Excerpt:

For more than a decade, engineers have been building this "energy kite" to harness wind power with 90 percent fewer materials than conventional wind turbines. But Makani, one of the oldest green-energy projects at Alphabet Inc.’s X research lab, is struggling to take flight. Support from its parent has waned in recent years, according to multiple people who have worked at and with the company. Several key Makani members have left. A former executive called it a "shell" of its former self. The people asked not to be identified discussing private matters.

The story of Makani is part of a broader struggle at Alphabet to develop clean energy technology with climate-saving promise. The tech giant is the largest corporate consumer of renewable power, and it continues to explore renewable ideas. But since Makani joined X in 2013, Alphabet has canceled or let languish an effort to create a smart grid system, a way to make fuel from seawater, and floating solar panels, a project that hasn’t been reported before.

For some, this is the result of Alphabet's naïve approach to the field. "The reason they're doing it is arrogance, not expertise," said Saul Griffith, a co-founder of Makani who left the company in 2009. "It's the triumph of novelty over rigor.”