In this video (on the two links below for the same video, credit to METRO TV and YouTube), we can see that both balloon and kites are really large.
China Tests World’s Largest Power Generating Kite - YouTube
From Doug’s link I put again but without the support:
Excerpts:
The kite, measuring 5,000 square meters (53,800 square feet), is part of China’s first national R&D project focused on harnessing wind energy from high altitudes.
At the test site, a helium balloon lifted the massive kite to about 300 meters (984 feet) above ground. Once airborne, the kite unfolded and pulled traction cables connected to a ground-based generator, converting wind energy into electricity.
During the recent test, the team also evaluated smaller kites measuring 1,200 square meters (12,900 square feet) each. The tests successfully demonstrated deployment, retraction, and stable energy conversion.
The two Chinese projects appear to be real.
Perhaps they took a look at the Comparison of the traction force of a static parachute kite and a crosswind kite, both with the same projected surface. 