China tests world's first megawatt-class flying wind turbine
China tests world's first megawatt-class flying wind turbine
We need better propulsion methods than Helium…
…but we don’t exactly have other lighter than air alternatives.
Not to mention that the flames while combusing are invisible by sight. It’s also really difficult to keep contained and if it leaks it has ~11x the impact of CO2 per this article.
I used to like the idea of hydrogen as an energy medium but all of its attributes combined just make it really infeasible to use except for immediate applications.

The 100-year Global Warming Potential of hydrogen falls in the range 11.6 ± 2.8, according to chemistry-model estimates, through its chemical impact on methane, ozone and stratospheric water vapor. It is therefore important to avoid leakages in a hydrogen economy, to help mitigate climate change.