3 ms·

Flywheels should be more efficient. With the current tech for mechanical <=> electrical conversion, a super-capacitor with 100% efficiency would be as efficient

by fathyb 4y ago

Flywheels should be more efficient. With the current tech for mechanical <=> electrical conversion, a super-capacitor with 100% efficiency would be as efficient as a flywheel with ~65% efficiency for regen braking. The flywheels by GKN are ~98% efficient. The downside is size and weight, which makes me believe miniaturization is the key.

aidenn0 4y ago
Miniaturization doesn't make sense for flywheels; to increase energy stored by a flywheel you need to do one of: 1. Increasing RPM 2. Increasing the mean radius of the mass 3. Increasing the weight Two of these directly impact either size or weight (#2 and #3 respectively) and the first one is limited by the tensile strength of the materials in use. I'm going to go out on a limb and suggest that the F1 teams were already using exotic materials, so there may not be a lot of ground to gain here.
- fathyb 4y ago
  Agreed with you on the physics, but I think there is much more progress to be made on the rotor to handle higher RPMs, time will tell. For the F1 experiment, they used magnetic composite materials.
  - Danieru 4y ago
    Why do you think that? What makes you think there is unexplored potential at spinning even faster? What material or process do you think is unexplored in specific?
  - aidenn0 4y ago
    UT Austin put about 30 years of research into air-core rotors for pulsed power delivery[1], so it's not like this is a field without extant research 1: e.g. https://www.researchgate.net/publication/261388468_Optimal_design_of_the_rotor_of_air-core_compulsator https://www.researchgate.net/publication/261388468_Optimal_d...
    - fathyb 4y ago
      It sure is, and there are even more funds and more people working on this today than there were 30 years ago. Breakthroughs have been found recently. People use busses and watch cars win 24h endurance races using this technology, partly thanks to the research on composite materials.

by fathyb 4y ago

aidenn0 4y ago

Miniaturization doesn't make sense for flywheels; to increase energy stored by a flywheel you need to do one of: 1. Increasing RPM 2. Increasing the mean radius of the mass 3. Increasing the weight Two of these directly impact either size or weight (#2 and #3 respectively) and the first one is limited by the tensile strength of the materials in use. I'm going to go out on a limb and suggest that the F1 teams were already using exotic materials, so there may not be a lot of ground to gain here.

fathyb 4y ago
Agreed with you on the physics, but I think there is much more progress to be made on the rotor to handle higher RPMs, time will tell. For the F1 experiment, they used magnetic composite materials.
- Danieru 4y ago
  Why do you think that? What makes you think there is unexplored potential at spinning even faster? What material or process do you think is unexplored in specific?
- aidenn0 4y ago
  UT Austin put about 30 years of research into air-core rotors for pulsed power delivery[1], so it's not like this is a field without extant research 1: e.g. https://www.researchgate.net/publication/261388468_Optimal_design_of_the_rotor_of_air-core_compulsator https://www.researchgate.net/publication/261388468_Optimal_d...
  - fathyb 4y ago
    It sure is, and there are even more funds and more people working on this today than there were 30 years ago. Breakthroughs have been found recently. People use busses and watch cars win 24h endurance races using this technology, partly thanks to the research on composite materials.