Maryland Plug-In Solar Rules

That is Maryland's statutory category.

It does not mean that every solar panel, microinverter or kit advertised as "plug and play" automatically qualifies.

The complete system still needs to fit the Maryland definition and the other requirements of § 7-321.

Maryland's statute uses specific wording.

A qualifying system must be:

limited to supplying a maximum power output of not more than 1,200 W back to the electrical system of the building.

That should not automatically be rewritten as:

"You can have 1,200 W of solar panels."

Panel capacity, inverter output and a legal power limit can refer to different measurements.

A kit may advertise one figure for its combined panels and another for its inverter. The Maryland limit needs to be read according to the statutory wording rather than whichever number is largest on a product page.

Maryland allows a person to purchase and install not more than one qualifying portable solar energy generating system per electric meter, for residential use only.

That means one system per meter, not one solar panel per meter.

A qualifying system may itself contain more than one component or panel, depending on its design.

No prior electric-company approval is required for a qualifying system under § 7-321.

The statute says an electric company may not require a customer using a qualifying portable solar energy generating system to obtain the company's approval before installing or using it.

It also prevents the company from imposing a fee or charge related to the system's ability to feed electricity back into the electric system.

But that does not mean there is no utility requirement.

If the system requires an automatic locking disconnect switch, the customer is responsible for the cost of having that switch installed.

There is no need to understand how that type of switch works to understand the requirement.

The Maryland Public Service Commission provides utility-specific notification forms or contact information on its official Balcony Solar page.

Its current resource includes routes for customers served by BGE, Pepco, Potomac Edison, Delmarva Power, SMECO, Choptank, Hagerstown Light Department and Easton Utilities.

Use the PSC's current page rather than an old third-party list because the notification routes can change.

Maryland's definition requires the qualifying device to be certified by:

Underwriters Laboratory

or:

an equivalent nationally recognized testing laboratory.

The statute does not simply say:

"Maryland requires UL 3700."

That distinction matters.

UL 3700 is important to the developing US plug-in solar category, but state laws do not all use identical certification language. Maryland's enacted wording is broader.

If a seller says a product is suitable for Maryland, look for clear, independently verifiable information about the certification claimed for the system rather than relying only on marketing language.

Maryland contains a narrower provision for systems with a maximum power output to a standard electrical outlet of not more than 391 W.

For these systems, § 7-321 provides an exemption from product-listing provisions from UL or an equivalent nationally recognized testing laboratory that would require alterations to the building's premises, wiring or electrical panels.

This needs to be read narrowly.

It does not mean:

"Systems at or below 391 W do not need certification."

And 391 W is not Maryland's general plug-in solar maximum.

The main qualifying-system definition still uses the 1,200 W maximum described above.

It can under some circumstances.

The Maryland Public Service Commission warns that a portable solar system can produce more electricity than the home is consuming, resulting in electricity being fed from the home back into the grid.

Maryland's statute also prevents an electric company from imposing a fee or charge related to a qualifying system's ability to feed electricity back into the electric system.

Neither point is a promise that exported electricity will be credited or paid for.

Do not assume so.

The Maryland PSC gives an important warning about electricity meters.

If a meter cannot track electricity flowing back to the grid, the PSC says that excess may, depending on the meter type, be treated as zero consumption or may be incorrectly added to recorded consumption.

The PSC advises consumers who expect power to flow back to the grid to check with their electric company about how their meter treats it.

So there are two separate questions:

Can surplus electricity physically flow outward?

and:

How will my utility and meter treat that electricity?

They are not the same question.

Do not assume that export means payment, bill credit or conventional net metering.

Maryland's § 7-321 creates the electrical and utility framework for qualifying residential portable solar systems.

It does not automatically answer every property-permission question.

A renter, condo resident or homeowner in a managed community may still need to consider:

Do not assume it will.

Maryland's plug-in solar law creates a route for qualifying grid-connected portable solar. It does not mean an ordinary qualifying system automatically provides backup electricity when the grid is unavailable.

Backup operation is a separate system capability.