Note: The program web site listed above links to the Maryland Public Service Commission's Net Metering Working Group page, which contains a variety of information resources related to the ongoing implementation of net metering in Maryland, such as meeting agendas, minutes, and draft utility tariffs.
Maryland’s net-metering law has been expanded several times since it was originally enacted in 1997. In their current form, the rules apply to all utilities -- investor-owned utilities (IOUs), electric cooperatives and municipal utilities. Residents, businesses, schools or government entities with systems that generate electricity using solar, wind, biomass, fuel cell, closed-conduit hydroelectric, and micro-CHP resources are eligible for net metering. The law permits outright ownership by the customer-generators as well as third-party ownership structures (e.g., leases and power purchase agreements). The provisions allowing for micro-CHP systems([http://mlis.state.md.us/2009rs/chapters_noln/Ch_436_hb1057T.pdf H.B. 1057]) and certain third-party ownership structures([http://mlis.state.md.us/2009rs/chapters_noln/Ch_341_sb0981T.pdf S.B. 981)] were added in May 2009 and took effect July 1, 2009. Net metering was extended to fuel cell electricity generation systems in May 2010([http://mlis.state.md.us/2010rs/chapters_noln/Ch_574_hb0821T.pdf H.B. 821]) and closed-conduit hydroelectric facilities in April 2011 ([http://mlis.state.md.us/2011rs/bills/sb/sb0271e.pdf S.B. 271]).
Other important details of Maryland's net metering policy include:
- Net metering is available statewide until the aggregate capacity of all net-metered systems reaches 1,500 MW. (The aggregate limit on net metering was 34.7 MW prior to the 2007 amendments.)
- System size is generally limited to 2 MW, except micro-CHP resources are limited to 30 kilowatts (kW). Systems must be primarily intended to offset all or a portion of a customer's on-site energy requirements and are limited in size to that needed to meet 200% of the customer's baseline annual electricity use.
- Net excess generation (NEG) is generally carried over as a kilowatt-hour credit (i.e., at the retail rate) for 12 months. Compensation for any NEG remaining in a customer's account after a 12-month period ending in April of each year is paid to the customer at the commodity energy supply rate.
- Customers own and have title to all renewable-energy credits (REC) associated with electricity generation by net-metered systems.
- Meter aggregation (either physical or virtual) is permitted for customers that use electrical service for agriculture, as well as non-profit organizations and municipal governments or their affiliates.
- The PSC must file with the Maryland General Assembly detailed annual reports (see [http://webapp.psc.state.md.us/Intranet/Reports/2012%20MD%20PSC%20Report%... 2012 Net Metering Report]) describing the status of the state's net-metering program.
Utilities must install a meter at a customer's facility capable of measuring the flow of electricity in both direction (if necessary), and must offer net metering through a tariff or contract at non-discriminatory rates compared to those offered to customers that do not net meter. Customers with systems that meet all applicable safety and performance standards established by the National Electrical Code (NEC), the Institute of Electrical and Electronics Engineers (IEEE), Underwriters Laboratories (UL) and any other PSC requirements may not be required by utilities to install additional controls, to perform or pay for additional tests, or to purchase additional liability insurance.