SilverNodashi

The geyserwise "reads" the thermostat and controls the element. If you tell it to heat up the water to 50degrees (I find this to be a sweet spot for saving money and enjoying a nice warm bath) it will do just that. In winter turn it up a bit if you want - without having to get into the dark, warm dusty roof. From about 35 - 50 takes about an 60-90 minuted on a 2KW element in a 150L tank. So I set mine to 50 degrees, then turns on the element at 5am and off at 8am. If I take a bath at 6:30, it would have heated up the geyser again by 8am for my wife to take a bath. And I don't need to remind her to switch off the geyser when she's done with the bath.

yes you will cause the Pi image created two partitions, on a memory card that's big enough. What's the size of your memory card? This particular one I have is just not a true 4Gb card

There isn't a second partition to resize, extend or remove. Only one partition, 3.7GB.

Just double checked, using the Pi itself (too lazy to install Linux on a spare HDD @ home right now) and this card is just too small: Disk /dev/sda: 3.7 GiB, 3965190144 bytes, 7744512 sectors Units: sectors of 1 * 512 = 512 bytes Sector size (logical/physical): 512 bytes / 512 bytes I/O size (minimum/optimal): 512 bytes / 512 bytes Disklabel type: dos Disk identifier: 0x00000000 Device Boot Start End Sectors Size Id Type /dev/sda1 8192 7741439 7733248 3.7G b W95 FAT32 The image file itself is 3.79 GB (4,075,290,624 bytes).

hmm, I just formatted the card using SDFormatter and it reports the card is only 3.68G: --------------------------- Damn! Need to get a 8GB card sometime.

my bad... haven't used a Pi in a long time. I forgot that you need to login as pi and then "sudo su -". All our Linux servers run CentOS so it's a bit different. I'm not sure either. I downloaded the .gz file, extracted it to my laptop and tried to write it to the 8GB card using Win32DiskImager. It writes successfully, but strangely when I try and browse to the SD card, Windows wants to format it. With the 32GB card it was fine. The size on disk is 3.79GB (4,075,290,624 bytes) so it should have fitted on the 4GB card (I see now it's a 4GB card, thought it was 8GB..

What is the root password, please? Just a quick question: what did you add to the image to make it so big? I tried to install it to an 8GB memory card but didn't fit so I had to backup my phone's 32GB card and use that instead.

I won't be able to install the infinisolar at this stage, as it was "upgraded" two 4x Axperts in December (perhaps I should sell it? It's 2 months old) on the farm and I don't have 3phase at our house.

I have some Axpert inverters and a 3phase Inifinisolar (not setup at this time) so I want to work with this but it seems I would need to learn Python first. Shouldn't be too much of an issue, I used to code CGI scripts many moons ago in PERL, and also some did PHP+MySQL coding. As matter of interest, do you hookup the Pi directly to the PV array, and battery bank as well, or solely rely on the inverter's information?

I prefer using VIM as well Can you please give me the github details, as I don't see it in the previous post. Hopefully by tonight I'll have some time to play with this.

I won't mind using a tablet either but it's simply too expensive for this kind of setup, IMO. I'm busy downloading the image and will put it on a Pi later today. How do we submit changes back? What coding environment do you use?

Have a look at these brackets: http://www.lizardsouthafrica.co.za/pv-mounting-systems-products/ They are SABS approved and the guys assured me it will work in the Cape as well. My boet stays in Brackenfell, still need to go put some PV on his roof sometime.

Where can i download it?

The BMV relay can handle 60V, 1A. I use relays like this to drive 220V, 5A pumps directly from an ardiuno: http://www.communica.co.za/catalog/Details/P1651500292 This one can handle a 220V, 10A load. I guess, if 10A isn't sufficient a similar PCB design can be done with a 20A relay instead. If you open up the geyserwise boxyou'll find a similar relay inside, switching the geyser element on and off. Get the product code and let's build a small PCB for it, should cost maybe R100-R200 Or you can use a Solar State relay instead. It's just much more expensive.

Wait till you start racing

My house also runs about 300W at night, without an extra PC running and I don't really want to add 300W to the existing load. I would like to run a Raspberry Pi but since there's no rPi software for the Axpert yet, this will have to wait.

The GSM commander is quite pricey, IMO. The same functionality could be put together with an Arduino + GSM shield, or a Raspberry Pi + GSM shield if you want to. Or if you only need to switch 1 channel on / off, a GSM intercom could work as well. Mine open / close the gate with either an SMS or miss call (my cellphone is pre-programmed to it so it can't be abused) and cost 1/3 of a GSM commander.

The problem is that you'll hardly ever run your batteries at the sweet spot. Let's use the figures from your next quote: Let's say you need to run the batteries for 19 hours (5 hours day light), with the figures above you can: run 443.37w/hour load run 454.74w/hr run 477.48w/hr That's quite a fine balance to keep, in order to stick to the 50% DOD or 70% if you want to. At this exact moment, my inverter reports 2.62Kw - we're watching TV and I'm making coffee. 10 minutes later and it will drop to 620W (assuming the kettle is 100% efficient, it'e 11years old). Later on, when we switch off the TV and lights it will drop to about 300W-250W There's no historical data so I can't see if it stays stable @ say 250W during the night but I have a suspicion it may drop a little bit since the ambient air around the fridge and freezer drops and they use a little less power as well. I want to take a wild guess that the LED flood lights also use a little less (perhaps 1W?) power when it's cooler around them? My battery bank is 244Ah but I have no idea how many cycles the batteries can give since I can't get a datasheet on the internet, and thus I don't know what I'm paying / saving per KW. The point I'm trying to make though is that although it's nice to calculate these figures on paper, it's quite difficult in reality to stick to it.

the biggest problem I have with this is that every piece of software available, free or not, has some limitations to some degree. Then another piece of software gets written cause "person X" needs a different feature which isn't supported on other applications. A "true" open source approach, IMO would have been best but as you said, no one wants to work for free - and I get that, but that's why applications are limited to how the developers develop their apps. I suspect in the near future there will be a bunch of applications which can manage these inverters, each one with their own set of features and limits.

Where do we see a list of these applications?

Is solarmon still under development? I tried to purchase a license but got a PayPal error.

So, what is everyone using on a 24/7 basis to monitor their inverters and upload stats to the internet? I only have a bunch of old PC's laying around which consume 300W+ power (I checked on the axpert!) and my laptop is in use, on the road, most of the day so it doesn't help much.

I wouldn't skimp too much on this part, especially in Cape Town. How many panels do you have, and what type of roof?

how much can you afford? "And arm and a leg" is a rather relative term....

108w may be a lot, or not much at all. it all depends on how much power you need If you need less than 2.9Kw, continuously, it shouldn't be a problem. But if you need the full 3KW, constantly, it will.