There are many people who claim to be working on it. Others who have worked on this and threatened disclosure have always died under suspicious circumstances. Most recently and notably was Amy Eskridge. I mean, think of what is at stake for those who have a monopoly on the present means we rely on. I do believe that another limiting factor of disclosure is greed.
My present understanding is that it is all predicated on first and foremost understanding of the aether, from which all energy is 'manifested', which would be the more accurate way of describing the process (nothing is being 'generated'). The aether is energy at rest, pure inertia, and it has different modalities which are manipulated through frequency and vibration. When using steam, water, coal or wind to 'convert' kinetic energy into electrical energy, we are in fact creating the conditions for manifesting electrical energy from the aether, rather than 'converting' the energy, which James Maxwell himself called an illusion.
Without getting too technical, many of the 'fathers' of field theory understood that there are two known geometric shapes when it comes to fields - the magnetic torus, and the dielectric hyperboloid (hourglass shape), which is surrounded by the torus. This is observable with any magnet under a ferrocell, where we can see these shapes and how the two fields interact with eachother. When you introduce movement (vibration and frequency) through space, you have the 4 factors required for the manifestation of electricity. When Tesla invented the AC motor, what he did was invert these fields, so you have the magnetic field surrounded by the dielectric field, and that discovery is what paved the way for our electrical grid.
Another way to look at it is think about when humans first encountered water, then the realization that through temperature modulation that it changed its state to ice, and then at some point we figured out that heat would produce steam. These are means of manipulating water into different states, even though it is fundamentally still water. It is no different than using field geometry arrangements (an arch form) to manipulate the state of the aether, and given the right conditions, it would be possible to create an arch form which doesn't suffer the atmospheric limitations that current processes do (solid state, no moving parts).
Here is a short explanation of this by Ken Wheeler, if you were interested.