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Even as US President Donald Trump swims ever deeper into the overflowing port-a-john of his authoritarian fever dreams, the grand plan for an oil-soaked future is crumbling around him. Exhibit A is the residential energy storage market, where investors are still hot on the trail of new opportunities to give consumers what they want — namely, more affordable electricity rates, preferably from renewable energy resources. That means home energy storage, and the startup Lunar Energy is making a big move in that direction.
Lunar Energy Is Coming For Your Fossil Fuels
On February 4, Lunar Energy reported a haul of $232 million in Series C and D financing. The cash infusion will enable the company to expand the market for its AI-powered energy storage system. The AI comes into play for “intelligently learning” patterns of electricity consumption on a house-by-house basis, enabling the system to make full use of any available solar energy for each ratepayer, including participation in virtual power plants that save money on electricity bills (see more VPP background here).
That’s similar to the technology deployed by other home storage systems, but different. Lunar states that on average, its customers have saved $464 by participating in virtual power plant programs, compared to $338 with a standard home battery.
“We built Lunar Energy to bring the best of hardware and software together, and this financing allows us to scale that model, helping homes electrify and become active participants in a smarter, more resilient grid,” Lunar CEO and founder Kunal Girotra said in a blog post announcing the Series C and D raise.
The total of $232 million includes an unannounced haul of $130 million for Series C, led by Activate Capital. Series D was oversubscribed at $102 million, an effort led by B Capital and Prelude Ventures.
“The Series C and Series D funding rounds also included participation from DCVC, Piva Capital, Leitmotif, Sunrun, Itochu Corporation, and Q Capital Partners,” Lunar notes.
Sunrun Invests In Lunar Energy …
If you caught the name Sunrun in that list, that’s where things get interesting. Kunal Girotra is a familiar face around energy storage circles, having been part of the Tesla Energy team from 2015 to 2020. He launched Lunar under the table in 2020, the same year he left Tesla, and he played his cards close to the vest for months afterward. Lunar didn’t emerge from stealth mode until August 24, 2022, at which point the company announced that it had already raised $300 million in two rounds of funding spearheaded by SK Group and — you guessed it — Sunrun.
And that’s where things get interesting. Sunrun was founded in 2007 and it began life as a solar installer. The company hooked up with Tesla in 2015, tasking its subsidiary AEE Solar with adding the Tesla Powerwall home battery system to its list of authorized residential energy storage products.
As for why Sunrun began investing in an ambitious energy storage competitor in 2022, that’s a question in need of an answer. However, the Lunar investment didn’t seem to interfere with the relationship between Sunrun and Tesla, at least not as of last year. On July 24, for example, Sunrun launched a new home energy plan in collaboration with the Tesla Electric branch of Tesla, aimed at maximizing solar production for the company’s “Sunrun Flex” subscription-based solar-plus-storage service.
“With the Tesla Electric + Sunrun Flex plan, Tesla Electric offers a low, fixed electricity rate and the most competitive sellback rates for excess solar energy sent back to the grid,” Sunrun enthused.
“Combined with abundant solar production from Sunrun Flex and seamless battery management, customers get maximum value, advanced outage protection, and greater peace of mind,” they added.
… And Lunar Energy Is Coming For Your Powerwall
Just a few months later, Sunrun and Tesla now seem to be drifting in different directions, and so is Tesla’s longtime solar panel supplier, Hanwha Q Cells.
Here’s the state of play (not in any particular order):
1. Tesla’s rooftop solar business was dying of neglect until the end of 2023, and possibly still is, but the company has stopped sharing data on that. In November of last year, however, the company announced that it started producing its own Tesla rooftop solar panels at its Buffalo, New York factory. Shipping is set to start sometime during Q1 of this year, if all goes according to plan. As reported by PV Magazine, the new Tesla solar panel is uniquely engineered to avoid power reduction caused by the single shadows cast by vent pipes, chimneys, and other rooftop infrastructure. This could mean that Tesla will no longer sell third-party solar panels, though it doesn’t necessarily mean that Tesla’s new solar panels will appear on Sunrun’s list of approved vendors.
