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Nerdishness and Solar power

Discussion in 'Everything Else' started by Pfitzy, Jan 28, 2016.

  1. cyclopath Phil Waugh (73)

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    And I thought he was just hiding the sun down there.
  2. Pfitzy Tim Horan (67)

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    THE SUN???

    boyo and cyclopath like this.
  3. 2bluesfan Nev Cottrell (35)

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    Pfitzy, this will be of interest to you. Musk makes an interesting offer.

    100MW wouldn't dramatically change things but would/could add some capacity to cater for spikes. It'll be interesting to see if anything comes of it.
    Pfitzy likes this.
  4. Pfitzy Tim Horan (67)

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    Yeah have been up to the nads in reading about it the last few days.

    Turns out one of the guys at Reposit went to school with Mike Cannon-Brookes so clearly wherever the fuck they went, get your kids in!

    It is going to be interesting with the announcement by SA Premier Jay Weatherill today - new capacity involving a fuckton of batteries and a new gas plant whic- what the fuck?

    Gas? Eat a dick, you can't go back there. You've GOT a gas plant that won't fire up so FIX THAT ONE! FFS.

    Anyway, that is all going to be interesting. At least the gas plant is going to be government-owned, and avoid the bullshit that goes on when gas peakers try to hold back capacity to wait until the prices skyrocket.


    Also the Mexicans are looking at a big battery setup, though maybe not the same capacity. Andrews proposed this back in January I think, but it didn't get much noise because its not Tesla out of the box, and no other billionaires were involved.

  5. Pfitzy Tim Horan (67)

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    Now sit down for a second kiddies, and let Uncle Pfitzy teach you a couple of things about electricity.

    Power is not equal to energy when we're talking grid thingees. And I still have to keep reminding myself of the difference in casual conversation.

    ENERGY is the capacity of something - it usually refers to the capacity of batteries in this case, and is measured in MWh or Megawatt Hours.

    So when someone says "She's a 300MWh setup mate" they're referring (laconically) to how much storage the thing has at maximum.

    POWER is the rate at which energy can be delivered.

    When the same someone says "She's a 20MW setup mate" they're referring to how much power can be delivered at a given moment.

    Use the water tank analogy: energy is the tank, power is the pipe.

    To put that into perspective: my house at any one time might draw between 200 Watts (or 0.2kW - when only the fridge is on at night) up to 12kW when the wife decides to go menal with the air con, the oven, the fucking microwave, blender, etc.

    Every 1000W = 1 kilowatt so if that is per hour that's 1kWh of energy consumed. Geddit?

    If you want to understand your usage a bit better, dig out your bills, look at each of the rates you pay, and the number of kWh assigned to those rates. Careful: you might learn something.

    I know from looking at all my charts and bullshit (http://unleashthepowerwall.com/statistics/) that I consume about 17kWh per day, or an average of 0.7kWh per hour. From looking at my old bills it was higher than that - in the range of 21 per day.

    Now to the balls of the argument - let's say we're talking about:
    1. 300MWh battery
    2. 20MW output
    3. Houses drawing 1kW on average across the day - or 24kWh per day
    If the shit hit the fan and the coal fired piece of ancient dog shit up the road died, how many houses could run off this facility, and for how long?

    Welp, we have 20MW - or 20,000,000 Watts - of output to feed houses drawing 1kW - or 1,000 Watts - at a time. That's 2,000,000 / 1,000 = 20,000 houses.

    And for how long can we do that?

    We're running at capacity of 20MW and we have 300MWh of battery storage at full.
    300 / 20 = 15 hours. So that is a fair bit of juice in the tank.

    The problem of course is that the grid comes under pressure (peak) during times of excess usage, like the shitty hot days we had back in Feb. At that point, my house is importing about 5kW to power the air con and related family bullshit that I'm not already running off my solar. Bump assumption 3 up to 5kW per residence.

    Suddenly we only have capacity to run about 4,000 houses, but still for 15 hours.

    As you can see, a 20MW power output is fairly shit. you're not going to do much with a pipe that big when your tank is massive. Its almost a stranded asset at that point. With 300MWh of energy, 15 hours is your best-case scenario (which is also your worst-case because people be losing their shit on hot days).

    Far better to get the energy and power to have a ratio well under double-digits. In this case, if we could deliver 100MW off a 300MWh facility, we can service 5 times as many houses, even though the energy will only sustain us for 3 hours.

