Heat Source in Solar Thermal Challenges Coal

A mining and processing business in California is replacing one coal plant but says another could stay online for many years.

· About half of the world’s energy is used for heat, which includes keeping people warm, according to the International Energy Agency. Transportation and electricity accounts for the other half.

· But GlassPoint’s system, which is made up of an array of mirrors that collect sunlight and concentrate it into heat, will require 500 acres to replace the coal plant at Searles Valley, which sits on about two acres.

· The company dates to the 1860s and early 1870s, when John Wemple Searles, a prospector and borax miner, started operations here with his brother. The company is now owned by Nirma, a company based in India.

· Virtually all solar power — about 99 percent — comes from panels that directly convert the sun’s rays into electricity. Just 1 percent or so comes from the kind of mirrors that GlassPoint uses to produce heat.

· “Just three years ago, the price of coal was four times higher than it is today,” Mr. Molchanov said. “The nice thing about having concentrating solar is that it provides a hedge or really a guarantee that no matter how high the price of coal might get, this source of industrial heat will be reliable and stable.”

[ABS News Service/04.07.2025]

Coal use has been declining for decades, but ending the use of the fuel isn’t going to be easy, even in a place like California, which has ambitious climate change goals.

In industry, many companies use coal, natural gas and other fossil fuels to achieve the high temperatures needed to make their products. And while start-ups and researchers are working on ways to produce heat without generating greenhouse gases, many of those approaches are not yet affordable or cannot produce heat that is hot enough.

About half of the world’s energy is used for heat, which includes keeping people warm, according to the International Energy Agency. Transportation and electricity accounts for the other half.

Rod MacGregor is chief executive of GlassPoint, a start-up that aims to help solve the heat problem for at least some industrial businesses. His company has designed the solar thermal system that Searles Valley plans to use.

“Globally, industry is predominantly heat,” Mr. MacGregor said. “It’s kind of the elephant in the room that’s not talked about.”

But GlassPoint’s system, which is made up of an array of mirrors that collect sunlight and concentrate it into heat, will require 500 acres to replace the coal plant at Searles Valley, which sits on about two acres.

Replacing coal with renewable energy or even natural gas isn’t always feasible. Various things can get in the way, including geography, the location of resources, access to pipelines or economics. Installing a technology to replace all of its power and processing equipment at Searles Valley Minerals with zero-emissions technology would be too costly, Mr. Cruise said.

Still, the United States has been slowly weaning itself off coal. After decades of producing more than half the nation’s electricity, coal plants contributed just 15 percent in 2024. Some of that decline was due to cheaper electricity produced from natural gas, wind and solar. And some of it was driven by the work of environmental groups like the Sierra Club.

This year, the power industry expects to retire about 5 percent of the remaining coal power plants that were operation in the United States last year, according to the Energy Information Administration.

President Trump is seeking to reverse that tide. In April, he signed executive orders to revive the use of coal, and his Energy Department has ordered some plants slated for closing to stay open. Energy experts say efforts to prop up the fossil fuel units are likely to fail because they can’t compete with cheaper resources.

California began phasing out the use of coal for electricity 20 years ago. The state began shuttering generators in and outside its borders. A utility-scale coal plant that was the last to supply electricity to California was scheduled to switch entirely to natural gas this year, but lawmakers in Utah, where the unit is, have worked to keep both fossil fuels in use.

The two Searles Valley coal generators are the only ones operating in California, according to the California Energy Commission. The mining operation taps the brine from Searles Lake to produce boron, soda ash and other chemicals.

The company dates to the 1860s and early 1870s, when John Wemple Searles, a prospector and borax miner, started operations here with his brother. The company is now owned by Nirma, a company based in India.

About two years ago, GlassPoint reached out to Searles Valley executives offering its solar thermal technology as an alternative to coal. Though not as cheap as conventional solar panels placed on roofs or in open fields, the price of solar thermal systems, which are also known as concentrating solar systems, has fallen sharply over the last decade or so, according to the International Renewable Energy Agency.

Virtually all solar power — about 99 percent — comes from panels that directly convert the sun’s rays into electricity. Just 1 percent or so comes from the kind of mirrors that GlassPoint uses to produce heat.

“It’s a rather esoteric, below-the-radar technology,” said Pavel Molchanov, an analyst at Raymond James who focuses on energy, climate and sustainability. “It’s very, very rare.”

Solar and wind farms do not generate the kind of heat that industrial plants need. And other renewable heat technologies are either not mature or affordable enough to meet Searles’s needs.

“Just three years ago, the price of coal was four times higher than it is today,” Mr. Molchanov said. “The nice thing about having concentrating solar is that it provides a hedge or really a guarantee that no matter how high the price of coal might get, this source of industrial heat will be reliable and stable.”

GlassPoint’s system uses mirrors to direct sunlight to a receiver. The resulting heat can be used directly in an industrial process or to make electricity via a steam turbine, even after the sun has gone down. The company is focusing on serving industrial users that need high heat.

One of the best-known concentrated solar power facilities operates in the Mojave Desert and is scheduled to close next year, largely because its electricity is too expensive to compete with cheaper solar panel systems.

Solar thermal technology is not suited for many places, Mr. Molchanov said, but it works well in arid and hot climates like those in Southern California, Arizona, Nevada, Chile, parts of Africa, Australia, the Middle East, and parts of Spain and Portugal.

Concentrated solar power works particularly well for certain industrial purposes in high-heat locations like Searles Valley that have few other options, Mr. MacGregor of GlassPoint said.

“It’s not like you can say, ‘Let’s move the mine,’” he said.

Mr. Cruise said it might take a decade or two to eliminate the company’s last coal unit, but he believes that Searles will ultimately need to find a substitute because of coal’s long-running decline.

“We just think coal is going to be a problem,” Mr. Cruise said. “We’re going to have a hard time sourcing it. We need to be ready to pivot.”