| Vaughn 2005-06-28, 12:25 pm |
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<nicksanspam@ece.villanova.edu> wrote in message
news:d9r24c$5mq@acadia.ece.villanova.edu...
quote:
> Ed Earl Ross <edearl@satx.rr.com> wrote:
>
> No.
>
>
> I'm asking "What's the uptime fraction, over a year," which is less
> than 100%, or "How many minutes per year is the system unable to
> produce energy, on average?" This works best with some sort of alarm
> to tell people a panel is broken and a short repair time estimate,
> compared to a single panel MTBF, in a Markov chain calculation.
>
> "1 out of N" (eg 1/25) redundancy can be a lot cheaper than 1/2
> redundancy, with a lower $/min investment for a given decrease
> in UNavailability, altho it helps to attack the parts that fail
> more often, eg inverters.
I may have missed something, but this discussion seems to ignore the fact
that larger systems are seldom 12 volt, and so you have panels wired in series.
In the case of series connection, the failure of one panel can remove several
(or even all) panels from operation.
Vaughn
quote:
>
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