Residential solar energy systems are exempted from property tax assessments in New Mexico in most circumstances. For the purposes of determining property taxes, the value of a property cannot increase by the greater of 3% of the previous year's assessment or 6.1% of the assessment from two years ago according to state law. An assessment may exceed these restrictions, however, if physical improvements are made to the property. Under H.B. 233, enacted in 2010, residential solar systems will not be treated as physical improvements and therefore will not increase the value of the property for property tax purposes. Future assessments, however, can include the value of a solar energy system if the property is sold.
A solar energy system is defined as a system that provides space heat, water heat, or electricity to the property. The term specifically does not include windows, dark-colored water tanks, or non-vented trombe walls.