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Thank you for the great forum, Safe Driving over the weekend. Sincerely Jason


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Bobster last won the day on September 17 2019

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  1. COJ say that they have that capability. At the moment all they offer is a seasonal tariff - you pay less in the summer, more in the winter. But in theory they can impose time of day pricing. The trouble is getting people to understand the strategy and respond to it. I am amazed by the number of people I know who Have converted to pre-paid electricity Think that COJ charges you differently at different times of the month. The truth is that there's a sliding scale. The first 350 units you buy in a month are the cheapest. Then 351 to 500 costs a little more and so on. Because they feed their meter a little bit each week they see less units for their money as the month goes on and just assume that COJ are changing tariffs as it suits them (which they may not do) or changing tariff according to the date in the month (which they may not do). My point is that even where there is a system, people don't bother to understand it or even know it's there, or the news doesn't get to them.
  2. There is a registration process on SEMS. Your inverter doesn't get included automagically. My installer did the registration of mine so that it's registered as a part of a group so that he can monitor all his installations.
  3. It's thirteen watts. This is for a Goodwe ES inverter. The inverter sends data to the portal. I would guess that this particular figure originates with the smart meter, but I'm not sure.
  4. Recently, in another thread, @Coulomb said Well I think it goes further than that now. When load shedding started, it was hard to know when it would strike and for how long. These days we all have apps on our phones, and neighbourhood whatsapp chats, and the municipalities publish load shedding schedules and so we start anticipating the load shed. My suburb starts shedding at 12:00 today. So what happened this morning? Everybody got the lawn mowers out and got their grass cut and all the appliances got used in the early morning. Apps showed momentary peaks of 5 kw in our house and sustained runs at 3kw. Since I am a boring fellow who loves watching SEMS portal, I can tell you that this is high for our house. What was happening was that the wife and housekeeper were trying to get the dishes clean, the ironing done etc before the shed starts. What @Coulomb and I were discussing is heavy loading after restoration of power. Some properties in my street were reporting under 200 V incoming. This slowly crept back to normal. So what had happened was that City Power turned us back on and everybody's geyser and everybody's deep freeze and lots of people's UPS all started drawing current at the same time. So now, I think, we get two peaks - one just before load shedding and one after. So does the strategy actually save anything? Well... I guess it must because the grid hasn't fallen over yet. But I wonder if it's not a game of diminishing returns. Which would mean that Eskom are going to have to go to a higher stage as we get better at mitigating against load shedding.
  5. I should try this. My example shows two instances in 30 days, but that's unusual, it's usually about once a month.
  6. Anything that makes an element hot is going to use a lot of power. An electric kettle, for example, uses a surprising amount, but only in short bursts. An element in a geyser will take a large chunk of your battery and at least 3KW of your 8. Dishwashers usually heat the water early in the cycle. Again this takes up a surprising amount of power, but not for too long. But it all adds up. If you turn on the dishwasher, then decide to have a cup of coffee and meanwhile the geyser element kicks in, that 8KW can get used up awful quick (for a few minutes). Think of the potential peak, not your average use per day.
  7. Is your stove all gas, or gas hob abd electric oven? If the latter you will probably have to give up the oven when the grid is down. Big load, big draw from batteries. Remember that the system is sized for peak load, not average load. Your installer should advise on this Be sure to get a new COC or at least a supplementary COC for the wiring mods. Give your insurers a copy. Dont assume your system is covered by the existing policy, call your broker and discuss.
  8. Hmmm... Must take a closer look at the reports available. I dont too much mind grabbing daily reports and going through them. I'd write a program to process the reports.
  9. Sure, but my property generally uses less than 500 kw/h a month. I say this because when I used to buy pre-paid credits I always bought 500, because, then, in Jhb, the first 500 in the calendar month were the cheapest. Doing this I built up a credit fairly quickly, so I was using less than 500 kw/h. What I'm getting around to saying is that this seems to me like a pretty fundamental bug. Whatever register is overflowing, I'm not pushing it very hard and certainly not unusually hard.
  10. I'd like to track the power I use against the power I actually pay for. In theory I can get this off the SEMS portal, but that throws me a curve ball at least once in each month. EG Huh? Suddenly I consume 453.91 kw/h in one day! I'd consider that an indelible stain on my reputation. The same exaggerated figures are present in the downloadable reports that the portal makes available. But the daily power graph seems OK So I don't think this is a case of GIGO with the GI coming from the Goodwe box in my house. So I'm thinking that maybe the truth is available via the RS485 socket on the Goodwe. I have some programming chops. I don't mind getting my hands dirty with programming languages that I don't use in my job (I'm actually looking for some motivation to get busy with Python). I have a Raspberry PI looking for gainful employment. Or is there another way of reading the two totals (used and paid for)? I have googled. Most of the DIY projects I find documented did scraping on an older version of the portal. They don't work now. Oddly there don't seem to be any well documented studies on how to query the RS485 port on the Goodwe. Any ideas on where to start? I could also use wifi, but the Goodwe wifi isn't a broadcast device and accepts only one connection from a smart phone at a time, and I don't want to take up that connection all day every day. I'll happily share whatever I come up with (whenever I come up with it) that actually works.
  11. Indeed. Though my conscience is clear because my house keeps running of batteries and either a) the batteries will recharge from solar (not grid) if the sun is up b) we have enough battery to get us through a night and then they start charging again in the morning. But the general point is a good one. The City talked about another method they were employing, but there's suspicion that all they were doing was talking about it. This was to use smart meters (which are now common in Johannesburg) to limit draw on a property by property basis. EG They can remotely set the meters to, for example, 15A and if you draw more than that the meter will first warn you by switching off and on a few times, and then, if you don't respond, disconnecting you for, say, 30 minutes and leave you to consider things. That seems a better way of doing things - get people to cut consumption but still be able to keep the lights on and the beer cold.
  12. When I used to have an inverter it certainly did that. Every now and then I'd hear it switch on and then shortly thereafter off, which I assumed was a brown out rather than black out (because non-backed up circuits kept working). @Coulomb's explanation, for the type of system I have now, makes sense. Otherwise it may be getting 190 in and trying to export 230, and also because I might have 190 on part of the DB and 230 on the rest, which doesn't sound like a very good idea.
  13. Do you have a choice of modes in which to run the Oasis? I can put my Goodwe into "backup" mode which means that it uses solar to charge the batteries and only discharges the batteries when the grid goes down. No savings there. Or I can (and have) put it into another mode where it powers the property first from solar (if available) then from battery and finally from grid (with some rules such as don't draw from battery if SOC <= 40% and grid is available). In that mode I save lots of money. Also analyse your bill, don't just look at the bottom line. EG in Johannesburg you pay about R700 pm in flat charges just to have a connection if you are on the post-paid tariff. If you go to pre-paid, your cost per kw/h goes up, but the flat fees fall away. The flat fees made up just over 50% of my electricity bill, so converting to pre-paid saved me good money.
  14. In this case the 189v was what he got immediately after restoration. I got 219, but I'm on a different phase from him. In both cases the incoming voltage climbed over the next half hour or so.
  15. It's not a pylontech thing. I have this with Revovs as well. The explanation that @Pietpower linked to resolved my confusion on this matter.
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