| Quick answer: The Lunar System is a modular home battery built from 5 kilowatt-hour blocks, configurable from 15 up to 30 kilowatt-hours behind a single integrated hybrid inverter. Its distinguishing features are that granularity — you can specify an exact capacity rather than stepping in whole units — and a 12.5-year warranty that is longer than most of the field. |
Most home battery comparisons collapse into a specification list that tells you very little about how a system behaves in a particular house. The Lunar System is worth understanding properly because its architecture differs from the market default in ways that matter for some households and are irrelevant for others. Here is what it actually is.
What the Lunar System is
Lunar Energy is a California company, headquartered in Mountain View and founded in 2020 by a former head of Tesla Energy. Its residential product, the Lunar System, is a complete home energy system rather than a battery alone: modular storage blocks, an integrated hybrid inverter, module-level solar electronics, and a software layer that can enrol the system into utility programs.
The company raised substantial new funding in early 2026 and is shipping in California among other states. That matters in a category where several manufacturers have failed and left owners holding warranties nobody honours — a manufacturer’s viability is a legitimate part of the specification.
The modular architecture — 5 kWh blocks
This is the genuinely distinctive part. Rather than shipping a fixed-capacity unit, the Lunar System is assembled from 5 kilowatt-hour battery blocks inside a single enclosure, giving configurations of 15, 20, 25 and 30 kilowatt-hours behind one inverter.
The practical consequence is precision. A household whose evening load and backup priorities point to 25 kilowatt-hours can be specified at exactly 25. With a platform built around fixed 13.5 kilowatt-hour units, the same household chooses between 13.5 and 27 — under-buying or over-buying by a meaningful margin. Where a design lands neatly on a fixed unit’s capacity, that advantage disappears entirely. It is a real benefit in some cases and no benefit at all in others, which is the honest way to describe it.
The block also appears on the California Energy Commission’s certified battery equipment list, which is where any storage product must appear to be used in California incentive programs, and is a useful independent check on any manufacturer’s claims.
Power output: reading the ratings carefully
The Lunar System is rated at 9.6 kilowatts continuous and 15 kilowatts peak for 5 seconds off-grid. Both numbers need context to be useful.
The continuous figure is the manufacturer’s full-sun rating — the output available when solar is contributing alongside the battery. Battery-only output, which is what governs an evening or an overnight outage, is lower and varies with how many blocks are installed. If your reason for buying is backup after dark, ask specifically for the no-sun continuous rating at the capacity you are being quoted, not the headline figure.
The peak rating is stated with its duration, which is the right way to publish it. What Lunar does not currently publish is a motor-start or locked-rotor amp figure, which is the specification that most directly predicts whether a system can start a central air conditioner. Some competitors do publish one. If air conditioning on backup is a requirement for your household, that is a question to put to the manufacturer rather than infer from the surge number.
How solar connects to it
The system uses module-level electronics — Lunar calls them Maximizers — that attach to individual solar modules and feed a hub, which in turn feeds the hybrid inverter’s DC bus. This is a different philosophy from a battery with several integrated maximum power point trackers handling whole strings.
Module-level electronics tend to perform better on complicated roofs: multiple planes, partial shading from a chimney or a neighbour’s tree, or mismatched module orientations. On a simple, unshaded south-facing roof the advantage is much smaller. The system also supports AC coupling, which is the mechanism by which storage is generally added to solar that already exists — though anyone retrofitting should have compatibility with their specific existing inverter confirmed in writing rather than assumed.
Warranty and throughput
The battery carries a 12.5-year warranty, against the 10 years that is common across the category. It is bounded by a throughput cap — a total quantity of energy that can pass through the battery over the term — which scales with the configured capacity, so a larger system carries a larger allowance.
Throughput caps are worth understanding rather than glossing over. A household cycling a battery hard every day, particularly one enrolled in a utility program that dispatches it frequently, will consume throughput faster than a household that uses it lightly. When comparing warranties, compare term and throughput together; a longer term with a tight cap is not automatically better than a shorter term with a generous one.
Gridshare and virtual power plants
Lunar operates a software platform called Gridshare, originally acquired from a UK company, which manages large fleets of distributed energy resources for utilities and energy retailers. It is notably hardware-agnostic — it manages devices Lunar did not manufacture — and it underpins virtual power plant programs including work with California community choice aggregators.
