Lunar Energy’s home battery system is designed to make solar easier to use

The Lunar System’s main home battery unit contains cells and an inverter, with add-on battery modules stacked underneath. | Image: Lunar Energy

Lunar System — from Tesla’s former head of energy — is a solar energy backup system with modular battery units that can power your whole home. It might even make you some money… eventually.

Lunar Energy, a home battery backup company that came out of stealth last year, is revealing its first product called the Lunar System. It’s an all-in-one hybrid inverter, expandable battery backup system, and energy controller that can smartly manage power from the Sun — using new or existing solar panels — and the grid while giving users control over the whole system in one app. Lunar’s so-called “personal power plant” is also being pitched as an opportunity to earn money by getting paid for any excess power you send back to the grid.

Lunar Energy is entering an increasingly crowded market for energy independence with the Tesla Powerwall being the most recognizable consumer product in the category. Lunar Energy’s founder and CEO, Kunal Girotra, just happens to be Tesla’s former head of energy, which made him responsible for Tesla’s solar and Powerwall ambitions before leaving in early 2020.

“We leapfrog them in a big way,” said Girotra of Tesla during a video call with The Verge that included a demonstration of the Lunar System. Girotra says that what the Lunar System offers — all-in-one control in a compact offering with so much storage capacity and the ability to control loads — doesn’t exist in the market.

Image: Lunar Energy
Lunar Energy’s app includes connected services that can make proactive decisions to help you through situations like expected power outages.

If you drive through any suburban neighborhood nowadays, you’ve probably seen homes with solar panels affixed to their rooftops. Those homeowners are likely trying to lower their electric bills by being energy-efficient during the day, but those panels aren’t adding much value when it’s dark or cloudy out. And when the grid goes down, solar panels alone aren’t generally going to keep all your appliances running. That’s why energy storage is such an important consideration.

Batteries from companies like Lunar Energy can be used to power the home when the grid goes down, at night, or during peak times to reduce reliance on electrical energy that could be coming from nonrenewable sources like coal-burning plants.

And with Lunar’s Bridge, which acts like a power gateway between the grid and battery, homes can automatically go on backup power in the event of an outage or proactively do so if there’s severe weather approaching. Users can also use the app to flip the switch from grid to battery power in a flicker-free 30 milliseconds.

Lunar’s app is packed with features and data — but only if users want to see it. On the surface, the app is designed to show you just what you need to know: how much power you have for backup, how much you’re consuming, and how much your solar is generating. It’ll also give you an easily readable report on how power is being utilized at any given time.

You’ll also be able to sell excess power back to the grid and connect with other Lunar System owners as a virtual power plant (VPP) to keep the local grid stable. And you can accurately calculate savings rates based on your local utility plans.

Image: Lunar Energy
The app interface is cleanly designed and easy to read for most users.

Lunar Energy is entering an increasingly competitive market. A whole lot of airtime has gone to Tesla’s Powerwall, which marries an attractive slate appliance (the Powerwall battery) to an app that follows a design language familiar to Tesla vehicle owners. Tesla had already disrupted the automotive market with its Silicon Valley software company approach — meanwhile, Lunar Energy is betting on its own software-forward advancements to home power.

The app has profiles you can set to make the Lunar System operate however you prefer. For instance, there’s a “self-consumption” mode, where the Lunar Bridge is “metering the connection between the grid and the home” and controlling it to be zero, as explained by Lunar Energy’s head of engineering, Kevin Fine, on a video call with The Verge.

Fine demonstrated the Lunar System live in a test environment. The hardware and software worked as intended, and Fine even showed how the power load of a live running dryer can be automatically caught and continue running when an emulated power outage occurred.

Of course, you’re going to need enough battery blocks and enough daily sun to handle a fully off-grid system. The Lunar System can be configured with 10kWh to 30kWh of capacity in a single unit, with 5kWh battery block increments in between.

Image: Lunar Energy
The top unit is both the hybrid inverter and 10kWh worth of pouch cells.

Lunar System is built around a powerful inverter included in the main battery unit that can handle up to 10kW of power, which can potentially tolerate loads from electric stoves, dryers, and HVAC units simultaneously. That’s compared to Tesla’s separate mini-Powerwall-looking inverter that, at best, can handle 7.6kW loads. And EcoFlow’s PowerOcean solar backup solution also has a 10kW inverter, but that system is currently only slated for Europe.

Lunar’s ecosystem also includes the Lunar Switch, which can automatically control and shut off unnecessary appliances such as a pool pump during a power outage. Lunar Switch can either be installed in an existing breaker panel or inside a Lunar Bridge (which can double as your primary breaker).

Per Lunar’s calculations: the average California home with a 20kWh Lunar System and 5kW worth of solar panels would pay for itself within seven years. Such an installed configuration could cost between $20,000 and $30,000, according to Lunar Energy.

Notably, the California Public Utilities Commission (CPUC) recently reformed solar incentives in the state that were proposed in November. Now, the new Net Energy Metering 3.0 (NEM 3.0) is active for all new solar installations, and it slashes earnings from exported energy generated by solar installs — thereby extending the time homeowners can recoup hardware and install costs.

Unlike Tesla, Lunar Energy does not make or sell its own solar panels. Instead, Lunar is partnering with Sunrun and other installers to handle not only customers’ solar needs but also to install Lunar System as well. Interested customers can configure their own system on Lunar Energy’s site now, and orders can be made through Sunrun starting in the fall.

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