1 How cryonics vessels behave during a blackout
Cryonics patients are stored inside large, vacuum-jacketed “thermos-like” dewars that are passively cooled by a pool of liquid nitrogen (LN₂) at –196 °C. The refrigeration is purely physical; no pumps or compressors are needed. If the mains power fails, the dewar just keeps boiling off nitrogen a little faster and vents the gas through relief valves, but the temperature inside hardly budges.
2 Typical hold-time before warming becomes a problem
Because the only heat input is through the dewar walls, boil-off is slow—about 0.5 % of the LN₂ volume per day for large 1 000–2 000 L “whole-body” vessels.
• A 2 000 L unit therefore loses roughly 10 L/day.
• If it starts full, it takes ≈180–200 days before the liquid is gone and the patient rises above −130 °C (the glass-transition point where real damage accelerates).
Facilities normally top up every 2–4 weeks and keep extra bulk tanks on site, so a weeks-long blackout poses essentially zero risk; you would need many months without any nitrogen resupply before real warming begins.
3 How likely is a resupply failure driven
only
by normal grid outages?
A convenient proxy is the SAIDI (System Average Interruption Duration Index):
| Region | Average unplanned outage per customer (2022–24) | Ratio vs. US |
|---|---|---|
| United States | 5.6 h / yr | 1× |
| Germany (typical of continental EU) | 12.8 min / yr | ≈ 1⁄26 |
Even in the less reliable U.S. grid, annual outages are measured in hours, not weeks. Delivery logistics (drivers, road access, industrial-gas plant downtime) dominate LN₂ availability, and those are usually restored within a few days after storms or regional failures. The chance that an ordinary blackout snowballs into a >3-month nationwide nitrogen shortage is comfortably <10⁻⁴ per year—orders of magnitude lower than the already-tiny chance you will ever be revived.
4 Extraordinary threats: EMPs and Carrington-class solar storms
Carrington-level geomagnetic events have an estimated ≈12 % probability per decade—about 1.3 % per year. A high-altitude nuclear EMP is harder to quantify, but U.S. national-security analyses often use a ∼0.4 % per-year probability of nuclear exchange. Both phenomena could fry transformers and cut electricity for months, halting bulk-gas plants and diesel-fuel supply chains.
Cryonics organizations are acutely aware of this: Alcor’s internal risk assessments list EMP or strong solar discharge as canonical worst-case scenarios that could “take years to repair.”
5 So what happens to the patients if an EMP really does hit?
- Immediate safety – Dewars remain cold for many months (see §2).
- On-site reserves – Most facilities keep several weeks to months of LN₂ in outdoor bulk tanks.
- Redundant production – Newer operators (e.g., European Biostasis Foundation in Switzerland) site themselves in politically stable areas and are moving toward on-site PSA/cryocooler nitrogen generators, eliminating dependence on external plants.
- Power-agnostic options – LN₂ can be produced with mechanical compressors or diesel gen-sets; it is WWI-era tech and could be restarted locally faster than a national grid.
Even assuming a Carrington-class storm (47 % cumulative probability over 50 years), you would still need all four layers of defence to fail before warming occurs. Conservative fault-tree models put the integrated thaw risk at roughly 0.5–5 % over half a century.
6 America vs. Europe—relative thaw risk
| Factor | United States | Europe (continental EU / CH) | Net effect |
|---|---|---|---|
| Routine grid reliability | Lower (hours of SAIDI) | Higher (minutes of SAIDI) | Europe safer |
| Target value for nuclear EMP | Higher (prime adversary of DPRK, Russia, etc.) | Lower | Europe safer |
| Latitude for solar GICs | Mid-latitudes, long east-west lines—moderate vulnerability | Similar or slightly higher at high-latitudes (Nordics) but with better transformer grounding | ≈ Tie |
| Political stability & diesel logistics | Variable by state; resilience plans uneven | High in CH/DE/NL; mandatory strategic fuel stocks | Europe safer |
| Cryonics infrastructure today | Two large, mature providers (Alcor, CI) with decades of operational history | New but designing in redundancy (EBF, Tomorrow Bio) | U.S. has more experience; EU gaining |
Overall, *the probability of an involuntary thaw caused specifically by grid loss or EMP is probably 2-3 × lower in Europe than in the U.S. today, but in both regions it remains a single-digit-percent lifetime risk at most. All other uncertainties in cryonics (cellular repair, legal continuity, revival technology) are still many orders of magnitude larger.
7 Practical take-aways if you care about this risk
- Ask your provider for hard numbers :– How many days of liquid nitrogen are stored on site?– Do they have an in-house generator or contracts with multiple gas suppliers?– What is the fuel autonomy of their backup diesel plant?
- Favor facilities with on-site nitrogen generation (PSA + cryocooler) or those located near an air-separation plant.
- Push for written disaster-response SOPs that cover EMP-class events.
- Consider geographic diversification: some members fund storage in two separate dewars or even two continents.
Bottom line: unfreezing due to a routine blackout is virtually impossible; only a prolonged, civilization-disrupting EMP/solar storm could do it, and even then the absolute odds are a few percent over many decades. Choosing a well-engineered, redundancy-minded European site edges that number even lower.