Energy / Residential storage & VPP · Deep dive

Lunar Energy

A former Tesla Energy chief's home-battery-plus-VPP-software play — the sleek Lunar System battery sold through installers, and Gridshare, the AI dispatch platform already orchestrating ~130,000 mostly-rival home batteries for Sunrun and across Japan.

emerging

The question that decides it: Lunar is really two businesses stapled together: a capital-intensive home battery it sells and leases through installers, and Gridshare, a device-agnostic VPP platform that already dispatches ~130,000 batteries — most of them built by rivals — for Sunrun and utilities abroad. The software is the higher-margin, more defensible asset; the hardware is the cash furnace that competes head-on with Tesla's Powerwall, Enphase's IQ Battery and Base Power's vertically integrated $13B machine. Does the Gridshare revenue-share economics (customers earned an average of ~$464 from VPP participation in 2025) plus leased hardware compound into durable margin before the U.S. residential-solar contraction — NEM 3.0, high rates, SunPower's 2024 bankruptcy — starves the installer channel Lunar depends on, and before Tesla's Autobidder and Base's owned fleet make an independent orchestration layer redundant?

My take ★★ Very interesting ★ Interesting − Maybe ✗ Not interesting

Snapshot

Lunar Energy is a Mountain View company founded in 2020 by Kunal Girotra, the former head of Tesla Energy, to sell an integrated home-energy system — the Lunar System battery — and, more importantly, to run the software that turns fleets of home batteries into virtual power plants. Its Gridshare platform is device-agnostic: it already dispatches roughly 130,000 home batteries for Sunrun across the U.S. plus tens of thousands more in Japan and Europe, most of them made by other manufacturers. In February 2026 Lunar disclosed $232 million in fresh capital — a previously unannounced $130 million Series C led by Activate Capital (closed 2024) and a $102 million Series D led by B Capital and Prelude Ventures — lifting total funding above $500 million. The company is trying to do two hard things at once: manufacture and deploy hardware in a brutal U.S. residential-solar market, and build the neutral orchestration layer that sits on top of everyone’s batteries. Whether those two businesses reinforce each other or compete for the same scarce capital is the whole question.

Founding story

Girotra ran the part of Tesla that most resembles Lunar. He joined Tesla’s energy group, led its consumer products — Powerwall, solar panels, Solar Roof — and by 2018 was running Tesla Energy, staying until February 2020. He left with a specific frustration: the pieces of a clean home — panels, battery, inverter, EV charger, thermostat — were still sold and controlled separately, and no one had built the coordinating brain that makes them behave as a single system. He founded Lunar in August 2020 to build that, hardware and software designed together from the ground up.

The company operated in stealth for two years, raising about $300 million across two rounds — roughly $150 million each from Sunrun, the largest U.S. residential solar installer, and South Korea’s SK Group, a battery-and-chemicals conglomerate. When it emerged in August 2022, it did two things at once: launched the Lunar System hardware and acquired Moixa, a British smart-battery software firm founded by Simon Daniel. Moixa is the unsung half of the story. Its GridShare platform already managed tens of thousands of home batteries — 35,000 homes and 330 MWh via ITOCHU in Japan, plus Honda EV smart-charging — and became Lunar Gridshare, the asset that now looks like the more valuable side of the business. Japanese trading house ITOCHU signed a capital and business alliance at launch.

How it works

Two distinct machines. The hardware is the Lunar System: a wall-mounted home battery built from 5 kWh modules, stacked up to six per cabinet, configurable at 15, 20, 25 or 30 kWh, paired with a 9.6 kW inverter that handles solar input and home output simultaneously. It stores rooftop solar, backs up the house during outages, and — critically — can discharge to the grid on command. Certified installers, not Lunar’s own crews, put it on the wall.

The software is where the interesting engineering lives. Gridshare is a cloud platform that aggregates distributed resources — home batteries, solar, EV chargers, thermostats — into optimized VPP fleets. At any moment it must know each home’s consumption, solar generation, forecast production, state of charge, upcoming electricity prices, and what the grid will pay for exported power, then decide in real time whether each battery charges from solar, discharges to the home, or exports to the grid. It runs a home-energy-management (HEMS) model that optimizes value per device, and it dispatches like a relay race — commanding full output from one set of homes, then handing off to another — rather than smearing a fractional draw across every battery, which preserves customer backup reserves and responsiveness. Being device-agnostic is the point: Gridshare runs batteries it did not build, which is why it can manage Sunrun’s overwhelmingly non-Lunar fleet.

