Electricity in Pennsylvania is largely produced by coal-fired plants and by oil burners which are limited and polluting resources. Turn off items when not in use (especially computers), unplug phone and computer chargers, switch to compact fluorescent light bulbs, and turn off lights when you find them on around campus.
Other, less obvious, techniques are also available to reduce your energy intake. Eat lower on the food chain; meats and dairy products require more energy for processing than fruits, vegetables, and grains. Eat foods that haven’t been shipped from across the country or world. Purchase goods made in Pennsylvania or the United States!