Why not give back to shareholders now?, page-15

"It would be very unwise for HGO to use shareholder funds to develop the PHES project and this would be a clear signal to divest our holdings."

Yes HGO does not have the expertise to develop a pumped hydro system on its own however it could JV with companies experienced in turbine installations and electrical sales
I had a farm and developed a quarry on the side with an experienced earthmover, it took negligible input from me financially or in time just some surveillance as I was on site 24/7 the earth mover supplied the crushers and excavators and ADTs and then we took a royalty from the quarry which worked out well for everyone similar approach could work here .