Solar and battery interconnection rules in Pennsylvania

Size bands and what each one obliges

The screens that decide it

• Within the 5 MVA chapter ceiling Limit 5000 kW.

  The interconnection procedures apply where the electric nameplate capacity is equal to or less than 5 MVA and the facility is not subject to regional transmission organization requirements.

• Within the 50 kW residential net metering limit Limit 50 kW.

  At a residential service location the alternative energy system must have a nameplate capacity of not greater than 50 kW. At other service locations the limit is 3 MW, or 5 MW under the microgrid and emergency provisions, and Commission approval is required to net meter at 500 kW or more.

• Aggregate generation on a shared secondary under 20 kW Limit 20 kW.

  Pennsylvania caps aggregate generation capacity on a shared secondary line at 20 kW.

• Aggregate generation under 15 percent of line section annual peak load 15 percent of line section peak load, a figure only the utility holds.

  Pennsylvania retains the 15 percent line section screen at Level 1 and Level 2, with a spot network separately limited to 5 percent of maximum load and a 240 volt service imbalance limit of 20 percent.

Ask the utility this, before you sell it

1. What is the inverter volt-amp rating for this system? Pennsylvania measures in volt-amps, which is not always the same number as the kilowatt rating, and it is the governing figure here.
2. Is there a percentage of annual consumption limit on this application? A 110 percent figure is widely repeated for Pennsylvania but does not appear in the published net metering section, so it must be confirmed rather than assumed.
3. Is this address served by a rural electric cooperative or a borough system? Neither is an electric distribution company under the Public Utility Code and the chapter does not reach them.

Worth knowing before you quote

Pennsylvania bars a utility from requiring additional equipment or insurance beyond what the chapter or a Commission order authorizes, and the chapter contains no insurance table, so the published answer for an ordinary residential system is no insurance. The fee amounts sit in a policy statement chapter rather than a binding regulation, which is worth flagging to a customer. Level 4 is Pennsylvania non export lane, available to customers who do not export beyond the point of common coupling, the only state read that gives non export its own named review level. The technical standard floats to the current edition of IEEE 1547 and UL 1741 as amended, so the 2018 revision applies by operation of that language. No statewide aggregate net metering cap is published.