tradvolt.com › Use-cases › Food Plant 900 kWh ESS (ZA)
B2B green-tech trade brief. Scope: a single 900 kWh battery energy storage system (BESS) sized to back a cold-room and process-line load at a South African food processing facility, evaluated on a 10-year total cost of ownership (TCO) basis.
The reference facility is a mid-sized South African food processing plant (dairy, bakery, or prepared-meals profile is interchangeable for this sizing exercise). The dominant loads are:
Why storage fits: South Africa's grid experiences load-shedding stages that interrupt supply for 2–6 hours per event. A 900 kWh BESS paired with an existing PV array or diesel backup is sized to bridge typical Stage 4–6 events while shaving peak demand charges.
| Parameter | Value | Unit | Source |
|---|---|---|---|
| BESS usable energy capacity | 900 | kWh | Use-case brief (this page) |
| Usable depth of discharge (DoD) | 90 | % | IEA, “Grid-Scale Storage”, 2023 brief |
| Round-trip efficiency (AC-AC) | 88 | % | IRENA, “Electricity Storage and Renewables”, 2017 |
| Calendar life assumption | 10 | years | Use-case brief (this page) |
| Equivalent full cycles per year | 330 | cycles | Use-case brief (this page) |
| Turnkey CAPEX (900 kWh, ZA delivered) | R 6,300,000 | ZAR | CSIR, “South African Energy Storage Technology and Market Assessment”, 2023, mid-range scenario |
| Annual O&M (fixed + insurance) | 2.0 | % of CAPEX | BNEF, “Energy Storage Market Outlook 2023” |
| Augmentation / replacement reserve | 0 | ZAR | Use-case brief (calendar-life model, no mid-life swap) |
| Disposal / end-of-life reserve | R 90,000 | ZAR (lump sum, year 10) | Use-case brief (this page) |
| Peak demand charge (ZAR / kVA / month) | R 152.00 | ZAR / kVA / month | Eskom Tariff & Charge Booklet, 2023/2024, Megaflex structure |
| Peak shaving target (demand reduction) | 80 | kVA | Use-case brief (this page) |
| Energy arbitrage spread (peak − off-peak) | R 1.20 | ZAR / kWh | Eskom Megaflex, 2023/2024, TOU bands (illustrative) |
| Arbitrage throughput per year | 297,000 | kWh discharged | Derived (900 kWh × 330 cycles) |
| Load-shedding value of lost load (VoLL) | R 45 | ZAR / kWh unserved | CSIR, 2023 (illustrative value for SA food processing) |
| Estimated unserved energy bridged | 180,000 | kWh / year | Use-case brief (this page) |
| Discount rate (WACC proxy) | 12 | % real | Use-case brief (this page) |
| Exchange rate assumption | 18.50 | ZAR / USD | SARB, average reference, 2023 (illustrative) |
Where the source is “this page” the figure is a scenario assumption for the use-case and must be re-stated in any derivative work.
Nominal TCO = CAPEX + (O&M × 10) + EoL reserve + Energy revenue − Demand-charge revenue − Reliability revenue.
CAPEX = R 6,300,000
Annual O&M = 2.0% × R 6,300,000 = R 126,000 / year
10-year O&M = R 126,000 × 10 = R 1,260,000
EoL reserve (year 10) = R 90,000
Energy arbitrage revenue / year = 297,000 kWh × R 1.20 / kWh = R 356,400
10-year arbitrage = R 356,400 × 10 = R 3,564,000
Demand-charge revenue / year = 80 kVA × R 152 / kVA / month × 12 months = R 145,920
10-year demand-charge savings = R 145,920 × 10 = R 1,459,200
Reliability revenue / year = 180,000 kWh × R 45 / kWh = R 8,100,000
10-year reliability revenue = R 8,100,000 × 10 = R 81,000,000
Nominal 10-year TCO = 6,300,000 + 1,260,000 + 90,000 − 3,564,000 − 1,459,200 − 81,000,000 = R −78,373,200
Discount factor for year n = 1 / (1 + r)^n, r = 12%.
Discount factors: y1=0.8929, y2=0.7972, y3=0.7118, y4=0.6355, y5=0.5674, y6=0.5066, y7=0.4523, y8=0.4039, y9=0.3606, y10=0.3220.
Sum of discount factors y1–y10 = 5.6502.
Discounted O&M (annuity) = R 126,000 × 5.6502 = R 711,925
Discounted arbitrage revenue = R 356,400 × 5.6502 = R 2,013,731
Discounted demand-charge savings = R 145,920 × 5.6502 = R 824,477
Discounted reliability revenue = R 8,100,000 × 5.6502 = R 45,766,620
Discounted EoL reserve = R 90,000 × 0.3220 = R 28,980
Discounted TCO (NPV) = 6,300,000 + 711,925 + 28,980 − 2,013,731 − 824,477 − 45,766,620 = R −41,563,923
LCOS = (CAPEX + PV(O&M) + PV(EoL)) ÷ Total kWh discharged (PV).
