The way I understood it even before in the long term it was cost effective because it provided consistent power with little maintenance but it was the large upfront that was the problem. The article is a little light on the technology that allows for it to be cheaper but I have seen stuff on the laser drilling company (which stated by making lasers for fusion) which both lowers cost and speeds up the process (normall drilling the drill head wears down and they have to pull the whole thing out to change it and then run it back down). Given it does not require as much rare materials as some other options and is consistant 24x7 I am very hopeful for geothermal.