Massachusetts power bills are high, but data centers aren't why. In PJM, they are.
Measured from 2020, New England's residential prices after inflation rose 22% more than the rest of the US outside PJM by 2023, and were still 10% ahead in 2026. Data centers are not the reason: Massachusetts has 67 MW of them operating and 300 MW proposed, and the capacity charge in a typical Massachusetts home's bill fell from $246 a year in 2018/19 to $84 for 2027/28.
PJM, the grid operator for 13 states and DC from New Jersey to Illinois, shows what it looks like when data centers do drive the market: a capacity shortfall driven largely by forecast data center demand now costs a typical household in a restructured state about $197 a year more than in 2024/25. For 2027/28, the same charge is $243 there against $84 in Massachusetts.1,2,3
The capacity charge in Massachusetts bills, and in other markets
The capacity charge pays power plants to be available at peak, and in Massachusetts basic service passes ISO New England's auction price straight through. For a typical home it fell from $246 a year in 2018/19 to $52 in 2023/24, then $103, $64, and $84 for 2027/28. New England's auctions have little data center demand behind them: 0.7 GW planned or under construction across the region, against 132 GW in PJM.
Massachusetts: median of the default-service utilities (National Grid's Massachusetts Electric and Nantucket Electric, Eversource, Unitil), from ISO New England Forward Capacity Auction prices for their zones; ISO New England's next auction is due in 2028. Other markets use the same method; see the comparison section below. Delivery years run June to May.
New England residential prices vs. the rest of the US
New England prices tracked the rest of the country outside PJM in 2021, then rose 8.2% more in 2022 and 22.0% more in 2023, measured from 2020, and were still 9.5% above in 2026. Capacity charges fell over the same years ($118 to $52 per Massachusetts home), so the rise did not come through the capacity auction, the channel that carries data center costs in PJM.
Same regression as the PJM comparison below (utility and month fixed effects, weather controls, standard errors clustered by utility), with New England utilities compared against the rest of the US outside PJM, so PJM's own rise does not set the baseline. 2026 covers January to August.
What Massachusetts utilities charge, after inflation
National Grid's price after inflation peaked at 41.2¢ per kWh in 2023 and was 33.2¢ in 2025. Eversource's was 32.5¢ in 2024; its EIA figures from March 2025 on are under check and left out. Massachusetts' municipal utilities charged 16.5¢, about half, and the New England average was 27.7¢ against 16.8¢ nationally.
Residential revenue per kWh from EIA's monthly survey, full calendar years, in dollars of August 2026 (Northeast CPI). Utility figures cover homes on the utility's own (basic) supply. Municipal utilities are combined, weighted by sales.
Competitive supply and town aggregation
76% of homes at the three investor-owned utilities buy supply from a competitive supplier or their town's aggregation program (55% through towns, 21% individually), as of June 2026. On EIA's statewide averages, competitive suppliers charged more than basic service in 6 of 11 years from 2015 to 2025: about $631 million more over the period. The average mixes town aggregation with individual contracts.4,5
Customer counts: Massachusetts DOER customer choice data (residential rate classes). Prices: EIA-861 annual, nominal cents per kWh. Basic service supply = investor-owned utilities' full-service revenue per kWh minus their delivery-only revenue per kWh; supplier price = energy-only revenue per kWh of competitive suppliers selling to Massachusetts homes. Years without both large utilities in EIA's file are left out.4
Data centers in Massachusetts
Massachusetts has 25 data center sites in the merged list, 67 MW operating. Nearly all of the 300 MW in the pipeline is one proposal: Servistar Data Center in Hampden County (300 MW). New England as a whole has 138 MW operating and 673 MW proposed or under construction; PJM has 132 GW in its pipeline. ISO New England's own first large-load forecast (2026) counts one data center in its formal study process, 200 MW in the Northeast Massachusetts and Boston zone, and expects all large new loads together to add about 110 MW to the region's peak in the 2030s.6
Largest sites by estimated power. Sites: FracTracker Alliance, PNNL IM3, OpenStreetMap contributors, PeeringDB, merged and checked for duplicates; MW is reported where the source gives it, otherwise estimated from floor or land area. See the map.
Where data centers are raising bills: PJM and other markets
PJM's capacity charge per household
Capacity costs for a typical home fell to $33 a year in 2023/24, then jumped to $218 when the 2025/26 auction cleared at $269.92 per MW-day, and reached $243 as the 2026/27 to 2028/29 auctions cleared at the price cap. That is the highest level in the record, about 1.5 times 2018/19. The market monitor attributes roughly $96 to $138 a year of it to data center load.1,7 In MISO, the central US grid, most utilities supply their own capacity, so auction prices reach household bills directly mainly at Ameren Illinois. There the cost has swung rather than climbed: $224 a year in 2022/23, $8 the next year, $204 in 2025/26 when the summer price hit $666.50 per MW-day, and $123 for 2026/27. MISO has 49 GW of data centers planned or under construction (3.0 MW per 1,000 homes, against 5.3 in PJM). New York has little data center load (2.7 GW planned or under construction, 0.4 MW per 1,000 homes), yet New York City's capacity price, which sets most of Con Edison's cost, reached a record $32.59 per kW-month in May 2026 and averaged $19.14 over summer 2026. Statewide, a typical New York home's capacity cost was $124 a year for 2025/26.
