3 ms·

Not to the point where it costs $14,000 per MW. At that pricepoint hiring humans to hand crank generators is not the laughably ridiculous proposition it should

by sbov 8y ago

Not to the point where it costs $14,000 per MW. At that pricepoint hiring humans to hand crank generators is not the laughably ridiculous proposition it should be.

jws 8y ago
For reference, a megawatt (MW) is 13000 humans cranking generators. You might get by with fewer since the problem being addressed is short bursts of capacity mismatch.
Retric 8y ago
A human might average 100W per hour over a workday at say 10$ per hour to keep the numbers clean (1$ = 10Wh). 14,000$ per 1,000,000Wh is 72wh per dollar so far cheaper. Except this is instantaneous power so they would need 1,000,000 people to sit around doing nothing most of the day and then occasionally have have some or all of them work, because again that battery caps at 100MW. Really, people in AU don't pay 14$ per kWh making 14$ per MWh meaningless. They are really paying to keep generating capacity online not for actual power. A backup generator that's never used costs infinite dollars per W, that does not make it useless. PS: Well under 1 million beause people can generate more power in short periods.
- imron 8y ago
  > to keep the numbers clean With Australia's minimum wage, it's likely to be at least double this.
  - Retric 8y ago
    Fair enough, I was thinking people might average more power and you might use someone outside Australia. On the other hand you need to pay for equipment so ~3W/$ may be more accurate but being generous does not change things much. Anyway ~20$ /h * 24 h a day * 1 million people / -123 MW (Tesla capacity) = ~3,900,000 $ / MWh which is closer than I thought it would be.
- Jedd 8y ago
  > Really, people in AU don't pay 14$ per kWh making 14$ per MWh meaningless. Agreed that consumers don't pay wholesale pricing - but disagreed it's meaningless. Consumers do (of course) end up paying an amount that includes the amortised cost of wholesale power over the course of their contract. Additionally, there are a range of incentives that result from these kinds of significant, if ephemeral, variations in wholesale pricing. Some of these incentives are bad for consumer, planet, etc. > They are really paying to keep generating capacity online not for actual power. A backup generator that's never used costs infinite dollars per W, that does not make it useless. A backup generator that's never used actually is useless.
  - Retric 8y ago
    > A backup generator that's never used actually is useless. Having a backup generator for your data-center means you can have less batteries. Even if you never directly use it you are benefiting by reducing overall capital costs while still mitigating the same risks. Put another way owning a generator can provide a revenue stream because you can sell that risk reduction to someone else. That's not a theoretical benefit that's cold hard cash.
- jessaustin 8y ago
  A human might average 100W per hour... This seems like the wrong unit to use. [EDIT:] I mean that power is already a "per time period" measure; there's no reason to say "joules per second per hour".
  - basementcat 8y ago
    A rule of thumb is a large hamburger with all the fixings is about one kWh.
    - wcarron 8y ago
      His point is that a Watt is a unit of power being equal to 1 joule per second. As an aside, this corresponds to an electric circuit with a potential difference of 1 volt and a current of 1 Ampere. Saying a human produces 100W/hr is wrong. What I assume he meant is this: A human can produce 100W for 1 hour, on average. This is reasonable, since humans produce about 1/8 Horsepower, on average; and 1 HP = 746W.
      - thaumasiotes 8y ago
        He meant a human can produce 100W. He specifically doesn't mean "for one hour"; he says the human works a full workday, producing 800 watt-hours of energy.
        wcarron 8y ago
        Right, but 100W/hr is very different from 800wHr.
        jessaustin 8y ago
        Mostly because "100W/hr" doesn't really mean anything sensible? If you wanted to write "100W" like "100W·hr/hr", that would be fine.
  - Retric 8y ago
deleted 8y ago
[deleted]
tgtweak 8y ago
Is this per mWh? That seems like a rediculous amount if true.
- roenxi 8y ago
  It does seem a bit high because that is a peak statistic, not an average. The energy regulator keeps some statistics on the subject at [1]. Regardless, there is a good point to be made that South Australia was a strong competitor in the hypothetical 2017 Worlds Most Expensive Electricity Competition. It is possible that the batteries success is due to some quirk of their particularly poorly run grid. It is also possible that wind-battery combinations are now a competitive option. The situation continues to unfold. [1] https://www.aer.gov.au/wholesale-markets/wholesale-statistics/trading-intervals-above-5000-mwh-annual https://www.aer.gov.au/wholesale-markets/wholesale-statistic...

by sbov 8y ago

Not to the point where it costs $14,000 per MW. At that pricepoint hiring humans to hand crank generators is not the laughably ridiculous proposition it should be.

jws 8y ago

For reference, a megawatt (MW) is 13000 humans cranking generators. You might get by with fewer since the problem being addressed is short bursts of capacity mismatch.

