Skip to main content

View Diary: The simple innovation that could make wind power a big player (230 comments)

Comment Preferences

  •  I've thought of it (0+ / 0-)

    I call this an "IBM problem". There's an old saying about new technology - "nobody ever got fired for buying IBM." In other words, go with what works.

    I tried to convince a team of engineers that we could go with a smaller, cheaper transformer at a low/medium wind site because of
    1) line losses
    2) efficiency losses
    3) wind conditions - i.e. the wind farm would only be producing full power something like 200 hours per year, or about 2.2% of the time.

    Taking all of that into account, you can run a transformer hot (105-120% of rated capacity) - utilities do it all the time during peak loads.

    I was completely ignored and belittled for the idea, so we spent an extra $200K.

    Javelin, Jockey details, all posts, discontinue

    by jam on Wed Jan 23, 2013 at 06:34:11 AM PST

    [ Parent ]

    •  Ah, the old oversimplistic view of safety factors. (2+ / 0-)
      Recommended by:
      Ohiodem1, jam

      "The book / the official documentation / whatever says that this is the safe X for device Y, so we can always run at X, and we can never exceed X."

      The real world is, of course, not that simple, and depends on the circumstances of how you're operating.  Sometimes your circumstances are such that your safety factor for device Y becomes compromised if some other system fails, and so it's not really a safety factor at all.  Sometimes you gain additional safety from a whole host of other factors related to other systems and so the safe X for device Y is actually way higher and you're wasting money pointlessly.  Systems must always be looked at as a whole, not as a sum of individual components.  Here's all of the possible use cases, here's all of the possible failures - what happens when we combine them and what are the odds of that situation?  Yes, that's a more challenging analysis, but that's the dang reason why engineers take home a salary, to do the analysis right.

      I see this sort of attitude a lot in discussions about wiring.  For example, I've heard a lot of electrical engineers argue that fast charging of electric cars is impossible without dangerously high voltages.  Why?  Because "the book" shows you the maximum rated current for a cord of given thickness with various insulators, and oh look, the cord would have to be too thick to bend or lift!  Great... except "the book" is talking about constant current flow in simple, fixed applications.  That's not taking into account that it takes time for a cord to heat up enough to where you're burning the insulation or risking irreversible deformation, and even if you get to that point, all you have to do to counter it is cool the cord.

      •  And some transformer standards are built around (1+ / 0-)
        Recommended by:
        jam

        a concept that if you use the transformer within its ratings, 100 per cent of the time, you can expect some figure, X hours, frequently I have seen the number 20,000 hours as the expected life.  So, if you run it above its ratings, then that number 20,000 hours may be expected to drop to maybe 19,000 hours if the temperature excursion is defined and predictable.

        Design activity may be undertaken to account for temperature excursions as well.  If for instance the insulation system rating is 180 Deg C, and the excursions would dictate a rating of 220 Deg C, then the act of purchasing the 220 Deg C insulation system may be a low cost alternative to a bigger transformer.  You are sized for 95 per cent of usage, with capability to handle a larger load 5 per cent of the time, without degradation of the expected life of the transformer.

        On the example of cool the cord, in my opinion, I believe a better, more reliable solution is to purchase a cord or cable with a higher temperature rating, for instance, replacing a 90 deg C wire with 105 or 130 Deg C wire which has higher ampacity in the first place and can take the higher operating temperature, which of course is a fire risk if the wire is used in excess of its capacity.  I have long experience in the electrical safety business, and if you submitted that kind of arrangement to a certification lab, it would be rejected out of hand.

        Alternately, if short term current excursions were expected, you could put a duty cycle rating on it  to cover for the excursion, but duty cycles are cumbersome and some consumers would ignore them, leading to a fire or electrical shock risk.

        Republicans are like alligators. All mouth and no ears.

        by Ohiodem1 on Wed Jan 23, 2013 at 08:06:44 AM PST

        [ Parent ]

        •  that was the other thing (0+ / 0-)

          temperature, I forgot. The highest winds (at this location) were only during the winter with ambient temps usually around 0-10 C. And the transformer we put in is ONAN. If temperature became a problem, they could always slap a couple of pumps on it to become OFAF, right?

          Ultimately, I'm not a transformer guy, I'm a little wires guy.

          Javelin, Jockey details, all posts, discontinue

          by jam on Wed Jan 23, 2013 at 08:27:24 AM PST

          [ Parent ]

        •  The cord cooling approach is actually being used.. (0+ / 0-)

          because realistically you need an order of magnitude or so better cooling than passive air cooling alone can provide, not something that a mere uprating of wire type or insulation can provide.  Rapid charging can be hundreds of amps for 5-15 minutes; the tables for passive air cooled steady-state wires state something like 0.5-1" diameter, give or take depending on the details - way too heavy and cumbersome.

          I don't know what sort of coolant they use, but I would expect that it is relatively nonconductive and non-flammable.  

Subscribe or Donate to support Daily Kos.

  • Recommended (141)
  • Community (68)
  • Baltimore (64)
  • Bernie Sanders (49)
  • Freddie Gray (38)
  • Civil Rights (36)
  • Hillary Clinton (25)
  • Elections (25)
  • Racism (23)
  • Culture (22)
  • Education (20)
  • Labor (20)
  • Law (19)
  • Media (19)
  • Economy (17)
  • Rescued (17)
  • Science (15)
  • Politics (15)
  • 2016 (15)
  • Texas (13)
  • Click here for the mobile view of the site