The power cut started at 11pm on a Wednesday in late January and ran until 6am on Friday. The temperature outside was 3C. We had 40 active cricket rearing bins at various life stages, a brooding room set to 28C, and about 20 minutes before the thermal mass of the building started working against us. This is the account of what happened and what we changed afterward.
The first eight hours
The brooding room held temperature better than we expected. The insulated walls and the residual heat from the egg incubators, which had been running at 30C before the cut, kept the room above 22C for roughly six hours. Below 22C, Acheta domesticus nymphs in the first two instars start to slow. Below 18C, early instar mortality climbs sharply.
We had two working strategies available:
- Battery-backed ceramic heat pads under the highest-priority bins (the egg trays and the sub-adult bins closest to harvest)
- Thermal blankets draped over the rack systems, which slowed convective loss significantly
What we did not have, and should have had, was a generator. We had discussed renting one several times. It remained a discussion.
By hour eight, the room was at 19C. We moved the egg trays and the closest-to-harvest bins into a small utility room and ran an extension cable from a neighbour’s outbuilding to power two heat pads. That bought us the critical window.
The time to test your contingency is not during the contingency. Test it cold, on a Tuesday, when nothing is at stake.
What we lost
Final losses across the 31-hour event:
- Egg trays: 0% loss (the pads held)
- First and second instar bins: approximately 34% mortality, concentrated in the bins furthest from the moved egg trays
- Sub-adult bins (harvest cohort): 8% mortality, primarily from stress rather than temperature
- Adult breeding colony: negligible direct mortality, but a 19-day disruption to oviposition
The sub-adult losses were recoverable within the same production cycle. The oviposition disruption pushed our next three cohort starts by nearly three weeks, which was the more expensive outcome in the end.
The cheap changes we made after
Four changes, none expensive:
- A 3.5 kVA generator now lives in the outbuilding, tested monthly.
- All rearing racks are fitted with reflective thermal curtains on a simple rail, deployable in under five minutes.
- The battery-backed heat pads were doubled in number and are now positioned permanently under every egg tray, not just during emergencies.
- The Platform now sends an SMS alert if the brooding room drops below 24C for more than 15 minutes, giving us time to respond before the damage starts.
Total cost of changes: under 900 GBP. Cost of a comparable future event without them: significantly more.