I put again the publication on
Page 7, figure 6 concerning the dual-airfoil 10 MW system. Two tether lengths are considered: 8 km then 15 km, involving in land use being respectively about 200 km² and 700 km² !!! Resulting a density of respectively 0.05 MW/km² and 0.014 MW/km².
When the power/land and space use ratio will be considered, some progress could occur.