USPS Saves Millions in Energy Costs: The U.S. Postal Service recently reported it had reduced total facility energy consumption by nearly 26 percent, or 8.6 trillion BTUs, since 2003. Robust energy measurement systems and practical steps, including actions such as the steps noted by the Go Green Forever Stamps, Adjust the Thermostat and Turn off Lights Not in Use, contributed to the reduction, which is about the same amount of energy used annually by 90,000 households.