Arcam AB fka AMAVF

[charlie T colton]

GE's 10MW superalloy turbine, 7" diameter, weighs 150 pounds.

OK. The question is how does GE make this? They don't say in any of the articles I've seen.

The Arcam Q20plus has a build envelope of 13.78" Diameter X 14.96"
The Arcam A2X has a build envelope of 7.87" X 7.87" X 14.96"

"The combination of high heat and pressure are what allowed Hofer to design a turbine that fits on a conference table but can generate 10 megawatts (MW), enough to power 10,000 U.S. homes."

" The turbine features a rotor that is 4.5 feet long, 7 inches in diameter, and only weighs 150 pounds."

" Hofer’s turbine and casing are made from a nickel-based superalloy because it can handle temperatures as high as 715 degrees Celsius and pressures approaching 3,600 pounds per square inch. “You need a high-strength material for a design like this,” he says."

"Full disclosure: The model in Hofer’s hand was 3D-printed from plastic. The real functional version of the turbine, made from high-strength metal, would make the scientist hold up about 150 pounds. But even that’s like lifting a feather. Machines generating this kind of power typically weigh several tons.


GRC’s Hofer says his “minirotor” could power a small town. Image credit: GE Global Research

All in GE Reports:

This Is What We Call Ecomagination: GE Is Building A CO2-Powered Turbine That Generates 10 Megawatts And Fits On A Table - Apr 11, 2017

Mind The Gap: How To Build A Power Plant Fueled By The Sun And CO2 - Sep 6, 2016

This Scientist Has Turned The Tables On Greenhouse Gas, Using CO2 To Generate Electricity - Mar 7, 2016

This Scientist’s Got The Power (Plant) In His Hands - Mar 15, 2016


All from the US Department of Energy:

EERE Success Story—Supercharging Concentrating Solar Power Plant Performance - March 2, 2017

DOE Announces $80 Million Investment to Build Supercritical Carbon Dioxide Pilot Plant Test Facility - October 17, 2016

U.S., Saudi Arabia Announce International Collaboration on Supercritical CO2 Tech Development - June 3, 2016

Energy Department Announces New Investments in Supercritical Transformational Electric Power (STEP) Program - December 10, 2015



Critical Thinking: GE Is Building A 10-Megawatt Turbine That Fits On A Table And Is Powered By CO2
Published on Apr 11, 2017
An engineer at GE Global Research is building a compact but superefficient turbine that replaces steam with ultrahot and superpressurized carbon dioxide.

This Is What We Call Ecomagination: GE Is Building A CO2-Powered Turbine That Generates 10 Megawatts And Fits On A Table
Apr 11, 2017 by Tomas Kellner

Ever since Thomas Edison used a steam generator in his Pearl Street Station to supply parts of lower Manhattan with electricity in 1892, people have been trying to improve the design. While Edison eked out 1.6 percent efficiency from his boiler and generators, the latest “ultra-supercritical” systems are clocking in at 47.5 percent.

But Doug Hofer, the scientist behind these developments, is just getting started. Hofer, an engineer at GE Global Research headquarters in Niskayuna, New York, is building a compact but superefficient turbine that replaces steam with ultrahot and superpressurized carbon dioxide. The turbine can be used with any thermal power plant, including concentrating solar power plants, which use solar heat to generate electricity. The technology was developed in partnership with Southwest Research Institute as part of a research project with the U.S. Department of Energy’s SunShot Initiative.

The combination of high heat and pressure are what allowed Hofer to design a turbine that fits on a conference table but can generate 10 megawatts (MW), enough to power 10,000 U.S. homes.

GE Reports first wrote about Hofer last year when he 3D printed a plastic prototype of the turbine. His team, partnered with Southwest Research Institute and Gas Technology Institute, has since submitted the design to the U.S. Department of Energy and won an $80 million award to build the 10 MW turbine. The turbine features a rotor that is 4.5 feet long, 7 inches in diameter, and only weighs 150 pounds. The engineers are now completing a scaled-down, 1 MW version of the machine and will test it in July at the Southwest Research Institute.

The idea of using CO2 to power a steam turbine has been around for a while. It first appeared in the late 1960s, and an MIT doctoral student resurrected it in 2004. “The industry has been really interested in the potential benefits of using CO2 in place of steam in advanced supercritical power plants,” Hofer says.

By “supercritical” Hofer means efficient power stations using CO2 squeezed and heated so much that it becomes a supercritical fluid, which behaves like a gas and a liquid at the same time. The world’s most efficient thermal power plant, RDK 8 in Germany, uses an “ultrasupercritical” steam turbine operating at 600 degrees Celsius and pressure of 4,000 pounds per square inch, more than what’s exerted when a bullet strikes a solid object.

Hofer says that the steam power plant technology “has been on a continuous march” to increase efficiency and steam temperature, but once it tops 700 degrees Celsius, “the CO2 cycle becomes more efficient than the steam cycle.” Hofer’s turbine and casing are made from a nickel-based superalloy because it can handle temperatures as high as 715 degrees Celsius and pressures approaching 3,600 pounds per square inch. “You need a high-strength material for a design like this,” he says.

The turbine can be used with any thermal power plant, including concentrating solar power plants, which use solar heat to generate electricity.

The hellish heat and pressure turn CO2 into a hot, dense liquid, allowing Hofer to shrink the turbine’s size and potentially increase its efficiency a few percentage points above where state-of-the-art steam systems operate today. “The pressure and fluid density at the exit of our turbine is two orders of magnitude higher than in a steam turbine,” Hofer says. “Therefore, to push the same mass through, you can have a much smaller turbine because the flow at the exit end is much denser.”

Hofer’s design uses a small amount of CO2 in a closed loop. “It’s important to remember that this is not a CO2 capture or sequestration technology,” he says. Hofer says that the technology, which is being developed as part of GE’s Ecomagination program, could one day start replacing steam turbines. “It’s on the multigenerational roadmap for steam-powered systems,” he says.

By virtue of becoming more efficient, the technology could help power-plant operators reduce greenhouse gas emissions. “The efficiency of converting coal into electricity matters: more efficient power plants use less fuel and emit less climate-damaging carbon dioxide,” wrote the authors of the International Energy Agency report on measuring coal plant performance.

Moving the current average global efficiency rate of coal-fired power plants, which supply the heat to convert water (or CO2) to steam, from today’s 33 percent to 40 percent by deploying more advanced technology could cut CO2 emissions every year by 2 gigatons, which is equivalent to India’s annual CO2 emissions, according to the World Coal Association.









Top and above: GE Global Research engineer Doug Hofer is building a compact and highly efficient turbine that fits on a conference table but can generate 10 megawatts (MW), enough to power 10,000 U.S. homes. The turbine, made from a nickel-based superalloy that can handle temperatures up to 715 degrees Celsius and pressures approaching 3,600 pounds per square inch, replaces steam with ultrahot and superpressurized carbon dioxide, allowing for a smaller design.