Carbon capture and storage (CCS) technology has long been considered a necessary part of the energy mix if we are to reduce carbon emissions enough to avoid the worst consequences of climate change. But it has so far proven to be financially infeasible without a set price on carbon, with recent efforts failing to get off the ground. Enter a new venture: NET Power. Instead of burning fossil fuels and capturing the carbon dioxide as a separate process after the fact, NET Power has designed an innovative power generation process that uses carbon dioxide to turn turbines, generating low-cost electricity while virtually eliminating all air emissions.
To explain the potentially game-changing technology, EPIC hosted NET Power CEO Bill Brown on January 10. Brown explained that NET Power’s business plan is to sell electricity with the same pure economics as traditional power plants, but capture all of the carbon dioxide and other emissions. If they succeed in doing this, “the world would be able to meet every climate target without having to pay more for electricity,” according to Brown.
The company’s strategy starts with a bold assertion.
“Although fire and water can be bad, and in California as of right now we’ve seen fire followed by water being bad, we generally think of fire and water as being good. I think we need to think the same way about CO2,” Brown said. “CO2 is okay, it’s just in the wrong place, just like fire and water.”
How can we get CO2 in the right place?
NET Power uses a unique process that at its most simple level uses a lot of hot CO2 and a little natural gas and oxygen to turn a turbine and produce electricity. From that process, what is left over is a large amount of CO2, as well as a small amount of water and some residualnitrogen and argon.
From there, NET Power cools the CO2 to condense out the water. The majority of the remaining, nearly-pure CO2 recycles back into the combustion process, and the rest of it is removed from the system at high pressure and high purity to be sequestered underground or sold it to make products such as concrete or to enhance oil and gas extraction from existing wells so as not to need to dig new ones.
The company can complete this process, Brown says, while remaining cost competitive with existing natural gas power plants—that is, through economies of scale, after 30 plants have been built. To be profitable in the short term, NET Power relies on the sale of the carbon for those other uses, as well as the sale of nitrogen and argon produced by an air separator the process uses for creating pure oxygen used in combustion.
Responding to a comment that the technology sounded too good to be true, Brown replied:
“You know, this is the problem with us. We were this too-good-to-be-true technology. In fact, people wouldn’t return phone calls in the early stages; they would just say, ‘You can’t do this.’ Then when people actually model it—at this point, hundreds of Ph.D. students have modeled this, energy companies have modeled this, they’ve done what is called heat-mass balance models—so yes, I agree with you, too good to be true. Sometimes that’s what every breakthrough starts out as.”
The technology could be a game changer for clean power, providing a low-cost and flexible compliment to intermittent solar and wind resources. But, that day isn’t here yet. Its model plant in Texas has begun the commissioning and start-up process, and should be up and running this year. NET Power plans to open the full-scale 300 megawatt plant in 2021.