Solar Battery Storage Cost 2026 — Powerwall, Enphase, Franklin Compared

Battery storage shifted from "luxury upgrade" to "near-required" in California (NEM 3.0) and increasingly attractive in other states. Here's what each major battery actually costs installed in 2026, and when payback math actually works.

The major batteries — installed prices 2026

Battery	Capacity	Installed price	Per kWh	Lifetime warranty
Tesla Powerwall 3	13.5 kWh	$13,500–$16,500	$1,000–$1,200	10 yr / 70% capacity
Enphase IQ Battery 5P	5 kWh (modular)	$5,800–$7,000	$1,160–$1,400	15 yr / 60% capacity
Franklin aPower 2	15 kWh	$13,000–$16,000	$870–$1,070	15 yr / 70% capacity
Generac PWRcell	9–18 kWh modular	$10,500–$22,000	$1,170–$1,220	10 yr / 70% capacity
FranklinWH aPower 2	15 kWh	$13,500	$900	15 yr
SunVault	13–26 kWh (modular)	$13,000–$26,000	$1,000	10 yr

After federal 30% ITC

Tesla Powerwall 3 (13.5 kWh): $15,000 gross → $10,500 net
Enphase IQ Battery 5P (10 kWh, 2 units): $13,000 → $9,100 net
Franklin aPower 2 (15 kWh): $14,000 → $9,800 net

Where battery payback actually works

California (NEM 3.0) — payback 6–9 years

Without battery, NEM 3.0 export rates kill solar economics (75% lower vs NEM 2.0). With a 10–13 kWh battery, self-consumption rises from 45% to 85% — capturing $0.32/kWh retail value instead of $0.058/kWh export value. The battery essentially pays for itself by recapturing what NEM 3.0 took away.

Hawaii — payback 5–7 years

Highest US electricity rates ($0.42/kWh statewide, $0.55+ on outer islands). Strong battery payback with or without solar.

Texas (variable utility) — payback 8–12 years

Depends entirely on your retail electric provider. Reliant, Octopus, Green Mountain offer net metering — battery payback longer here. Avoided-cost-only providers — battery makes more sense to capture self-consumption value.

States where battery payback is poor

Florida: full retail net metering means 1:1 export credit. Battery adds resilience value (hurricanes!) but math alone doesn't work — 14+ year payback.
Massachusetts, New York, North Carolina: full retail net metering, similar math.
Washington, Oregon: low electricity rates + decent net metering = 13+ year battery payback.

In these states, battery purchase is justified by resilience (whole-home backup during outages) more than financial payback.

Powerwall vs Enphase vs Franklin — quick decision tree

Pick Tesla Powerwall 3 if:

You want one big unit, simplest install (3-hour install typical)
Your inverter situation is flexible (PW3 has built-in inverter — replaces or supplements existing)
You're already in the Tesla ecosystem (Solar Roof, Tesla EV)

Pick Enphase IQ Battery 5P if:

You have an Enphase microinverter system already (most cohesive integration)
You want modular sizing (5 kWh increments — start small, expand later)
Long warranty matters (15 years vs Powerwall's 10)

Pick Franklin aPower 2 if:

You want 15 kWh in one unit at a slight discount per-kWh
You want generator-replacement levels of resilience (whole-home backup including HVAC)
Smart Home X (Franklin's energy management) appeals to you

Lithium iron phosphate (LFP) vs NMC chemistry

2024–2025 saw industry shift toward LFP (lithium iron phosphate) chemistry, away from NMC (nickel-manganese-cobalt):

LFP advantages: longer cycle life (6,000+ cycles), better thermal stability (lower fire risk), no cobalt ethical issues
LFP disadvantages: 15–20% lower energy density (slightly larger physical size for same capacity)
Currently LFP: Tesla Powerwall 3, Franklin aPower, FranklinWH
Currently NMC: older Powerwall 2, Enphase, Generac (varies by model year)

For new installations in 2026, LFP is the safer long-term choice.

Battery sizing — how much do you need?

Two common sizing strategies:

Daily consumption shifting: capture ~4 hours of evening peak usage. Average home 6 PM–10 PM uses 6–10 kWh. → 10 kWh battery.
Whole-home backup: survive a 24-hour grid outage running essentials. ~15–20 kWh for typical home (refrigeration, lights, internet, HVAC partial).

Most NEM 3.0 California homes pick 10–13 kWh as the consumption-shifting sweet spot. Hurricane-zone Florida homes lean toward 15–25 kWh for resilience.

State + utility battery rebates (stack on top of ITC)

California SGIP: $200–$1,000 per kWh for low-income or wildfire-zone customers
Mass Save (MA): ConnectedSolutions program pays $200–$400/kW/year for ~5 years
Maryland: $5,000 grant per battery system
New York NY-Sun: battery adder being added 2026, exact rates TBD
Hawaii BatteryBonus: $850/kW for Oahu customers committing to peak-demand response