Converting seawater to fuel, storing energy in salt, and using robotics to drill geothermal wells. These are all ideas that have gone through Alphabet's “moonshot factory" named X, formerly Google X, which builds and tests out prototypes in an attempt to address really big global problems like climate change.

At the New York Times' ClimateTECH conference on Thursday in downtown San Francisco, the head of X, Astro Teller, detailed some of the internet giant’s most successful, and most unsuccessful, projects that relate to energy and reducing carbon emissions.

Some X projects were created specifically to fight climate change, like the seawater idea. Others, Teller said, will likely have the indirect effect of reducing emissions, like Google’s self-driving car efforts, which were once part of X, but are now a separate division at Alphabet.

Teller -- dubbed the captain of moonshots -- is as gleeful about his team's failures as he is about the successes. For example, he related that he was quite pleased when he and a colleague quickly rejected an idea to harness energy from avalanches. Working through some of the crazier ideas and swiftly proving why they won’t work is a key part of the process at the Google lab, as Teller describes it.

He highlighted the seawater project, called Foghorn, which Google killed off two years after it was born because the group didn’t see how it could deliver alternative fuel economically. “It’s one of the ones we’re most proud of that didn’t work,” he said.

Foghorn, working with scientists at PARC, built technology that collected hydrogen and carbon dioxide from seawater and combined those ingredients to make a fuel used in engines. The program was led by Kathy Cooper, the colleague with whom Teller hashed out the avalanche energy brain teaser.

“We were making vials of methane. We were unbelievably excited about this,” said Teller.

Alas, as many entrepreneurs and investors have learned from the biofuels markets, at the end of the day it’s all about the cost of making a gallon of fuel. While the Foghorn team originally thought they could make the seawater fuel for $5 to $6 per gallon of gasoline equivalent, after two years the technology appeared to be closer to $15 per gallon. At the same time, the price of gasoline had dropped closer to $3 per gallon.

Cooper spearheaded winding down the project and published details about the technology in an effort to see if anyone outside of Google could continue the work. After the project closed, Cooper got a promotion and later went on to lead another X project, Teller said. X has created a culture that enables researchers to take risks, fail and move on to new ideas.

The salt battery is an example of an X project that the lab took halfway to the finish line, but now needs partners to complete, said Teller. The technology, called Malta, is based upon the work of Stanford physics professor Robert Laughlin, who created a model for storing thermal energy in molten salt with high efficiency.

“It’s like pumped hydro in a box,” Teller said. Malta is now looking for partners to help it build a “megawatt-scale” prototype plant large enough to test the technology at a commercial scale.

However, it’s unclear what institution would be willing to put up the funds for such an unproven concept, particularly since the cost of lithium-ion batteries has dropped dramatically.

Another X project has focused on using robotics to build geothermal pipes to heat and cool homes. This year the project was spun out into a separate company called Dandelion.

Teller described the technology behind Dandelion as speeding up the process of drilling a geothermal system from several weeks to several hours. “This is a real business, but not one that X should be in,” said Teller, explaining the spinoff. Cooper, the former head of Foghorn, is now heading up that company.

Teller briefly touched on X’s high-altitude wind project, which it acquired several years ago through the startup Makani Power. While Makani’s tech has appeared to struggle to be commercialized, Makani’s head Fort Felker told Greentech Media earlier this year that the company still remains committed to the technology.

It’s easy to dismiss Google’s moonshot climate-change work as irrational, uneconomic and uninformed. And it can be all of those things.

But that’s not the point. It's an R&D lab developed by a wealthy company that can afford it and that inspires its workers and partners.  

Google has no doubt had a much bigger effect on fighting climate change by spearheading corporate efforts to embrace clean energy. The company has spent over $2 billion on using clean energy for its energy-hungry data centers. At the same time, Google has often acted as a customer for young energy-tech startups, like Bloom Energy (when it was first founded).

But the X lab is an effort to create something else entirely: an environment that can birth new ideas and keep its talent engaged. It’s understandable that many of them would naturally gravitate to trying to tackle climate change. 

Teller compared Google’s moonshot lab to the work being done by Breakthrough Energy Ventures, a billion-dollar venture led by Bill Gates, John Doerr, Vinod Khosla and others to invest in energy research and development.

With dwindling federal government support, efforts to invest in innovative climate tech are becoming increasingly rare. “Two is not enough," said Teller, referring to Breakthrough and Google X. "We need another ten."