How is system size measured for interconnection in Maryland?

The published limits are stated in kilowatts without saying whether that is the inverter alternating current rating or the array direct current rating.

What is the interconnection request fee in your tariff for this level? Maryland expressly defers the amounts to each utility rather than publishing them.

Only the utility holds this figure. Ask before you quote the job.

Maryland defines the nameplate capacity as the maximum rated output at the point of common coupling and does not say alternating or direct current. Confirm which figure will be used.

Only the utility holds this figure. Ask before you quote the job.

Maryland solar interconnection rules, tiers and fees

How the size is measured: not published

The published limits here are stated in kilowatts without saying whether that is the inverter rating in alternating current or the array rating in direct current. On a system near a threshold that decides which band it lands in, so the checker asks the question rather than choosing an answer.

Size bands and what each one obliges

Level 1 Size 0 to 20 kW	An inverter based facility, or several interconnecting at one point of common coupling, with a nameplate capacity of 20 kW or less. A utility may not charge an interconnection request fee for a Level 1 request. Maryland publishes no insurance requirement at any level. No interconnection request fee No insurance published in the regulation
Level 2 Size 20.001 to 2000 kW	A nameplate capacity of 2 MW or less with lab certified or field approved equipment, on a radial circuit or a spot network serving one customer. The fee is set in each utility tariff rather than in the regulation. Fee set in the utility tariff Lab certified or field approved equipment
Level 3, non exporting Size 2000.001 to 10000 kW	Non exporting systems, up to 50 kW on an area network and up to 10 MW on a radial circuit. Inadvertent export is not permitted at this level. Non exporting configuration Fee set in the utility tariff

Level 1 Size 0 to 20 kW

An inverter based facility, or several interconnecting at one point of common coupling, with a nameplate capacity of 20 kW or less. A utility may not charge an interconnection request fee for a Level 1 request. Maryland publishes no insurance requirement at any level.

No interconnection request fee
No insurance published in the regulation

Level 2 Size 20.001 to 2000 kW

A nameplate capacity of 2 MW or less with lab certified or field approved equipment, on a radial circuit or a spot network serving one customer. The fee is set in each utility tariff rather than in the regulation.

Fee set in the utility tariff
Lab certified or field approved equipment

Level 3, non exporting Size 2000.001 to 10000 kW

Non exporting systems, up to 50 kW on an area network and up to 10 MW on a radial circuit. Inadvertent export is not permitted at this level.

Non exporting configuration
Fee set in the utility tariff

The screens that decide it

Within the 10 MW radial ceiling Limit 10000 kW.
Above the Level 3 radial ceiling the request moves to Level 4 or to PJM jurisdiction.
Within the 2 MW net metering ceiling Limit 2000 kW.
Maryland does not provide net energy metering to a generating system with a rated capacity of more than two megawatts, or five megawatts for a community solar generating system.
Aggregate generation on a shared secondary under 20 kW Limit 20 kW.
Maryland caps aggregate generation on a shared secondary line at 20 kW as an absolute figure.
Aggregate generation under 15 percent of line section annual peak load 15 percent of line section peak load, a figure only the utility holds.
Maryland retains the classic 15 percent line section screen at Level 1 and Level 2. A spot network is separately limited to 5 percent of its maximum load, and a center tap neutral to 20 percent of the service transformer nameplate.

Ask the utility this, before you sell it

What is the interconnection request fee in your tariff for this level? Maryland expressly defers the amounts to each utility rather than publishing them.
Maryland defines the nameplate capacity as the maximum rated output at the point of common coupling and does not say alternating or direct current. Confirm which figure will be used.
What is this customer baseline annual usage? Maryland sizes an eligible system at 200 percent of it, which is the most generous sizing allowance of the states read.

Worth knowing before you quote

Maryland publishes no insurance requirement and no insurance prohibition anywhere in the interconnection chapter, confirmed by reading the general requirements section rather than inferred. The statewide aggregate net metering limit is 3,000 megawatts and the Commission reported installed capacity of about 1,415 megawatts as of 30 June 2024, roughly 47 percent of the cap, so it is open. Note the regulation still recites the superseded 1,500 megawatt figure while the statute says 3,000; the statute governs. Level 1 review runs 5 business days to completeness, 15 to verification, and 20 to permission to operate, making Maryland one of the few states publishing a permission to operate clock.

Source

Code of Maryland Regulations 20.50.09, small generator facility interconnection standards, with net metering at COMAR 20.50.10 and Maryland Public Utilities Article Section 7-306

Read and recorded 2026-09-12. The scope sentence is broad and names no utility class, and the Commission own net metering report lists Southern Maryland Electric Cooperative, Choptank Electric Cooperative, Thurmont Municipal Light Company and Williamsport Municipal Electric Light Plant as reporting participants. Maryland is therefore the northeastern state where cooperatives and municipals are clearly inside the program.

Solar and battery interconnection rules in Maryland

Size bands and what each one obliges

The screens that decide it

Ask the utility this, before you sell it

Worth knowing before you quote

What to do with this