Product and business overview

Three components. First, the Lunar System — the integrated battery-and-inverter hardware, sold and serviced through a network of certified Lunar installers rather than a direct sales force. Second, Gridshare — the VPP/energy-management software, licensed to energy companies and utilities to orchestrate their own fleets, and the layer that bids aggregated capacity into grid-service and wholesale markets. Third, an emerging retail-electricity motion: through an April 2026 partnership with Octopus Energy in Texas, Lunar bundles its battery into a consumer electricity plan, moving downstream toward owning the customer relationship.

The tension is visible in the components. Gridshare’s value grows with every battery under management regardless of brand — a software network effect. The Lunar System drags Lunar into the capital-intensive, installer-dependent hardware fight against Tesla, Enphase and Base. The bet is that owning both captures VPP value it would otherwise share; the risk is the hardware consumes the capital the software needs.

Business model and pricing

Revenue comes from three places: hardware sales and leases through installers, Gridshare software licensing and VPP revenue-share, and now retail-electricity margin. Lunar leans on the lease/no-money-down model that dominates U.S. residential solar — homeowners pay little or nothing upfront, and Lunar (and its partners) monetize the asset over time plus the grid-service income the battery earns. The company says VPP participants earned an average of about $464 in 2025 — the number the entire leasing economics hinges on.

The clearest published price point is the Octopus Energy Texas plan launched April 22, 2026: a 30 kWh Lunar battery at $0 upfront, a $45 monthly subscription, and a flat electricity rate starting at 8 cents/kWh for three years, with the battery providing both backup and grid services. That is a direct answer to Base Power’s Texas model — retail electricity fused to a subsidized battery whose grid value the provider harvests. Lunar publishes no outright sticker price; through installers a 15-30 kWh system is quoted like any premium residential storage product, in the tens of thousands installed before incentives.

Traction over time

Reading the series: the software has scaled faster and cheaper than the hardware. Gridshare went from Moixa’s ~35,000 Japanese homes in 2022 to roughly 130,000 U.S. batteries under management by 2026, plus a footprint across three continents — and it did so largely on other companies’ hardware. The Lunar System, meanwhile, is only now ramping from about 10,000 units a year to a target of 100,000 by end-2028, and physical deployments concentrate in California, Georgia and Washington, with Texas added via Octopus. The device fleet is a fraction of the software fleet — a telling gap.

Market analysis

The demand backdrop is strong and the near-term U.S. picture is complicated. Fortune Business Insights put the global residential battery energy storage market at roughly $8.7 billion in 2026, growing ~17.8% annually; the virtual-power-plant software market is pegged anywhere from ~$4.6 billion to ~$7.7 billion in 2026 depending on the analyst, with residential the fastest-growing slice. BloombergNEF forecasts about 158 GW / 459 GWh of storage deployed globally in 2026. VPPs already delivered hundreds of megawatts of grid relief in California, Puerto Rico and New England in summer 2025.

But the U.S. residential-solar market feeding Lunar’s hardware is in a genuine downturn. High rates crushed loan-financed installs; California’s NEM 3.0 gutted the export-credit math that made rooftop solar pencil; and SunPower — once a marquee national installer — filed for bankruptcy in 2024. That is exactly why the battery-plus-VPP pitch exists (a battery earns grid revenue even when net-metering is stingy), but it also thins the installer base Lunar sells through just as it spends to scale manufacturing.

Competitive intel

Lunar is squeezed from both ends (full profiles above). On hardware, Tesla owns the default home battery and the brand; Base Power is deploying a vertically integrated, retail-plus-owned-battery model with a war chest — ~$1.3B raised and a $13B valuation by August 2026 — that dwarfs Lunar’s; Enphase ($1.5B 2025 revenue) already sits in the installer channel Lunar needs. On software, Tesla’s Autobidder (3 GW-plus dispatched) and Renew Home/Google Nest (anchoring ~60% of a 16 GW Tesla-Sunrun VPP) compete for the same grid-service contracts Gridshare bids into, and Renew Home does it with an asset-light thermostat model at far larger scale.

