Roughly 750,000 households, or an estimated 2 million people, have participated in the program, according to the city, which estimates savings to be several millions of dollars. Much of those savings, however, occurred in the beginning of the program when ComEd's rates were still high. As of last summer, about 60 percent of residents were still seeing savings, however many were paying more or the same under the program than they would have been paying with ComEd.