If you were to ride a beam of light, as Einstein famously said, you would experience no passage of time. Therefore, light itself is timeless.
So, if one considers things such as light (or electromagnetic waves to be technical), you're considering something which in it's own nature is outside of this cause and effect chain.
If you look at consciousness as being similar to light, in the sense that it is infinite, and timeless, then there is a part of you which is not bound by any causal chain.
Just because you do not experience time, does not mean it does not pass, nor are you (or light) exempt from cause and effect. Light is in no way infinite either.
Light is not timeless, not infinite, and not exempt from cause and effect. It has a cause (emission from a source, like a light bulb) can be affected (gravity and water can both alter its trajectory) and can affect other things (like the receptors in our eyes allowing us to perceive it). Why would consciousness be different?
Therefore, consciousness is not producing energy. The measurement of brain cells firing is measuring consciousness, in the terms of energy transmission through cells.
How can a physical entity, like brain cells, be influenced by something that is both immaterial and lacking in energy?
ADDENDUM: What about the reverse? How can a physical entity, like brain cells, respond? Because our consciousness obviously recieves input from our physically-dependant senses of sight, smell, hearing, touch, and taste, and so the brain would need not only receptors, but transmitters as well.