On the roof there are 36 solar hot water panels. Inside are a 157 washing machines and 145 dryers. So it’s big. Maybe not still living up to its moniker of the World’s Largest Laundromat. But the aspect that gets our attention is that the panels, installed by Solar Service, save the laundry, in Berwyn, Chicago “about $2,000 a month." They do this by displacing around 2 million Btu (British Thermal Units, if you must know) of natural gas per day for washing clothes. The 40 square foot panels, arrayed in two banks, heat some 2,400 gallons (9,000+ litres) of water a day, which is about 20% of the laundromat’s needs. The laundry anticipates a return on investment (ROI) of about 5 years. It helps that the state covered half of the cost on a dollar-per-dollar program. The total package is said to be the largest solar hot water system in the State of Illinois. Oh yeh, it is a community based venue too. In 2004 they gave away a dozen bikes to kids, who participated in a "Read to Ride" literacy campaign with the local library. Thanks to Tipster Anthony B. for pointing us to the story in the ::Chicago Tribune (might require a subscription), with other info gleaned from the Sun Times. NB: See also the world's largest solar kitchen.