You asked about Energy Storage
18 people built something like it. 5 are gone.
That is 31% of the ones whose fate we could settle, against 23% across the whole register. 2 were acquired.
| Launched | What it was | Today |
|---|---|---|
| 2021-01-01 | Mobile Energy Storage Technology · moxionpower.com | gone |
| 2021-01-01 | Electricity price forecasts for energy storage, ev charging, etc. · inbalanceresearch.com | acquired |
| 2021-01-01 | YCGridware Protecting the grid today, preparing the grid for tomorrow · gridware.io | still up |
| 2021-01-22 | userbase.com | still up |
| 2021-06-01 | YCStownest Flexible On-Demand Storage Space for Household, SMEs & Travellers. · stownest.com | still up |
| 2021-01-01 | YCEnode Energy Orchestration Platform · enode.com | still up |
| 2021-01-01 | YCShepherd Modernizing commercial insurance · shepherdinsurance.com | still up |
| 2021-04-29 | airbox.ai | still up |
| 2021-06-01 | Low-cost, high-scale EV charging platform for apartments (and more). · heycharge.com | still up |
| 2021-06-01 | YCFerveret Nuclear-inspired cooling that turns wasted power into more AI compute · ferveret.com | still up |
| 2021-02-12 | teams.cubbit.io | still up |
| 2021-06-01 | YCHeimdal Affordable and verified direct air carbon capture and storage · heimdalccu.com | gone |
| 2021-01-01 | YCAurabeat Providing clean, safe, virus free air for homes, buildings and cars · aurabeattech.com | still up |
| 2021-12-17 | engula.io | gone |
| 2021-01-11 | datoji.dev | gone~12mo |
| 2021-06-01 | YCEndla Software that increases the value of oil & gas wells · endla.com | still up |
| 2021-06-01 | Reducing energy costs & emissions in buildings. · kapacity.io | acquired |
| 2021-04-22 | drivestats.io | gone |
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.