Maryland

In May 2007, Maryland established a property tax exemption for residential solar energy systems. Under this law solar energy devices “installed to heat or cool a dwelling, generate electricity to be used in the dwelling, or provide hot water for use in the dwelling” were exempt from state -- but not local -- property taxes. However, in April 2008 H.B. 377 was enacted, repealing this exemption beginning July 1, 2008. In place of the rescinded exemption, H.B. 377 inserted another provision exempting solar photovoltaic (PV) and solar hot water systems from real property taxes. The exemption now applies equally to state and local real property taxes. In addition, by removing the term "dwelling" and replacing it with "structure", the revised exemption appears to no longer be limited to residential systems.

In May 2009 the exemption was amended yet again by H.B. 1171 to add "residential wind energy equipment" as an eligible technology. In order to qualify, equipment must be sited on residential property and produce electricity to be used in a structure on that property. The new law also revised the definition of eligible solar property to include devices that use "solar thermal electric energy" to generate electricity for use in a structure. A separate piece of legislation, S.B. 621, subsequently amended the definition of solar energy property to include property that generates electricity which is put on the electrical grid (e.g., as in a net metering arrangement). These new provisions took effect July 1, 2009.

A separate provision of Maryland property tax law offers a special assessment for geothermal and solar heating and cooling systems. Thus, solar hot water, PV, and wind energy systems are granted an exemption from real property taxes while solar and geothermal heating and cooling systems are granted a special assessment that makes their assessed value equivalent to a conventional system.