Data logging desperate style

[desperate]

Ok so never in a million years am I going to get my head round this electronickery stuff so here maybe is the cactusville method of data manipulation, I say maybe cos I have just lost a post  while trying to upload a MS works spreadsheet, and got a message saying "an error has occurred, you cannot upload that file only files of the gobbledeygookblahblahroobarbroobarb type can be uploaded. No help to me that

Anyway what I have done is taken readings throughout the year of the, Time,S2 and S3 , if I ever manage to upload it you'll see what I mean.

I figure if I take enough readings at random times of the day and on enough days through the year without any regard of the weather, and knowing the  heat capacity of our cylinder when S2 and S3 readings are identical, it will be easy to work out an accurate power input, neatly sidestepping the flowrate and pipeloss issues, and a usefull energy delivered quantity to said cylinder. Most of the charts are recorded on days when I am working at home and Mrs and micro Desp are at work/school, so I can be sure there is no water drawn off. Some of the charts are taken at the weekend so there maybe some water drawn, but I figure this will cause the calculations to understate the energy delivered, better than an over estimation I think.

The next stage is to average all the power inputs when the S2 and S3 readings are the same, and then multiply that by the total run hours as recorded by the TDC3 controller, to give me a yearly energy input and a Gas and financial saving.

Is this a usefull exercise and would it be worth many of us pooling our results with a view to calibrating the controllers and to ensure the thermal FIT, if it ever happens, is based on some kind of reality?

Ok now to chat up Mrs Desp to help me upload this damn spreadsheet...............


Desperate

[KLD]

Desperate,

That's exactly the way I started recording data when our system was new. And surely it is good for you, especially if the thermometers are upstairs and you have to go up there every 15 min 

What you will get from your  random data intervals during one day, is a curve of heat deposited into your store. You can then compute the differences between the time points (both the time interval length and the temperature difference), and transform those figure into the average heating power for that time span. I've done that now for many days over the year, and there is surprisingly little variation in the maximum power the panels produce. The was a thread in spring when I reported about that finding.

What you probably can't do, is to get a good estimate of your annal total harvest. For this you'd need morning and evening readings for each day. 

I'll attach a spreadsheet (for you even in M$ .xls format.  Good luck with it  )

Klaus

[KLD]

Desp, here is a link to the old thread: http://www.navitron.org.uk/forum/index.php/topic,10821.0.html
K.

[desperate]

Hallo Klaus,

Thank you for that, it is sort of what I have, although a lot less scientific, but it is in MS Works 2009?, or something in MS7 on the lappy, and the forum does not like it , i still have office 97 on the pc, which is fine, but I cant face re entering it all. Bonkers eh?

Desp

PS, back on the lappy now , doc here is xlr which is no good, apparently xls is

[StBarnabas]

Desp
if we can sort out the StBC visit hopefully I can set you up with a better system...
Sean

[desperate]

Sean, thank you. Lets do it, I am tearing whats left of my hair out. Did you get my phone numbers? if so ring me tommorow anytime and we can get things diarised.

Desperate

[desperate]

Is anything here perchance..........


blimey have at last managed to convert to xls, a little list of basic data, I have loads more to play with, but from this selection I think it is possible to calculate an average power ionput, Then using a similar logic that the tdc3 uses to calc the energy input, IE flow*delta *time= energy I can calculate power from my tablesthen multiply by time, and I,m there.


Or have I finally gone mad


Desperate

[martin]

there is indeed - it downloaded ok into Ubuntu, I clicked on it, "Open Office" fired up and presented me with one of those spreadsheet thingummyjigglers! All systems would appear to be "go"

[desperate]

Thanks Martin,

I,m never quite sure what I,m doing

Desp

[KLD]

Desp

The time column needs reformating, otherwise Excel or OpenOfficeCalc don't know what to do with it
I currently looking at the data from 17/04, which must have been one of the best-est solar days ever. We gad 8kWh from our 40 tubes 

Your data seem to indicate that you had about 2kW peak production, but there is a lot of scatter.
I'll post more tomorrow...

Klaus

[KLD]

One more:
one of the issues will be that there are only two sensors in the tank. On 17/04 the bottom sensor starts out at 22°C, and jumps up to 41°C after only 1:15h. Calculating the energy content of your tank means you must assume either a 50/50 split (bottom half 22°C, top half 55°C), or a continuous gradient. Both aren't quite true fro the early readings.

