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plonkster last won the day on February 15

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About plonkster

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  1. Water harvesting and use, same logic as solar systems.

    Again, I am so tired at people quoting this "we knew" story. Yes, we did, and we still do. The question is WHAT it was that we knew. We knew that on average, rainfall would come down. That was the prediction, and that is still the prediction. This year however, the last three in fact, is completely OFF the average, they are outliers. We didn't know that in 2011. No model could predict that, that is precisely the trouble with stats: It cannot predict outliers. It can only tell you that they are outliers. If the past few years followed the model that we KNEW about, we'd be at significantly less stringent water restrictions. Instead it threw an outlier we didn't know about.
  2. New Infini Super

    I think this is where the Pylontechs are coming in. We're at the point where a good set of Trojans cost the same as a comparable (mostly) Pylontech rack.
  3. Which batteries should I buy (rhetorical question)

    I was led to believe that the BMS uses the same (CAN) protocol as the BYD battery, which is also used by LG-Resu, and also used by Pylontech. Though it seems there are tiny differences between them. But their website seems to suggest they are using ODB2 (aka SAE J1939). It probably does not matter. These things all work the same way, they stuff all the data end to end into 8-byte packets with either the 11-bit ID in front or the extended 29-bit one, and chuck it onto the can bus. All you have to do is read them, chop it up in the right spots, potentially swap for endianness, and you're done :-)
  4. Anyone use Solarus panels before?

    Agreed, but I'm willing to bet money on it that those people telling you that this is "4 times more efficient" was looking at the overall output, ie hot water (reverse-calculated at 1.16Wh/liter/Kelvin) plus the PV output. Then 4x is not that surprising. Looking at PV output only... even a 50% improvement sounds too good to be true.
  5. Grid tie without battery backup question

    You mean SunnyIsland. Let's get technical. I think what those SMA inverters do (most likely) is include really big capacitors that act like small batteries, so you have a kind of self-consumption setup: The PV panels charge the capacitors, and a small inverter draws from it. Control electronics shut things off really quickly if they go out of bounds. And the PV array has to be 4x oversized. So the question is if this recipe can be scaled to 7kw. I suspect it can... but at what cost? Might be cheaper to put in a small lithium bank then and do a proper self-consumption setup. Of which Victron remains the best... (also, could not resist :-) ).
  6. Grid tie without battery backup question

    You sound as muddled as I do :-) Just read the SMA link I posted. It is simple enough. The inverter only provides a portion of the power so that even if there is some cloud cover it can still drive smaller loads. If you attempt to draw more power than it can handle, it switches off. If the cloud cover is really heavy, it switches off. Easy as that. Subtext: Don't be a dumbass and try to run your house off this feature :-) But.... never ever seen an actual model with this feature. Even in the US... that feature costs extra money so it's rare.
  7. Grid tie without battery backup question

    The secure power feature, at least on the SMA, is meant for small loads. It's sized no more than 25% of the nominal capacity. It's for charging of phones, non critical things. I've never seen it on a South African model. It's on some of the US models, presumably for areas that get bad weather where the power might be off for a few days. Then you can at least run some essentials. This case with the Goodwe was the first time I ever heard of it happening with another brand. So what I am saying is that it is at least possible in principle, and before you assume that it is a mistake, check the documentation. It might be a feature :-)
  8. Anyone use Solarus panels before?

    We all know that solar water heaters are significantly more efficient than PV panels. So it sounds about right, if you combine a single panel, generate some electricity and absorb the heat into water, you'll make at least 3 times the energy.
  9. Grid tie without battery backup question

    Yes. @Chris Hobson called me the other day about that. He had a Goodwe powering loads even though the grid was down. Keep in mind though that the Goodwe has an input and an output, and this was on the output, so no feedback rules are being broken here. I am also aware that some SMA models have a secure power feature that can power some loads when the power is out. It's meant to power smaller loads.
  10. 5kva Axpert MKS model - faulty

    Oh yes! I think the mypower24/solarmd people have the ability to repair as well.
  11. Water harvesting and use, same logic as solar systems.

