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What You're Noticing

Why Do My Lights Flicker?

Noticing more brownouts, dimming lights, or power outages? You may be experiencing the effects of a grid under increasing stress from data center demand.

6 min read

Key Takeaways

  • 1 Power quality issues like flickering lights and brownouts often signal a grid approaching its limits
  • 2 Data centers create unique stress: constant, massive demand concentrated in specific areas
  • 3 Grid operators warn of shrinking reserve margins, with PJM's capacity prices up 1,100% since 2024
  • 4 Understanding the connection helps you prepare and participate in decisions about your local grid

Something's Different

You've started noticing things. Lights dimming briefly when the air conditioning kicks on. Clocks resetting more often than they used to. Maybe a few more outages than you remember from previous years. It's easy to dismiss as "just the grid" or aging infrastructure.

But something is different. Across the country, grid operators are warning that power reliability is getting harder to maintain. The culprit isn't just aging infrastructure or extreme weather. It's a fundamental shift in how electricity is being consumed.

That shift has a name: the AI data center buildout. And whether or not there's a data center near you, its effects may be reaching your home.

What Causes Power Quality Issues

The electricity that reaches your home isn't just "on or off." It has quality characteristics that affect how well your appliances work. When the grid is stressed, that quality suffers.

Voltage Sags

Brief drops that cause lights to dim, motors to slow, and sensitive electronics to malfunction.

Brownouts

Intentional voltage reductions by utilities trying to prevent blackouts when demand exceeds supply.

Rolling Blackouts

Scheduled outages that rotate through areas when supply can't meet demand.

These aren't random failures. They're symptoms of a grid running close to its limits, where any spike in demand or hiccup in supply can cascade into problems you notice at home.

The Data Center Connection

Here's the connection most people don't see: data centers are adding enormous, concentrated demand to the same grid that serves your home.

100-1,000 MW
Power per large AI data center
750,000
Homes equivalent (at 1 GW)
24/7/365
Near-maximum capacity

Unlike residential demand, which peaks in the evening and drops at night, data centers run at near-maximum capacity around the clock. This creates unique stress.

The slack is gone. Traditional grid planning assumed demand would be "peaky," with buffers built in during off-hours. Data centers eliminate that slack. The grid must now maintain higher capacity around the clock.

Even if the data center is miles away, the effects propagate through the interconnected grid. When a utility adds 500 megawatts of data center load, it often means less reserve capacity for everyone else. The buffer that protected you during heat waves or cold snaps gets thinner.

What Grid Operators Are Saying

This isn't speculation. Grid operators themselves are sounding alarms.

PJM Interconnection Alert 13 states + D.C. • 65 million people
7
Energy Emergencies in 2024
1,100%
Capacity Price Increase
$329.17
Per MW-day (2026/27)

Similar warnings have emerged across the country:

ERCOT
Texas
Tight margins
MISO
Midwest
Capacity concerns
CAISO
California
Demand growth

The pattern is consistent: demand is growing faster than new generation and transmission can be built. Data centers are a major driver of that growth.

What This Means for You

You may have already noticed the early effects:

Utilities asking you to reduce usage during peak hours
"Demand response" programs that adjust your thermostat remotely
Time-of-use pricing that makes evening electricity more expensive

These are all strategies to manage a grid that's running closer to its limits.

The flickering lights you've noticed aren't necessarily permanent. But they're also not random. They're signals that the infrastructure serving your home is under increasing pressure, and that pressure is growing.

Understanding this connection doesn't mean you can single-handedly fix the grid. But it does help you make sense of changes happening in your community and participate in decisions about how the costs and impacts of grid expansion are distributed.

Next Steps

If you want to get involved in decisions affecting your local grid and community:

  1. Document what you're experiencing. Keep a log of power quality issues with dates, times, and what you observed.
  2. Report issues to your utility. Utilities track complaints and investigate areas with multiple reports.
  3. Learn what's happening in your area. Check our state-by-state database for data center projects near you.
  4. Take action. See our Take Action guide for seven things you can do this week.

Go Deeper

Chapter 5 of This Is Server Country examines how the electric grid works, why it wasn't designed for this kind of demand growth, and what the long-term implications are for electricity reliability and cost across the country.

Learn more about the book