As AI data centers expand, households are increasingly caught in a debate over who should pay for the electricity and grid upgrades the facilities require. The answer varies by utility and state, and experts say there is no reliable nationwide figure for the cost passed on to residential customers. A Maryland estimate puts the added annual cost to customers at roughly $168 to $216 per household, largely tied to the data center boom. In the PJM electricity market, which serves 13 states and Washington, D.C., the independent market monitor estimates data centers have imposed about $29 billion in costs on 67 million ratepayers over roughly two years. Those costs can come from higher wholesale electricity prices as demand grows, as well as new power lines, substations and other infrastructure. Some upgrades may serve a data center alone; others may benefit the wider community or replace aging equipment. How utilities divide those expenses among customers depends on their contracts, rate structures and decisions by state regulators. “Everyone pays those costs,” said Ari Peskoe, director of the Harvard Electricity Law Initiative, describing how some regional grid expenses are spread among residents and businesses. The question is becoming a focus in Congress ahead of the midterm elections. The House passed the Ratepayer Protection Act in September with bipartisan support. The measure would require state utilities to consider making large electricity users responsible for increased costs. Senate Minority Leader Chuck Schumer has criticized the bill’s protections as voluntary and is backing a separate proposal, the GRID Savings Act, which he says would provide stronger safeguards. The debate is especially consequential in Northern Virginia, home to the world’s largest concentration of data centers. Dominion Energy says it recovers costs for transmission and distribution infrastructure from customers, with expenses reviewed and approved by Virginia’s State Corporation Commission. In Maryland, regulators’ estimate illustrates how data center-driven costs may reach household bills, though the precise share depends on local circumstances. Public scrutiny is also hampered by confidentiality agreements surrounding development deals. A University of Mary Washington study found that nondisclosure agreements had been signed in 80% of Virginia localities with existing, approved or proposed data centers. Residents opposing projects have raised concerns about limited public visibility into negotiations and the financial arrangements behind them. Large data center customers often pay less per kilowatt-hour than residential customers, a volume discount that can add to public frustration when household bills rise. But not every recent rate increase is attributable to data centers: fuel prices and infrastructure repairs needed because of aging equipment or extreme weather also affect costs. The rapid pace of data center construction may create additional pressure. University of Maryland public policy professor Lucy Qiu said utilities seeking to meet demand quickly may rely on less efficient power plants, with the resulting costs eventually passed on to customers. At the same time, she said, data center investment can speed grid upgrades and may improve reliability for nearby residents by strengthening local infrastructure. That mix of shared costs and possible benefits makes it difficult to assign a single price to the AI buildout. Without clearer public accounting of data center payments and the infrastructure they use, residents may struggle to determine whether the economic and reliability benefits justify the costs appearing on their electric bills.