# PV as IT Load Headroom Solar PV on a data center isn't primarily a sustainability play — it's an engineering input that expands your usable IT power budget. **The math:** - Grid allocation per rack: 20kW - PV contribution per rack: ~2kW - Usable IT load per rack: **22kW** The solar panels offset part of the facility's overhead (cooling, lighting, controls), which frees up grid power for IT load. You're not feeding PV directly to servers — you're reducing the non-IT draw on the grid connection, which means more of your grid allocation goes to compute. **Why this framing matters:** If you treat PV as a sustainability checkbox, you'll size it for carbon offset targets. If you treat it as engineering headroom, you'll size it for the power budget delta you need. The second approach gives you 10% more usable IT capacity from the same grid connection. **Practical implication:** When calculating rack power budgets, include PV offset as a design input — not an afterthought. A 400kW MDC with 20 racks at 20kW grid allocation actually delivers 440kW of usable IT power when PV covers 2kW/rack of facility overhead. --- See also: [[Power Usage Effectiveness - PUE]] | [[Modular Data Centers MoC]]