In a way this like getting my own Enphase AC Battery ;) well, sort of ...
If you recall, I have been testing 3 LEAF Battery Modules for 6 months, then put them into a 6-bottle wine crate along with a Charger and Grid Tie Inverter to make what I called a Mini ESS - Energy Storage System -
Since November 2014, it has been running 24/7, for more than 4 months, until last weekend when a strange smell caught my attention while it was pushing power back into our grid in the morning, after its usal night low TOU rate charge cycle; It must be a vented capacitor, leaking inside .... It happened on another of the SUN-250G grid tie inverter I am using since the beginning of my Energy Storage activities
During last week I stumbled across an ad for 18 used Enphase M215 - 2 years old - Micro Inverters at 79 EUR per piece, and decided to give it a try; I already did try to use them last year but realized the US version will not work in France (split phase/single phase & 60Hz/50Hz)
I got in touch with the seller, a professional in Solar and Wind, who was nice enough to deliver 2 units for free saturday morning at home; In our email exchange I learned that they need to have a profile flashed into them before they can operate, and this is done during their first comissioning via the Enphase Engage gateway, using power line communication
So the 2 units I got have this profile already inside and he told me they should operate just fine, once they have DC through their MC4 connectors and the grid with 230V AC on the other end of the Enphase Engage cable - which I already got last year, EU version -
I quickly took my Mini ESS downstairs, unscrewed the cover, and connected the Battery pack to the DC side using crocodile clamps and MC4 connectors, plug the AC side to a wall outlet, through a wattmeter, and turned main switch to the GTI - Grid Tie Inverter - position
After a long 2mn and 20s, and different status LED colors, it started producing 235W :) ! which is normal but I was happy to have working units now, opening my Storage experience new horizons ...
After running fine for an hour or so, the external temprature is only reaching 32°C, no fan required, no noise (you have to put your ear onto it to ear something), it's just great !
It pushed a steady power for 3 hours or so ... nice !
Sunday morning: now let's swap the 2 GTIs and make this Enphase M215 fit inside the box
After trying different positions and measuring the length of DC wires, I cut them and soldered them to their MC4 connectors
Voila ! DC side is wired and fits inside the crate :)
This new layout will leave the 10A charger outside, and I decided to hang it in the back, less vibrations this way
After testing both Charging and Discharging, I put my Mini ESS back upstairs, next to its big brother in the living room, right in time before night rate kicks in ...
It charged during the night, and this morning pushed all this stored Energy back into our home grid for 4 hours in a row, helping the heat pump warm up the apartment and breakfast consumption
Notes: After realizing it takes the M215 2mn and 20s to initialize and start producing power and I was disappointed first, because it takes only few seconds for my SUN-250G to start doing the same! Thinking over this during the weekend I tried leaving the DC side ON, and it worked, now reducing the startup time to 15s, much better !
Also there might be the fact that I am not using the Envoy GAteway, and the M215 might be waiting, trying to connect to it before producing ...
Well I still have to learn about that part, but overall this is a huge step towards more Efficiency and this is key !
Follow my 2 ESS units 24/7 live: http://wattson.energyhive.com/dashboard/diyesskit