The two questions that decide a data center’s local impact are simple to ask and often hard to get answered: how much power will it draw, and how much water will it use? Here’s what those numbers mean and where to find them.
Following the megawatts
Electricity is a data center’s defining demand. A large hyperscale campus can request hundreds of megawatts — a scale that can rival a small city and reshape a utility’s long-term planning. That new demand, or “load,” has to be met somehow: new transmission lines, a new or expanded substation, and sometimes new generation. In some regions, surging data-center demand has been cited as a reason to delay retiring older fossil-fuel plants or to build new gas capacity.
The accountability question isn’t only how much power, but who pays for the infrastructure to deliver it. If the grid upgrades a campus requires are spread across everyone’s utility bills, ordinary ratepayers can end up subsidizing a private facility. Utility filings, interconnection queues, and rate cases are where these details live — and most are public.
Following the water
Cooling is the other big draw. Many data centers use water to shed the heat their servers generate, often through evaporative cooling that consumes water rather than returning it. Withdrawals can be substantial, and in water-stressed regions they compete directly with households, farms, and ecosystems for the same supply.
There’s a catch worth understanding: a facility can advertise a very efficient power profile precisely because it uses water instead of electricity to stay cool. Looking at power alone can hide the water cost, and vice versa. That’s why both a project’s power demand and its water use — its source, volume, and permits — belong on the table together.
The clean-energy fine print
Operators frequently pledge that a campus will run on renewable energy, often through a power purchase agreement. These commitments can be real and meaningful — but a contract to buy clean power somewhere doesn’t necessarily change what the local grid burns to serve the campus at 2 a.m. It’s worth asking whether a clean-energy claim reflects the actual electricity flowing to the site or an accounting arrangement layered on top of it.
Where to find the real numbers
You rarely have to take a developer’s word for it. Power demand appears in interconnection requests and utility filings; water use appears in withdrawal permits and utility applications; both often surface in the project’s zoning and permit paperwork. These are public records. Our records-request guide walks through exactly what to ask for, and the glossary defines the terms you’ll run into.