Configure computers to automatically shut down in the evenings in order to save energy.
Cut back on air conditioning. Federal buildings are notoriously over-chilled. If we set the thermostate at 72 or even 70 degrees it would save money, save energy and still be comfortable indoors. Having to wear a winter sweater at my desk in July makes no sense at all! It's too cold indoors!
Stop sending me check stubs in the the mail! Even my bank emails me my bank statements in password protected pdf files. This would save money in paper and mail delivery costs. I know everyone does not have access to the internet, so you could have the default option set to receive paycheck stubs by email and allow individuals to request that their check be mailed to them.
Put solar panels on all government facilities and reduce the use of interior lighting where natural light sources are.