Interconnection Standards

New Hampshire requires all utilities selling electricity in the state to offer net metering to customers who own or operate systems up to one megawatt (MW) in capacity that generate electricity using solar, wind, geothermal, hydro, tidal, wave, biomass, landfill gas, bio-oil, or biodiesel; the capacity for group net-metered systems with a municipal host only is 5 MW. Combined heat and power (CHP) systems that use natural gas, wood pellets, hydrogen, propane, or heating oil are also eligible.*

The PUC's rules for net metering, which distinguish between small customer-generators (up to 100 kilowatts) and large customer-generators (greater than 100 kW and up to 1 MW; 5 MW for group net-metered systems with a municipal host only), include interconnection provisions. Interconnection for large systems is generally governed by each utility’s interconnection practices as outlined in the utility’s tariff filed with the PUC.

The interconnection provisions include timelines for the application process and inspection process, and guidance for technical studies and analysis (if necessary). Utilities generally may not require an external disconnect switch for inverter-based systems that comply with the IEEE 1547 & UL 1741 technical standards, unless the following is true: the customer-generator's revenue meter is not routinely accessible to the utility; the facility uses multiple inverters connected in series; or the utility connection is through a transformer rated meter.  

Utilities may not require customers to purchase or maintain property insurance or comprehensive personal liability insurance to protect against potential liability resulting from the installation, operation, or ownership of the generation and interconnection facility. A mutual indemnity agreement is generally required.

Utilities generally may not require customers who comply with these provisions to meet additional requirements, perform or pay for additional tests, or pay additional interconnection-related charges.

* CHP systems up to 30 kW must have a system efficiency of at least 80% to be eligible. CHP systems greater than 30 kW and up to 1 MW must have a fuel system efficiency of at least 65%.