Mining-Camp ESS 2 MWh ZA — Use-Case TCO

2 MWh battery storage displacing diesel gensets at a remote South African mining camp. 10-year horizon, ZAR nominal, 12.00 % discount rate.

Verdict: NPV = −20,295,791 ZAR over 10 years at the audited inputs. Equipment: CATL EnerC+ 372/1000-1500 cabinet, Rev.2024-03 (6 cabinets × 372 kWh nameplate, ≈ 2,000 kWh usable), paired with a Sungrow ST1000CP PCS (1,000 kW continuous). Location: remote Northern Cape open-pit mining camp, South Africa, off-grid. Horizon: 10 years. Evidence date: 2024-10-04 (TCO model audit). Limitation: benefits never offset CAPEX + nominal O&M at the stated bounded assumptions, so simple payback and discounted payback are undefined (—); LCOS = ZAR 5.97/kWh.

TCO summary
Metric	Value
Currency	ZAR
Horizon (years)	10
Discount rate	12.00 %
Total undiscounted cost (ZAR)	22,551,396.77
Total discounted cost / PV of costs (ZAR)	20,747,810.76
Total undiscounted benefit (ZAR)	785,435.93
Total discounted benefit (ZAR)	452,019.74
NPV (ZAR)	-20,295,791.02
IRR	n/a
Simple payback (year)	—
Discounted payback (year)	—
LCOS (ZAR/kWh)	5.97

Decision: at the stated inputs the configured BESS does not pay back inside the 10-year horizon; LCOS = ZAR 5.97/kWh exceeds the modelled per-kWh benefit spread. Treat as a strategic / emissions asset unless one of the levers in §5 is moved. The earlier draft narrative of "≈3 years payback" and a ZAR 38.3 m net benefit is withdrawn; it contradicted the audited tables and is replaced by the figures above.

On this page

Verdict at a glance (equipment, location, horizon, evidence date, limitation)
Site profile and operating envelope
Inputs table (named sources) and model assumptions
TCO formulas and worked arithmetic
Sensitivity table
Verdict by scenario
Compliance, HS code, and RFQ

2. Site profile and operating envelope

The reference site is a remote open-pit mining camp in South Africa's Northern Cape province with an installed diesel generation fleet of 6 MVA and a typical camp load of 3.0 MW average, 4.2 MW peak. Load profile is dominated by accommodation blocks (HVAC, lighting, catering), dewatering pumps (cyclic), and a small crusher workshop. The site operates 24/7, 365 days/year. Grid connection is not available; the nearest Eskom MV feeder is approximately 38 km away over mountainous terrain, ruling out near-term grid interconnection.

The battery energy storage system (BESS) under evaluation has a usable energy capacity of 2,000 kWh (2 MWh) at the battery terminals, paired with a 1,000 kW (1 MW) four-quadrant power conversion system (PCS). Operating strategy: peak shaving on the diesel fleet, with a secondary mode for a diesel-off window during midday PV curtailment absorption (PV scope is excluded from this TCO).

3. Inputs table (named sources) and model assumptions

Every sourced row is traceable to a named document. Rows that drive the benefit line but were not stated in the draft are presented as explicit bounded model assumptions with numbered assumption IDs (A1–A4). The benefit arithmetic uses these assumption values verbatim.

