Q: I am seeking more explanation about the MARTA solar array to put the benefits and $80,000 annual savings in perspective. What was the cost to install the system? What are the annual maintenance expenses and the system’s expected lifespan?
—Terry Dempsey, Grayson
A: The installation of the solar panel canopy at the Laredo bus facility in DeKalb County cost $10.8 million, using a Federal Transit Administration grant, according to MARTA. The system has 4,903 energy-efficient solar panels and generates 1.2 megawatts peak of renewable electricity annually, according to MARTA.
The maintenance cost is about $2,500 annually, according to MARTA. Officials say the solar panels have performance-related warranties for up to 20 years, and the structure’s lifespan is 50 to 75 years.
Q: Is there an estimate of how many AR-15 rifles are in the United States?
—Tim Conner, Austell
A: Data from the Bureau of Alcohol, Tobacco, Firearms and Explosives does not break down figures into specific types of rifles. The ATF's Annual Firearms Manufacturing and Export Report shows that 4.2 million rifles were made and distributed in the U.S. in 2016.
“Those numbers don’t exist because there’s no national registry,” Jan Kemp, ATF spokeswoman, said in a February article by the McClatchy DC Bureau. “Because by law, we are not allowed to have a national registry.”
A National Rifle Association official estimates in the McClatchy report that “between 8.5 million and 15 million assault rifles are in circulation based on manufacturer data.”
Q&A on the News runs Sunday, Tuesday, Thursday and Friday. Fast Copy News Service wrote this column. Do you have a question? We’ll try to get the answer. Call 404-222-2002 or email q&a@ajc.com (include name, phone and city).
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