What to do with the weath­er data?

As can be read in the pre­vi­ous blog post­ing, I have now some weath­er data around. Here the head­er from the CSV file I gen­er­ate out of the XML file of the soft­ware:

Date;Humidity (room);Temp (room);Humidity (out);Temp (out);Pressure (abs);Wind (ave);Wind (gust);Wind (dir);Rain

Cur­rently I pro­grammed the weath­er sta­tion to save the data every 5 minutes. The long-​term goal is to de­cide if a giv­en wind tur­bine de­liv­ers a sane amount of en­ergy (dur­ing a com­plete year) at a giv­en place. As I do not want to wait that long to get some in­form­a­tion out of this, the ques­tion arises, what I can do with this weath­er data?

Here an ex­ample of the out­put (ig­nore the rain and wind val­ues, the sensors are not at­tached at a place where there is wind or rain, the com­plete set is ho­ri­zont­ally on the floor in­stead of ver­tic­ally how they are sup­posed to be; and do not be shocked about the room  val­ues, it is the “serv­er room” in the base­ment):

2010-​09-​02 12:55:01;52.0;18.700;30.0;27.000;978.600;0.0;0.0;135.0;4.200
2010-​09-​02 12:50:01;53.0;18.700;30.0;27.500;978.600;0.0;0.0;135.0;4.200
2010-​09-​02 12:45:01;53.0;18.600;30.0;27.300;978.500;0.0;0.0;135.0;4.200
2010-​09-​02 12:40:01;53.0;18.600;30.0;27.800;978.600;0.0;0.0;135.0;4.200
2010-​09-​02 12:35:01;53.0;18.600;30.0;27.700;978.500;0.0;0.0;135.0;4.200
2010-​09-​02 12:30:01;54.0;18.500;31.0;27.500;978.700;0.0;0.0;135.0;4.200

Some things I came up with my­self:

  • A line-​graph of the val­ues dur­ing a day/​week/​month.
  • A graph of the amount of ac­cu­mu­lated rain per hour/​day/​week/​month/​year.
  • The av­er­age temperature/​humidity (as an er­ror bar, so see the min/​max too) per day and night, but what to use as the times where the day starts/​ends? I would like to have the day-​part cov­er the real day­light time (minus some ramp-​up and ramp-​down time), but I do not have any idea how to get this for each day and for my region.Does it make sense to do the same per hour (without any ramp-​up/​-​down)?
  • Does the com­bin­a­tion of tem­per­at­ure and hu­mid­ity and maybe wind tell some­thing? If yes, how to com­bine them and how to in­ter­pret the res­ult?
  • Sim­il­ar for the pres­sure. I do not know what it tells me, but in a graph I can maybe add some ho­ri­zont­al lines which tell some­thing (rain prob­ab­il­ity and maybe danger zones?).
  • For the wind speed the in­struc­tion manu­al comes with a nice table of the beaufort scale and a cor­res­pond­ing de­scrip­tion. This can be put in­to some colored ho­ri­zont­al lines which show more or less dan­ger­ous speeds.

For the plot­ting of the data, I in­tend to use gnuplot with the CSV data as the in­put. It should al­low me to auto­mate a lot of things, and some of the graphs should also be easy to real­ize in­side gnuplot it­self without any ex­tern­al pro­cessing, the ques­tion is only how to real­ize it. For ex­ample for the av­er­age of some val­ues I do not know if it makes sense to use some­thing else than the arith­met­ic mean.

3 thoughts on “What to do with the weath­er data?”

  1. Know­ing the wind speed you can use this to pre­dict your power out­put for a real tur­bine. Dif­fer­ent tur­bines are op­tim­ised for dif­fer­ent loc­a­tions – the cut in speeds and max­ing out speeds var­ies. Every wind tur­bine should have a power/​wind speed curve. For ex­ample there are some here:
    http://​west​windtur​bines​.co​.uk/​p​r​o​d​u​c​t​s​/​1​0​k​w​w​i​n​d​t​u​r​b​i​n​e​.​asp. You can feed in the curve data and in­teg­rate hourly for a good es­tim­ate. How­ever, gusti­ness will af­fect it too and I don’t know much about that. Also, ob­vi­ously you need to have meas­ured the wind speed where the tur­bine is go­ing to be. Wind speed in­creases with height above the ground, usu­ally.

    1. That is the reas­on why I bought the weath­er sta­tion. After a year of col­lect­ing data, I want to get the data sheets of in­ter­est­ing tur­bines and cal­cu­late the power out­put.

  2. An­oth­er thing you can do – you can work out your de­gree days and cor­rel­ate that with your home heat­ing con­sump­tion to see how well your house is per­form­ing insulation-​wise. De­gree days is the sum of (days * de­grees C heat­ing need) over time. It al­lows you to mean­ing­fully com­pare your en­ergy use from one week to the next when it isn’t the same tem­per­at­ure out­side. There is a good ex­plan­a­tion of it here

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