Jump to main content or area navigation.

Contact Us

Combined Heat and Power Partnership

Maryland Interconnection Standards

Date Last Updated8/13/2014
Policy TypeInterconnection Standard
State/FederalMD
Policy Administrator/Contact OfficeMaryland Public Service Commission (PSC)
Policy Initiation Date6/9/2008
Policy SummaryMaryland has developed interconnection standards for systems, including CHP. The rules apply to all types of utilities including investor-owned utilities (IOUs), rural cooperatives, and municipal utilities. The rules employ a 4-tiered approach to determine the level of review required. Different levels of review are subject to specific technical screens, review procedures, and time lines. The basic four levels of review are:
  • Level 1: applies to lab certified inverter-based systems up to 10 kW. No application fees are charged for this level. There are no insurance requirements under Level 1.
  • Level 2: applies to lab certified or field approved systems up to 2 MW that are connected to a radial distribution circuit or to a spot network serving one customer. An application fee of $50 plus $1/kW of capacity is charged for this level of review. Liability insurance of at least $2 million per occurrence and $4 million in aggregate for systems >1 MW is required.
  • Level 3: applies to systems that will not export power to the grid and which do not require new facility construction by the utility. Systems being located on an area network must be inverter-based, use lab certified equipment, and be 50 kW or less. Systems located on a radial network must be 10 MW or less and not be served by a shared transformer. These systems are also subject to additional criteria dealing with the aggregate capacity of interconnected systems on a given network. An application fee of $100 plus $2/kW of capacity is charged for this level of review. Liability insurance of at least $2 million per occurrence and $4 million in aggregate for systems 1 MW or larger is required.
  • Level 4: applies to systems up to 10 MW that cannot be approved or do not meet the criteria for review under a lower tier. An application fee of $100 plus $2/kW of capacity is charged for this level of review. Liability insurance of at least $2 million per occurrence and $4 million in aggregate for systems 1 MW or larger is required.
Lab certified equipment means equipment tested and approved by a nationally recognized testing laboratory (NRTL) as being in accordance with IEEE 1547, UL 1741, and the National Electric Code (NEC). Field approved systems are generally non-certified systems that have been tested and approved under a prior review by a utility. All interconnected systems must be equipped with a utility accessible "lockable isolation device" or alternately, a "draw-out type circuit breaker with a provision for padlocking at the draw-out position". This requirement is equivalent to an external disconnect switch.

Standardized interconnection agreements are available on the PSC renewable portfolio standard website for all levels of interconnection requests. The regulations also contain provisions for dispute resolution and utility reporting requirements.
CHP Eligibility RequirementsBoth fossil-fueled and renewably-fueled CHP systems are eligible for standardized interconnection.
Eligible Project Size (MW)Standardized interconnection applies to systems up to 10 MW.
Resource Website(s)

Top of page

Jump to main content.