Why this newest power source is a game changer
When we first read about what China had done late last year, our first reaction was “why isn’t this getting more attention?”. Not only is it different to anything we’ve seen before, but the potential impact on the future of energy generation is extremely exciting.
Here’s what happened: In December, China flipped the switch on the world’s first commercial power plant that runs on supercritical carbon dioxide, sCO2, at the Shougang Water City Steel Group in Liupanshui, Guizhou Province.
If we lost you at “supercritical’, don’t worry. It’s actually a brilliant idea that’s easier to understand than you might think.
It’s a big deal because …
Traditional power plants, whether they’re fuelled by burning coal or gas or use nuclear energy, all work basically the same way. They heat water to make steam, that steam spins a turbine, and the spinning turbine generates electricity. We’ve been doing it this way for over a century.
This new plant does something different: instead of water and steam, it uses carbon dioxide in a special state called “supercritical”.
And supercritical CO2 is …?
Just as water can be solid (ice), liquid (water), or gas (steam), so can carbon dioxide. However, with CO2, there’s a fourth state that happens under specific conditions.
When you heat CO2 to about 31 degrees and squeeze it under really high pressure – about 73 times normal air pressure – something fascinating happens. It’s not quite a liquid and not quite a gas. It’s somewhere in between, and we call this state “supercritical”.
In this supercritical state, CO2 behaves like a superfluid. It flows like a gas but is as dense as a liquid. Think of it as getting the best of both worlds.
What makes it better
Using supercritical CO2 instead of steam has some major advantages:
It’s more efficient. The same amount of fuel can produce more electricity, potentially 10-20% more than traditional plants. That means less fuel burned for the same power output.
The equipment is smaller. Because sCO2 is denser than steam, you need smaller pipes, smaller turbines, and less physical infrastructure. A plant that might “traditionally” take up several football fields could potentially fit in a fraction of that space.
It works at lower temperatures. Traditional steam turbines need extremely high temperatures to operate, often over 500°C. Supercritical CO2 systems can work efficiently at lower temperatures, which means they can pair well with renewable energy sources like solar thermal plants.
Less water is needed. Water-based steam plants consume enormous amounts of water for cooling. Supercritical CO2 systems need far less, which is crucial in areas facing water scarcity.
Easier to maintain. Fewer moving parts and less wear and tear than conventional steam-driven turbines.
How it works
The basic process is so simple you might call it elegant!
– A heat source (could be burning fuel, nuclear reactions, or concentrated solar heat) warms up the supercritical CO2.
– The hot, high-pressure CO2 rushes through a turbine, spinning it to generate electricity.
– After passing through the turbine, the CO2 gets cooled down.
– The cooled CO2 gets compressed and sent back to be heated again.
– The cycle repeats.
The bonus is no emissions, because the CO2 stays inside a closed loop. You’re just moving the same CO2 around and around, so it’s never released into the atmosphere.
What this means for the future
While other potential breakthroughs in energy generation are still being hypothesised or, perhaps, being trialled at small scale in basement labs, this technology has been proven to the point of having a real, working commercial power plant. China has shown this technology can operate at scale in the real world, with two 15-megawatt turbine generator units in place.
The implications are significant. As countries try to generate more power while reducing carbon emissions, technologies that can squeeze more electricity from the same fuel become incredibly valuable. Even better, supercritical CO2 systems could make renewable energy sources more practical by storing solar or geothermal heat more efficiently.
Other countries are watching closely. The U.S., Europe, and South Korea have all been researching this technology. Now that China has proven it works commercially, expect to see more of these plants popping up around the world.
A similar project, led by GTI Energy and funded by the U.S. Department of Energy, is testing sCO2 at the $169 million Supercritical Transformational Electric Power (STEP) Demo pilot plant in San Antonio. We’re not sure how advanced they are right now, but they did complete the first testing phase in September 2024.
What makes it so exciting
For the past 10 years, we’ve read (and written) about some potentially remarkable breakthroughs in energy generation. Almost all of them remain “potentially” remarkable. At GloBird, anything that genuinely delivers cheaper electricity isn’t just interesting, it matters.
While we’re always positive and optimistic, because there are some incredibly brilliant people busting every brain cell to take us forward, we’re also realistic enough to concede that even when we see a breakthrough in the lab, it could be another decade or more before it can be scaled up to the commercially-viable version (not to mention another decade-plus before there’s any chance of it becoming commonplace).
China’s supercritical CO2 power plant represents one of those rare moments when we actually improve on century-old technology in a meaningful way. It’s not just incrementally better, but a genuine leap forward in how we convert heat into cheaper electricity.
At the same time, we do recognise that this is only one plant (for now), and the technology is still evolving. Yes, the potential is enormous, but we’re yet to see how sCO2 performs over time to prove that the efficiency gains hold up at commercial scale.
The Chinese already have big plans
While the rest of the world remains cautious, China has made it clear they intend to move ahead as fast as possible. Making reliable, cheap energy at scale is clearly a strategic priority.
They plan to rapidly scale this pioneering project, with the sCO2 power generation system expected to be deployed across steel, nuclear, and solar plants in the near future, before eventually extending to mobile nuclear sources and even spacecraft.
This approach aligns with China’s broader policy goals, including peaking carbon emissions before 2030 and achieving carbon neutrality before 2060, with nuclear power playing a central role.
At GloBird, our focus is simple: following innovations that have the real potential to deliver cheap, reliable energy for customers. Great value energy is what we do and who we are. If all of this comes to pass, we’ll likely look back on this moment as a genuine game changer.