Determine the optimal battery size to reduce demand charges and maximize your energy savings.
Your highest recorded demand in a billing period
Percentage of peak demand to shave
How long the battery needs to sustain discharge
Monthly demand charge from your utility
Total installed cost per kWh of capacity
Usable capacity percentage (typically 80-90%)
Number of working days with peak demand
Expected battery system lifetime
Required Battery Capacity
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Total nameplate kWh
Usable Capacity
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kWh at rated DoD
Power Rating
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kW continuous discharge
Demand Reduction
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kW shaved from peak
Annual Savings
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Demand charge reduction/year
Total System Cost
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Installed battery cost
Simple Payback
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Years to recover investment
Lifetime ROI
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Net return over lifecycle
To calculate battery size for peak shaving, multiply the power reduction needed (in kW) by the duration of peak demand periods (in hours). For example, if you need to reduce 100 kW for 4 hours, you need a 400 kWh battery. You should also account for depth of discharge (typically 80-90%) by dividing the required capacity by the DoD factor.
Peak shaving can reduce demand charges by 20-50% depending on your load profile and battery system size. Demand charges typically account for 30-70% of commercial electricity bills. A well-sized battery system can pay for itself in 3-7 years through demand charge reduction alone, with additional savings from energy arbitrage and grid services.
Peak shaving reduces the maximum power drawn from the grid by discharging a battery during high-demand periods, directly lowering demand charges. Load shifting moves energy consumption from peak to off-peak hours to take advantage of time-of-use rate differences. While both use battery storage, peak shaving targets the power component (kW) of your bill, while load shifting targets the energy component (kWh).