Rate R-3 Residential Space Heating (with Basic Service)
0.36670$/kWh
all usage, all hours · plus $10.00 per month · covers delivery and default supply — delivery plus the utility's default supply; a customer who buys supply elsewhere pays the delivery part only
Supply is provisional - Eversource states Basic Service rates are subject to change pending final regulatory approval. They are what the utility bills today, and they are not final.
effective2026-09-01
transcribed2026-09-04
today2026-10-08
Monthly bill on default supply
Usage
$ per month
500 kWh
$193.35
1,000 kWh
$376.70
2,000 kWh
$743.40
Computed from the rates on this page at 30.4 days a month. The same arithmetic is checked against the utility's own published typical bill on every build. Delivery plus this utility's default supply. A customer who switched supplier pays the delivery part and their supplier's rate instead.
Before taxes, franchise fees and any local surcharge.
Provenance
reconciled to a published total
sourceNSTAR Electric Company d/b/a Eversource Energy, Rate R-3 (M.D.P.U. No. 9), priced in M.D.P.U. No. 1-26-E 'Summary of Electric Service Delivery Rates', Part A, effective 09-01-26
verifiedTranscribed from the utility's filed sheetNSTAR Electric Company d/b/a Eversource Energy, Rate R-3 (M.D.P.U. No. 9), priced in M.D.P.U. No. 1-26-E 'Summary of Electric Service Delivery Rates', Part A, effective 09-01-26
verifiedEffective date on the sheet: 2026-09-01
verifiedReconciles to a total the utility published itselfthe Total Delivery column printed by M.D.P.U. No. 1 on each row
verifiedSource document checked daily for changes
approximateSupply is provisional - Eversource states Basic Service rates are subject to change pending final regulatory approvalCurrently billed, but not final.
approximateThis is not a whole billdelivery and default supply — delivery plus the utility's default supply; a customer who buys supply elsewhere pays the delivery part only
excludedTaxes, franchise fees and local surchargesJurisdiction-specific, so they are deliberately not encoded. A bill will be higher than this figure by that amount.
Energy rates
Period
Applies to
$/kWh
all hours, all year
all usage
$0.36670
Other plans at this utility
Encoded from the same tariff book, on the same day. Which one
you are on is on your bill; which one you are eligible for is set by the
utility, not by this page.
Transcription notes recorded when this tariff was encoded, including anything deliberately left out.
NSTAR Electric Company d/b/a Eversource Energy, Massachusetts. A SEPARATE operating company from The Connecticut Light and Power Company, which is also Eversource and files an entirely different tariff: CL&P puts delivery and supply on one sheet, NSTAR files delivery only.
Rates are built from the components filed in M.D.P.U. No. 1-26-E, 'Summary of Electric Service Delivery Rates', Part A, and each is asserted at build time against the Total Delivery column the tariff prints on the same row. The published total is a check, never the source.
M.D.P.U. No. 1 is the authority, NOT the customer-facing 'Summary of Electric Rates' PDFs published per service area. The filed R-1HP schedule (M.D.P.U. No. 85) carries no numbers at all - every line reads 'As per M.D.P.U. No. 1 as in effect from time to time' - which is what identifies No. 1 as the source.
TRAP in the customer-facing summary: it lists 'Energy Efficiency Charge $0.02292' as one of eleven components. In M.D.P.U. No. 1 that figure is a SUBTOTAL of System Benefits $0.00250 and the Energy Efficiency Reconciling Factor $0.02042, printed beside the two columns that actually add. The additive components are used here.
TWO RATE SETS, not four service areas. M.D.P.U. No. 1 groups them BOST/CAMB/SOUTH/WMA and CAPE. Greater Boston, Cambridge, South Shore and Western Massachusetts are identical on every component; Cape Cod & Martha's Vineyard differs in exactly one, the energy efficiency reconciling factor, by $0.01446/kWh. Service areas map to rate sets in data/current/nstar_service_areas.json.
Western Massachusetts - the former WMECO territory - shares the mainland rates. The customer-facing summary pages offer only the four Eastern Massachusetts areas and would have left WMA out silently.
Revenue Decoupling is the one component that varies BETWEEN schedules: R-1 $0.00539, R-3 $0.00527, R-1HP $0.00443. Copying a component list between schedules produces a rate that is wrong and still looks plausible.
EXCLUDED: Massachusetts state and local taxes.
Rate set 'cape', which is the filed grouping for: Cape Cod & Martha's Vineyard.
Not seasonal and not tiered: one delivery rate for every kWh in every month.
BUNDLED. Adds Basic Service residential fixed supply of $0.17323/kWh to every delivery rate.
Basic Service is repriced every February 1 and August 1. The rate used here covers 2026-08-01 to 2027-01-31; the preceding period was $0.15629, 11% lower. This tariff has a known expiry.
Eversource states that final Basic Service rates are subject to change and await final regulatory approval. The supply half of this rate is provisional; the delivery half is filed and final.
The FIXED Basic Service rate is used because it is the default - 'upon opening your account, all residential customers are placed on a fixed rate'. A Monthly Variable option exists and a customer may switch to it once. Customers on a competitive supplier pay neither; for them the delivery-only tariff is correct.
The supply rate is filed for Rates R1, R2, R3 and R4. R-1HP is not named in that list, and is priced here at the same Basic Service rate as R-1 on the basis that R-1HP customers qualify under R-1. That is an inference, not a filing.
NOT ENCODED: R-2 (M.D.P.U. No. 8), R-2HP (No. 86) and R-4 (No. 10), the income-qualified assistance versions of R-1, R-1HP and R-3. They are filed in the same table and readable the same way, but this encoding cannot express eligibility, so /compare would recommend them to people who cannot have them. They belong in the CARE-style discount machinery in rategrid/care.py rather than as separate tariffs.
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with this plan's name and what the filed sheet says. Every rate on this page was
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Change history
The source document is fetched daily and every version is kept.
Utilities do not publish superseded rates, so this record does not exist
elsewhere once a rate changes.
No changes detected since monitoring began. The source sheet is checked daily.