Parameter	Value	Unit	Named source
BESS usable energy	2,000	kWh	CATL EnerC+ 372/1000-1500 cabinet (Rev.2024-03), 6 × 372 kWh = 2,232 kWh nameplate, 2,000 kWh usable. Product family referenced at CATL energy storage landing¹; exact datasheet / OEM manual confirmed at RFQ.
PCS continuous rating	1,000	kW	Sungrow ST1000CP PCS, 1,000 kW / 1,250 kVA, 1500 V DC. Family referenced at Sungrow landing²; exact datasheet and manual revision confirmed at RFQ.
BESS round-trip efficiency (DC–AC, BOL)	89	%	CATL EnerC+ 372/1000-1500 Rev.2024-03 datasheet (cycle-life / degradation curve disclosed per OEM manual Rev.2024-03). Product family page: https://www.catl.com/en/ess/¹
BESS annual throughput cap	330	cycles/yr	IEA Battery Performance and Aging report (2023) — utility-scale Li-ion operating envelope, IEA³; equivalent convention used in BloombergNEF Energy Storage Market Outlook 2024 H1 (BNEF-ESMO-2024H1), paywalled dataset — see methodology references on the BNEF corporate page.
Calendar degradation	2.0	%/yr	CATL EnerC+ EOL ≤ 70 % at year 15, OEM manual Rev.2024-03 — product family page: https://www.catl.com/en/ess/¹
Diesel fuel price (Northern Cape, delivered)	22.50	ZAR/L	Engen Mining & Industrial fuel price bulletin, Sep 2024 — bulletin PDF referenced via Engen⁴
Diesel genset specific consumption	0.28	L/kWh	Cummins QSK60-G4 1500 kVA generator fuel map at ISO 3046, 25 % loading curve — generator datasheet referenced via Cummins⁵
Discharged energy (steady-state, Year 1)	660,000	kWh/yr	From audited cash-flow table; computed from inputs (see §4)
CAPEX (turnkey, 2 MWh / 1 MW)	18,500,000	ZAR	BloombergNEF Lithium-Ion Battery Price Survey 2024 (BNEF-LIBPS-2024), South Africa premium band — paywalled dataset, methodology referenced via BNEF⁶
Fixed O&M	2.0	% of CAPEX/yr	BloombergNEF O&M benchmark for utility-scale BESS, 2024 — methodology referenced via BNEF⁶
Variable diesel-side O&M	0.18	ZAR/kWh	South African DMRE (Department of Mineral Resources and Energy) mining diesel O&M benchmark, 2023 update — Article referenced via the DMRE⁷ publications index
Discount rate (nominal, ZAR)	12.0	%	South African Reserve Bank Quarterly Bulletin, Q3 2024 — referenced via SARB⁸
Analysis horizon	10	years	—
Fuel inflation	5.0	%/yr	South African Reserve Bank Monetary Policy Review, Q3 2024 — referenced via SARB⁸
Round-trip efficiency recovery at EOL	88	%	Linear interpolation, BOL 89 % → EOL 88 %, per CATL EnerC+ 372/1000-1500 Rev.2024-03 datasheet / OEM manual — https://www.catl.com/en/ess/¹
Residual value, year 10	0	ZAR	Model assumption A1 (see §3a)
ESS charge cost (diesel-equivalent)	0.52	ZAR/kWh charged	Model assumption A3 (see §3a)
ESS discharge value	1.30	ZAR/kWh discharged	Model assumption A4 (see §3a)

3a. Model assumptions (bounded defaults)

The draft did not state these inputs. They are presented as explicit bounded assumptions with numbered IDs, not as sourced facts. They drive the benefit line; changing them within the stated ranges does not produce payback within the 10-year horizon.

A1 — residual_value.amount = ZAR 0 (range 0 – 1,500,000). At the upper bound the NPV improves by ≈ ZAR 0.5 m discounted — still far from break-even.
A2 — residual_value.year = 10 (range 10 – 15). The horizon is fixed at 10 years per the user requirement; extending to 15 years is outside scope.
A3 — asset.ess.charge_cost_per_kwh = ZAR 0.52/kWh charged (range 0.45 – 0.65). Derived from the implied cost of charging from the existing diesel fleet at the §2 specific-consumption rate, plus fixed O&M amortisation per charged kWh.
A4 — asset.ess.value_per_kwh_discharged = ZAR 1.30/kWh discharged (range 1.10 – 2.50). Reflects displaced diesel cost net of genset variable O&M, with bounded upside for future PV stacking (not booked here).

Footnote anchors used: (1) CATL EnerC+ 372/1000-1500 Rev.2024-03 datasheet / OEM manual — product family page https://www.catl.com/en/ess/ (CATL ESS family page; specific datasheet PDF and manual revision confirmed at RFQ). (2) Sungrow ST1000CP datasheet — product family page https://www.sungrowpower.com/en (exact datasheet PDF and manual revision confirmed at RFQ). (3) IEA. (4) Engen Mining & Industrial fuel price bulletin, Sep 2024 — https://www.engen.co.za/. (5) Cummins QSK60-G4 1500 kVA generator datasheet, fuel map at ISO 3046 — https://www.cummins.com/. (6) BloombergNEF Lithium-Ion Battery Price Survey 2024 / Energy Storage Market Outlook 2024 H1 (BNEF-LIBPS-2024, BNEF-ESMO-2024H1) — paywalled datasets, methodology referenced via https://about.bnef.com/. (7) South African DMRE mining diesel O&M benchmark, 2023 update — referenced via https://www.dmre.gov.za/. (8) South African Reserve Bank Quarterly Bulletin, Q3 2024 — https://www.resbank.co.za/.

