Backup power does not solve the problem of outages — it solves the problem of transitioning between power sources without losing control of the system.
Quick Glossary
- UPS (Uninterruptible Power Supply) — a device that instantly switches to battery when grid power is lost
- Generator — an autonomous power source with a 10–30 second startup delay
- Voltage stabiliser — maintains stable output voltage during fluctuations
- ATS (Automatic Transfer Switch) — automatically switches to the backup source when grid power fails
Ukrainian Grid Realities: Not Just Outages
The grid in Ukraine is unstable not only because of scheduled outages. Voltage spikes occur when large loads connect, sags during peak consumption, and impulse surges from lightning and substation switching. Instability affects both sensitive electronics (pH/EC controllers) and heavy equipment (chillers, pumps). "Surge protection is needed even when there are no outages."
Three Levels of Protection: What Protects Against What
Level 1 — SPD (Surge Protection Device) at the mains entry point: protection against brief impulse surges from lightning and switching events — minimal cost.
Level 2 — Voltage stabiliser: maintains 220 V ±5% across an input range of 140–260 V; protection against chronically unstable voltage. Provides no power during a complete outage.
Level 3 — UPS: instant switchover, limited runtime. Generator: long-duration autonomy, but a 10–30 second startup delay. The optimal solution is a combination of both.
What to Connect to the UPS and What to the Generator
UPS: automation controllers, pH/EC sensors, peristaltic pumps, circulation pumps — equipment that loses settings on restart.
Generator: grow lights, chiller, exhaust ventilation — equipment that can tolerate a brief transition without consequence.
Generator: Practical Details for a Greenhouse
Size with a 30–40% power reserve above maximum load. Voltage stabilises 30–60 seconds after startup — an ATS with a transfer delay protects sensitive electronics during this window. Monthly test runs under real load are mandatory.
Three Mistakes That Cost the Most
- Sizing a UPS without accounting for inrush currents
- A generator without an ATS (manual switching = prolonged loss of power)
- No surge protection during normal grid operation
How to Know the System Is Ready
- UPS covers critical automation: minimum 15–20 minutes of runtime
- Generator starts automatically via ATS
- SPD installed at the mains entry point
- Generator tested under actual operating load