You asked about Fusion Energy
25 people built something like it. 3 are gone.
That is 13% of the ones whose fate we could settle, against 23% across the whole register. 1 were acquired.
| Launched | What it was | Today |
|---|---|---|
| 2023-02-28 | scribblediffusion.com | moved |
| 2016-01-01 | AI + Robotics for the Built World · geckorobotics.com | still up |
| 2022-09-08 | tattoosai.com | still up |
| 2018-06-01 | YCTENDERD AI Platform for Efficient and Sustainable Operations · tenderd.com | still up |
| 2022-06-01 | YCPaces Agentic AI for Power Projects and AI Infrastructure · paces.com | still up |
| 2022-01-01 | YCKorrAI Traceable AI for billion-dollar infrastructure. · korrai.com | still up |
| 2020-01-01 | YCPowerX AI powered sensors that save energy, water and emissions · powerx.co | acquired |
| 2021-06-01 | YCFerveret Nuclear-inspired cooling that turns wasted power into more AI compute · ferveret.com | still up |
| 2022-01-01 | YCPosh Turning power into AI compute at speed with modular data centers at… · poshenergy.com | still up |
| 2022-01-01 | AI-driven HVAC control system for improved energy performance · axross.co | still up |
| 2026-09-01 | YCInvertix Energy Superintelligence, AI that operates critical infrastructure · invertix.ai | still up |
| 2023-01-23 | freyja.software | still up |
| 2023-06-01 | YCNectar Manage energy cost & usage with AI for facility & sustainability teams · nectarclimate.com | still up |
| 2019-01-01 | AI driven professional engineering firm · traverse.ai | gone |
| 2024-01-01 | YCSpark AI-powered workflows for energy infrastructure · sparkhq.ai | still up |
| 2026-09-01 | Self contained solar-powered AI inference modules: the NanoDC · liquidenergy.world | still up |
| 2026-06-01 | YCMarengo AI-Native Engineering Firm designing Data Centers · marengox.com | still up |
| 2022-06-01 | Claim solar incentives with AI · jasmine.energy | gone |
| 2026-01-01 | YCSquid AI agents for power grid planning 🦑 · squid.energy | still up |
| 2023-06-01 | AI Energy Management · trycardinal.ai | gone |
| 2026-09-01 | AI-native manufacturing for data center and energy projects · appliedkinetics.ai | still up |
| 2026-06-01 | The robot workforce for infrastructure of the AI era · librabots.com | still up |
| 2026-06-01 | YCEdviro AI That Operates Energy Infrastructure · edviroenergy.com | still up |
| 2025-01-01 | AI-native remote operations center for hardware fleets · dartboard.ai | still up |
| 2026-01-01 | The first AI-powered uranium discovery company · terranox.ai | still up |
| 2025-01-01 | YCAstro Power-ready land for AI data centers · astroenergy.ai | still up |
How this compares
Y Combinator reports its own outcomes, including acquisitions. The other two are judged by asking the domain, so they are not measured the same way and are never averaged together.
The register re-probes every domain it holds. Some that answered last month stop answering. We send that list — what went quiet, and what it was — once a month. Nothing else.
How this was made. Show HN entries are every post from 2021 to 2023 with at least five points that linked to its own domain; code hosts and free hosting are excluded, because a repository outlives the effort behind it. Product Hunt entries needed 100 votes — a far higher bar, so they are the promoted top slice rather than a like-for-like sample. Both are judged by asking the domain whether it still answers: gone means it no longer resolves, refuses the connection, serves a parking page, or says plainly that it shut down. An HTTP error is not counted as gone — a server answering 404 is one somebody still pays for, and an audit of 25 gone-calls found two such sites alive with only a moved homepage. Y Combinator entries use the status YC publishes itself, which is why only those can say acquired. Squatted domains — a lapsed name now serving somebody else's site — are not detected, so these figures run slightly low.