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Enphase IQ Battery 5P Calculator

Enter your electricity bill and module count — get installed cost, 30% ITC savings, backup hours, TOU arbitrage at 96% efficiency, and payback period.

Your electricity profile
$
$/kWh
Time-of-Use (TOU) pricing
IQ Battery 5P configuration
kW
Enphase IQ Battery 5P system estimate
1 × IQ 5P module — 5.0 kWh / 3.84 kW
Total installed cost$5,500
ITC 30% federal tax credit-$1,650
Net cost after credits$3,850
Backup hours (essential loads ~1.5 kW)3.3 hrs
Solar self-consumption increase+38%
Est. annual savings$547/yr
Payback period7.0 yrs
10-year net savings$1,622
Modular expansion cost/kWh (after ITC)$770/kWh
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How to Use This Calculator

Enter your electricity profile

Start with your average monthly electricity bill and select your state — the calculator pre-fills the state's average utility rate. You can override this with the exact rate from your bill. The bill amount is used to estimate your annual kWh usage and the savings potential from shifting consumption away from the grid.

Enable TOU pricing if your utility offers it

Time-of-Use plans charge more during peak hours (typically 4–9pm weekdays) and significantly less overnight. IQ Battery 5P can charge at the cheap off-peak rate and discharge during expensive peak hours, generating TOU arbitrage savings on top of solar self-consumption benefits. California's E-TOU-C, Arizona's TOU-E, and Massachusetts's basic service TOU plans are particularly well-suited.

Configure your IQ Battery 5P system

Select 1–8 modules (each 5 kWh / 3.84 kW continuous). If you already have Enphase microinverters, toggle that on — IQ Battery integrates directly into the Enphase ecosystem without requiring a separate battery inverter, saving $1,000–$2,000 in installation costs. This is the key advantage of the all-Enphase system over adding battery storage to a non-Enphase installation.

The Formula

Total Capacity = Modules × 5.0 kWh Total Power = Modules × 3.84 kW Total Cost = Modules × $5,500 (installed mid-point) Net Cost = Total Cost × (1 − 0.30 ITC) − Enphase Integration Savings TOU Arbitrage = Total kWh × 0.96 RTE × (Peak Rate − Off-Peak Rate) × 365 Self-Consumption Increase = 38% base + 6% per additional module (max 58%) Backup Hours = Total kWh ÷ 1.5 kW essential load Expansion Cost/kWh = Module Cost × 0.70 ITC ÷ 5 kWh

The 96% round-trip efficiency (RTE) of IQ Battery 5P is among the highest in the industry — significantly better than Tesla Powerwall's 90% RTE. This means for every 100 kWh you store, you get 96 kWh back. The modular design means you can start with 1 module and add more later at the same per-module cost, unlike systems that require a larger upfront commitment.

Example

Marcus — 4 IQ 5P modules with Enphase solar in California

Marcus has a 10 kW Enphase microinverter solar system, a $220/month bill, and is on PG&E's E-TOU-C plan. He wants to maximize self-consumption and TOU savings.

Monthly bill$220/mo ($0.27/kWh)
Existing solar10 kW Enphase system
IQ Battery modules4 (20 kWh / 15.36 kW)
TOU rates$0.45 peak / $0.15 off-peak

Result

Total installed cost$22,000
ITC 30% credit-$6,600
Enphase integration savings-$1,500
Net cost$13,900
Essential backup hours~13.3 hrs
TOU arbitrage/yr (96% RTE)~$2,810/yr
Solar self-consumption increase+56%
Payback period~4.6 yrs

Four IQ Battery 5P modules give Marcus 20 kWh of storage and 13+ hours of essential backup. The Enphase-to-Enphase integration eliminates a separate inverter, and the 96% RTE squeezes more value from every stored kWh. With California TOU rates, the payback under 5 years makes this one of the stronger battery storage cases in the US.

FAQ

The Enphase IQ Battery 5P costs approximately $5,000–$6,000 per module installed — about $1,000–$1,500/kWh installed. The 30% federal ITC reduces this to approximately $770–$1,050/kWh net. If you already have an Enphase microinverter system, you avoid the cost of a separate battery inverter, saving an additional $1,000–$2,000. Costs vary by state, labor rates, and whether panel upgrades are needed.
When you already have Enphase microinverters, IQ Battery 5P integrates as a native part of the system. There's no additional battery inverter required — the IQ Battery uses the existing Enphase microinverter infrastructure. This saves $1,000–$2,000 in installation hardware and simplifies the system. Everything monitors through the Enphase Enlighten app. Non-Enphase solar systems require an additional AC-coupled inverter to integrate IQ Battery, eliminating this advantage.
IQ Battery 5P has a 96% round-trip efficiency compared to Powerwall's 90%. This means for every 100 kWh you store, IQ Battery returns 96 kWh vs. Powerwall's 90 kWh — a 6.7% real-world advantage. Over 10 years of daily cycling, this adds up to meaningful extra output. The trade-off: each IQ Battery 5P module provides only 3.84 kW continuous (vs. Powerwall's 7.6 kW per unit), so peak power capacity is lower per module — requiring more modules for high-draw loads.
Yes — this is one of IQ Battery's strongest selling points. Because the system is modular, you can add modules at any time without replacing the base system. Start with 1 module (5 kWh) and add modules as your budget or needs grow. Each additional module costs the same per-kWh as the first. Contrast this with Powerwall, where adding units also requires scheduling a Tesla installation appointment — Enphase's certified installer network is generally broader and more accessible for expansion work.
IQ Battery 5P comes with a 10-year limited warranty, guaranteeing at least 70% of rated capacity at end of warranty. Enphase also offers extended warranty options through installers. The system includes remote monitoring via Enphase Enlighten, and Enphase's microinverter-based architecture means individual module failures don't take down the entire system — a reliability advantage over single-inverter designs.

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