Buried in energy legislation the D.C. Council is taking up Thursday is a requirement that businesses and commercial establishments keep their doors closed if they have the air conditioning on.

The proposed law, up for first reading on Thursday, applies to any "income producing" commercial properties like office buildings, retail stores and service facilities. It exempts small stores, hotels and restaurants.

The new law would still apply to about 4,000 establishments in D.C. and those caught in violation would be fined $100 for a first offense, then $200, $400 and $800 for subsequent offenses.

Ward 3 Councilwoman Mary Cheh told the Washington Business Journal, which first reported the provision, that the idea was a "modest effort" for conservation, "given concerns about peak energy use especially during the summer time."

Cheh is co-sponsoring the bill, along with Chairman Phil Mendelson, Ward 6 Councilman Tommy Wells and Ward 1 Councilman John Graham. The bill also clarifies that electric vehicle charging stations should not be charged as part of a property's utility bill and exempts solar energy and cogeneration energy systems from property taxes.