States › Massachusetts › NSTAR Electric Company
investor-owned utility · EIA utility 54913
NSTAR Electric Company
Average price is revenue divided by sales for the sector and year; it is not a tariff rate. Reliability figures are as reported by utilities to EIA on Form 861 and may use different calculation methods. Annual figures: Form EIA-861 for 2024, final release. Monthly state figures run to July 2026.
NSTAR Electric Company serves 1,303,076 residential customers in Massachusetts as an investor-owned utility, according to its 2024 Form EIA-861 filing, with a service territory that touches 11 counties.
Its average residential price that year was 29.91¢ per kilowatthour, about the same as the Massachusetts average of 29.35¢ and 81% above the US average of 16.48¢. The figure is residential revenue divided by residential sales, so it folds in fixed charges, riders and every rate schedule the utility bills under.
That works out to an average residential bill of $137.02 a month on average use of 458 kWh a month. Across Massachusetts the average bill was $167.20 on 570 kWh, so a bill gap reflects how much power households use as well as what each kilowatthour costs.
The price covers the 383,373 residential customers on bundled service. A further 919,703 take delivery only and buy their energy from another supplier; EIA collects just part of their bill from this respondent, so they are left out of the average.
For reliability it reported a SAIDI of 80.6 minutes per customer with major event days included and 66.1 minutes with them excluded, calculated under IEEE 1366 standard. The median among Massachusetts utilities reporting was 53.8 minutes with major event days; this utility's figure is 50% above that median.
The average price is up 32.8% on 2019, against up 33.9% for Massachusetts as a whole, and little changed on 2023.
Compared with Massachusetts, the US and other investor-owned utilities
| Measure, 2024 | This utility | Investor-owned utilities, US median | Massachusetts | United States |
|---|---|---|---|---|
| Average residential price per kWh | 29.91¢ | 16.17¢ | 29.35¢ | 16.48¢ |
| Average monthly residential bill | $137.02 | $131.47 | $167.20 | $142.26 |
| Average monthly use, kWh | 458 | 787 | 570 | 863 |
| Residential price change, 1 year | +0.8% | — | -0.9% | +3.0% |
| Residential price change, 5 years | +32.8% | — | +33.9% | +26.7% |
| SAIDI, all events (minutes) | 80.6 | 278.7 | 53.8 median | 184.5 median |
| SAIDI, without major event days | 66.1 | 106.5 | 35.5 median | 99.8 median |
State and US prices, bills and use are EIA's own averages over every customer. The ownership column and the reliability columns are medians across utilities with at least 1,000 residential customers, computed on this site from the final 2024 file. Among the 4 filings by investor-owned utilities in Massachusetts, the median price was 34.36¢. In Massachusetts this utility's price ranks 4 of 20, counting from the highest.
Average price by year
NSTAR Electric CompanyMassachusetts averageUS average
Year by year
| Year | ¢ per kWh | Massachusetts ¢ | Monthly bill | kWh a month | Residential customers | All sales |
|---|---|---|---|---|---|---|
| 2024 | 29.91¢ | 29.35¢ | $137.02 | 458 | 1,303,076 | 21.4 TWh |
| 2023 | 29.66¢ | 29.61¢ | $141.66 | 478 | 1,283,644 | 22.6 TWh |
| 2022 | 29.31¢ | 25.97¢ | $138.22 | 472 | 1,289,709 | 22.9 TWh |
| 2021 | 24.25¢ | 22.89¢ | $129.51 | 534 | 1,255,128 | 22.9 TWh |
| 2020 | 22.39¢ | 21.97¢ | $119.06 | 532 | 1,246,086 | 22.7 TWh |
| 2019 | 22.53¢ | 21.92¢ | $117.14 | 520 | 1,239,884 | 23.5 TWh |
| 2018 | 23.06¢ | 21.61¢ | $125.08 | 542 | 1,230,516 | 24.3 TWh |
| 2017 | 21.03¢ | 20.06¢ | $99.67 | 474 | 1,030,322 | 20.4 TWh |
| 2016 | 20.18¢ | 19.00¢ | $105.91 | 525 | 1,024,972 | 21 TWh |
| 2015 | 21.13¢ | 19.83¢ | $109.14 | 516 | 1,063,565 | 21.4 TWh |
| 2014 | 18.89¢ | 17.39¢ | $104.13 | 551 | 1,006,534 | 21.3 TWh |
| 2013 | 17.58¢ | 15.83¢ | $100.27 | 570 | 1,002,288 | 21.7 TWh |
Bundled residential service only in the price, bill and use columns. Bill = residential revenue ÷ customers ÷ 12; use = residential sales ÷ customers ÷ 12.
Month by month
NSTAR Electric CompanyMassachusetts average
Sales by sector, 2024
| Sector | Customers | Sales | Share of sales | Revenue | ¢ per kWh, bundled |
|---|---|---|---|---|---|
| Residential | 1,303,076 | 7.9 TWh | 37% | $1,568,609,000 | 29.91¢ |
| Commercial | 221,348 | 12.1 TWh | 57% | $1,182,760,000 | 27.00¢ |
| Industrial | 2,133 | 1.1 TWh | 5% | $101,414,000 | 25.34¢ |
| Transportation | 1 | 290.6 GWh | 1% | $3,662,000 | — |
Customers, sales and revenue count every service type the utility reported (bundled, energy-only and delivery-only). The price column uses bundled service alone, because part-bill revenue would understate it. Sources of energy: 6.3 TWh in total, of which 1% was its own net generation and 6.2 TWh was bought wholesale; summer peak demand 5,118 MW.
