That is a brilliant idea! However, you would either need to be capable of handling that energy alone (and if you were, you wouldn't really need stonehenge to access it) or a large group of competent people. However, there is still the slight problem of how to use the energy once you have it

Luz, assuming you aren't using a wormhole/associated theory then that could be problematic, but once you're capable of moving your consciousness beyond the realms of your body then it isn't problem