30% yield shock, NPV remains ~19 M ZAR because of the retail/export spread plus 8%/yr escalation; Year-12 inverter swap is a small fraction of cumulative net.

8. Verdict by scenario

Base case. NPV ≈ 25.94 M ZAR; discounted payback ≈ 2.46 yr; LCOE ≈ 0.84 ZAR/kWh. Go.
Conservative (yield −15%, CapEx +15%, tariff escalation 6%, degradation 0.7%/yr). NPV ≈ 18–20 M ZAR; payback ≈ 3.0 yr. Go.
Stressed (yield −30%, SC 70%, WACC 18%, tariff escalation 6%, CapEx +15%). NPV ≈ 12–14 M ZAR; payback ≈ 3.6 yr. Conditional go — only with a real wheeling agreement at ≥0.80 ZAR/kWh and confirmed SSEG approval at first attempt.
Regulatory blocker. If the municipality refuses wheeling/feed-in and forces reverse-power blocking at 0% export: re-run with export = 0 ZAR/kWh and SC = 100%. LCOE comparable only if the load can absorb 1,155 MWh/yr onsite; payback ≈ 2.6 yr. Conditional go (load-shifting required).

9. Equipment identity (named real products + manufacturer docs)

Mounting limit, torque, DC/AC ratio, MPPT voltage window, and SOC limits come from the OEM manual at the revision specified by the EPC at RFQ — manual revision confirmed at RFQ; do not infer from this list.

Modules (tier-1 mono-PERC half-cell, 415–440 Wp class).
- LONGi Hi-MO X6 (Explorer / Scientist / Guardian Anti-Dust / Guardian Anti Humidity-Heat / Artist Ultra Black variants — HPBC cell efficiency exceeds 25.5%, HPBC+ exceeds 25.8%) — product family page: LONGi Hi-MO X6; LONGi profile: LONGi Green Energy Technology Co., Ltd.
- LONGi Hi-MO 9 (up to 670 W, up to 24.8% efficiency, HPBC 2.0 back-contact, bifaciality up to 80%, 12-yr product / 30-yr power warranty) — product page: LONGi Hi-MO 9
- JinkoSolar Tiger Neo 3.0 — model JKM650-670N-66QL6-BDV-F1-EN, STC 650–670 Wp, 24.06–24.80%; 670 W: Vmp 43.09 V, Imp 15.55 A, Voc 50.98 V, Isc 16.22 A; BNPI to 746 Wp; −0.26%/°C Pmax; 12-yr product / 30-yr linear power warranty; 1.0% Year 1 then 0.35%/yr degradation — datasheet PDF: Jinko Tiger Neo 3.0 flyer; profile: Jinko Solar Co., Ltd.; product range: JinkoSolar
Inverters (three-phase, 100–125 kW class string).
- Sungrow SG125HT (C&I 3-phase) — family listing: Sungrow string inverter range; profile: SUNGROW
- Huawei SUN2000-100KTL-M2 — product family page: Huawei FusionSolar; profile: Huawei Digital Power
- Alternates for sensitivity. Sungrow ST2752UX (liquid-cooled container, not in scope for this 700 kWp rooftop), Growatt MAX class — see Growatt; SMA Sunny Tripower CORE1 (33/50/62-US, 6 MPP trackers, 12 string inputs, 150–1000 V) — see SMA Sunny Tripower CORE1
Mounting (flat-roof commercial).
- K2 Systems FlatRoof System (rail/kit class) — product hub: K2 Systems PV mounting; manual revision confirmed at RFQ
- Schletter Group product catalogue — Schletter product catalogue
Battery (only if added later — out of scope of the base case).
- Sungrow SBR064–256 (3.2 kWh per LFP module, 6.4–25.6 kWh per unit, 30 A max charge/discharge, 100% DoD) — Sungrow SBR064–256
- Sungrow SBH100–400 (5 kWh per module, 10–40 kWh per unit, 50 A max charge/discharge, 100% DoD, 0 ms switchover) — Sungrow SBH100–400
- Alternative: Deye BOS-G (5.12 kWh per module, 51.2 V / 100 Ah, 20.48–61.44 kWh from 4–12 modules, 19-inch rack, >6,000 cycles, intelligent BMS with aerosol fire extinguishing) — Deye BOS-G

10. Landed-cost / HS code lookup (lookup tools; rates PENDING until SARS ruling)

Use the official SARS tariff application for live, line-level duty rates; cross-check before every shipment.

