Smart Control of appliances with Solar PV & Bluetooth

[bigapple]

:cool4: Does anyone have any experiences (or know of any websites - I've drawn a blank) - about using the bluetooth data available from some inverters (mine is a Sunny Boy 4000TL with a 3.9kw system) to make semi intelligent decisions to control x 10 modules and turn on home appliances, such as washing machines, tumble dryers, dishwashers etc according to the level of power being generated.

I realise that there are problems about knowing if the power is going to continue at a particular rate for a washing machine / dishwasher - so that would have to be best guess. But for tumble dryers & water heating a more direct on/ off approach could be taken.

 

[SolarCity]

The 4000TL comes with a relay which you can configure to switch at a certain load. This should be good enough for turning on something like a tumble dryer.

More than that, I know there is a device coming from SMA soon which will do exactly what you're asking. I don't think it's going to be cheap though and the name of it escapes me right now.

 

[BruceB]

If you already have a 4000TL then read here:
http://files.sma.de/dl/5692/ZusatzFunktNG-TEN105011.pdf

Regards
Bruce

 

[bigapple]

Thank you gentlemen - obviously came to the right forum! Off to play.............

 

[confounded]

The 4000TL comes with a relay which you can configure to switch at a certain load. This should be good enough for turning on something like a tumble dryer.

More than that, I know there is a device coming from SMA soon which will do exactly what you're asking. I don't think it's going to be cheap though and the name of it escapes me right now.

Sunny Home Manager which is coming out early next year.

SUNNY HOME MANAGER. SMA Solar Technology AG

 

[bigapple]

It gets better.................

Cheers

 

[stuart99]

:cool4: Does anyone have any experiences (or know of any websites - I've drawn a blank) - about using the bluetooth data available from some inverters (mine is a Sunny Boy 4000TL with a 3.9kw system) to make semi intelligent decisions to control x 10 modules and turn on home appliances, such as washing machines, tumble dryers, dishwashers etc according to the level of power being generated.

I realise that there are problems about knowing if the power is going to continue at a particular rate for a washing machine / dishwasher - so that would have to be best guess. But for tumble dryers & water heating a more direct on/ off approach could be taken.

I'm just working on such as system now! I've got a Sunny 3000HF and using Bluetooth and a Current Cost power meter to record energy usage and just about to setup a on/off control for my immersion hot water coil.

I'm doing this using a program I've written myself.

PM me if you want more info.

 

[JohnBoyZ]

I'm just working on such as system now! I've got a Sunny 3000HF and using Bluetooth and a Current Cost power meter to record energy usage and just about to setup a on/off control for my immersion hot water coil.

I'm doing this using a program I've written myself.

PM me if you want more info.

That's interesting, I would certainly be interested in some more details, does your program interface directly with the inverter via bluetooth?
I've been working on various ideas for monitoring PV and utilising any excess power to heat the hot water but using a power controller rather than a simple on/off. So far my circuits are only theoretical and one of the problems I have is how best to measure the available export power. It's easy enough to measure the current in the main supply but does anybody know of a way to tell direction of current i.e. import or export. So far my circuit ideas rely on calculating excess power based on current flow from the inverter and subtracting current used in the house but there must be a simpler solution. Any Ideas?

John

 

[Scooby]

Has anyone here looked at the 'Wattson' power monitor? It detects power use via a wireless transducer that simply clips on to the power cables and sends this info to the main unit. This unit appears to be a fairly basic device, but it does have one big plus: you can attach a second transducer on to your PV 'export' cable as it feeds in to your CU. The Wattson will then provide a real time reading of your 'balance' - consumption versus generation. It has a USB port for downloading something like a month's readings, but I'd be surprised if it didn't also deliver this info in 'real time'. A few lines of programming should then be able to use this info to send switching outputs to whichever appliances you wish?

And the unit only costs around £100-ish, with a second 'clip' for - I dunno - a further £20?




(Of course, running a computer uses the best part of 200W in itself... :bucktooth

 

[BruceB]

I have supplied a coupled of Wattsons to customers. The ones I supply come with the second transducer in the box. The software to interrogate them is called Holmes and available for download. It would be relatively straightforward to monitor the messages between Wattson and Holmes on a network to work out the protocols if you want to programme something yourself.
Regards
Bruce

 

[JohnBoyZ]

Thanks Scooby & BruceB, I already looked at the wattsons but if I remember correctly it was really only designed to monitor cumulative power usage so assumed any current flow was being used in the house whereas of course with PV installed it could be could be measuring export current. I believe the two sensors were there for dual meters (i.e economy 7).

Sorry, just had another look and your right the second sensor can be used to measure generated power but the main sensor will just measure the current flow regardless of direction so won't know if its import or export?

It is described in their renewable energy installation guide,
http://www.diykyoto.com/store/assets/0000/0619/WATTSON_RENEWABLES_Eng_v0.5_low_res.pdf:-
" So if more renewable energy is being producing than energy is being used and power is being exported back to the grid (denoted by some meters spinning backwards); then the Net Power and Used power displayed on the wattson will not be measured correctly. This is due to the inability of wattson to determine the direction of current "

 

[BruceB]

Depends where you put the sensors. Wire it as per page 11 in the manual you cited and:
- one sensor measures power generated
- one sensor measures power consumed in house
- the Watson works out the net power correctly.

Regards
Bruce

 

[JohnBoyZ]

Cheers BruceB, Thanks for pointing that out, I should have read further.
That 2 sensor method is OK but does rely on combining PV and main supply before the CU, I was hoping to come up with something that could also be used in the more common situation where PV is added simply as a new circuit i.e.via an MCB in the CU. Its looking looks like my initial thoughts were correct and that there probably isn't a practical way of monitoring export current using a single sensor on the main supply cable.

Unless anybody has any other ideas.

Thanks
John

 

[j2d]

Does anyone know where I can purchase a Wattson solar unit? Been after one for a while

John

 

[SolarCity]

I'm still trying to work out why the clip for the PV system can't be clamped around the phase conductor at the fuseboard. Anyone tried this?