[quote=@ERode]
Energy shields is a bit vague, but doable depending on the underlying concept. What energy specifically and how does it work as a shield? And the all important question: what does it run on?[/quote]
Here's my idea. The machine is powered by a big combustion turbine, fueled by oil/other hydrocarbons, that generates electricity - in which the electricity powers some form of shield-tech that makes solid light and projects said light onto others to protect them.