The Bend energy Challenge has installed LED light bulbs in Bend, a city in Oregon, U.S., over the past six months. The 18,000 bulbs installed were assisted by two AmeriCorps National Civilian Community Corps (NCCC) team, reported KTVZ.

The installation will save the residents US $136,000 per year, said the Bend Energy Challenge. The LEDs selected have approximately 20 years of lifetime, which is expected to save the city US $3.7 million in the long run.

The LED installation program was kicked off in fall of 2015 when NCCC team installed 18,000 bulbs and 1,800 water-saving devices in more than 1,200 local homes.

Each LED bulb is to save nearly 2 million kwh of electricity that, which prevents the emission of 17 thousand metric tons of CO2. The emission is equivalent to the carbon burned in 1.9 million gallons of gasoline.

Residents living within Bend city are free to sign up for 16 free LED light bulbs and two free showerheads at bendenergychallenge.org/freebulbs to save up to US $100 a year.