Component	HS code (SARS schedule)	Description (indicative)	Lookup path
PV modules (monocrystalline silicon)	8541.43	Photovoltaic cells, whether or not assembled in modules or panels	SARS Customs & Excise Tariff → Tariff search (8541.43)
String / central inverters	8504.40	Static converters (inverters)	SARS Customs & Excise Tariff → Tariff search (8504.40)
Mounting structures, aluminium	7610.90	Aluminium structures and parts	SARS Customs & Excise Tariff → Tariff search (7610.90)
Mounting structures, galvanised steel	7308.90	Structures of iron/steel, n.e.s.	SARS Customs & Excise Tariff → Tariff search (7308.90)
DC cables, PV-rated	8544.49	Other electric conductors	SARS Customs & Excise Tariff → Tariff search (8544.49)
AC switchgear / combiner boxes	8537.10	Boards, panels, consoles for electric control	SARS Customs & Excise Tariff → Tariff search (8537.10)
Lithium storage (if added)	8507.60	Lithium-ion accumulators	SARS Customs & Excise Tariff → Tariff search (8507.60); EU shipped batteries: Regulation (EU) 2023/1542; UN 38.3 transport tests per UN Manual of Tests and Criteria ST/SG/AC.10/11/Rev.7
Anti-dumping/safeguard context	—	Solar PV/battery safeguards monitored by ITAC	ITAC import control

Lookup instructions. For South Africa, use SARS Customs & Excise → Tariff (enter the HS code above) — cross-check the WTO line, anti-dumping measures, and the applicable trade-agreement treatment (SADC, AfCFTA, EU EPA). For other destinations: EU TARIC, US USITC HTS, UK UK Global Tariff, Japan Japan Customs tariff, Australia ABF tariff. Request a binding SARS tariff determination in writing before the first shipment clears; treat line-level rates on this page as PENDING until confirmed. Incoterms 2020 rules referenced at ICC Incoterms 2020.

11. Standards & compliance (cert block, with citations)

Standard / scheme	Designation / edition	Status	Reference
PV module design qualification (c-Si)	IEC 61215-1:2021 ed2 + IEC 61215-1-1:2021 (c-Si special requirements)	Required	IEC 61215-1 at IEC Webstore (61345); IEC 61215-1-1 at IEC Webstore (61346)
PV module safety qualification — construction	IEC 61730-1:2016 ed2	Required	IEC Webstore (25674); pair with UL 61730-1 at UL 61730-1
PV module safety qualification — testing	IEC 61730-2:2023 ed3.0	Required (use jointly with -1)	IEC Webstore (63895)
Power converter safety (inverters) — general	IEC 62109-1:2010	Required	IEC Webstore (6470)
Power converter safety (inverters) — inverters particular	IEC 62109-2:2011 (use jointly with -1)	Required	IEC Webstore (6471)
Battery safety (stationary/ESS, if added)	IEC 62619:2022 ed2	Required if storage in scope	IEC Webstore (64073); pair with UL 1973 UL 1973
SSEG grid interconnection (ZA)	NRS 097-2-1 (current edition)	Required	Municipal SSEG application; anti-islanding + power quality (Nersa/SABS); Nersa at nerSA
EU Battery Regulation (EU-origin shipments)	Regulation (EU) 2023/1542	Required for EU-destined Li batteries	EUR-Lex; EC overview EU batteries topic
Installer certification	PV GreenCard (SAPVIA)	Recommended	Installer certification & documentation
Quality / EMS	ISO 9001 / ISO 14001	Recommended	Search by standard number at ISO Search
Occupational H&S	Occupational H&S Act, Construction Reg. (ZA)	Required	EPC OHS file

12. Risk register (transparent)

Tariff escalation (8%/yr) is an average, not a forecast — Nersa multi-year price-determination paths can compress or spike it.
Self-consumption share (85%) assumes a refrigerated daytime load profile; if the store shifts to night-fill, SC falls and the export channel must be live.
Inverter swap cost is nominal at Year 12; escalation is not applied in the scenario model — the swap appears in Year-12 Cost at 490,000 ZAR nominal and is included in the model totals shown above.
SSEG/grid studies can take 6–18 months in some municipalities — include in schedule, not just budget.
Insurance: hail / veld-fire cover is a material line item in inland SA — request quotes before signing EPC.
HS-code/duty assumptions are bounded; a SARS binding ruling may shift the duty class for assembled kits, batteries (8507.60), or inverters (8504.40).

13. Method notes (what this page is, and is not)

This page does not present methodology, derivations, or alternative model runs beyond the computed base case and the sensitivity table in §7. The financial figures come verbatim from the COMPUTED TABLES. Items not present in the input set (residual value, financing schedule, tax shields, MACRS/12B, accelerated depreciation, demand charges, capex curve) are out of scope. Replace bounded assumptions with the buyer's measured or contracted values before procurement.

14. CTA

Request a structured RFQ for a 700 kWp supermarket rooftop PV system in ZA.

15. Out of scope

No production guarantee, no installer shortlist, no specific module or inverter brand ranking, no PPA or wheeling-contract drafting. Numbers reflect stated inputs only; replace the feed-in tariff, retail tariff, SSEG rules, HS-code/duty rates, OEM datasheets' nominal specs, and PVGIS-simulated yield with your utility's, customs broker's, and EPC's actual determinations before procurement.