Creative ideas to solve my problem?

11 replies [Last post]
DoubleSpeed
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Bristol, United Kingdom
Joined: 31 Mar 2012

Just wondering if anyone has any creative ideas to solve my problem of how I can monitor my home power consumption now I have PV Solar as the reading from my Current Cost is skewed by the Solar generated power being feed back into the grid?

g7pkf
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United Kingdom
Joined: 11 Jan 2011
Forums

search for solarPV within the forums there has been multiple discussions on this very subject

 

Dean

DoubleSpeed
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Bristol, United Kingdom
Joined: 31 Mar 2012
lua filter applet by EJ-Ambient

After reading some more I see that member 'EJ-Ambient' mentions his lua filter applet which will adjust the measurement of consumption where do I get this I can't see a download link?

g7pkf
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United Kingdom
Joined: 11 Jan 2011
have a look at this

have a look at this thread:-

 

http://www.homeautomationhub.com/content/script-switching-onoff-water-he...

 

also you could just message him? he is fairly active so will probably be along soon anyway :)

 

dean

DoubleSpeed
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Bristol, United Kingdom
Joined: 31 Mar 2012
OK thanks I will mail him as
OK thanks I will mail him as I can only see 2 scripts on that topic PowerMonitorV1.1.lua and JGPlugApplet.lua Doesn't seem to mention the lua filter applet
allanayr
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Ayr, United Kingdom
Joined: 25 Sep 2011
I'm not sure that it quite works

The script is a work in progress at the moment but I have a version, although, it doesn't quite work correctly.

If you look at my PVoutput data

http://pvoutput.org/intraday.jsp?id=3748&sid=2946

which is posted via Pachube, you'll see  that the power consumed occasionally drops to 0.

I've taken the view that if I'm exporting to the grid then I'm not consuming any power and therefore I record a value of 0. The script is based on the assumption that if you are generating more than your house base consumption that you can tell if the figure on the meter tail is an import or an export.

 

This is done as follows:

if solar gen > normal house consumption then

 additional power = (power on meter tail - (solar gen - normal house consumption))

As I say it doesn't quite work as you can see from the traces on my PVoutput readings or my pachube readings. (36589)

I've attached my versionof the script if you want to have a play.

AttachmentSize
consumed.lua 1.82 KB
DoubleSpeed
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Bristol, United Kingdom
Joined: 31 Mar 2012
Thanks for this will have a
Thanks for this will have a go at my end and see what I get overall I'm not too worried about the home consumption being exact I just need to know when the demand is high so I don't trigger my immersion when the tumble dryer is on etc. I see you say work in progress though are you actively trying to improve accuracy
allanayr
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Ayr, United Kingdom
Joined: 25 Sep 2011
Work in progress

OK these are 2 facets of basically the same problem, which is how to maximise the use of "surplus" power generated by a solar PV array. I don't know how much of the other threads you have managed to read through but I'll give a quick summary of the situation as I see it.

The ideal way to do this seems to be with Dean's hardware modification which detects whether the consumer meter is importing or exporting. If you can know for sure then it is relatively easy to switch appliances on or off using RF.
If you haven't got the capability to detect import/export for certain then you are left with trying to work it out. All of the methods which I have tried so far seem to be "hit and miss".

Jamesg says that, for him, his script allows him to basically produce all his hot water in summer for free. The problem is that his script is written for an old version of the plugboard and will not work on the latest version. I have tried to modify the script to work with the latest version but in my experience it's not very successful with my setup. That said, I don't actually have the 2 500 watt immersion heaters that he uses so I can't test it under the same conditions. He says that it works for him, and that is all he really needs to know. It may be that my conversion of his script is not particularly accurate ( I don't fully understand the script ) or it may be that in order to work correctly it needs to be switching 2 500 watt heaters. The thread is here:


http://www.homeautomationhub.com/content/script-switching-onoff-water-he...

"EJ-Ambient" contributed to the discussion with his ideas about how to calculate whether the house was importing or exporting and he is tweaking his script to try to make it more accurate. I don't know if you have tried the script that I posted the other day, but that is my modification of his idea. Again, for me, it doesn't quite work because it randomly reads that I am importing when I'm exporting and vice versa. This may be because establishing what the "base load" of my house has not been done accurately enough.

At the moment I am not actively modifying the script because I'm away from home until the end of May. I'll probably have a go at tweaking it again when I get back.

To sumarise: my view is that with a hardware detection system then switching is fairly straightforward without one it is pretty unreliable.

Allan

DoubleSpeed
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Bristol, United Kingdom
Joined: 31 Mar 2012
Thanks Allan, I will give
Thanks Allan, I will give your and EJ-Ambient's scripts a go and see what results I get I did have communication with another PV Output User and he said his solution to this was simply that as he has a modern electric meter the Current Cost OptiSmart which reads the flashing light on the meter is what he uses to measure his consumption. Unfortunately I don't have this type of meter so I'm stuck. Someone did say to me that if you tell your supplier that you’ve got PV Solar they may well want to upgrade your meter to a new type as some of the old meters actually go backwards when power is being fed back into the grid!!
allanayr
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Ayr, United Kingdom
Joined: 25 Sep 2011
Old meter

I have an old meter as well. I told my supplier more than 9 months ago but they haven't bothered to replace the meter. And yes it goes backwards when I feed the grid. :-)

EJ-Ambient
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Ringwood, United Kingdom
Joined: 5 Aug 2011
Filter lua

Hi guys.....I've just noticed this thread, so forgive my tardiness.....

Yes, DoubleSpeed, I'm developing a 'Filter' script and have shared the early version with Allan - I guess that's the one that's been passed to you.....beware - it doesn't work very well, which is why I've been trying to iron out the wrinkles and make it more useable.

I'm well on my way to having a demonstrable lua, but it comes with all the usual caveats, so 'buyer beware'.... anyway PM me and I'll send you the script and some instructions and you can join my merry band of beta testers..... I'll send you an update as well, Allan.

Take a look at my Pachube feed - as you can see the ConsumedW datastream is looking quite stable nowadays (it doesn't fall to zero anymore!!!!)...   https://pachube.com/feeds/34982

I've also put in an ImportedW and ExportedW stream which help me tweak the lua....

I'm taxiing an ailing relative around this week so it might be a while before I get back to zip up the scripts.....

Keep on keeping on....

EJ

DoubleSpeed
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Bristol, United Kingdom
Joined: 31 Mar 2012
Great yes I would like to
Great yes I would like to join your merry band of beta testers! Will PM you now with my contact details, Thanx
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