I think once we went through these data, and you see what can be extracted from them and how, you can then go back and design your experiment to get the most useful information. And then it won't be long before we get you a 1-wire system installed 

Klaus
 

Good  for now.

[desperate]

hi Klaus

as I say some of those figures were subject to varying amounts of water drawn off and also varying weather conditions which would account for the scatter, I.m hoping that with enough data an average would be representative.

!7/04/10 was during the no fly volcanic dust episode I think, how significant do you think that is? no or a lot less high level Cirrus?


Desperate

[KLD]

Desperate

In your original post you gave us your motivation for the data logging:

I figure if I take enough readings at random times of the day and on enough days through the year without any regard of the weather, and knowing the  heat capacity of our cylinder when S2 and S3 readings are identical, it will be easy to work out an accurate power input, neatly sidestepping the flowrate and pipeloss issues, and a usefull energy delivered quantity to said cylinder.
(...)
and would it be worth many of us pooling our results with a view to calibrating the controllers and to ensure the thermal FIT, if it ever happens, is based on some kind of reality?

So, the main quest here is to find out how much heat your system has gathered during various time intervals, may be (A) a few minutes -- that would lead to a figure for the heating power; (B) a day -- from many of these you could calculate an average daily energy gain, and even a distribution over the year; (C) a year -- these would provide you with an argument about how much of your annual DHW requirement can be covered by solar.

The issue then is: will your method of collecting data help answer these questions?
I'd say you are nearly there for (A). IMO, to all intent and purpose, the answer to that question is known: 500 to 600W per 20x 47mm panel peak. Very little variation over the year. Also, not an enormous variation with respect to the store temperature. Both of these results I found quite unexpected.
For (B) and (C) your really need a different set of data, namely daily average tank temperatures before solar input and after.

I'll attach a few plots to highlight the various measures:
From the daily temperature readings (mornings and evenings) I calculate the daily solar input into the store. The first plot gives an impression about the variations over the year. I find it difficult to learn much from these.
The second plot has summarised data per month. Much nicer already :-)
The third plot gives the distribution, i.e. how often did we have days with a solar harvest between 4 and 5 kWh for instance.
And finally, two numbers: the total gain during the summer 2009 was 520kWh, whereas this year we had 750kWh.

Hope this helps to illustrate one way of data logging and interpretation. I too would be very interested to see more of these data, especially if somebody with a flat plate collector was to join in!

Klaus

[Poolguy]

Desperate

As you probably remember, SUNeLog programme especially adapted for the TDC3e and TDC4e is still available. It capabilites are being expanded as we speak to include weather station data and multi appliance contrall capabilities of the soon to be released XTDC.

You can see the output on www.poolguyenergy.com There are quite a few other installations soon to come on line for comparison, as their owners solve their connectivity issues (ethernet et al) but as you can see for the charts, it works and its easy to use and doesn't take a computer genius to down load. Let e kow if you want more details.

Andrew

[desperate]

Poolguy, thank you for that, sadly though we have the TDC3 without the e so not sure if that would help.

Klaus as you say peak power delivery is easy to calc from my stats, but I have no way of estimating average tank temp at the start and end of the day so A we have but B and C, well maybe?

The TDC logic used to calculate energy harvested over the year if I am not mistaken is

1 we know the flowrate
2we know the temp difference between cylinder input and output
3we know the hours pumped throughout the year

Therefore the total energy harvest can easily be calculated.

Desperate logic is as follows

1we know the power input at lots of times through the year and can work out an average.
2we know the hours pumped through the year

I contend that these 2 situations amount to the same thing, providing that my power input is calculated from the time intervals where the S2 and S3 temps are the same, therefore we know that the full 216 litres is being heated, and because my system is obviously switched according to a temperature difference, this does not change through the year so the lower insolation in winter is automatically taken into account by the time the pump is on or off. Or in other words when the pump is running we know the power input.

What do you think? is my logic in need of a pie or two?


Mind you this may well be an academic exercise that may be about to become obsolete. After a conversation with Sean StB I may be dragged into the 20th century with a datalogging system. Would you Adam and eve it?

Desperate