Montana interconnection applications

Montana Public Service Commission

ARM 38.5.8401 - 38.5.8413 (Small Generator Interconnection) – Small Generator Interconnection · source

Electric distribution companies (EDCs) subject to PSC regulation (NorthWestern Energy, Montana-Dakota Utilities, Black Hills); not electric cooperatives or municipal utilities

Utility-specific standard interconnection request form, agreements and fee schedule filed with and approved by the PSC (ARM 38.5.8403/8404)

Level 1: completeness 10 business days, screens 15 BD, agreement 5 BD, applicant signs within 30 BD. Level 2: completeness 10 BD, evaluation 20 BD. Applicant gives 20 BD notice of commissioning test; EDC witness test within 10 BD or deemed waived; deficiencies report 5 BD, cure 30 BD (ARM 38.5.8408-8410).

EDC files fee schedule and study rates with PSC for approval; no deviation without approval (ARM 38.5.8404). No amounts in rule.

Not addressed in reviewed rules.

Required: lockable, visible-break isolation device accessible to EDC, owned/maintained by generator owner, between facility and point of interconnection (ARM 38.5.8408(6)).

NEM – MCA 69-8-601 to 69-8-605
Statutory net metering applies to NorthWestern Energy (public utility) only; monthly kWh credit carried forward, unused credit granted to utility at end of customer-chosen 12-month period (69-8-603). 50 kW system cap per DSIRE/legislative primer, not verified in statute text.

Electric cooperatives are exempt from the net metering statute and PSC interconnection rules and set their own policies; MDU largely exempt from the statutory net metering part.