Another of Alphabet’s audacious renewable energy plans is faltering. Bloomberg reports that the company's X lab is struggling to make a go of its Makani project, featured in the video above, which uses large and elaborate kites to float wind turbines in the air. Makani, originally an independent venture, joined X in 2013. But the new report says that it’s since struggled to gain interest in the utilities sector. Meanwhile, staff numbers have fallen by 100 in the past two years and one former exec called it a "shell" compared to what it once was.

Moonshots are, by definition, facing long odds to success. That’s why Alphabet’s secretive X lab, established to “invent and launch ... technologies that … could someday make the world a radically better place,” keeps many of its projects under wraps. But Makani is one of several energy projects to struggle at X. Earlier this year, Fast Company reported that X killed off a project called Foghorn that sought to make liquid fuel out of sea water, calling it “ahead of its time.” Bloomberg reports that a floating solar panel project, called Horizon, and a smart grid software venture have also been trialled with little success at X.

That doesn’t appear to be stopping it from trying, though. Earlier this week, X announced that it had developed a new, affordable grid storage solution that stores energy in molten salt. And it has managed to successfully spin off another company, called, Dandelion, which plans to heat homes from the ground up, with a new, efficient way of installing domestic geothermal. But it remains to be seen how successful either of those ventures will be. For now, X's moonshots have missed their mark.