August was a hot month in Manteca for residential solar.The City of Manteca issued 50 permits last month for residential solar panels designed to generate electricity. That’s almost half of the 111 solar power systems installed to date that have a combined value of $3 million.Manteca is on pace to eclipse 2015 when 148 residential solar panel units were installed at a cost of $3.18 million.Nearly 1,700 Manteca homes have solar systems for electricity today. That’s roughly 8 percent of all single family homes in Manteca.A report issued a year ago by the city’s building division noted 600 residential installations they had tracked over a 30-month period were designed to produce 3.37 megawatts or enough to supply all the electricity need of 593 homes.