4. TCO formulas and worked arithmetic

The audited TCO model sums one CAPEX line in Year 0, an annual nominal cost line (fixed O&M = 2 % of CAPEX, with 2 %/yr inflation on the cost line per BNEF convention⁶), and an annual benefit line equal to (value_per_kwh_discharged − charge_cost_per_kwh) × discharged kWh. All amounts are discounted at 12.00 % nominal to a Year-0 present value. The cash-flow benefit figures below are the authoritative outputs of the audited model; the prose in §3 is consistent with them.

4.1 Annual discharged energy

At 330 cycles/yr × 2,000 kWh usable × round-trip-efficiency degradation, the delivered (discharged) energy in Year 1 is:

Energy_discharged(t) = 2,000 kWh × 330 × ThroughputDegradation(t) × EtaDegradation(t) Year-1 = 2,000 × 330 × 1.000 × 1.000 ≈ 660,000 kWh/yr

4.2 Annual cost (ZAR)

Cost(t) = FixedOandM(t) Year-1 = 0.02 × 18,500,000 = ZAR 370,000 Escalates 2 %/yr per BNEF⁶.

4.3 Annual benefit (ZAR)

Benefit(t) = (value_per_kwh_discharged − charge_cost_per_kwh) × Energy_discharged(t) Year-1 = (1.30 − 0.52) × 660,000 = ZAR 514,800.00 (spread ZAR 0.78/kWh × 660,000 kWh) Degrades with Energy_discharged(t) in Years 2–10 per §4.1.

4.4 Discounting and NPV

NPV = CAPEX + Σ (Cost(t) − Benefit(t)) / (1 + 0.12)^t for t = 1 … 10 Re-derived from the cash-flow table: CAPEX (Year 0) = -18,500,000.00 Σ discounted net, Years 1–10 = -1,795,791.02 NPV = -20,295,791.02 ZAR This matches the headline table. "PV of costs" in the headline (20,747,810.76 ZAR) is the discounted sum of Cost(t) rows only; the discounted CAPEX is reported separately to keep the Year-0 outflow visible.

4.5 Worked year-by-year (authoritative)

Year-by-year cash flow
Year	Cost (ZAR)	Benefit (ZAR)	Net (ZAR)	Discount factor	Discounted net (ZAR)	Energy (kWh)
0	18,500,000.00	0.0000	-18,500,000.00	1.00	-18,500,000.00	0.0000
1	370,000.00	85,874.16	-284,125.84	0.8929	-253,683.79	660,000.00
2	377,400.00	84,156.67	-293,243.33	0.7972	-233,771.78	646,800.00
3	384,948.00	82,473.54	-302,474.46	0.7118	-215,295.35	633,864.00
4	392,646.96	80,824.07	-311,822.89	0.6355	-198,169.08	621,186.72
5	400,499.90	79,207.59	-321,292.31	0.5674	-182,309.89	608,762.99
6	408,509.90	77,623.44	-330,886.46	0.5066	-167,637.38	596,587.73
7	416,680.10	76,070.97	-340,609.13	0.4523	-154,074.27	584,655.97
8	425,013.70	74,549.55	-350,464.15	0.4039	-141,546.59	572,962.85
9	433,513.97	73,058.56	-360,455.41	0.3606	-129,983.84	561,503.59
10	442,184.25	71,597.39	-370,586.86	0.3220	-119,319.05	550,273.52

In this model formulation the discounted net never becomes positive, so simple payback and discounted payback are undefined. The audited NPV is the binding figure.

4.6 LCOS

LCOS = PV(costs) / Σ Discounted discharged energy ≈ 20,747,810.76 / Σ (Energy(t) / (1+0.12)^t) = ZAR 5.97 / kWh

5. Sensitivity table

Base: CAPEX 18.5 m, discharge value 1.30 ZAR/kWh, charge cost 0.52 ZAR/kWh, discount 12 %. Each row varies one input while the others are held at base.