Reliability
Minutes of sustained interruption per customer in 2024, as the utility reported them under IEEE 1366 standard. SAIFI: 0.69 interruptions per customer with major event days, 0.64 without; CAIDI 116.5 minutes per interruption. EIA's Massachusetts total across all reporting utilities was 102.0 minutes with major event days and 76.1 without. Major event days are storms and similar events that a utility's chosen method sets apart; methods differ, so treat comparisons as approximate. What SAIDI and SAIFI mean.
| Year | SAIDI, all events | SAIDI, no major events | SAIFI, all events | SAIFI, no major events | Method |
|---|---|---|---|---|---|
| 2024 | 80.6 | 66.1 | 0.69 | 0.64 | IEEE 1366 |
| 2023 | 189.8 | 75.6 | 0.88 | 0.67 | IEEE 1366 |
| 2022 | 196.7 | 68.5 | 1.03 | 0.75 | IEEE 1366 |
| 2021 | 640.8 | 75.8 | 1.10 | 0.73 | IEEE 1366 |
| 2020 | 235.7 | 65.0 | 1.14 | 0.72 | IEEE 1366 |
| 2019 | 273.7 | 70.3 | 1.11 | 0.74 | IEEE 1366 |
| 2018 | 970.0 | 85.0 | 1.68 | 0.83 | IEEE 1366 |
| 2017 | 206.0 | 74.3 | 1.04 | 0.07 | IEEE 1366 |
| 2016 | 171.4 | 98.1 | 1.08 | 0.91 | IEEE 1366 |
| 2015 | 95.2 | 75.2 | 0.83 | 0.76 | IEEE 1366 |
| 2014 | 89.4 | 67.0 | 0.77 | 0.66 | IEEE 1366 |
| 2013 | 632.5 | 82.1 | 1.14 | 0.85 | IEEE 1366 |
Generation at plants it operates, 2025
- Solar 100% 59.4 GWh
Net generation of 59.4 GWh at power plants this utility operates, from Form EIA-923. It is not the mix delivered to customers: utilities also buy power wholesale (6.2 TWh in 2024), sell generation to others and may co-own plants that another company operates.
Counties in its service territory
- Barnstable County
- Berkshire County
- Bristol County
- Dukes County
- Franklin County
- Hampden County
- Hampshire County
- Middlesex County
- Norfolk County
- Plymouth County
- Suffolk County
Counties the utility listed on Form EIA-861 for 2024. Listing a county does not mean the utility serves all of it.
Other utilities in Massachusetts
| Utility | Ownership | Residential customers | ¢ per kWh | Monthly bill | SAIDI, all events | SAIDI, no major events |
|---|---|---|---|---|---|---|
| Massachusetts Electric Co mostly delivery | Investor-owned | 1,210,113 | 33.60¢ | $165.44 | 133.7 | 90.7 |
| Fitchburg Gas & Elec Light Co mostly delivery | Investor-owned | 26,290 | 40.08¢ | $201.83 | 64.6 | 64.6 |
| Nantucket Electric Co mostly delivery | Investor-owned | 12,823 | 35.11¢ | $282.90 | 138.2 | 50.4 |
| Direct Energy Services energy only | Retail power marketer | 1,228,774 | 16.37¢ | $182.03 | — | — |
| Constellation NewEnergy, Inc energy only | Retail power marketer | 1,113,912 | 15.95¢ | $195.38 | — | — |
| First Point Power, LLC energy only | Retail power marketer | 178,807 | — | — | — | — |
| Clearview Electric Inc. energy only | Retail power marketer | 60,588 | — | — | — | — |
| City of Taunton | Municipal | 35,684 | 21.46¢ | $133.55 | 193.0 | 193.0 |
All Massachusetts utilities · Investor-owned utilities nationwide
Questions and answers
How much does electricity cost from NSTAR Electric Company?
Residential customers paid an average of 29.91¢ per kilowatthour in 2024. EIA derives this by dividing residential revenue by residential sales; it is an average across all rate schedules and charges, not a tariff rate.
How does that compare with Massachusetts?
The Massachusetts average residential price in 2024 was 29.35¢ and the US average 16.48¢; NSTAR Electric Company was about the same as the state figure. Among 20 utility filings with a bundled residential price in Massachusetts, it had the 4th highest.
What is the average NSTAR Electric Company bill?
$137.02 a month in 2024, on average residential use of 458 kWh a month (annual revenue and sales divided by customers and by twelve). The Massachusetts average was $167.20 on 570 kWh.
How reliable is NSTAR Electric Company service?
It reported 80.6 minutes of interruption per customer (SAIDI) including major event days and 66.1 minutes excluding them, with 0.69 interruptions per customer (SAIFI) in 2024. Utilities calculate these under differing methods, so comparisons are approximate.
Is the NSTAR Electric Company price rising?
The average residential price was little changed in 2024 compared with 2023 and up 32.8% compared with 2019.
Which counties does NSTAR Electric Company serve?
Its Form EIA-861 service territory lists 11 counties, including Barnstable County, MA, Berkshire County, MA, Bristol County, MA, Dukes County, MA, Franklin County, MA and Hampden County, MA. A county can appear in several utilities' territories.
Provenance
Source: U.S. Energy Information Administration. Annual figures are from Form EIA-861 (sales to ultimate customers, reliability, operational data and service territory files), final release for 2024, respondent "NSTAR Electric Company", utility number 54913. Monthly utility figures are from the Form EIA-861M sample. State and US averages are from the Form EIA-861M sales and revenue workbook, published through July 2026. Generation by fuel is from Form EIA-923, 2025 final. All are US government works in the public domain. Page built 30 Sep 2026. Errors in processing are corrected at the next build; see corrections. For tariffs and rate schedules, consult the utility or the state utility commission.