2. In February of 2025, Korean news media reported that Hanwha was hooking up with LG in a plan to “develop and sell solar energy devices as a package to challenge Tesla Inc.” This could mean they will undercut Tesla’s new solar panel plan, or its Powerwall business, or both. However, in the US market, that partly depends on whether or not Qcells’ US manufacturing plan survives the Trump chopper.
3. Powerwall home battery sales showed signs of weakening in 2025 as customers-to-be registered extreme displeasure with Tesla CEO Elon Musk’s extracurricular activities. If a Cybertruck-worthy slide continues, that spells trouble.
4. On February 4 of this year, Lunar Energy announced two more rounds of financing totaling $232 million, with Sunrun participating among others. That could mean Lunar aims to nudge Powerwall off the Sunrun platform, with an assist from Sunrun itself.
Next Steps For A US Energy Storage Startup
I’m reaching out to Sunrun to see if they can provide a definitive statement on their plans for marketing Tesla Powerwall batteries and/or Tesla solar panels.
In the meantime, Lunar is powering forward on its new $232 million haul. The company notes that it already has 650 megawatts under management, spread across thousands of energy storage systems in various parts of the globe, with Sunrun front and center.
“Sunrun leverages Lunar’s Gridshare platform for its distributed power plants across a dozen markets, including New England, Hawaii, and Puerto Rico,” Lunar also notes.
In a press release announcing the new funding, Lunar investors took the opportunity to suggest that Lunar is already beating Powerwall at its own game. “The combination of Lunar’s DC architecture, intelligent hardware, and ease of installation differentiates its residential battery from others in the industry and has led to significant market traction in 2025,” explained Prelude Managing Director Tim Woodward in a press statement.
“Lunar uses sophisticated energy optimization intelligence to help homeowners manage rising home electricity bills. We’re excited to partner with the company as it shapes the next generation of decentralized grid operations,” Woodward added.
Raj Atluru, Managing Partner of Activate Capital, also chipped in his two cents. “Lunar brings together two powerful insights: first, that the future of solar is integrated solar and storage to deliver truly resilient homes; and second, that flexibility at the edge is becoming increasingly valuable for both grid stability and household resilience.”
Next Steps For Tesla
If you can name the CEO of Lunar without scrolling up through this article, run right out and buy yourself a cigar. Tesla’s chances of competing in a consumer market crowded with no-name CEOs are diminishing practically by the day, alongside a never-ending march of scandal.
Among the latest developments are Musk’s failure to manage the pedophile-adjacent behavior of his Grok chatbot, enabling millions of sexualized, non-consensual images of women, and thousands of girls, to circulate around his X social media platform, and his failure to provide for a kill switch on Starlink terminals, enabling Russia to deploy terminals on drones to murder Ukrainian civilians.
Now comes word that a judge has ordered Musk to sit for a deposition on his true role at DOGE and the decision to shut down the USAID program, an act that would normally require authorization from Congress. Deferring that authority to a lifelong rule-breaker is on the Republican members of Congress who refused to exercise their majority power to stop the catastrophe. Be that as it may, the loss of USAID funding has been a disaster for at-risk communities around the world, with the organization Oxfam among those putting the blame squarely on the shoulders of Elon Musk.
Stay tuned for more on that deposition. Musk was previously ordered to depose and he appealed the order. In the current case, the judge denied his appeal on the grounds that he and his co-defendants have “effectively acknowledged” that the orders to shut down USAID were given orally, without any documentation, and without the presence of any lower-ranking officials. That makes Musk’s testimony essential to the case — that is, if Musk ever decides to sit for a deposition just like any other person under a deposition order. Don’t hold your breath….
Featured photo: The US startup Lunar Energy has raised another $232 million towards its goal of dominating the US home energy storage market (cropped, courtesy of Lunar Energy).
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