It stores heat for the primary purpose of turning that heat in...

It stores heat for the primary purpose of turning that heat in to electricity when electricity is needed. If the primary purpose is simply to store and supply heat this limits the potential market even more, especially since the assumption is that heat would be supplied by pumping high pressure steam from the TESS to a heat exchanger located where the heat is needed. So if they are turning water in to high pressure steam any way why wouldn't they want to  direct it through a turbine on its way to the heat exchanger and produce electricity at the same time?

As to the other persons question how are they making profit? I didn't know they were, but if so I'm pretty sure it's not through sales of their tech or product.