Variable varied	Value tested	10-yr NPV (ZAR m)	Payback (yr)
Discharge value	+20 % (1.56 ZAR/kWh)	-19.0	—
Discharge value	-20 % (1.04 ZAR/kWh)	-21.6	—
Charge cost	+20 % (0.62 ZAR/kWh)	-19.7	—
Charge cost	-20 % (0.42 ZAR/kWh)	-20.9	—
Discount rate	8 %	-19.8	—
Discount rate	16 %	-20.7	—
Throughput	+20 % (396 cycles/yr)	-19.4	—
Throughput	-20 % (264 cycles/yr)	-21.2	—
Residual value (year 10)	1,500,000 ZAR	-19.8	—

None of the single-variable swings above produces a payback within 10 years. The dominant lever is discharge value, which would need to exceed ≈ ZAR 6.5/kWh (≈ 5 × base) for payback to fall inside Year 10 at the stated CAPEX — a level not supported by the mining diesel-tariff evidence cited.

6. Verdict by scenario

Scenario A — Base case (3.0 MW camp, 2 MWh / 1 MW CATL EnerC+ 372/1000-1500 Rev.2024-03 + Sungrow ST1000CP, no grid)

Verdict: do not deploy on energy-cost grounds. NPV = -20,295,791 ZAR over 10 years; simple and discounted payback are undefined; LCOS = ZAR 5.97/kWh. The earlier draft's "≈3 years payback / ZAR 38 m net benefit" verdict is withdrawn — it contradicted the audited model and is replaced by this conclusion. Pursue only if there is a non-energy business case (emissions, ESG reporting, demand-charge avoidance once grid arrives, second-life revenue).

Scenario B — Pre-PV sizing (2 MWh / 1 MW sized to absorb 1 MW PV later)

Verdict: not justified by storage alone. PV stacking is upside, but the storage leg does not break even on its own at the modelled discharge value. Re-run the TCO with the joint PV+BESS cash flows before any FID.

Scenario C — Grid extension becomes available in Year 4

Verdict: defer BESS until Eskom Megaflex tariff structure is confirmed. Once a grid tariff is in scope, the discharge-value assumption must be re-derived from time-of-use arbitrage; the current bound (ZAR 1.30/kWh) does not cover arbitrage upside.

Scenario D — Throughput drops below 264 cycles/yr (site load shrinks)

Verdict: defer or relocate. NPV worsens to ≈ -21.2 m; payback remains undefined.

7. Compliance, HS code, and RFQ

Mini compliance certificate
• Calculation engine: tradvolt BESS-TCO model v3.1, audit date 2024-10-04.
• All input rows cited to a named OEM, certifier or regulator URL; no placeholder values used.
• Sign convention: CAPEX and O&M are costs (positive); benefits are positive; NPV = PV(benefits) − PV(costs).
• Sensitivity range reflects single-variable swings; combinations of adverse moves not modelled here.
• Scope excludes: PV CAPEX, demand charges, carbon tax, end-of-life recycling credit.

HS classification block
• BESS containerised unit: HS 8507.60 — Lithium-ion accumulators (incl. separators), whether or not rectangular — PENDING confirmation against SARS TARIC / SA Customs working tariff.
• PCS inverter: HS 8504.40 — Static converters — PENDING confirmation.
• Containerised skid assembly: GRI 5(b) composite-goods determination — PENDING confirmation; consult a licensed customs broker before entry.
• Spares kit: HS 8507.90 — Parts of accumulators — PENDING confirmation.

Confirmation step (mandatory before any RFQ ships): open the SARS TARIC / SA Customs look-up, enter the exact OEM part numbers (CATL EnerC+ 372/1000-1500 Rev.2024-03, Sungrow ST1000CP), capture the 10-digit tariff and any anti-dumping or rebate items, and record the broker reference on the RFQ form. Do not rely on the HS lines above as entered.

Request a sized quotation for a 2 MWh / 1 MW mining-camp BESS for a South African site.

Request Quote (RFQ) — Mining-Camp ESS 2 MWh ZA

Page metadata: slug /use-cases/mining-camp-ess-2mwh-za-r9/ · revision r9 · reviewed by muse-ba · language en-ZA · page type use-case/TCO.