New York City was the first to roll out a hybrid street sweeper in 2010, and it has plans to introduce more green sweepers into its fleet of 450. With $690,000 in stimulus funding, the city purchased five new diesel-powered hybrid-electric street sweepers in September, a Department of Sanitation (DSNY) spokesperson told Governing in an email. The new trucks use a third less fuel than traditional sweepers, are expected to save the city more than $30,000 a year and emit 100 fewer metric tons of greenhouse gases into the air, reports the Recovery Blog. Right now, the environment-friendly street cleaners are used in four of the city's five boroughs, according to the department. But the New York City’s ARRA Tumblr blog post claims that if the sweepers are successfully integrated, “there is potential to multiply the impact by 90 fold.” The fate of the sweepers' expansion depends on their cost, reliability, performance and efficiency -- all of which the city is testing now, according to a DSNY spokesperson.