I'm an electronics engineer with an interest in water and solar energy harvesting initially for domestic use, but a complete newcomer to open source communities and internet fora, so some advice on how and where to post would be most welcome. I think I could do with a mentor.
I was working on a project to divert surplus solar power to water heating, but on coming to the OEM found that I'd been beaten to it. However, with a 3.4kW peak solar system installed now using a SunnyBoy inverter with Bluetooth, I'm keen to explore using the Bluetooth data rather than a separate CT as input to the surplus power diverter. Some advice on the best parts to buy to make a start would be most helpful.
Also I have other concerns about metering and the effects of phase controllers (choppers producing high harmonic current flows) upon the CTs and domestic meters both mechanical and electronic.
So, if anyone out there would like to help lead this newby down the right path I'd be most grateful.
Re: Interfacing with SMA SunnyBoy PV Inverters (Bluetooth)
Welcome. I think you have got a lot of reading and a lot of learning to do. However, there are plenty of willing helpers around here. Your CV reads a bit like mine so don't be put off, the complexity will unravel given time.
Did you find this thread about your inverter? http://openenergymonitor.org/emon/buildingblocks/interfacing-with-sma-su...
The preferred choice for controller is burst-fire. See http://openenergymonitor.org/emon/node/841 - there are a couple more threads where this basic design has been developed. I believe there are quite a few working systems now using this system.
There is also a fair bit of accumulated knowledge on meters and how they respond to generation and burst-fire loads.
Re: Interfacing with SMA SunnyBoy PV Inverters (Bluetooth)
Welcome onboard, Robins Mk2 diverter doesn't use the output from the inverter for measurement so the Bluetooth from your inverter won't be of use if you go that way. What the Mk2 does is to measure the power being imported or exported at any given time and using a voltage & phase reference calculates weather to burst fire a triac in order to balance the net power flow to zero (assuming there is sufficient solar) it utilizes practically every spare watt of power.
One problem with using Bluetooth wireless etc is reliability, with a CT you have a solid connection and with the Mk2 you only have one CT on the supply lead from the meter to the consumer unit and it can usually fit into the consumer unit, mine does, have a look at page 4 of the thread Robert wall mentioned there are two posts with pictures of my installation.
You also have PM.
Re: Interfacing with SMA SunnyBoy PV Inverters (Bluetooth)
The SMA bluetooth stuff has already been done as well...
https://github.com/stuartpittaway/nanodesmapvmonitor