PJM: median across 24 utilities in DC, DE, IL, MD, NJ, OH, PA whose default supply passes auction prices through. New England: median across 12 utilities in CT, MA, ME, NH, RI, from ISO New England Forward Capacity Auction prices; its next auction is due in 2028. MISO: Ameren Illinois, from MISO Planning Resource Auction prices (seasonal since 2023/24, weighted by days). New York: median across 7 utilities, from 12-month averages of NYISO's monthly spot auctions by locality (New York City, Long Island, lower Hudson Valley, rest of state), May-to-April years through 2025/26. Auction results from PJM Base Residual Auction reports through 2028/29; data center attribution from PJM's Independent Market Monitor through 2027/28. Delivery years run June to May.7,1
PJM residential prices vs. the rest of the US
PJM prices tracked the rest of the country through 2021. The gap opened in 2022 (+3.3%), jumped in 2023 (+11.1%), and widened to +15.7% in 2026 as capacity costs reached bills. The confidence band excludes zero from 2022 on.
Regression on utility-month residential prices with utility and month fixed effects and weather controls; standard errors clustered by utility. 2026 covers January to August.
Four markets, one data center boom, different bills
Baltimore Gas & Electric's customers, in a PJM state with few large data centers of its own (0.1 GW operating in Maryland vs. 14 GW in Virginia), saw real prices rise 36% between 2019 and 2026 (+12.9% versus the same months last year). Dominion's real price changed +9% over the same period (+16.7% versus the same months last year, its first full year inside the PJM capacity auction). Texas, an energy-only market with 87 GW of new generation planned (PJM: 27 GW), was at 97, and Georgia Power at 102, on a 2019 = 100 scale.8
Residential price after inflation (Census-region CPI), indexed to 2019 = 100. The 2026 point (dashed) applies the January to August change vs. the same months of 2025, so seasonal rates don't distort it. Texas is the statewide total, which includes some areas outside ERCOT.
Across 326 US utility service areas from 2015 to August 2026, a utility's own data center load has not pushed up its residential prices relative to neighbors in the same market.
What doesn't explain it. Comparing each utility with others in its own regional market and month, a 40% rise in its own commercial load goes with a −1.0% change in residential price (95% CI −1.6% to −0.4%). More sales spread fixed costs. The burden comes from regional supply shortfalls and how each market passes them through.9,10 This matches EPRI's state-level causal study, which estimates that data center growth from 2019 to 2024 lowered average residential rates about 6%.9
What about reliability? Across 1,342 utilities (2013-2025), a 40% rise in a utility's own commercial load has not gone with more outages: −2.2% in everyday outage minutes per customer (95% CI −4.6% to +0.4%) and −1.8% in the number of outages, compared with utilities in the same regional grid and year. Including major storms, −4.3%. The 32 counties with the most operating data center load had no more outage hours than other counties in their state (2025: −14.2%). These are local outages that have already happened; the forward risk is supply: PJM's 2027/28 auction cleared about 6,600 MW short of its reliability target.11,12
Caveats. The PJM premium began in 2022, before capacity prices spiked, which is consistent with 2022 gas prices being locked into default-service supply contracts; capacity costs explain its widening since 2025. Auction totals are cleared MW times price, which PJM notes overstates cost to load because some load is hedged or self-supplied, so household figures are upper-bound averages.7 In 9 states (CA, CT, IL, MA, NH, OH, PA, RI, TX), at least 10% of homes buy supply from competitive suppliers or aggregation programs, about 20,704,874 homes in all; EIA's monthly data price only the utility's own supply there, so price comparisons in those states describe homes on utility supply (see Data status). Dominion's 2026 increase also includes an approved base-rate increase of $11.24 a month.13
Every statement on this page is checked against the data each time the analysis runs; one that no longer fits is marked for review. See an error, or disagree with a conclusion? Report an issue.
Sources: EIA-861M, EIA-861, EIA-930, EIA-860M; ISO New England, PJM, MISO, and NYISO capacity auction results; Monitoring Analytics (PJM Independent Market Monitor); Massachusetts DOER customer choice data; BLS CPI; NOAA nClimDiv; Census ACS. Data center locations: FracTracker Alliance, PNNL IM3, OpenStreetMap contributors, PeeringDB. Code and methods: github.com/yottachem/grid-impact.