In 2006, Oberlin became one of the charter institutions to sign the ACUPCC and set a target climate neutrality date for 2025. Oberlin's innovative Adam Joseph Lewis Center For Environmental Studies, a building the Department of Energy labeled as one of the "milestone" buildings of the 20th century, incorporates a 4,600 square foot (425 square meter) photovoltaic array, the biggest of its kind in Ohio at the time. The AJLC also features a Living Machine, garden, orchard, and parking lot solar array.