    Mostly, that's what you need to meet a peak demand, so everything there should be good.
    And if half of those houses have a solar setup of their own, and only need a couple of kW here and there, you can spread your reach a lot further.
  6. Dismal Pillock Geoff Shaw (53)

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    I made it this far..
    ..and my bracelet started vibrating.
  7. Braveheart81 Rocky Elsom (76)

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    Dean from Reposit did the same degree as Mike at uni.

    I went to school with Mike.
  8. Pfitzy Tim Horan (67)

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    Potato, Tomato.
  9. cyclopath Phil Waugh (73)

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    So, using the tank and pipe analogy....errr, how many nanoPillockhours were involved?
    Dismal Pillock likes this.
  10. Tex Peter Johnson (47)

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  11. Dismal Pillock Geoff Shaw (53)

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    Pfitzy likes this.
  12. Dismal Pillock Geoff Shaw (53)

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    "Just re-redirecting them towards the sun now. Had another irate phone call, this time from the Pitcairns, telling me to 'rewire those subwoofers into all the Mcintosh amps and set the coordinates for the heart of the sun, DO IT NOW, HANS'. Damn it, this job is confusing at times."
    Pfitzy likes this.
  13. Pfitzy Tim Horan (67)

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    Paywall got me, but I assume from the date its the "Tesla coming for your power bills!" article.

    Chris Griffith is an interesting dude, who is very interested in battery tech. We had a couple of long chats on the phone for his first article, then felt it wasn't quite the right vibe so he asked for my bills and did another one.

    The comments section is, as usual in the Oz, full of old fucking cranks who accuse rich men like me :rolleyes: of driving up prices for poor people.

    Those poor people are also apparently there, complaining about the fact they can't afford a dryer. They completely miss the fact that, by subscribing to The Oz, they're pissing away a dryer's worth of money every fucking year, and probably the running cost of one, too.

    Chris even admits the readership are a mixture of loons and luddites, though not in so many words.

    I've seen the comments section, and mostly they're laughable. The first article he did this time around even had some supporters of the technology in there, trying to correct the fwits. But to no avail: the 1960s should be good enough for anyone, and pass the coal, Gina!


    However, the second article managed to bring the real turd-sniffers out of the woodwork. Check out this tweet I got for some random cock jockey:

    Basically saw the article, trolled my shit on LinkedIn and, in the kind of Hi-def fuckwittery that can only be generated by the mentally infirm, implied that I was selling Powerwalls.

    Once I pointed out that I wasn't selling shit, and he was more than welcome to go comb the site for my sale department info, he fucked off back under his bridge.

    Some canutes have way too much time free on the internet.
    Braveheart81 and boyo like this.
  14. Pfitzy Tim Horan (67)

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    Amusing though it is, that isn't his real profile pic. So I tracked the shunt down myself :D

  15. Pfitzy Tim Horan (67)

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    Looks like a barrel of laughs, eh?
  16. Pfitzy Tim Horan (67)

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    Fuck his website is a bunch of toss as well.
  17. Pfitzy Tim Horan (67)

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    HJ Nelson likes this.
  18. Lindommer Steve Williams (59)

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    Give us a rundown on the same size system as yours re pricing.
  19. Sully John Eales (66)

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    Damn! That's a good price.

    Sent from my D5833 using Tapatalk
  20. Pfitzy Tim Horan (67)

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    Comparison to my system is kind of invalid, as things have leaped ahead a generation almost. Can't buy my little battery any more so the LG offerings blow it out of the water. But adding another battery at ~$5K (less STCs) looks tasty.

    So, the comparison you need is versus today's Powerwall 2, to be equitable. Let's say you're spending $16k - which is Package #6 in the LG Chem doco:

    Powerwall 2 package would include ~5kW of panels and 13.5kWh of battery storage.
    LG Package package has 9.6kW of panels (+92%) and 19.6kWh of storage (+45% storage)

    Really it comes down to what your usage is. Figure our your daily usage and then get the battery that is about 75% of that. Should see you through pretty much every day with a bit of planning.

    For example, if your annual power bills add up to using 22kWh per day (8000kWh per year or roughly 2000kWh per quarter), then you could probably get by with Package #5 in that document (7.2kW of panels, 13.1kWh of storage).

    Maybe even Package #4 (4.8kWh / 9.8kWh storage).

    Need to think about things like electric hot water, which is usually done "off-peak" (controlled load) and therefore is a low price and not affected by storage.

    Someone in that situation might even consider Package #4 and a smaller solar system, and solar hot water.
    cyclopath and HJ Nelson like this.

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