the energy is always there

Yes it is.  Always.  How can it not be?

The only question left to ask ourselves is what to do it.

We are always expending energy.  From the moment we wake up to the moment we fall asleep, every second passed in time consumes a unit of this energy that we own.  Whether we are thinking, talking, seeing, daydreaming, hesitating, or even being depressed, it takes (our) energy to perform any of these actions, whether we are conscious of this or not.

Owning this energy is as part of being human as breathing is.  We have the energy by default; it's not like as if we can say, "Oh, can you come back later Mr. Energy?  You are truly wonderful and all, but right now I am tired and certainly not ready to use you."  At worst, that is just synonymous with spending (our) energy on procrastinating for the most part, so, at the end of the day, we are not really tired.  Dare I say never?

So now that we all agree that this energy will be there unconditionally for us until our life is over (which is the same for breathing), why don't we take control of it and use it to do what we truly want?

"We create ourselves by how we invest this energy. Memories, thoughts, and feelings are all shaped by how we use it.  And it is an energy under our control, to do with as we please." -- Mihaly Csikszentmihalyi, "Flow"