Are data centers raising electricity bills in Pennsylvania?

Indirectly but clearly. PA is in PJM, and PJM's market monitor attributed 40% ($6.5B) of the record $16.4B capacity auction to data-center demand — $6.2B of it for data centers not yet built. That regional cost flows into PA bills; PECO, for one, is phasing in a ~10% increase over two years driven largely by capacity costs.

Is Three Mile Island really restarting for data centers?

Yes. Constellation signed a 20-year deal in September 2024 to restart the 837 MW reactor (the undamaged Unit 1, retired in 2019) and sell the power to Microsoft to match its data-center electricity use. Restart is targeted for around 2027–2028 — a projection that has already shifted.

Did my own electricity use go up?

Almost certainly not — Pennsylvania residential usage has been essentially flat (about +1% from 2020 to 2025) while the average residential rate rose 42%. You're not using more; the cost of the grid around you went up, and data-center demand is a big driver.

PJM projects regional peak demand to grow ~32 GW by 2030, almost entirely from data centers, and PA's marquee projects (Amazon's $20B build, Homer City's up-to-4.5-GW gas plant, the TMI and Susquehanna nuclear deals) are under way. The size is debated, but the direction isn't.

Independent · sourced data

Are Pennsylvania's data centers raising your electric bill?

Pennsylvania has become ground zero for the data-center power rush — restarting a nuclear reactor for Microsoft, a $20 billion Amazon build, the largest gas plant in the country planned at a former coal site. None of it is your home using more power. But the cost of feeding that demand is landing on your rate.

What grew in Pennsylvania, 2020 → 2025

Your PA residential rate +42%

13.58¢ → 19.30¢ per kWh

Your household usage +1%

PA residential kWh — essentially flat

Your rate jumped 42%. Your own usage didn't move. The demand surge is in the data centers, not your house.

The scale, in real numbers

837 MW

Three Mile Island restart

Constellation is restarting the reactor under a 20-year deal to power Microsoft's AI data centers (signed Sept 2024)

$20 billion

Amazon's PA investment

the largest private-sector investment in Pennsylvania history (announced June 2025)

up to 4.5 GW

Homer City (ex-coal site)

billed as the largest planned gas-fired power plant in the U.S., to serve data centers

40% / $6.5B

Data centers' share of PJM's record auction

of the $16.4B 2027/28 capacity auction — and $6.2B of that was for data centers not yet built (PJM market monitor)

What's coming

PJM peak-demand growth by 2030: +32 GW

Data centers ~30 GW

~2 GW

PJM projects peak demand to grow about 32 gigawatts by 2030 — and all but ~2 GW of it is data centers (projection).

PJM projects peak demand across its region will grow roughly 32 gigawatts by 2030 — and all but about 2 GW of that is data centers. PPL Electric carries PJM's steepest long-term growth forecast of any utility (about 6.4% a year). These are projections, and PJM has flagged the forecasts carry 'extreme uncertainty' — but the direction is clear, and the buildout (TMI, Amazon, Homer City, Talen/Susquehanna) is already under construction.

The fight over who pays

When Talen tried to wire an Amazon data center directly into the Susquehanna nuclear plant, FERC rejected the arrangement (Nov 2024). Other utilities argued co-location like that could shift up to $140 million a year in grid costs onto everyone else's bills, calling the data centers potential 'free riders' on a transmission system households paid for. In December 2025 FERC ordered PJM to write clear co-location rules. The core question — does a data center wiring straight into a power plant dodge its share of grid costs, leaving you to cover them — is still being decided.

Be precise: the $140M/year figure is the protesting utilities' estimate, not a neutral finding. And don't conflate one auction with the trend — the December 2025 capacity auction was roughly flat for a typical PECO customer because a price cap held, but that was the last capped auction, and PECO is phasing in a ~10% bill increase over two years as capacity costs climb.

The line to your PJM capacity charge

Pennsylvania is in PJM, so the regional capacity price flows straight into PA bills. That auction hit a record $16.4 billion for 2027/28 — its third straight clearing at the price cap — and PJM's own market monitor calls data-center load growth 'the primary reason' for the tight supply and high prices.

See the 2025–26 rate increases and the PJM capacity spike →

What you can do about your own bill

Is your bill too high? — compare it to your state's average and see if it's usage or rate.
Run the free bill audit — check whether a supplier is overcharging you.
Pennsylvania bill help — assistance and your shutoff protections.

Common questions

Are data centers raising electricity bills in Pennsylvania?: Indirectly but clearly. PA is in PJM, and PJM's market monitor attributed 40% ($6.5B) of the record $16.4B capacity auction to data-center demand — $6.2B of it for data centers not yet built. That regional cost flows into PA bills; PECO, for one, is phasing in a ~10% increase over two years driven largely by capacity costs.
Is Three Mile Island really restarting for data centers?: Yes. Constellation signed a 20-year deal in September 2024 to restart the 837 MW reactor (the undamaged Unit 1, retired in 2019) and sell the power to Microsoft to match its data-center electricity use. Restart is targeted for around 2027–2028 — a projection that has already shifted.
Did my own electricity use go up?: Almost certainly not — Pennsylvania residential usage has been essentially flat (about +1% from 2020 to 2025) while the average residential rate rose 42%. You're not using more; the cost of the grid around you went up, and data-center demand is a big driver.
What's coming next?: PJM projects regional peak demand to grow ~32 GW by 2030, almost entirely from data centers, and PA's marquee projects (Amazon's $20B build, Homer City's up-to-4.5-GW gas plant, the TMI and Susquehanna nuclear deals) are under way. The size is debated, but the direction isn't.

The same story is reshaping bills in other states we cover:

Virginia data centers & your bill →Ohio data centers & your bill →Maryland data centers & your bill →Illinois data centers & your bill →

Sources

Last reviewed June 19, 2026. Verified facts and modeled/forecast projections are distinguished in the text; demand forecasts are projections. General consumer information, not financial advice. RateWatchdog is independent and takes no supplier commissions.