WebCTel is headquartered in the Greenworks Building in East Cambridge, site of a former rubber manufacturing facility. The contaminated building has been reclaimed and now provides office space to businesses and non-profit organizations that place an emphasis on environmental protection and implementing social change. Heliotronics, Inc., a solar energy company, recently installed a grid of solar panels on the roof of the building. Capable of generating up to six kilowatts of electricity each day, this grid is being used by WebCTel to power New England's first and only solar-powered ISP.