I heard an interview with the inventor on NPR last night where he claimed that all the materials and indeed, the technology needed to do this already exist.
The reason this contradicts your reading is likely because, as others have commented, it's not a real space elevator. It doesn't go to space, and it is more like a super-tall building with an interesting adaptive stability system than a tether connected to a counterweight as in traditional space elevator designs.
So this also means it may not be prior art. The innovation is located in however it is they plan to keep a 20km tall structure stable and attach an electric elevator for rockets to it.
The reason this contradicts your reading is likely because, as others have commented, it's not a real space elevator. It doesn't go to space, and it is more like a super-tall building with an interesting adaptive stability system than a tether connected to a counterweight as in traditional space elevator designs.
So this also means it may not be prior art. The innovation is located in however it is they plan to keep a 20km tall structure stable and attach an electric elevator for rockets to it.