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Hello! I work at Makani (https://makanipower.com https://makanipower.com), which is mentioned in the article: > Nor is it absolutely necessary that the electri

Hello! I work at Makani (https://makanipower.com https://makanipower.com), which is mentioned in the article: > Nor is it absolutely necessary that the electricity generation is done on the ground. Makani, a firm recently absorbed by Alphabet, Google’s parent company, has a different approach. It is lifting the generators into the sky, on board a pilotless aircraft with a wingspan of 26 metres. This craft has eight rotors, which act as propellers for take-off and landing. Once at operating altitude, however, they become miniature turbines. The electricity they generate (600 kilowatts at full capacity) is sent to the ground through a power line encased in a tether nearly half a kilometre long. Makani’s prototype has been tested in Hawaii and, later this year, a further series of tests from an oil platform off the coast of Norway are planned. I'm excited to report that we really did pull off the offshore test a few months after this Economist story went to print. Video of our recent offshore test: https://www.youtube.com/watch?v=F6NW0QeKLZA https://www.youtube.com/watch?v=F6NW0QeKLZA (I know it almost looks like a rendering, but it's for real!) And a company blog entry about the test: https://medium.com/makani-blog/makanis-airborne-wind-power-system-takes-flight-offshore-907fd4c9af86 https://medium.com/makani-blog/makanis-airborne-wind-power-s... Makani was funded in part by ARPA-E earlier in its existence, and they recently also made a video about Makani that might be of interest: https://www.youtube.com/watch?v=C9Ly6na58e0 https://www.youtube.com/watch?v=C9Ly6na58e0

abdullahkhalids 7y ago
How visible are these things from the ground? Edit: Ignore the following line. It is too early in the morning. --A single one is producing 600KW, so you need a few per household, and many thousands for a town.--
- jdc 7y ago
  600KW / (1500W / microwave oven) = 400 microwave ovens See https://en.wikipedia.org/wiki/Kilowatt_hour#Confusion_of_kilowatt_hours_(energy)_and_kilowatts_(power) https://en.wikipedia.org/wiki/Kilowatt_hour#Confusion_of_kil...
- homero 7y ago
  That's kw hours. A big house running air conditioning is only 6kwh.
  - dredmorbius 7y ago
    kWh is a unit of energy, that is, power over time, kW is a unit of power, that is, instantaneous energy. Your car engine is rated in power (typically horsepower in the US, though kW is equivalent), your car fuel tank is rated in energy, that is kWh or joules. Power determines how hard you can work. Energy determines for how long. A big house running AC for a hour would give you a kWh number. The instantaneous load is measured in kW.
    - homero 7y ago
      Yeah but if it makes 600kw then it can do it for an hour since it's a generator not a battery
- abetusk 7y ago
  The average US residential annual electricity consumption is around 11 MWh or around 30kWh / day (11,000 kWh / 365 days) [1]. Assuming it produces 600kW for 24h or around 14MWh / day, this services around 480 homes (600 kWh * 24h / 30 (kWh / home)). Their website explicitly says [2] (Overview 1.4): > designed to transfer up to 600 kilowatts of electrical power—enough to power about 300 homes [1] https://www.eia.gov/tools/faqs/faq.php?id=97&t=3 https://www.eia.gov/tools/faqs/faq.php?id=97&t=3 [2] https://makanipower.com/ https://makanipower.com/
- rhinoceraptor 7y ago
  If you were standing directly under a 36 meter wingspan kite, 500 meters off the ground, it would be about 16 times as wide as the size of the moon.
dr_dshiv 7y ago
Will this eventually look like the city power supply in Big Hero Six?
fraggle222 7y ago
Lol, these things are big !!! I had the scale all wrong. When I saw the pictures and video I thought this plane was something one or 2 people could hold (6-12 ft wing span). Then I saw people talking about 600kW and I was like, no freaking way can you get that much power from a plane that size. Then I saw this: https://makanipower.com/makani/images/pages/technology/cta.jpg https://makanipower.com/makani/images/pages/technology/cta.j...
- imtringued 7y ago
  Compared to a single blade of a wind turbine it looks like a toy.
  - woodandsteel 7y ago
    True, but they fly up where the wind is a lot stronger. Plus being much smaller means they might be cranked out in large numbers by a factory, which would make them relatively inexpensive, and also they don't have the major shipping problems that onshore turbines have.
gehsty 7y ago
Hi, I work in offshore wind, subsea cabling, and I’m very interested in the cable tether that connects the kite to the base station and how you over come the issues with fatigue in the metallic elements of the cable, seems like this would be an interesting challenge as you try to balance weight / fatigue life / transmission capability.

abdullahkhalids 7y ago

How visible are these things from the ground? Edit: Ignore the following line. It is too early in the morning. --A single one is producing 600KW, so you need a few per household, and many thousands for a town.--

jdc 7y ago
600KW / (1500W / microwave oven) = 400 microwave ovens See https://en.wikipedia.org/wiki/Kilowatt_hour#Confusion_of_kilowatt_hours_(energy)_and_kilowatts_(power) https://en.wikipedia.org/wiki/Kilowatt_hour#Confusion_of_kil...
homero 7y ago
That's kw hours. A big house running air conditioning is only 6kwh.
- dredmorbius 7y ago
  kWh is a unit of energy, that is, power over time, kW is a unit of power, that is, instantaneous energy. Your car engine is rated in power (typically horsepower in the US, though kW is equivalent), your car fuel tank is rated in energy, that is kWh or joules. Power determines how hard you can work. Energy determines for how long. A big house running AC for a hour would give you a kWh number. The instantaneous load is measured in kW.
  - homero 7y ago
    Yeah but if it makes 600kw then it can do it for an hour since it's a generator not a battery
abetusk 7y ago
The average US residential annual electricity consumption is around 11 MWh or around 30kWh / day (11,000 kWh / 365 days) [1]. Assuming it produces 600kW for 24h or around 14MWh / day, this services around 480 homes (600 kWh * 24h / 30 (kWh / home)). Their website explicitly says [2] (Overview 1.4): > designed to transfer up to 600 kilowatts of electrical power—enough to power about 300 homes [1] https://www.eia.gov/tools/faqs/faq.php?id=97&t=3 https://www.eia.gov/tools/faqs/faq.php?id=97&t=3 [2] https://makanipower.com/ https://makanipower.com/
rhinoceraptor 7y ago
If you were standing directly under a 36 meter wingspan kite, 500 meters off the ground, it would be about 16 times as wide as the size of the moon.

dr_dshiv 7y ago

Will this eventually look like the city power supply in Big Hero Six?

fraggle222 7y ago

Lol, these things are big !!! I had the scale all wrong. When I saw the pictures and video I thought this plane was something one or 2 people could hold (6-12 ft wing span). Then I saw people talking about 600kW and I was like, no freaking way can you get that much power from a plane that size. Then I saw this: https://makanipower.com/makani/images/pages/technology/cta.jpg https://makanipower.com/makani/images/pages/technology/cta.j...

imtringued 7y ago
Compared to a single blade of a wind turbine it looks like a toy.
- woodandsteel 7y ago
  True, but they fly up where the wind is a lot stronger. Plus being much smaller means they might be cranked out in large numbers by a factory, which would make them relatively inexpensive, and also they don't have the major shipping problems that onshore turbines have.

gehsty 7y ago

Hi, I work in offshore wind, subsea cabling, and I’m very interested in the cable tether that connects the kite to the base station and how you over come the issues with fatigue in the metallic elements of the cable, seems like this would be an interesting challenge as you try to balance weight / fatigue life / transmission capability.