Massachusetts interconnection applications

Massachusetts Department of Public Utilities (DPU)

DPU-approved uniform 'Standards for Interconnection of Distributed Generation' tariff of each distribution company (National Grid M.D.P.U. No. 1468; Eversource/NSTAR M.D.P.U. No. 55D; Unitil/FG&E M.D.P.U. No. 484); dockets incl. D.P.U. 19-55, D.P.U. 23-140 – Standards for Interconnection of Distributed Generation · source

The investor-owned electric distribution companies (Eversource/NSTAR Electric, National Grid/Massachusetts Electric & Nantucket Electric, Unitil/Fitchburg Gas & Electric). Municipal light plants are not subject.

Uniform tariff exhibits: Exhibit A Simplified Process Interconnection Application (with Certificate of Completion attachment), Exhibit B Pre-Application Report form, Exhibit C Expedited/Standard application; Interconnection Service Agreement.

All time frames in Company Business Days. Simplified (radial): acknowledgement 3 BD, completeness 10 BD, screen review (20 BD if failing screen 5), conditional approval by signed application, witness test within 10 BD of Certificate of Completion or deemed waived, Authorization to Interconnect within 5 BD. Pre-Application Report required >= 250 kW, issued within 10 BD (fee $100 <250 kW, $250 250-500 kW, $750 >500 kW).

Simplified $28; Expedited/Standard $4.50/kW (min $300, max $7,500) plus supplemental review/studies at cost; witness test actual cost up to $300 plus driving time (Table 6).

No insurance required for facilities eligible for Class I net metering (<= 60 kW) per 220 CMR 18.03(2) (company recommends adequate insurance). Otherwise general liability: $500,000 for >10-100 kW; $1M for >100 kW-1 MW; $2M/$5M aggregate for >1-5 MW; $5M for >5 MW (tariff Sec. 11.1).

For Listed inverters the Company MAY require an external disconnect switch (or comparable device by mutual agreement) at the PCC, accessible at all times, gang-operated, visible break, lockable open (tariff 4.2.3.1(b)).

NEM – M.G.L. c. 164 §§ 138-140; 220 CMR 18.00 (Net Metering)
220 CMR 18.02: Class I <= 60 kW (any eligible generation); Class II > 60 kW to <= 1 MW and Class III > 1 MW to <= 2 MW (agricultural, anaerobic digestion, solar or wind). Subject to aggregate net metering caps (not re-read). Applies to distribution companies only.

Municipal light plants (about 40, e.g., WGELD) are not subject to the DPU interconnection tariff or 220 CMR 18.00 and set their own interconnection and net metering policies (some use a similar simplified application).