Ah yes... the huge Maryland Solar Farm on the grounds of the Maryland Correctional Institute (MCI) just outside of Hagerstown on MD Rt. 65. I drive past it all the time coming from home just across the Potomac River in West Virginia to shop in Hagerstown. Place is literally a stone's throw from the Tesla Supercharger at the Premium Outlets in Hagerstown at the intersection of Rt. 65 and I-70.
I have a love/hate relationship with Washington County, MD. Home to great places to shop, one of the East Coast's largest solar arrays and a Tesla Supercharger. But if you're driving a Nissan Leaf or anything with a J1772 plug, you're SOL aside from a rather uncooperative Nissan dealership. Major interstates (I-70 & I-81) and routes (Rt. 11 and Rt. 40) cross in Hagerstown making it an ideal home for EV charging structure but alas, none is currently to be found for those of us in the J1772 crowd.