Free solar + storage economics tool
Solar + Battery Peak-Shaving ROI Calculator
Combine solar energy savings with battery demand-charge reduction — while checking whether the battery has enough inverter power and usable energy to hold the peak shave for the full utility demand window.
Simple hybrid sizing model
Peak Coverage GateBuild the solar, battery and utility peak case
Facility load & tariff
Solar system
Battery peak-shaving system
Project horizon & degradation
Peak-credit ruleBattery demand reduction is limited to the smallest of the target shave, available inverter kW, and available battery kWh ÷ peak-event duration. Solar demand reduction uses the entered solar kW actually coincident with the utility peak, not average solar production.
Strategy Comparison
Solar Only vs Battery Only vs Hybrid
| Strategy | Net capex | Year-1 energy value | Year-1 demand savings | Recharge + O&M | Year-1 net savings | Simple payback | Project NPV |
|---|
Peak-Shaving Bridge
How solar and battery combine at the utility peak
Demand Tariff × Battery Size
Hybrid NPV sensitivity
Advanced 12-month dispatch model
Peak-Shaving Value QueueAudit seasonal solar, demand and battery value
Shared utility billing constraints
Shared solar assumptions
Shared battery assumptions
Project horizon
12 monthly utility + solar periods
Advanced dispatch logicEach month separately calculates the solar kW coincident with the measured peak, the useful battery kW available before the billing floor, the resulting billed demand, solar energy value and battery recharge cost. Ratchets can block demand savings even when the physical peak falls.
Peak-Shaving Value Queue
Rank months by solar + battery demand value
| Rank | Month | Peak kW | Solar at peak | Useful battery kW | New billed demand | Solar demand savings | Battery incremental savings | Total demand savings | Recharge cost | Signal |
|---|
Annual Value Bridge
Solar energy, peak shaving and operating cost
Battery Size Stress Test
What happens as inverter power changes?
| Battery power scale | Battery kW | Sustainable shave | Annual demand savings | Recharge cost | Year-1 net savings | Project NPV |
|---|
Demand Tariff × Battery Power
Hybrid NPV sensitivity
Scope
Physical dispatch and tariff rules still need engineering review
This is a financial planning and preliminary sizing model. Actual solar output, battery dispatch, interconnection, controls, degradation, warranties, charging strategy, fire/life-safety requirements, demand intervals, utility ratchets and incentives can materially change project economics. Use interval meter data, a site-specific solar production model and the actual utility tariff before investment approval.