BESS Savings
Battery Energy Storage System arbitrage and demand reduction analysis
Key Metrics
Installed Capacity
4 MWh
3.28% of 121.94 MWh target
Monthly Arbitrage
R 514K
From peak price differential
Demand Reduction
600 kVA
R 27K/month savings
Price Differential
R 5.40/kWh
Off-peak to peak spread
Monthly BESS Arbitrage & Demand Savings
Breakdown of BESS revenue streams (R thousands)
Arbitrage Mechanics
Monthly arbitrage calculation breakdown (R thousands)
Daily Charge/Discharge Cycle
BESS State of Charge throughout the day (%)
BESS Savings Composition
Monthly gross savings breakdown
Arbitrage Savings
Demand Reduction
Net BESS Performance
Revenue streams vs operational costs (R thousands)
Arbitrage Formula
SBESS,arb = Edischarge × τPeak − Echarge × τOff-Peak
Edischarge: 97.40 MWh/month (3.2 MWh × 30.44 days)
Echarge: 108.22 MWh/month (accounting for 90% efficiency)
τPeak: R 6.47/kWh | τOff-Peak: R 1.08/kWh
Demand Reduction Formula
SBESS,dem = ΔD × τdemand
ΔD: Peak demand reduction = 600 kVA
kreduction: 150 kVA/MWh (empirical coefficient)
τdemand: R 44.32/kVA/month
Monthly BESS Financial Summary
| Component | Monthly | Annual |
|---|---|---|
| Peak Avoided Cost (97.4 MWh × R6.47) | R 630,597 | R 7,567,164 |
| Charging Cost (108.2 MWh × R1.08) | −R 116,772 | −R 1,401,264 |
| Net Arbitrage Savings | R 513,825 | R 6,161,680 |
| Demand Reduction (600 kVA × R44.32) | R 26,592 | R 319,104 |
| BESS Operational Cost (4 MWh × R165K) | −R 660,000 | −R 7,920,000 |
| Net BESS Position | −R 119,583 | −R 1,439,216 |
Key Insight: While BESS operates at a net deficit of R119K/month, the PV gross savings of R7.13M/month provide 5,962% coverage of BESS net costs, enabling viable storage deployment.