Lunar Energy battery storage in California
Modular storage that scales past a single unit — and what that is actually worth to you.
The Lunar System is a modular home battery that Lunar Energy configures from 15 to 30 kWh in a single wall-mounted tower. Rather than buying a fixed block of capacity, you buy 5 kWh blocks and stack the ones you need. It is the only platform we work with that can be sized precisely to your evening load rather than rounded up to the nearest whole unit.
Lunar Energy is a California company, based in Mountain View and founded in 2020 by a former Tesla Energy executive. The system is developed and tested in California and assembled in the United States. For a homeowner buying a product designed around California's rate structures, that is not just trivia.
A battery does two jobs. The first is financial. Under NEM 3.0 your utility pays you far less for exported power than it charges you at peak, so storing your own generation and using it in the evening is worth more than selling it. The second is backup. When the grid fails, the system takes over.
Where Lunar goes further than most is software. Lunar AI builds a new dispatch plan for your home every day against your rates, your weather and your usage patterns, rather than running the same schedule regardless. That is the platform's real argument, and it is worth understanding before you compare it on capacity alone.
What the numbers mean
Six things worth knowing
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15 to 30 kWh
Modular capacity
Built from 5 kWh battery blocks in one vertical tower, in 15, 20, 25 or 30 kWh configurations. You can add blocks later as your usage grows, without replacing the system or starting again.
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9.6 kW continuous
Output power
Enough for whole-home backup in most California houses, with 15 kW peak for 5 seconds and a 134 A LRA motor start rating. Lower continuous output than Powerwall 3 and aPower 2, which matters if you run several heavy loads at once.
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95.5%
Round-trip efficiency
The share of stored energy that reaches your circuits. Lunar publishes 95.5%, which is high for a residential battery, and it compounds every single day you cycle the system rather than showing up once.
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Lunar AI
Daily optimization
The software writes a new plan each day against your tariff, the forecast and your household pattern. Lunar reports that California customers gained an average of $338 in additional value from Lunar AI in 2025.
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12.5 years
Warranty
12.5 years, with a throughput cap that scales with system size, reported as 56 MWh on the 15 kWh configuration and 75 MWh on the 20 kWh. Longer than Tesla and SolarEdge at 10 years, shorter than FranklinWH at 15.
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Load control
Outage behavior
With Eaton AbleEdge smart breakers the system drops non-essential circuits automatically during an outage, so the battery spends what is left on what matters instead of treating the house as one load.
Full specifications
| Usable capacity | 15, 20, 25 or 30 kWh |
|---|---|
| Block size | 5 kWh per battery block |
| Continuous output | 9.6 kW |
| Peak output | 15 kW for 5 seconds |
| Motor start | 134 A LRA |
| Chemistry | Lithium-ion (NMC) |
| Coupling | DC or AC, new or existing solar |
| Round-trip efficiency | 95.5% |
| Depth of discharge | 100% |
| Warranty | 12.5 years, throughput cap by size |
| Solar optimization | Lunar Maximizers, module level, 650 W max input |
| Certification | UL 9540A, indoor and outdoor rated |
| Electrical | Single 50 A breaker for solar and battery |
Per Lunar Energy published specifications. Last reviewed 12 August 2026.
Being straight about it
When Lunar is not the right answer
- You want the highest continuous output. Lunar is 9.6 kW. Powerwall 3 is 11.5 kW and aPower 2 is 10 kW. If you plan to run air conditioning, an oven and a well pump simultaneously during an outage, that gap is real.
- You want the longest warranty. FranklinWH is 15 years against 12.5 here.
- You want LFP chemistry. Lunar uses NMC cells. Both chemistries are certified for home use, but LFP is more thermally stable, and Powerwall 3 and aPower 2 both use it.
- You are on a tight budget with modest usage. The smallest Lunar configuration is 15 kWh. If your evening load is small, a 9.7 kWh SolarEdge or a single Powerwall may be all you need and less to pay for.
- You want the longest track record. Lunar is a newer company than Tesla or SolarEdge. The technology is strong and the team came out of this industry, but there is less field history behind it, and that is a fair thing to weigh.
