I just caught Leaseweb trying to slip a ratchet clause past me. Here's what to look for:
- Ratchet clauses: your demand charge is based on the highest 15-min peak in the last 12 months, not actual usage. Used 500kW once? You pay for 500kW all year.
- Coincident peak: you're charged based on grid-wide peak times you can't predict or control. Some colos pass this through raw.
- Load factor penalties: low average vs peak ratio triggers surcharges. Virtualization tax on your power bill, basically.
- "Simplified" flat rate: almost always 15-40% higher than metered with good load balancing.
Check your UOS (utility-owned substation) rider too. Some providers markup pass-through charges 8-12% "for administrative convenience."
I run mostly KVM with some LXC. Cgroup v2 makes power attribution per tenant possible now. If your colo won't give you 15-min interval data, that's a red flag.