Traveling down State Highway 225 in Deer Park, about twenty miles southeast of Houston, drivers can see a plume of flame shoot skyward from a massive Shell refinery, a blazing reminder of the environmental cost of zipping down the freeway in gas-burning cars and trucks. A few miles away, off West Fairmont Parkway in La Porte, near the upper end of Galveston Bay, a far smaller plant sits tucked behind a thicket of trees. It’s hidden from passing motorists and the new homes nearby, and it doesn’t spout anything at all. If its designers have their way, it—and others like it—never will.
This unique power plant is run by a North Carolina company called NET Power. Like many others in Texas and elsewhere, it burns natural gas to generate electricity. But unlike any other gas-burning plant in the world, the La Porte facility doesn’t release any carbon emissions.
NET Power has been developing its process for generating carbon-free electricity since 2014, but its first test of delivering power—enough for about one thousand homes—to Texas’s electrical grid last November was hailed as breakthrough by some in the industry, especially NET Power’s bombastic CEO, Ron DeGregorio. “I believe firmly that we are changing the world with this technology,” DeGregorio told me a few weeks after the successful November test, which he’s compared to the Wright Brothers’ first flight at Kitty Hawk. “We really have, in concept, a new engine,” he said over a Zoom call from his home in Hobe Sound, Florida. “Just like what the steam engine was, or the internal combustion engine was, this is a new engine.”
The plant is unique because it reuses most of the carbon dioxide that’s produced from generating electricity and captures the rest, meaning it emits nothing into the atmosphere. “It’s notable as an engineering achievement,” said Michael Webber, a professor of energy resources at the University of Texas at Austin. “But it’s particularly relevant for Texas [because] it is a low- or zero-carbon way to use natural gas.” Indeed, if NET Power’s approach catches on, it could make the burning of West Texas natural gas far more environmentally friendly than it is now.
Still, NET Power’s carbon-free promises have a too-good-to-be-true ring to them. Other ballyhooed clean-energy saviors, such as cellulosic biofuels and flywheel energy storage, failed to live up to their early hype. So, proving that its technology works, as NET Power did last November, is just the first step. Making it as affordable—and as widely accepted—as conventional power generation may be a greater challenge. Stricter federal regulations and taxes on carbon emissions would help by raising costs on other electricity generators, but they are far from guaranteed in gridlocked Washington.
NET Power has some big energy-industry backers who are betting it will become a game changer even with that uncertainty. The company’s investors include Exelon, one of the country’s largest power generators; Houston-based Occidental Petroleum, one of the largest oil and gas producers in West Texas’s Permian Basin; and Houston-based McDermott International, a global engineering and construction firm that specializes in projects for the energy industry. One of those backers, Exelon, has publicly advocated for the U.S. to adopt “carbon pricing” policies, which would function as something of a tax on carbon emissions. If the U.S. were to adopt carbon pricing, plants such as NET Power’s would pay nothing while existing natural-gas power plants would either pay plenty or shoulder the high costs of retrofitting existing facilities to capture carbon emissions using devices such as scrubbers, which attach to smokestacks to collect carbon as it’s released. But that’s a big “if,” considering that some powerful lawmakers oppose carbon pricing as well as other regulations on natural-gas power plants. That leaves NET Power “operating in uncertain policy territory,” Webber said.
DeGregorio believes that uncertainty won’t last forever. As more companies pledge to meet “net-zero” carbon emissions by 2050, he says it will become increasingly difficult to build conventional, CO2-belching power plants in many areas of the country. “It’s only a matter of time,” he says, “before a strong position can be made that you can’t go build a plant unless you do it with this [NET Power’s] technology, or you come up with very expensive back-end controls,” such as carbon capture.
The science behind NET Power’s plant is much more certain than the politics. The patents for NET Power’s system are held by 8 Rivers Capital, a private equity group founded by Bill Brown, a former Morgan Stanley managing director, and Miles Palmer, a veteran of defense contractor SAIC. The pair set up the fund in the wake of the 2008 financial crisis to develop clean coal technology. In 2014, they partnered with Exelon to begin developing the NET Power test facility in La Porte.
