Endurance is on a historic run. During our mission to the Axial Seamount, we successfully drilled the world’s first subsea geothermal well and generated net-positive power a mile beneath the Pacific. This mission was the first end-to-end test of subsea geothermal, and our fifth just over a year. For three weeks, we worked around the clock over an active underwater volcano, running the drill and generator and handling every deployment and recovery. Along the way, we:
- Landed our drill within feet of target, drilled two holes, and cased and completed the second as a geothermal well, flowing at 260°C.
- Landed Adélie, our 3-ton test plant, and ran it in real time from Seattle over subsea fiber.
- Drilled with filtered seawater, not drilling mud, and monitored the site on every dive.
- Recovered, serviced, and redeployed Adélie in about 16 hours.
- And on Sept. 27, connected to a 281°C natural vent, spun the turbine up to 26,000 rpm and ran the plant net positive for 8.7 seconds, peaking at 16.5 kW.

Net power is the threshold every new energy source has to cross. For Endurance, it proves subsea geothermal is real, and gives us the confidence to keep sprinting towards commercial scale.

With a test like this, success comes from what we learn: a battery protection trip ended the run, a pump cable failed on restart, and the new well was too restrictive to run the plant. Those lessons go straight into Gentoo, our next test plant, this winter and Leopard, our 2 MW commercial generator.

We’re incredibly proud of what we accomplished together. It took creativity, precision, an uncompromising focus on safety from everyone on board, and it’s only the beginning of what we’re capable of. We couldn’t have done it without Stabbert Maritime and the crew of the Ocean Guardian, the ROPOS team, the University of Washington, WASSOC, and the National Science Foundation.

Last week at @thebatteryshow @ManaBatteryInc was awarded Battery Innovation of the Year. Last year, this award was given to @GM and @LG_ensol. This year, the award recognizes Mana's pioneering work on anode-free sodium-ion cells and electrolytes. globenewswire.com/news-release/2…

Arbor is building zero-emission gas turbines to power data centers and our energy future - and they just cleared a huge milestone

The team recently hit full power on their 1 MW direct-fired sCO2 turbocompressor - 60,000+ RPM and 2+ hours of run time

I did my PhD in thermal ard one. Plenty of folks have drawn this system on a whiteboard, but Brad, Andres, and the cracked Arbor team pulled a world first and spun it up. Oxy-combustion, sCO2 bearings, compressor mapping and 3D printed rotors all had to work together, at speed

This team is the real deal. They’ve pulled through every time where others have failed - it’s why we’re all in at @VoyagerVC

Next up: the full 1 MW ATLAS pilot, then the 25 MW HALCYON unit, built for mass production. Proud to have backed them since the seed and to be on the journey with our friends @cantos @lowercarbon @gigascale and more

The anode is one of the most supply-constrained parts of a battery cell, and in a lithium battery its materials come almost entirely from China.

Mana Battery, Inc. builds a cell without one. Its batteries run on sodium instead of lithium, drawn from earth-abundant and non-FEOC materials. The design cuts materials cost by 40% against the cheapest lithium-ion cells on the market, while matching or beating their energy density.

The cells are drop-in, built on existing lithium-ion lines. In under three years the team has put prototypes in the hands of tier-one battery makers, defense contractors, and the U.S. Army.

We’re proud to back @tylerjevans_1 and his team, leading Mana’s seed round alongside @usv and @buffgoldventure.

Full @WSJ story here: wsj.com/pro/venture-ca…

Mana Battery is out of stealth.

Taking the anode out of the cell is one of the biggest levers left in batteries - fewer materials, lower cost, higher energy density. Mana is doing it with sodium, so no lithium and no China supply chain. And the team builds incredibly fast - I've nce pre-seed.

At @VoyagerVC we invest in the tech rebuilding American energy and industry - proud to lead their $10.15M seed, welcoming @usv to the cap table alongside existing investors like Buff Gold.

Full story in the @WSJ below 👇

Showed this video to someone and they were like "that's not AI, right?" 😂 Guess we're building the "real world AI" everyone's been talking about! 🛠️

After three years of quietly building at Mana Battery, Inc., @RhiannonHoyle's feature in @WSJ announces our team’s progress and our over-subscribed Seed Round with @VoyagerVC @usv and @buffgoldventure. Proud to be a part of this team.

wsj.com/pro/venture-ca…

While more investors are realizing battery storage will continue to see massive growth, @Moment_Energy just made the MIT @techreview 10 Climate Tech Companies to Watch in 2026.

@VoyagerVC is proud to support the team making battery repurposing a reality - well done team!

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Boom - inevitable. Texas, the top US oil producer, just passed California in solar gen and leads the nation in battery storage. When an O&G state laissez-faires its way to clean power because it's the cheapest + fastest option, nothing's stopping this now.

In NYC for Climate Week, fasting for Yom Kippur today. If you're around this week, say hi. I'll be the one staring longingly at the Eataly sandwiches.

Proud to back a team that builds this fast. Adelie's launch will be worth the wait. 🚀

@endurancegeo

See you at London Deep Tech Week!

More thoughts on the state of US battery manufacturing coming soon.

For now: proud to highlight portfolio company Electroflow's coverage in the WSJ today. Turning lithium brine directly into structurally cheaper, fully US-made LFP, this is what reshoring the battery supply ke.

@ChEMcShane @albertwenger @LarsenJensenUSA @Alexteng @usv @VoyagerVC @fiftyyears @HarpoonVentures

Read more here: wsj.com/pro/venture-ca…

Expecting a wave of next-gen gas turbine startups over the next 6 months. Already seeing an uptick in aeroderivative, sCO2, organic Rankine cycle plays. No offense to my fission friends - as exciting as nuclear is for data centers and grid, turbines win the near term: faster to power, less regs, and generally cheaper. Gas is also a mature, deep fuel market, nowhere near the HALEU/TRISO bottleneck nuclear startups are stuck with.