Tesla Powerwall 3 vs Lunar Energy: an honest comparison
We sell both. Here is how we decide which one to recommend — including when we recommend the cheaper one.
The Tesla Powerwall 3 and the Lunar Energy system are both lithium home batteries suited to California homes under NEM 3.0, and neither is better in general. Powerwall 3 offers the higher continuous power output from a single unit on Tesla’s published specifications and has by far the larger installed base. Lunar scales in smaller modules and is more software-led, which suits households needing more capacity than one or two Powerwalls provide. The deciding factors are your evening peak load, how much backup you want, your available wall space and your budget.
| Tesla Powerwall 3 | Lunar Energy | |
|---|---|---|
| Usable capacity | 13.5 kWh per unit (Tesla published) | [VERIFY: per-module and total] |
| Continuous output | 11.5 kW (Tesla published) | [VERIFY] |
| How it scales | By adding complete units | By adding modules |
| Solar inverter | Integrated | [VERIFY] |
| Software | Tesla app, established | Lunar states rate-plan and forecast optimisation |
| VPP participation | [VERIFY: which California programmes] | Lunar states VPP capability. |
| Installed base | The most-installed home battery in America | Considerably smaller — a newer product |
| Warranty | [VERIFY] | [VERIFY] |
| Installed cost in California | [VERIFY: range] | [VERIFY: range] |
| SGIP eligible | [VERIFY] | [VERIFY] |
How we actually choose
The number that matters is how much power your house draws at once between roughly four and nine in the evening. That determines output requirements, which is a different question from how many kilowatt-hours you use in a year.
Essential loads — fridge, lights, internet, a few outlets — is a much smaller system than whole-home backup with air conditioning. Most people who say they want whole-home backup change their mind when they see what it costs, and that is a legitimate choice rather than a failure.
Essential loads — fridge, lights, internet, a few outlets — is a much smaller system than whole-home backup with air conditioning. Most people who say they want whole-home backup change their mind when they see what it costs, and that is a legitimate choice rather than a failure.
If two configurations both do the job, we recommend the cheaper one. This is not generosity; a system sized honestly is one that performs the way we said it would, and that is what generates the referral.
FAQ
Comparison FAQ
Neither in general. Powerwall 3 has the higher single-unit power output and a much larger installed base; Lunar scales in smaller modules and is more software-led. The right choice depends on your evening peak load, backup expectations and space.
Cost comparison is only meaningful at equivalent usable capacity and output, which is not the same as comparing one unit to one unit.
Backup performance is governed by continuous output and usable capacity. Powerwall 3 has the higher published single-unit output; Lunar can reach higher total capacity through modules. Which matters more depends on whether your constraint is running big loads or running for longer.
Lunar states VPP capability as a core feature.
Because we will put the reasoning in writing. You get the sizing calculation, the assumptions behind it and the comparison, not just a number. If the cheaper system does the job we will say so, and you can hold us to the document.