A home battery can backup your fridge—or it can bid into grid programs when your utility and inverter ecosystem allow it. The question is not whether technology works; it is whether net dollars after wear beat leaving the pack at 90% SOC for outages only.
Gross revenue vs. net profit
Program brochures quote monthly capacity payments. Your wallet cares about:
Net ≈ gross grid-service revenue − degradation cost − aggregator fees − retail opportunity cost
Gross revenue is where the Grid Frequency Response Reward Calculator starts.
Example workflow
- Enter available kW (export-limited inverter cap, e.g. 5 kW)
- Set participation hours (e.g. 16 h/day when SOC policy allows dispatch)
- Pick $/kW-month from aggregator sheet (or $/kWh if energy-only)
- Set availability conservatively (85–90% until you have telemetry history)
- Read monthly and annual columns in the scenario table
If annual gross is $400 and degradation + fees are $350, you are running a reliability service, not an investment.
Battery wear: the silent line item
Frequency programs add cycles—shallow, frequent pulses still count:
- Calendar aging — time at elevated SOC and temperature
- Cycle aging — equivalent full cycles from regulation dispatch
- Warranty — some OEMs exclude “grid services” without approval
Rule of thumb for planning: assign $0.03–$0.08 per kWh throughput as a wear placeholder until your installer quotes cycle cost. Multiply monthly dispatched kWh (shown in energy-rate mode) or estimate from program duty cycle.
When wear dominates
- Small batteries (5–7 kWh) with aggressive dispatch
- Hot garages without thermal management
- Programs requiring deep cycling to qualify
When wear dominates, TOU arbitrage alone may net more with fewer mystery cycles—compare Battery Arbitrage ROI.
Availability: the lever homeowners control
Missed communications, Wi-Fi outages, or SOC held for backup shrink effective payments. The calculator’s availability scenario table shows:
- 60% availability — outage-heavy or strict backup reserve
- 90% — realistic enrolled homeowner
- 100% — best case (rare with backup reservations)
If you refuse dispatch below 40% SOC for storm prep, model lower availability—even if hardware is online.
Stacking services (carefully)
Some sites stack:
- Frequency response (grid services)
- TOU arbitrage (retail tariff)
- Solar self-consumption
Controllers prioritize signals; double-counting revenue in spreadsheets is common. Model one product at a time, then ask the aggregator how stacks interact.
Decision matrix
| Signal | Lean toward enrollment | Wait |
|---|---|---|
| Published $/kW-month in your utility territory | ✓ | |
| OEM approves grid services | ✓ | |
| Annual gross >> 2× estimated wear | ✓ | |
| Export blocked or no VPP | ✓ | |
| Backup-only mindset (need 100% SOC) | ✓ | |
| Program < 12 months / pilot ending | ✓ |
Checklist before you sign
- Run calculator at 85% and 95% availability
- Get degradation quote or warranty grid-services clause in writing
- Confirm backup SOC floor still covers outage plan
- Compare gross to one year of arbitrage-only profit
- Keep interconnection export rules on file
Related reading
- Grid Frequency Response Rewards Guide — why programs exist
- Frequency Response Compensation for Investors — VPP and market structure
A home battery becomes a revenue asset when net cash flow is positive after wear—not when a headline $/kW-month rate sounds impressive. Run the calculator, subtract real costs, then decide if your pack works for the grid or only for your home.