    Schmutzdecke. Got to love the German language.
  12. Victron BMV 702 - No Power?

    Sounds like it isn't getting power. There's a fuse in the red cable that goes from the battery positive to the shunt. Check that fuse. Also check the RJ-11 cable running from the shunt to the monitor itself. I don't know the pinout of the cable, otherwise the obvious check is to measure if there is voltage on the cable where it plugs into the back of the monitor. The system will continue to work because the shunt is just a low-value high-current resistor and that still works as intended.
  13. Water harvesting and use, same logic as solar systems.

    Rumour has it JZ has changed his middle name to Takata. (If you don't get the joke, you probably don't drive a Japanese car).
  14. Water harvesting and use, same logic as solar systems.

    My purification is a hack job :-) A hack that seems to work well enough. The video shows more or less everything you need to see. I'll add another one below from earlier when I was testing the concept in a bucket. I bought the ozone generator and the Venturi from these guys. You want to talk to Ian. It was about 3.5k for a 1000mg/hour generator and the venturi. I think the price was rather steep, but I didn't want to wait for it to come across the waters. You can get the same stuff on eBay (of course), for much less, but you don't quite know the quality or how long it would take to get here. So basically I paid because I didn't want to wait :-) The quality of the stuff I got was good. My treatment tank is a 250 liter tank made by Nel. They are not too hard to come by, it's the 1000-liter and above that tends to sell out everywhere. The pump I have on the tank is a CRI pressure pump that does 1000 liters an hour. That means it should circulate the contents of my tank in about 15 minutes. With the Ozone output of 1000mg/hour, that means 250mg in 15 minutes, and with a 250 liter tank that means around 1mg/liter every 15 minutes. I treat it for 25, because the ozone generator has no external cooling and cannot run for longer than 30 minutes at a time. This is where things get a bit hand-waving. Just because I put a milligram in per liter doesn't mean that I'm actually getting that kind of exposure (since some of the ozone bubbles out and drift off into the atmosphere). I do think that I get close though. Now if you look at some tables on the internet (I just googled for it), you will see that 1) the half life of ozone is around 20 minutes, and 2) even 1mg/liter kills basically anything that might be in there with the exception of cryptosporidium. But as I said, it is a hack job. After some hours, I can visually see coagulated junk drifting around in the water, so visual inspection tells me it does work. I then put in the floculant only to drop the cloudy stuff out of the water. Now... Ozone is complete overkill for rainwater. For rainwater, you want to use a sediment filter in case there's some dirt from the roof in there... but rain water is practically clean already. We used to drink that stuff straight from the tank when I grew up. Rain water is also slightly acidic (carbonic acid, due to reacting with carbon dioxide on the way down), and this tends to preserve it somewhat. I'm not sure about using Ozone for grey water. Ozone's sole claim to fame is merely that it extremely unstable (not explosion unstable, but I-have-an-extra-atom-to-shed unstable) and so it oxidises everything in its path (I have no idea how the pump will hold up... I guess I'll find out). It is extremely effective at this. So it works well whenever you have dissolved stuff in the water that you want out. And it also kills things. If you read some posts on forums of aquarium/fish people... there are some people on there messing with ozone, the advice is to be careful: It kills even larger organisms such as fish! But there are some stuff that gets nastier when you oxidise them. You don't want to chlorinate before oxidising, and besides, powdered chlorine is in itself an oxidising biocide. That is to say: I don't know if Ozone is a good idea for grey water. I'm not saying it is a bad idea. I'm saying I don't know. More study is needed. This is the previous video where I was testing it in a bucket:
  15. ICC Serial

    There is of course a way to fake the serial number of a pi and put the old one back in... but I'm not telling, and I only know by accident because I messed around in the guts of the system :-)