Where Lunar wins: Gridshare is genuinely device-agnostic and already at scale on rivals’ hardware — a neutral layer Tesla’s walled garden cannot be — backed by an ex-Tesla-Energy pedigree and deep Sunrun/ITOCHU/Octopus ties. Where it is exposed: Sunrun is investor, biggest customer and competitor at once, and the hardware business is a rounding error next to Tesla and Base with no cost or scale moat.

History and evolution

• Aug 2020 — Founded in stealth by Kunal Girotra, months after he left Tesla Energy.
• 2020-2022 — Raises ~$300M quietly from Sunrun and SK Group.
• Aug 2022 — Emerges from stealth; launches the Lunar System; acquires Moixa (Gridshare); ITOCHU signs a capital and business alliance.
• Summer 2023 — Powers what it calls the largest U.S. residential battery VPP, ~27 MW average over 90 days in California for Sunrun.
• 2024 — Gridshare takes over Sunrun’s nationwide VPP fleet (toward ~130,000 batteries); closes a $130M Series C led by Activate Capital, left undisclosed at the time. Broader industry stumbles: SunPower’s bankruptcy, NEM 3.0’s bite.
• Apr 2026 — Launches the $0-down, 8¢/kWh Octopus Energy battery plan in Texas, moving into retail electricity and onto Base Power’s turf.
• Feb 4 2026 — Discloses the $130M Series C and a new $102M Series D (B Capital, Prelude Ventures), $232M total, $500M+ to date; sets a 100,000-units-by-2028 manufacturing target.

The stumbles are real if under-reported: Lunar has conducted layoffs, and Glassdoor reviews cite churn from lean teams and aggressive timelines — the residual scar tissue of building hardware through a solar downturn.

What people say

The case for. Trade press (Canary Media, Heatmap, Latitude Media, TechCrunch, February-April 2026) treats Lunar as one of the more credible residential-VPP stories precisely because Gridshare is already dispatching ~130,000 batteries — most of them not Lunar’s — which is a harder, more defensible thing than shipping another battery. The device-agnostic software plus a founder who literally ran Tesla Energy is a differentiated combination, and the Octopus Texas plan shows Lunar can package the value into a clean consumer offer. Employees rate the company well: about 4.3 out of 5 on Glassdoor across ~67 reviews with ~86% recommending, praising the mission, the talent and Girotra himself. The ~$464 average 2025 VPP earnings give the leasing math a real, if modest, number.

The complaints. The bear case is structural and sharp. First, this is arguably a software company dragging a hardware anchor: the Lunar System competes with Tesla, Enphase and a $13B-valued Base Power in a market where Lunar has no cost or scale advantage, burning capital that Gridshare would spend more efficiently. Second, the customer concentration is extreme — Sunrun is investor, largest software customer and competitor simultaneously; if Sunrun in-sources orchestration or falters, Gridshare’s headline number evaporates. Third, VPP revenue-share economics are unproven at scale; ~$464 a year per home is thin against battery cost, and grid-service prices are policy-dependent. Fourth, the macro is ugly — NEM 3.0, high rates and SunPower’s 2024 collapse are shrinking the installer channel Lunar rides. And the internal signals corroborate the strain: layoffs, lean teams, and Glassdoor gripes about aggressive timelines and management that some engineers say lacks technical depth. The uncomfortable read: Lunar may be a good software business wearing an expensive hardware costume in the worst residential-solar market in a decade.

Outlook: the open question

Lunar works if Gridshare becomes the neutral, device-agnostic orchestration standard for residential VPPs — compounding revenue-share across hundreds of thousands of batteries it did not build — and if the leased/bundled hardware (via Octopus-style plans) throws off enough grid value to self-fund without a Tesla- or Base-sized balance sheet. It fails if the hardware business consumes the capital before the software network effect locks in, if Sunrun’s concentration turns from asset to liability, or if Tesla’s Autobidder and Base’s owned fleet make an independent orchestration layer redundant while the residential-solar downturn starves the installer channel. The two-sidedness is the whole story.

