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Net Power Delivers Electricity to Grid in Major Technological Breakthrough

mikece 5y ago
As usual for a press release this is more hype than insight but it looks like they are doing three things here: - Burning natgas - Capturing all CO2 from the combustion process - Using supercritical CO2 in the power turbines in place of (water)steam Honestly it's the last part that has my attention. Most heat->(water)steam->turbine systems have a maximum 33% efficiency. NREL has been working with supercritical CO2 for quite a while because it gets well over 40%, possibly as high as 50% efficiency. In part it's because there's not a phase transfer taking place like in a normal water-steam turbine system so the cooled CO2 after the high pressure and low pressure turbines requires less energy to be re-heated. Also, at super-critical state the CO2 behaves more like a fluid than a gas and has greater "horsepower" (for lack of a better term). Either I'm behind on the supercritical CO2 news cycle or this is the first time they are making it work at near-utility scale. The goal for a long time has been to get this to work at the 600MW+ power stations (be it coal, natural gas, or any other sufficiently hot heat source) as the jump in thermal-to-electrical efficiency would be massive.
- Accujack 5y ago
  Plus it seems like the technology could be retrofitted to existing natural gas power plants... not the turbines and combustors necessarily, but the infrastructure to supply natural gas and distribute the electricity produced is already in place. If they can find an option for retrofit sites that handles the produced CO2, then it should be possible to retrofit nat gas power generation plants for the increased efficiency fluids while simultaneously turning them carbon neutral. If this can be commercialized and distributed quickly, it could well turn out to be a major means of reducing CO2 release to the atmosphere while simultaneously reducing the need for (and cost of) total replacement of fossil fuel power generation plants.

As usual for a press release this is more hype than insight but it looks like they are doing three things here: - Burning natgas - Capturing all CO2 from the combustion process - Using supercritical CO2 in the power turbines in place of (water)steam Honestly it's the last part that has my attention. Most heat->(water)steam->turbine systems have a maximum 33% efficiency. NREL has been working with supercritical CO2 for quite a while because it gets well over 40%, possibly as high as 50% efficiency. In part it's because there's not a phase transfer taking place like in a normal water-steam turbine system so the cooled CO2 after the high pressure and low pressure turbines requires less energy to be re-heated. Also, at super-critical state the CO2 behaves more like a fluid than a gas and has greater "horsepower" (for lack of a better term). Either I'm behind on the supercritical CO2 news cycle or this is the first time they are making it work at near-utility scale. The goal for a long time has been to get this to work at the 600MW+ power stations (be it coal, natural gas, or any other sufficiently hot heat source) as the jump in thermal-to-electrical efficiency would be massive.

Accujack 5y ago
Plus it seems like the technology could be retrofitted to existing natural gas power plants... not the turbines and combustors necessarily, but the infrastructure to supply natural gas and distribute the electricity produced is already in place. If they can find an option for retrofit sites that handles the produced CO2, then it should be possible to retrofit nat gas power generation plants for the increased efficiency fluids while simultaneously turning them carbon neutral. If this can be commercialized and distributed quickly, it could well turn out to be a major means of reducing CO2 release to the atmosphere while simultaneously reducing the need for (and cost of) total replacement of fossil fuel power generation plants.