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Princeton Municipal Light Department

Massachusetts Utility Interconnection & net metering rules
Net Metering Allowed1
Line Taps Allowed1
Load Taps Allowed1
AC Disconnect RequiredYes

Net metering & export

Net Metering Allowed
1
TOU Utility
0
Post Solar Billing Method
Export Rate
Solar Export Type
Avoided Cost
Net Excess Generation Notes

PMLD will credit the solar owner’s account in dollars ($) on a monthly basis for the avoided cost for exported power. PMLD will round the consumed power up to 200 kWh per month minimum should actual consumption be less. Any annual net credit greater than $25 can be requested by check each April for the previous April through March time period. Net credits not claimed by April 30 will be applied to the Town of Princeton’s electric bill.

Rebates Offered
0

Interconnection & taps

Approval Req To Install
Yes
Interconnection Level
3
Line Taps Allowed
1
Load Taps Allowed
1
Tap Criteria

Line Side Tap allowed per NEC

Automatic Transformer Upgrade Size
0
Meter Aggregation Allowed
0

System size & offset

System Size Restrictions
30
System Size Restriction Type
AC kW
System Size Battery Included
0
System Size Includes Existing Systems
0
Offset Type
Combination
Offset Value
100
Offset Calculation Basis
Historical
Offset Calculation Period
12
Industry Standard Watts Sqft
2
Offset Calc Tool
Historical Usage

Metering & disconnect

Production Meter Required
No
AC Disconnect Required
Yes
AC Disconnect Labeling
Visible Lockable Labeled Disconnect
Allowed Meter Adapter
None

Plans & docs

Site Plan Reqs

Standard

SLD Reqs

Standard, PE stamp required

Electric Service Reqs

Systems 30kW or Less:

  • PMLD will require an external disconnect switch at the PCC
  • Must be gang operated, have a visible break when open.
Placards
  • All meter enclosures shall have a red plastic placard with white embossed writing attached by rivets either directly above or below the meter.
  • The embossed wording will be "Caution, Interconnected Generator".
  • The attached placard will be a minimum of 1 1/2" high and 3" wide.
  • The placard will be provided by PMLD to the customer/installer and be properly installed prior to PMLD's final witness test and approval.
Electrical Stamp Required
1
Equipment Approvals
California Energy Commission
Meter Num Req SLD 3LD
0
ESID Num Req SLD 3LD
0
Website
link
Phone
(978) 464-2815

Other details

Restrict Inspection
0
Mod Swap Requires Planset
1
Address ID
126077
Express Planset Eligible
Yes
Compiled from public records, 2026. Tariffs and interconnection rules change; verify with Princeton Municipal Light Department before you rely on this. The useful move: if an installer says you need a main panel upgrade, ask how these tap and interconnection policies were considered first.