[Bldg-sim] working out the 95 percentile of wind speed

Chris Yates chris.malcolm.yates at gmail.com
Thu Mar 15 16:23:57 PDT 2012


We're doing an off grid system on a farm house in Cumbria, North 
England. If anybody has ever seen the film Withnail & I, it's just down 
the road from where the famous country retreat was filmed.

I'm trying to work out how often there's a need for the backup generator 
to kick in. I've done a crude exercise based on hourly data using vba 
which will suffice for now. It doesn't take into account rate at which 
batteries can be re-charged (yet), but it does allow for quite a big 
margin (70%) by assuming everything does a round trip through the 
batteries when they're not fully charged, plus the Depth of Discharge is 
relatively modest at 20%.

Talking to one supplier, the frequency of the generator kicking in 
sounds like a moot point - they're plc logic brings in the generator on 
a fairly regular basis to condition the batteries.

Cheers

Chris

On 15/03/2012 22:50, Linda Lawrie wrote:
> Each of the EPW files have a "stat" file.
>
> But you might investigate the "DView" software.
>
> I'm not quite sure what you're after -- detailed analysis 
> (spreadsheetable) or just viewable.
>
>
> On 15.03.2012 16:39, Chris Yates wrote:
>> Thanks Dru,
>>  It's actually minimum wind speed occurrences that I'm interested in -
>> when we aren't generating from the wind turbine. Perhaps the best
>> solution is just get to grips with the E+ WTG model and use hourly
>> data.
>>  Best
>>  Chris
>>
>>  On 15/03/2012 11:39, Dru.Crawley at bentley.com [12] wrote:
>>
>>> The design conditions in the ASHRAE Handbook (which CIBSE uses some
>>> of) includes Extreme Annual Wind Speed of 1%, 2.5%, and 5%. Have a
>>> specific location in mind?
>>>
>>> FROM: bldg-sim-bounces at lists.onebuilding.org [1]
>>> [mailto:bldg-sim-bounces at lists.onebuilding.org [2]] ON BEHALF OF
>>> Chris Yates
>>> SENT: Thursday, March 15, 2012 7:24 AM
>>> CC: bldg-sim at lists.onebuilding.org [3]
>>> SUBJECT: Re: [Bldg-sim] working out the 95 percentile of wind speed
>>>
>>>
>>> Dear All,
>>>
>>> Thank you very much. This is all useful stuff. I guess binning
>>> isn't in the engineering culture over here in the UK in the same way
>>> it is in the UK. We tend merely to use hourly weather data to do
>>> simulations and can take design data from CIBSE (most of the time).
>>>
>>> I'll definitely undertake these exercises. In the mean time, I
>>> wrote some very crude vba to step through the weather data and
>>> calculate its effect on battery charge which I'll be happy to share
>>> once I've tidied it up a bit.
>>>
>>> Cheers
>>>
>>> Chris
>>>
>>> On 15/03/2012 02:36, Joe Huang wrote:
>>>
>>> Can't you just sort the data and then look at the values
>>> corresponding to the percentiles of interest, i.e.,
>>> 8322 for 95% percentile of 8760 hourly data? Am I missing something
>>> here ? The only wrinkle in respect to wind speeds is that the hourly
>>> values are spot measurements, and not time-averaged over the hour.
>>>
>>> Joe
>>>
>>> Joe Huang
>>> White Box Technologies, Inc.
>>> 346 Rheem Blvd., Suite 108D
>>> Moraga CA 94556
>>> yjhuang at whiteboxtechnologies.com [4]
>>> www.whiteboxtechnologies.com [5]
>>> (o) (925)388-0265
>>> (c) (510)928-2683
>>> "building energy simulations at your fingertips"
>>>
>>> On 3/14/2012 9:09 AM, Chris Yates wrote:
>>>
>>> Dear bldg-sim'rs,
>>>
>>> I usually take this kind of data for granted (our industry has been
>>> commoditized so much!).
>>>
>>> Statistics not being my strong point, does anybody know of any good
>>> web resources for working out percentile data of various weather
>>> characteristics? I have hourly data available and would like to
>>> undertake the task in excel (or openoffice).
>>>
>>> Thanks
>>> -- 
>>>
>>> Chris Yates C Eng MCIBSE
>>>
>>> /Building Physics Consultant /
>>>
>>> Tel:+447960731576 [6]
>>>
>>> Email: chris.malcolm.yates at gmail.com [7] [8]
>>>
>>> Skype: christopher.m.yates
>>>
>>> _______________________________________________
>>> Bldg-sim mailing list
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>>> [9]
>>> To unsubscribe from this mailing list send a blank message to
>>> BLDG-SIM-UNSUBSCRIBE at ONEBUILDING.ORG [10]
>>>
>>> -- 
>>>
>>> Chris Yates C Eng MCIBSE
>>>
>>> _Building Physics Consultant_
>>>
>>> Tel: +447960731576
>>>
>>> Email: chris.malcolm.yates at gmail.com [11]
>>>
>>> Skype: christopher.m.yates
>>
>> -- 
>>
>> Chris Yates C Eng MCIBSE
>>
>> _Building Physics Consultant_
>>
>> Tel: +447960731576
>>
>> Email: chris.malcolm.yates at gmail.com [13]
>>
>> Skype: christopher.m.yates
>>
>> Links:
>> ------
>> [1] mailto:bldg-sim-bounces at lists.onebuilding.org
>> [2] mailto:bldg-sim-bounces at lists.onebuilding.org
>> [3] mailto:bldg-sim at lists.onebuilding.org
>> [4] mailto:yjhuang at whiteboxtechnologies.com
>> [5] http://www.whiteboxtechnologies.com
>> [6] http://mail.fortlawrie.com/Tel:+447960731576
>> [7] mailto:chris.malcolm.yates at gmail.com
>> [8] mailto:chris.malcolm.yates at gmail.com
>> [9] http://lists.onebuilding.org/listinfo.cgi/bldg-sim-onebuilding.org
>> [10] mailto:BLDG-SIM-UNSUBSCRIBE at ONEBUILDING.ORG
>> [11] mailto:chris.malcolm.yates at gmail.com
>> [12] mailto:Dru.Crawley at bentley.com
>> [13] mailto:chris.malcolm.yates at gmail.com
>

-- 

Chris Yates C Eng MCIBSE

/Building Physics Consultant/

Tel:+447960731576

Email: chris.malcolm.yates at gmail.com

Skype: christopher.m.yates

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