The Borough of Manhattan Community College pool got a new, energy-efficient lighting system thanks to an $800,000 grant from Borough President Scott Stringer. Stringer joined college president Antonio Perez for a ribbon cutting at the pool Tuesday, one of the hottest days of the summer so far. In addition, B.M.C.C. also recently received $11 million in federal stimulus funds to make other environmentally-friendly upgrades. Some of the money will be used for a new gymnasium lighting system, which currently must be kept on all day in order for the lights to function properly. The upgrades will save the school $1 million a year in energy costs and reduce its carbon emissions by an estimated 5,400 metric tons — the same amount that’s produced by about 940 cars a year.