A typical “combined-cycle” power plant burns natural gas to turn turbines, and the hot exhaust is then used to heat water, which makes steam. That steam then drives another turbine that produces electricity. One by-product of all that is carbon dioxide. NET Power, though, employs a process developed by a British chemical engineer named Rodney Allam to remove the steam and recycle some of the CO2. Its plant works by feeding natural gas, pure oxygen, and carbon dioxide into a chamber and igniting the gas. The burning gas and oxygen reach 700 degrees Celsius, creating “supercritical carbon dioxide,” which has liquid properties and drives a turbine that produces electricity.
NET Power cools and captures some of that supercritical CO2 while returning the rest to the beginning of the loop. Because the carbon dioxide is, by then, already heated, it requires less energy the next time around—and far less than required to convert water to steam. By burning pure oxygen, NET Power’s plant also doesn’t produce noxious by-products such as nitrogen oxides or sulfur dioxide, which can account for as much as 85 percent of conventional power plant emissions, according to Webber. The burning of oxygen, though, does produces one by-product: water.
Such water could be a boon to drought-prone regions where growing power demand and increasingly tight water supplies are on a collision course. “In places like West Texas, we could actually be a net producer of water,” said NET Power president Charlie Bowser, a veteran of Exelon’s nuclear power plants.
DeGregorio, also a former Exelon executive (he came out of retirement to run NET Power), says the company has already had inquiries from buyers interested in licensing its patented technology and using it to build commercial plants. It plans to license two types of facilities. One is an industrial-scale operation that will generate about 150 megawatts on-site to power large manufacturing plants. The other is a utility-scale operation that will produce about 300 megawatts at peak production, roughly enough to power 120,000 Texas homes. The company has five plants in development in the U.S., Canada, and the UK, but DeGregorio doesn’t expect those commercial operations to enter service before 2025.
It remains to be seen how widespread NET Power’s approach will become. The power industry has been slow to embrace new technology, preferring to use equipment and designs of proven reliability and, if necessary, retrofitting them to capture carbon. Around the world, only about twenty large-scale commercial carbon-capture projects exist. So far, the most common use for excess carbon is stimulating oil production—essentially capturing carbon to make more carbon. That’s why getting a few plants built and operating will be critical to whether the NET Power technology catches on, Webber says.
In La Porte, NET Power proved it could put power on the grid through what is known in the industry as “carbon capture and storage,” or CCS. But the La Porte facility is a test plant, with a maximum capacity of just 50 megawatts of thermal energy (25 megawatts of electricity). Commercial facilities would need to be capable of producing three to six times that much power to put a significant amount of electricity onto a state power grid. DeGregorio says that NET Power’s electricity-generating process, when operational at that commercial level, will compete with conventional natural gas plants on cost. But there are caveats to his confidence. For one, NET Power will need to sell not only the electricity its plants produce but also the carbon dioxide they capture. There’s a limited market for CO2 resale, although one of NET Power’s backers, Occidental, happens to be a buyer of residual carbon dioxide. (Occidental injects CO2 deep underground into aging oil wells to boost oil production.)
To keep its power prices competitive, NET Power is also counting on piling up tax credits for carbon capture. The federal government today pays up to $50 for every ton of CO2 captured by power producers, and lawmakers this year have discussed raising that to $85 per ton for any plant that captures at least 75 percent of its carbon. Those discussions have their detractors, but NET Power, of course, would easily exceed that proposed threshold by capturing 100 percent.
All of that, DeGregorio figures, “makes me, on a cents-per-kilowatt-hour basis, competitive to” traditional gas-burning power plants. Without the tax credits and CO2 sales, however, NET Power would be about twice as expensive as the most efficient natural gas plants.
Among traditional natural-gas and coal generators, this dependence on tax credits is often derided as a “government subsidy.” But all energy endeavors, even that of Texas’s beloved crude oil, have received government help, including through generous tax breaks. As more companies struggle to meet carbon-reduction goals, NET Power’s design could catch on. Yet its plants are going to have to put a lot more electricity on the grid, and keep it flowing for a lot longer, before it will.
Correction: This article previously misspelled the name of NET Power CEO Ron DeGregorio.