Drones will fly for days with new photovoltaic engine

Post by mac01021 » Mon, Jul 29, 2019, 6:28 PM UTC

flanbiscuit wrote: post #83

dwighttk wrote: post #57

"For the past 15 years, the efficiency of converting heat into electricity with thermovoltaics has been stalled at 23 percent. But a groundbreaking physical insight has allowed researchers to raise this efficiency to 29 percent. Using a novel design, the researchers are now aiming to reach 50 percent efficiency in the near future by applying well-established scientific concepts." ^interesting part, the drone stuff is…

left out the actual science part of this interesting part: > According to Yablonovitch, this finding builds on work that he and students published in 2011, which found that the key to boosting solar cell efficiency was not by absorbing more photons (light) but emitting them. By adding a highly reflective mirror on the back of a photovoltaic cell, they broke efficiency records at the time and have continued to do so w…

Post by baking » Mon, Jul 29, 2019, 6:44 PM UTC

IanCal wrote: post #20

zaarn wrote: post #4

It reads a bit overhyped, considering they claim to power a house with a generator the size of an envelope; that's a hard no since there is a limit on how much energy hits every square meter and it's not THAT much.

That is talking about heat and power cogeneration, not solar power if that's what you're thinking. The paper they site [0] says the density can 300-400kW/m^2 and so at 300kW, 50% efficiency and a small C5 envelope you're looking at over 5kW. [0] https://scholar.google.com/scholar_lookup?author=M.+Bianchi&...

Post by baking » Mon, Jul 29, 2019, 7:06 PM UTC

dwighttk wrote: post #57

"For the past 15 years, the efficiency of converting heat into electricity with thermovoltaics has been stalled at 23 percent. But a groundbreaking physical insight has allowed researchers to raise this efficiency to 29 percent. Using a novel design, the researchers are now aiming to reach 50 percent efficiency in the near future by applying well-established scientific concepts." ^interesting part, the drone stuff is…

Post by baking » Mon, Jul 29, 2019, 9:49 PM UTC

raducu wrote: post #63

IanCal wrote: post #23

People seem to be misinterpreting this a lot. This is not about solar cells. This is about thermophotovoltalics, and the application here is using a burning fuel source to generate electricity. The "drone" the paper talks about seems to be a reference to another paper on unmanned sea vehicles though. Edit - to be fair the flying drone part is from the corresponding author.

Why couldn't this be used in cars -- 50% seems better than traditional internal combustion engines?

Post by baybal2 » Tue, Jul 30, 2019, 6:31 AM UTC

radarsat1 wrote: post #56

baybal2 wrote: post #51

Earlier quoted context omitted.

Too bad, solar cell don't like much radiation. Add shielding and all mass benefit will be negated.

What about collecting the "waste" IR emissions from the heated water vapor?