4 ms·

The point is to store the thermal energy for later use to smoothen out photovoltaic's intermittency issues.

by guelo 5y ago

Manuel_D 5y ago
Right. But we already have that technology with conventional heat engines which have the advantage of much, much, lower operating temperature requirements. If you have a 3,000 degree vat of thermal storage material this new engine stops working after draining 1000 degrees. Existing heat engines can usually work down to several hundred Celsius - though superheated steam engines need around 700 Celsius. But that's still an extra 1000 degrees you can bring it down, even in the conservative case.
- gibolt 5y ago
  This is the first of its kind to reach this efficiency, correct? I assume that means there could be room to significantly improve its efficiency or operating requirements with more investment and research. Having one example, even if 'useless' or elementary, is key to developing new technology.
  - Manuel_D 5y ago
    Compared to other TEGs. Not compared to steam turbines. The article is actually being very generous in saying it's "as efficient" as steam turbines. Steam turbines are more efficient with scale, and industrial ones for power generation are over 90% efficient [1]. This new TEG's efficiency is "around 40 percent". Higher than the previous TEGs in the 25-35% range. But not compared to steam engines, that also benefit from much lower operating temperatures. 1. Multistage (moderate to high pressure ratio) steam turbines have thermodynamic efficiencies that vary from 65 percent for very small (under 1,000 kW) units to over 90 percent for large industrial and utility sized units. https://www.epa.gov/sites/default/files/2015-07/documents/catalog_of_chp_technologies_section_4._technology_characterization_-_steam_turbines.pdf https://www.epa.gov/sites/default/files/2015-07/documents/ca...

4 ms·

The point is to store the thermal energy for later use to smoothen out photovoltaic's intermittency issues.

by guelo 5y ago

The point is to store the thermal energy for later use to smoothen out photovoltaic's intermittency issues.

Manuel_D 5y ago
Right. But we already have that technology with conventional heat engines which have the advantage of much, much, lower operating temperature requirements. If you have a 3,000 degree vat of thermal storage material this new engine stops working after draining 1000 degrees. Existing heat engines can usually work down to several hundred Celsius - though superheated steam engines need around 700 Celsius. But that's still an extra 1000 degrees you can bring it down, even in the conservative case.
- gibolt 5y ago
  This is the first of its kind to reach this efficiency, correct? I assume that means there could be room to significantly improve its efficiency or operating requirements with more investment and research. Having one example, even if 'useless' or elementary, is key to developing new technology.
  - Manuel_D 5y ago
    Compared to other TEGs. Not compared to steam turbines. The article is actually being very generous in saying it's "as efficient" as steam turbines. Steam turbines are more efficient with scale, and industrial ones for power generation are over 90% efficient [1]. This new TEG's efficiency is "around 40 percent". Higher than the previous TEGs in the 25-35% range. But not compared to steam engines, that also benefit from much lower operating temperatures. 1. Multistage (moderate to high pressure ratio) steam turbines have thermodynamic efficiencies that vary from 65 percent for very small (under 1,000 kW) units to over 90 percent for large industrial and utility sized units. https://www.epa.gov/sites/default/files/2015-07/documents/catalog_of_chp_technologies_section_4._technology_characterization_-_steam_turbines.pdf https://www.epa.gov/sites/default/files/2015-07/documents/ca...