The bull case: the grid needs distributed flexibility, Gridshare already runs a large multi-vendor fleet, and a former Tesla Energy chief with Sunrun, ITOCHU and Octopus behind him is credibly positioned to be the software layer on top of everyone’s batteries. The bear case: Lunar is fighting a capital war on hardware it cannot win against Tesla and Base, leaning on a single customer that is also a rival, and monetizing thin, policy-dependent VPP value through the worst residential-solar stretch in years — with layoffs already on the record. What settles it toward success: Gridshare’s managed fleet and per-battery revenue climbing on non-Sunrun, non-Lunar hardware; the Octopus/Texas model proving grid value covers subsidized batteries; manufacturing hitting its 100,000-unit 2028 target without a cash crisis. What settles it against: Sunrun pulling its fleet or stumbling; VPP economics staying sub-scale; or the next raise arriving at a down round because the hardware burned the runway. With $500M-plus raised against rivals measured in billions, Lunar has enough capital to prove the software thesis — but not enough to win the hardware war it has also chosen to fight.

How a challenger would attack it

Be the software company Lunar can’t afford to be. Lunar’s exposed flank is its own architecture: the defensible asset is Gridshare, but the balance sheet is committed to a hardware ramp — 10,000 units a year climbing to 100,000 by 2028 — against Tesla’s brand and Base Power’s $1.3B war chest, in a residential-solar market where NEM 3.0 and the SunPower bankruptcy are thinning the installer channel Lunar sells through. A challenger builds pure-play, device-agnostic VPP orchestration with no factory: no capital furnace, no channel conflict, and — the sharpest angle — no hardware line competing with the very manufacturers whose batteries it wants to orchestrate. Every Enphase, SolarEdge or Sonnen fleet is easier to sign when the orchestrator doesn’t also sell a rival cabinet. The second vector is the Sunrun dependency: ~130,000 of Gridshare’s batteries ride on a single customer that is simultaneously investor and competitor, so the challenger targets every other fleet owner — utilities, retailers, community solar operators — and pitches Lunar’s concentration as its fragility, especially after the June 2026 Tesla-Sunrun-Renew Home 16 GW announcement showed Sunrun shopping the orchestration layer. Third, undercut the consumer math: $464 a year of average VPP earnings is thin; a Base-style owned-fleet model in deregulated markets keeps the whole grid-revenue stack instead of revenue-sharing it, out-economizing Lunar’s $45/month Octopus plan with deeper capital.

Same playbook, new buyer

The Gridshare half of the playbook travels better than the battery. The proven pattern — device-agnostic orchestration licensed to whoever owns the fleet — has buyers Lunar is barely touching: regulated U.S. utilities running battery incentive programs, European retailers navigating dynamic tariffs, and Japanese and Australian markets where Moixa’s ITOCHU and Honda relationships already prove the model works on three continents. A focused player selling orchestration to utilities as ratepayer-funded grid infrastructure — rather than revenue-sharing with homeowners — sells into a budget that doesn’t depend on solar-install volume at all, which matters in a downturn that is starving Lunar’s channel. The second shift is the asset class: Gridshare’s relay-race dispatch logic applies to EV fleets, heat pumps and C&I behind-the-meter storage, where per-site grid value is a multiple of a home’s $464 and no incumbent orchestrator owns the category the way Tesla owns the home battery. Lunar can’t chase these adjacencies aggressively because every spare dollar and engineer is mortgaged to the 100,000-unit manufacturing target — the hardware bet is precisely what pins the software where it is.

Sources and further reading

• Lunar Energy raises $232M to deploy home batteries that prop up the grid (TechCrunch, February 4 2026)
• Lunar Energy lands $232M to boost smart home batteries (Canary Media, February 2026)
• Lunar Energy Raises $232 Million to Scale Virtual Power Plants (Heatmap News, February 2026)
• Home battery startup Lunar Energy aims to quadruple its manufacturing (Latitude Media, February 2026)
• Inside the software running Sunrun’s home solar-battery fleets (Canary Media, 2024)
• Tesla’s former energy head has a new electric-home startup (Bloomberg, August 2022)
• Lunar Energy enters solar+battery field with $300M investment (Canary Media, August 2022)
• Octopus Energy, Lunar Energy roll out battery-enabled electricity plans in Texas (Utility Dive, April 2026)
• Base Power raises $1B to roll out its giant new home battery (Electrek, August 2026)
• Tesla, Sunrun and Renew Home’s 16 GW VPP (Solar Builder, June 2026)
• Lunar Energy Reviews (Glassdoor, accessed 2026)