The software case
Where Lunar earns its keep
Most home batteries run a fixed schedule. Charge on solar, discharge at peak, repeat. That is fine, and it captures most of the value.
Lunar AI writes a different plan every day, weighing your tariff, the weather forecast and how your household actually behaves. On a mild day it may hold charge for a grid event. Ahead of a storm it fills. When rates shift, it adapts without anyone touching it.
The second piece is grid participation. Lunar's Gridshare platform enrolls batteries into virtual power plant and demand response programs, including California's Demand Side Grid Support program, so the battery earns on days it would otherwise have sat mostly full.
Lunar reports that in 2025 its California customers gained an average of $338 from Lunar AI and earned an average of $464 through its virtual power plant, for around $802 in combined additional value. Those are Lunar's own figures for participating customers, not a guarantee, and your result depends on your utility, your rates and your usage. We will tell you which programs your system can actually enroll in where you live.
Cost
What it costs, honestly
We do not publish a price, because a number without your bill attached is a guess. With Lunar there is one extra variable: because capacity is modular, the size you buy is a decision rather than a fixed spec, and that decision moves the price more than anything else.
The federal 30% residential clean energy credit under Section 25D expired on 31 December 2025, so a cash or loan purchase in 2026 receives no federal credit. What is left depends entirely on your utility, and the amounts vary widely between PG&E, SCE, SDG&E, SMUD, LADWP and the community choice aggregators. Send us a recent bill and we will tell you exactly what is open where you live.
Questions
Lunar System questions
What size Lunar System do I need?
That is the point of the platform. It comes in 15, 20, 25 or 30 kWh built from 5 kWh blocks, so we size it to your actual evening consumption rather than rounding up. We work that out from a recent utility bill, not an estimate.
Can I add capacity later?
Yes. Blocks stack into the same tower, so if you add an EV or electrify your heating you can expand without replacing the system. That is worth weighing against buying more capacity than you currently need.
Will it work with solar I already have?
Lunar supports both DC and AC coupling, so it can work with new or existing solar. On some retrofits an AC-coupled battery such as the FranklinWH aPower 2 is still the simpler route. We check your existing equipment before recommending anything.
What is Lunar AI, really?
Software that decides when your battery charges and discharges, rebuilt daily against your tariff, the forecast and your household's pattern rather than running one fixed schedule. Lunar reports an average of $338 in additional value for California customers in 2025. That is their figure for their customers, not a promise about yours.
How much can I earn from a virtual power plant?
Lunar reports an average of $464 in 2025 for California customers participating in its virtual power plant. What you can actually earn depends on which programs your utility runs and whether your system is eligible, so we check that rather than quoting an average at you.
Can it run my air conditioning during an outage?
Usually, at 9.6 kW continuous and 134 A LRA motor start. If you have a large compressor and want to run it alongside other heavy loads, Powerwall 3 at 11.5 kW or aPower 2 at 185 A LRA has more headroom. This is exactly the kind of thing we size around.
What does the warranty cover?
12.5 years with a throughput cap that scales with system size, reported as 56 MWh on the 15 kWh configuration and 75 MWh on the 20 kWh. Throughput is the total energy passing through the battery over its life, so heavy daily cycling could reach that limit before the years run out. Read Lunar's warranty document for the full terms.
Is NMC chemistry a problem?
No, but it is a difference worth knowing. NMC cells are more energy dense, which is part of how the system stays compact. LFP cells, used in Powerwall 3 and aPower 2, are more thermally stable. Both are certified for residential use and the Lunar System is UL 9540A rated for indoor and outdoor installation.
Do I need a permit for a home battery in California?
Yes. A building permit and utility interconnection approval. We manage both, along with the schedule, so you are not chasing your city's permitting office or your utility.
Do you install it?
No. We do not install solar or batteries. We specify your system, secure the incentives and rebates you qualify for, and manage the project. We have partnered with experienced installers across California who handle the fulfillment.
Next step
Is Lunar right for your house?
Send us a recent utility bill. We will read your real usage and rate plan, work out the right capacity rather than the biggest, check what your utility currently offers, and tell you which of the four platforms fits. Including when the cheaper one is the right answer.
Solari Storage is a California battery sales and program-qualification company. We do not install solar or batteries. Our install partners handle fulfillment.