Note: In March 2012 the Pennsylvania Public Utilities Commission (PUC) issued a Final Order (Docket M-2011-2249441) approving the use of third-party ownership models (i.e., system leases or retail power purchase agreements) in conjunction with net metering. The Order allows these types of arrangements for net metered systems, subject to a restriction that the system be designed to produce no more than 110% of on-site electricity needs. As applied to virtual net metering customers, the 110% limit refers to cumulative consumption across all qualifying meters.
The PUC adopted net-metering rules and interconnection standards for net-metered systems and other forms of DG in 2006, pursuant to the Alternative Energy Portfolio Standards (AEPS) Act of 2004. In 2007, H.B. 1203 amended the Pennsylvania AEPS and also expanded net metering. Revised rules consistent with these amendments were adopted by the Pennsylvania Public Utilities Commission (PUC), effective November 29, 2008 ([http://www.puc.state.pa.us/PcDocs/1017499.doc PUC Omitted Rulemaking Order, Docket L-00050174]).
In Pennsylvania, investor-owned utilities must offer net metering to residential customers that generate electricity with systems up to 50 kilowatts (kW) in capacity; nonresidential customers with systems up to three megawatts (MW) in capacity; and customers with systems greater than 3 MW but no more than 5 MW who make their systems available to the grid during emergencies, or where a microgrid is in place in order to maintain critical infrastructure. It is important to note that electric generation suppliers (EGSs) in Pennsylvania are permitted but not required to offer net metering. Thus customers who choose an electricity supplier other than their utility must check with the supplier to see if it offers net metering service. Net metering is available when ''any portion'' of the electricity generated is used to offset on-site consumption (i.e., system size is not limited by the customer's on-site load).
Systems eligible for net metering include those that generate electricity using photovoltaics (PV), solar-thermal energy, wind energy, hydropower, geothermal energy, biomass energy, fuel cells, combined heat and power (CHP), municipal solid waste, waste coal, coal-mine methane, other forms of distributed generation (DG) and certain demand-side management technologies.
Net metering is achieved using a single, bi-directional meter that can measure and record the flow of electricity in both directions at the same rate. Net excess generation (NEG) is carried forward and credited to the customer's next bill at the full retail rate. Customer-generators are compensated for remaining NEG at the utility's "price-to-compare" at the end of the year. The price-to-compare includes the generation and transmission components -- but not the distribution component -- of a utility's retail rate. In order to reconcile net metering with Pennsylvania's broader renewable energy goals, the "year" referenced above is defined to coincide with the compliance year (June 1 - May 31) used for Pennsylvania's Alternative Energy Portfolio Standard (AEPS).
The utility must provide this meter if a customer’s existing meter does not meet these requirements. If a customer agrees, a dual-meter arrangement may be substituted for the bi-directional meter. Utilities must provide net metering at nondiscriminatory rates identical with respect to rate structure, retail rate components, and any monthly charges to the rates charged to non-net-metered customers. Utilities may not charge net-metered customers any fees or other charges that do not apply to non-net-metered customers. Furthermore, utilities may not require customers to install any additional equipment or carry liability insurance.
Customers retain ownership of alternative-energy credits (commonly referred to as “renewable-energy credits” or "RECs" when associated with renewable energy) unless there is a contract with an express provision that assigns REC ownership to another entity, or unless the customer expressly rejects REC ownership. If a net-metered customer chooses to take ownership or transfer ownership of alternative-energy credits, then the customer is responsible for installing metering equipment required to measure alternative-energy credits.*
Pennsylvania’s rules allow meter aggregation on properties owned or leased and operated by a customer. This primarily benefits farms that are commonly owned and operated. Aggregation is limited to meters (in a single utility’s service territory) that are located on properties within two miles of the boundaries of the customer’s property. The utility must provide the necessary equipment for physical meter aggregation, but the customer must pay the costs. In addition, "virtual meter aggregation" is allowed for properties owned or leased and operated by a customer and located within two miles of the boundaries of the customer's property and within a single utility's service territory. For virtual meter aggregation, the customer is responsible only for any incremental expense involved in processing the account on a virtual meter aggregation basis.
If a net-metered customer’s self-generation results in a 10% or higher reduction in the customer’s purchase of electricity for an annualized period, the customer must pay for its share of stranded costs to prevent inter-class or intra-class shifting.
''*In November 2008, [http://www.puc.state.pa.us/PCDOCS/1023111.doc amended rules] for the Pennsylvania Alternative Energy Portfolio Standard (AEPS) took effect. These rules exempt PV systems of 15 kW or less from a requirement that alternative energy credit (AEC) certification be verified by metered data, and instead provide a more general instruction that it be verified by the system administrator. Thus, despite the reference to "required" equipment that remains in the net metering rules, small solar facilities may not be required to install additional metering equipment in order to generate AEPS eligible credits.''