Depending on how nit picky one gets about measuring small amounts of energy, in general, "energy" is not a necessary part of "The Economy"

One could have an economy where folks trade jokes and folk stories with one another.

Take a look at:
http://en.wikipedia.org/wiki/Economics

There are sectors of economic life where energy consumption decreases with growth. Take for example, the transition in the electronics industry from vacuum tubes to highly integrated transistor circuits. Vacuum tubes wasted great amounts of energy in heating their electrodes.

Yes, all that you say is true, but humankind can not live off of the transitino from vacumn tubes to silicon wafers. They don't taste good, with or without mustard.

The point I am making is that the overall economy, and certainly the U.S. economy and all similar 'western' economies, are inextricably tied to the availability of increasing amoungs of energy. Less energy = less potential growth.

That's today's picture and has been the picture since the industrial revolution. The picture is not going to change overnight, no matter how many jokes we tell.

Can we substitute energy and reduce dependence? Sure, but it will take time, much time, and time we may not have.

Extend this problem to less developed countries - those transitional economies are actually in a worse pickle, particularly those that are importers of oil. They use more energy (oil) per GDP $ than we do, although one might argue that its use is concentrated more on basic needs than our use is, except to the extent where developing economies energy use is directed towards fueling the west's insatiable desire for replacable coloured covers for our cell phones, et al.