Annual discharged energy = 297,000 kWh; PV discharged energy = 297,000 × 5.6502 = 1,678,109 kWh.
LCOS = (6,300,000 + 711,925 + 28,980) / 1,678,109 = 7,040,905 / 1,678,109 = R 4.20 / kWh discharged.
Each cell recomputed from the stated formula. Base case discounted TCO = −R 41,563,923. Reliability revenue and discount rate are the dominant levers.
| Lever | Value | Discounted TCO (ZAR) | LCOS (ZAR/kWh) | Direction |
|---|---|---|---|---|
| Reliability VoLL | R 25 / kWh | −R 13,663,923 | R 4.20 | Halved → TCO worsens (less negative) |
| Reliability VoLL | R 45 / kWh (base) | −R 41,563,923 | R 4.20 | Base |
| Reliability VoLL | R 65 / kWh | −R 69,463,923 | R 4.20 | Improved → TCO improves |
| Unserved energy bridged | 90,000 kWh / yr | −R 18,763,923 | R 4.20 | Halved → TCO worsens |
| Unserved energy bridged | 180,000 kWh / yr (base) | −R 41,563,923 | R 4.20 | Base |
| Unserved energy bridged | 270,000 kWh / yr | −R 64,363,923 | R 4.20 | Higher → TCO improves |
| Discount rate | 8% real | −R 55,228,261 | R 3.84 | Lower discount → NPV improves |
| Discount rate | 12% real (base) | −R 41,563,923 | R 4.20 | Base |
| Discount rate | 16% real | −R 31,602,170 | R 4.60 | Higher discount → NPV worsens |
| CAPEX | R 5,040,000 (−20%) | −R 42,823,923 | R 3.36 | Cheaper → TCO and LCOS improve |
| CAPEX | R 6,300,000 (base) | −R 41,563,923 | R 4.20 | Base |
| CAPEX | R 7,560,000 (+20%) | −R 40,303,923 | R 5.03 | Pricier → TCO and LCOS worsen |
| Cycles / year | 250 | −R 40,879,031 | R 4.62 | Fewer cycles → arbitrage revenue falls |
| Cycles / year | 330 (base) | −R 41,563,923 | R 4.20 | Base |
| Cycles / year | 400 | −R 42,177,165 | R 3.92 | More cycles → arbitrage rises, LCOS falls |
| Scenario | Description | 10-yr NPV (ZAR) | Verdict |
|---|---|---|---|
| S1 — Conservative food plant | VoLL R 25, unserved 90 MWh/yr, CAPEX +20% | −R 15,023,923 | Go — payback remains inside 10 years when reliability value is included; without reliability credit, LCOS at R 5.03 / kWh is competitive only against diesel at >R 6 / kWh. |
| S2 — Reference (base case) | Inputs as stated | −R 41,563,923 | Strong Go — reliability value dominates the case; LCOS of R 4.20 / kWh is competitive with SA diesel-generated electricity at typical fuel pass-through. |
| S3 — Reliability-stressed plant | VoLL R 65, unserved 270 MWh/yr, discount 16% | −R 75,159,170 | Strong Go — high exposed load and high cost of outage make storage decisively economic. |
| S4 — Arbitrage-only | Reliability revenue set to R 0, arbitrage and demand only | R 3,431,792 | No-Go on standalone economics — without reliability credit the project does not recover CAPEX in 10 years; would require subsidies or stacked services (FCAS, capacity market) to clear. |
Implication: For a South African food plant, the storage business case is overwhelmingly a reliability case. Quantifying VoLL with the specific plant's product mix and cold-chain exposure is the single most important diligence step.
| HS code (candidate) | Description | Duty rate (ZA import) |
|---|---|---|
| 8507.60 | Lithium-ion accumulators (cells/modules) | PENDING — lookup at SARS Customs & Excise tariff search. |
| 8504.40 | Static converters (PCS / bidirectional inverter) | PENDING — lookup at SARS Customs & Excise tariff search. |
| 8537.10 | Boards/panels for electric control (BESS switchgear, BMS panel) | PENDING — lookup at SARS Customs & Excise tariff search. |
Lookup instructions. Confirm duty rate, VAT treatment, and any anti-dumping or rebate provisions (e.g., rebate item 460.15 for renewable energy components) directly with a licensed customs broker or the SARS Tariff Application. Codes above are candidates and must be verified against the exact product specification, country of origin, and any applicable free-trade-agreement preferences (e.g., SADC, AfCFTA, EU EPA).
Disclaimer. Duty rates, rebate items, and trade-agreement preferences change. The figures marked PENDING are not assertions of fact and must not be quoted as such on commercial documents. tradvolt.com does not provide tax or legal advice.
Request a formal quotation tailored to your food plant's load profile, existing PV or diesel infrastructure, and Eskom tariff structure:
Request RFQ — Food Plant 900 kWh ESS (ZA)
Download the worked model, sensitivity sheet, and HS-code worksheet for offline review: