slow rotational motion detection (solar PV surplus monitoring)

[jbella]

Hi,

I am not an electrician and my knowledge about electricity is quite limited but I believe that this is the right place where to submit my question.
I recently had a solar PV panels installed and I am monitoring solar PV generation and whole house consumption by Current Cost EnviR energy monitor with two clumps and transmitters.
I have another clamp and monitor on the live cable between main fuse box and house electricity meter which monitors how much electricity I am importing from the grid or exporting the surplus electricity to the grid but it does not monitor direction of the current - in or out.

I would like to monitor current direction (in / out) but I am not sure whether there is any clamp meter/multimeter which would monitor direction of current flow.

I think simpler solution would be to monitor the motion of my classical electricity meter disk. Basically when the surplus electricity is exported to the grid electricity meter disk is steady and obviously it is (slowly) rotating when the electricity is imported from the grid.
I believe that there are reflective optical sensor based detectors which could monitor this slow rotational motion I could attach to the electricity meter. Ideally I would like to have two stage (moving / standby) remote led indicator as an output from this detector.
I've tried to detect this motion by optical mouse but it did not work. It might be that the distance between electricity meter disk and mouse optical sensor was out of focus.
I was searching on the web quite intensively but I could not find anything commercially available or I was just using wrong keywords.
Since I do not have any electrician / soldering skill I would prefer kind of plug and play device rather that just individual components.

Has anyone come across with something similar or have you got any idea?

Thanks for reading

 

[siliconskum]

Hi, I'm not an electrician either, but I do work with electronics. Yes, what you suggest could be done with a disk meter, but it might be a little complicated to get very accurate results. If you don't mind only knowing single Kwh increments (which should be fine for what you want), and depending on which type of meter you have, then It could be done with a few basic parts. Getting that data into something useable might be the tricky part.

One way is to use an LED and an photodiode (very cheap, I assume your in the UK, so it's available from Maplin stores). On most meters there is usually a black line / mark on the top side of the disk or band on the edge of the disk (very thin, but the disk is very reflective, so should work). You would then need to connect the LED and photodiode up to something that can either count the pulse directly, or transfer it to your computer (and use a program to count the pulses). I would recomend something like an Arduino Microcontroller (you can get cheap clones for about £15), and these are VERY easy to program (all the code you need is available for free on the internet, you just have to copy it and save it to the microcontroller chip.

Check out the meter projects on this link:

power meter - Hack a Day

Don't wory about the "Hack" name, it nothing to do with breaking into computers, it means "hardware hacking" - as in building your own kit.

This is the cheapest controller:

Boarduino - Breadboard-compatible Arduino Clone

It's a kit, so you would need to solder it yourself (very easy, full instructions above)

Or you could buy a ready built Arduino board, which is a little more expensive at £25 :

Maplin Electronics : Arduino Kits

It is VERY easy to do this, most of the code used in the Hackaday link should work just fine for you, so you don't even have to know anything about writing computer code - just copy, paste and write it to the arduino.

The Arduino is a great little tool, you can do LOTs of things with it, and you will probably find additional uses for it, so it won't be a waste of money after you finish with it.
Even if you have no clue about electronics, it should take you less than 20 mins to figure out how to hook it up, program it and then start using it. Just follow the basics of the projects I posted above.

Hope thats of some help.

SS

 

[Scobo]

I think what your looking for is a Current Cost Optismart sensor.
As you already have the Envir you will just need the sensor which fits to your PV meter and reads the LED pulses....
Current Cost - Reducing your energy bills so you can live a greener life!

Ignore the comment about it not being compatible with PV meters.
I and many others are using it with a PV meter and it works fine.
Its much more accurate than a clamp sensor.

 

[jbella]

One way is to use an LED and an photodiode (very cheap, I assume your in the UK, so it's available from Maplin stores). On most meters there is usually a black line / mark on the top side of the disk or band on the edge of the disk (very thin, but the disk is very reflective, so should work). You would then need to connect the LED and photodiode up to something that can either count the pulse directly, or transfer it to your computer (and use a program to count the pulses). I would recomend something like an Arduino Microcontroller (you can get cheap clones for about £15), and these are VERY easy to program (all the code you need is available for free on the internet, you just have to copy it and save it to the microcontroller chip.
SS

Hi,

thanks! It sounds that it should be doable although I do not need such a sophisticated counter. Yes the question is what to connect LED and photo-diode to. Arduino might be a challenge for me :-(
I just really want to monitor whether the disk is moving or stand by.

 

[jbella]

I think what your looking for is a Current Cost Optismart sensor.
As you already have the Envir you will just need the sensor which fits to your PV meter and reads the LED pulses....

I was looking into this CC Optismart sensor but I do not have either property smart electricity meter or electricity meter which would have any
flashing LED. (I am not looking to monitor solar PV).
Anyhow do you think that this Optismart reader could monitor (detect) movement of the disk of my pretty old home electricity meter?
If so than it might be worth to buy one since I believe that soon or later they will change my old property electricity meter for the smart meter.

 

[Scobo]

I was looking into this CC Optismart sensor but I do not have either property smart electricity meter or electricity meter which would have any
flashing LED. (I am not looking to monitor solar PV).
Anyhow do you think that this Optismart reader could monitor (detect) movement of the disk of my pretty old home electricity meter?
If so than it might be worth to buy one since I believe that soon or later they will change my old property electricity meter for the smart meter.

Sorry, must have misread your post.
Thought you already had a smart meter.