I visited the Potomac OverLook Nature Center, now the James Mayer Memorial Nature Center, the other day to see what the Energerium is all about. The Energerium consists of a number of plaques affixed to the inside walls asking visitors to turn off unused lights, buy compact florescent bulbs, etc. The solar panel demonstration project is apparently not producing energy. Solar water heating panels were recently installed on the Park Ranger's home, and are working well. The worst of the invasive plants have been removed.