For a homeowner this matters in one specific way. Virtual power plant and demand-response programs pay owners for making stored energy available to the grid at critical times, and participation is generally arranged through an aggregator rather than signed up for directly. Whether a given platform is enrolled in a program available in your territory is a real consideration, and the answer changes by year and by utility.
How it compares to a Powerwall 3
| At a glance | Lunar System | Tesla Powerwall 3 |
| Capacity steps | 5 kWh blocks; 15, 20, 25 or 30 kWh | 13.5 kWh per unit; scale by adding units |
| Continuous output | 9.6 kW (manufacturer full-sun rating) | 11.5 kW on-grid, configurable from 5.8 kW |
| Peak / off-grid | 15 kW for 5 seconds off-grid | Up to 15.4 kW off-grid, configurable, conditions apply |
| Motor-start rating | Not published | 185 A LRA published |
| Solar architecture | Module-level Maximizers into a hub | Integrated MPPTs, no module-level electronics |
| Warranty | 12.5 years, throughput-capped | 10 years, internet connection required |
| Fleet software | Gridshare, hardware-agnostic | Tesla’s own platform, Tesla hardware |
Read honestly, this is a set of trade-offs rather than a winner. Lunar offers finer capacity granularity, a longer warranty term and module-level solar electronics. The Powerwall 3 publishes a higher on-grid continuous rating, a published motor-start figure, and more solar input capability. Which set matters depends entirely on the roof, the loads and the priorities of a particular house.
Who it suits — and who it does not
The Lunar System tends to suit households whose right capacity falls awkwardly between fixed-unit steps, homes with complicated or partially shaded roofs where module-level electronics earn their place, and owners who weight a longer warranty term heavily.
It is a weaker fit where the deciding requirement is starting a large single-stage air conditioner on backup power, simply because the specification that answers that question is not published; and where a household’s ideal capacity lands neatly on a competing platform’s fixed unit, in which case the modularity buys nothing.
What to check before choosing any platform
Four things, in order. What your evening usage actually is, from a recent bill rather than an estimate. What must run during an outage, and what each of those loads demands at startup. What programs your utility territory currently offers and which platforms are eligible. And how the system will interconnect — every battery in California connects under the CPUC’s Rule 21 tariff, with inverter certification requirements that apply regardless of brand.
Solari works across four battery platforms rather than representing one, which is the reason the specification conversation can start from your house instead of from a product. Send a recent utility bill and you will get a read on what your household actually needs and which platform fits it — and if storage does not make financial sense for your house, you will be told that instead. You can send a bill over with no obligation and no sales call unless you ask for one.
Frequently asked questions
Can the Lunar System be added to solar I already have?
The system supports AC coupling, which is the usual route for adding storage to an existing array. Compatibility depends on your specific existing inverter and should be confirmed in writing before you commit.
Can I add capacity later?
The architecture is built from 5 kilowatt-hour blocks, so expansion within the supported range is part of the design. Confirm the maximum for your configuration and whether later expansion carries the same warranty terms as the original blocks.
Will it run my air conditioning during an outage?
Possibly, depending on your compressor and whether a soft starter is fitted, but Lunar does not publish a motor-start rating, so this needs confirming for your specific unit rather than assuming from the peak figure.
Is 12.5 years better than a 10-year warranty?
Longer on term, but warranties are also bounded by energy throughput, so compare both together. How hard you cycle the battery determines which limit you reach first.
How do I work out which platform is right for my house?
Send a recent utility bill to Solari, along with what needs to run during an outage, and you will get a straight read across the platforms rather than a recommendation for one — no obligation, and no sales call unless you ask. Reach Solari at (916) 507-1626 or stephen@solaristorage.com. Coverage is California only.
Key takeaways
- The Lunar System is modular — 5 kWh blocks giving 15 to 30 kWh behind one integrated hybrid inverter — which lets a design land on an exact capacity instead of a fixed step.
- Its 9.6 kW continuous rating is a full-sun figure; ask for the battery-only rating if backup after dark is the point, and note that no motor-start specification is published.
- The 12.5-year warranty is longer than the category norm but is bounded by a throughput cap, so term and cap should be compared together.
- Send a recent utility bill to Solari for a read across platforms rather than a pitch for one — (916) 507-1626 or stephen@solaristorage.com.
