Tesla Powerwall 3 vs. Enphase vs. FranklinWH for Illinois homes

Specs change with new versions, so check the datasheet for the exact model in your quote. The rebate is based on the battery's nameplate capacity, so your installer's figure may differ a little from this table.

Powerwall 3 is often the simplest choice for a new system, because it has a solar inverter built in: Tesla's design guide lists six solar inputs and up to 20 kW of panels. That means one box does both jobs. The tradeoff is that panel-level electronics, such as microinverters or optimizers, don't readily fit its typical setup. Berkeley Lab found that use of panel-level electronics fell in 2025 and tied the drop to Powerwall 3's popularity.

If you want microinverters for a shaded or complicated roof, an Enphase system with Enphase batteries keeps everything on one platform and one app. See microinverters vs. string inverters.

Enphase and FranklinWH batteries are AC-coupled: they connect on your home's electrical side rather than to the panels, which makes them easier to add to an existing system. FranklinWH says aPower 2 works with existing solar from other brands. Enphase batteries are the natural fit for homes that already have Enphase microinverters.

Powerwall 3 can also be added to some existing systems, but compatibility depends on the gateway and the other inverter, so have the installer confirm it in writing. If you're expanding your panels at the same time, see adding solar panels to an existing system.

For a big home with central air, power matters as much as storage. One Powerwall 3 delivers 11.5 kW and one aPower 2 delivers 10 kW, enough to run many 240-volt appliances at once. An Enphase 5P delivers 3.84 kVA per unit, so whole-home Enphase systems usually stack several units.

FranklinWH's aGate can also start and stop a standby generator automatically when the battery runs low, which suits homes that want backup for multi-day outages. Generator support varies by model and controller for the other brands, so ask. See whole-home battery backup and standby generator vs. battery.

Tesla warrants Powerwall to keep 70% of its capacity after 10 years, with unlimited cycles when it's used for solar self-consumption, time-based control and backup. FranklinWH warrants aPower 2 to keep at least 70% for 15 years or 60 MWh of throughput, whichever comes first. Enphase's datasheet lists 15 years or 6,000 cycles at 60% capacity.

Illinois' rebate now requires enrolling the battery in a utility virtual power plant, which uses it at set summer peak times. Ask the installer how that dispatch counts against the warranty's cycle or throughput limits. See the Illinois battery rebate guide.

1. 1

   How many units, and what will they run?

   Get the backed-up circuits in writing, including central air if you need it.

2. 2

   Is the battery priced separately?

   An itemized price lets you compare brands and subtract the storage rebate.

3. 3

   Who files the rebate and VPP enrollment?

   Confirm the installer handles the ComEd or Ameren paperwork.

4. 4

   Who services it?

   Ask whether the installer is certified by the battery maker and who handles warranty claims.

Check the solar side of the quote with our quote checker.