Retric 8y ago

A human might average 100W per hour over a workday at say 10$ per hour to keep the numbers clean (1$ = 10Wh). 14,000$ per 1,000,000Wh is 72wh per dollar so far cheaper. Except this is instantaneous power so they would need 1,000,000 people to sit around doing nothing most of the day and then occasionally have have some or all of them work, because again that battery caps at 100MW. Really, people in AU don't pay 14$ per kWh making 14$ per MWh meaningless. They are really paying to keep generating capacity online not for actual power. A backup generator that's never used costs infinite dollars per W, that does not make it useless. PS: Well under 1 million beause people can generate more power in short periods.

imron 8y ago
> to keep the numbers clean With Australia's minimum wage, it's likely to be at least double this.
- Retric 8y ago
  Fair enough, I was thinking people might average more power and you might use someone outside Australia. On the other hand you need to pay for equipment so ~3W/$ may be more accurate but being generous does not change things much. Anyway ~20$ /h * 24 h a day * 1 million people / -123 MW (Tesla capacity) = ~3,900,000 $ / MWh which is closer than I thought it would be.
Jedd 8y ago
> Really, people in AU don't pay 14$ per kWh making 14$ per MWh meaningless. Agreed that consumers don't pay wholesale pricing - but disagreed it's meaningless. Consumers do (of course) end up paying an amount that includes the amortised cost of wholesale power over the course of their contract. Additionally, there are a range of incentives that result from these kinds of significant, if ephemeral, variations in wholesale pricing. Some of these incentives are bad for consumer, planet, etc. > They are really paying to keep generating capacity online not for actual power. A backup generator that's never used costs infinite dollars per W, that does not make it useless. A backup generator that's never used actually is useless.
- Retric 8y ago
  > A backup generator that's never used actually is useless. Having a backup generator for your data-center means you can have less batteries. Even if you never directly use it you are benefiting by reducing overall capital costs while still mitigating the same risks. Put another way owning a generator can provide a revenue stream because you can sell that risk reduction to someone else. That's not a theoretical benefit that's cold hard cash.
jessaustin 8y ago
A human might average 100W per hour... This seems like the wrong unit to use. [EDIT:] I mean that power is already a "per time period" measure; there's no reason to say "joules per second per hour".
- basementcat 8y ago
  A rule of thumb is a large hamburger with all the fixings is about one kWh.
  - wcarron 8y ago
    His point is that a Watt is a unit of power being equal to 1 joule per second. As an aside, this corresponds to an electric circuit with a potential difference of 1 volt and a current of 1 Ampere. Saying a human produces 100W/hr is wrong. What I assume he meant is this: A human can produce 100W for 1 hour, on average. This is reasonable, since humans produce about 1/8 Horsepower, on average; and 1 HP = 746W.
    - thaumasiotes 8y ago
      He meant a human can produce 100W. He specifically doesn't mean "for one hour"; he says the human works a full workday, producing 800 watt-hours of energy.
      - wcarron 8y ago
        Right, but 100W/hr is very different from 800wHr.
        jessaustin 8y ago
        Mostly because "100W/hr" doesn't really mean anything sensible? If you wanted to write "100W" like "100W·hr/hr", that would be fine.
- Retric 8y ago

deleted 8y ago

[deleted]

tgtweak 8y ago

Is this per mWh? That seems like a rediculous amount if true.

roenxi 8y ago
It does seem a bit high because that is a peak statistic, not an average. The energy regulator keeps some statistics on the subject at [1]. Regardless, there is a good point to be made that South Australia was a strong competitor in the hypothetical 2017 Worlds Most Expensive Electricity Competition. It is possible that the batteries success is due to some quirk of their particularly poorly run grid. It is also possible that wind-battery combinations are now a competitive option. The situation continues to unfold. [1] https://www.aer.gov.au/wholesale-markets/wholesale-statistics/trading-intervals-above-5000-mwh-annual https://www.aer.gov.au/wholesale-markets/wholesale-statistic...