Alphabet Sees Power in Molten Salt, a New Moonshot -- Update

By Jack Nicas Features Dow Jones Newswires

Google parent Alphabet Inc. is pitching an idea to store power from renewable energy in tanks of molten salt and cold liquid, an example of the tech giant trying to marry its far-reaching ambitions with business demand.

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Alphabet's research lab, dubbed X, said Monday that it has developed plans to store electricity generated from solar panels or wind turbines as thermal energy in hot salt and cold liquids, such as antifreeze. The lab is seeking partners in the energy industry, including power-plant developers and utilities, to build a prototype to plug into the electrical grid.

Whether the project, called Malta, ever comes to market depends as much on a sound business model as it does on science. Academics said the technology is likely years away from market, if it ever makes it. An X spokeswoman said it could reach the market "in the foreseeable future."

Malta is the latest example of Alphabet seeking to use new technologies to enter new industries, sometimes in surprising ways. X first developed self-driving cars almost a decade ago, and is also building delivery drones and high-altitude balloons that beam internet connections to the ground below. X encourages its engineers to try audacious projects and, as a result, far more fail than succeed.

The lab has also shown interest in energy. One X team is building wind turbines that use drones attached to cables as their propellers, and X recently spun off a firm called Dandelion that uses geothermal energy -- via underground pipes -- to heat and cool homes. Dandelion says its product is already available in New York.

X's plan to partner with other firms to bring Malta to market reflects new financial discipline at Alphabet under Chief Financial Officer Ruth Porat, who joined from Morgan Stanley in 2015. The X spokeswoman said in an email that "it's safe to say that X isn't going to start building power plants!"

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Storing electricity is an area of intense interest right now for the energy industry. In California, solar panels sometimes generate more power than the grid can handle. And in Texas, overnight winds sometimes drive power prices down below zero -- so that companies must pay for the right to put power on the grid. Finding a cost effective way to store solar and wind power during times of surplus and deploy it when needed is the holy grail in the power industry.

Existing storage solutions have downsides. Lithium-ion batteries can be inefficient, for example, although the price of storing power in batteries has been falling rapidly in recent year. Water can be stored behind dams, releasing it through generators when needed -- but this doesn't work well in warm climates. X says Malta, its thermal-energy system in salt, can be durable, flexible and cheap.

Malta builds on a theoretical system designed by Robert Laughlin, a Stanford University professor who won the 1998 Nobel Prize in physics for separate research. X said fewer than 10 researchers have been working on it for more than two years. Several other firms are pursuing similar technology, including a solar-power plant in Morocco.

X says its system works by sending electrical power from solar panels or wind turbines through a heat pump that converts the power to thermal energy, splitting it between hot and cold, which is then stored in tanks of molten salt or a cold liquid, such as antifreeze. The thermal energy can be stored for days or weeks depending on the tanks' insulation. To return the energy to the grid, the hot and cold thermal energy is recombined, creating a stream of wind that spins a turbine, re-creating the electrical energy.

Academics agreed that X's system makes technical sense, but the financials will determine its success. X declined to detail the expected costs of the system, but said it relies on inexpensive components, including salt.

"The devil is in the details in how you manufacture it and install it at low costs," said Massachusetts Institute of Technology professor Jessika Trancik, who studies storing electricity from renewable sources.

Other academics said new demand for energy storage may mean the idea could now work. "Molten salts aren't new, and thermal storage isn't new. What's new about this is there's a big brand-name backer behind it," said mechanical-engineering professor Michael Webber, deputy director of the Energy Institute at the University of Texas at Austin. "And the rise of renewables means there's more demand (for energy storage). So maybe the time is right for an old idea."

--Russell Gold contributed to this article.

Write to Jack Nicas at jack.nicas@wsj.com

(END) Dow Jones Newswires

July 31, 2017 17:17 ET (21:17 GMT)