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Sarel

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Everything posted by Sarel

  1. @Tariq, these are just facts. Every person does what they can within their means. It's not meant to say anybody is doing stuff wrong, it's just the facts. Your system, it's my guess, are within design specs, or at least close to that, by the looks of what you mentioned, I could be wrong. It does not matter if I am right or wrong, it's your system after all. My observations is only because of best practise from power design considerations, warrantees etc.
  2. Hahahaha as if the CancER ever listened to anybody, this ain't the EU folks. Talk is cheap, look at the Taxes on EVs: Price — EVs attract 45% in import taxes and duties. Administratively, with the stroke of a pen, EVs kept out.... This is a deliberate act, not an oversight, not an incentive.... This was in 2019. for perspective: "The minister of transport, Blade Nzimande, updated that information in March 2019 and said that there are a total of 867 EVs registered in the country." In 2018: New data from analytics group Lightstone shows that 375 electric vehicles have been sold in South Africa since the inception of electrically powered vehicles (EV) in the country. And in 2020: A total of 92 electric vehicles were sold in South Africa in 2020, representing just 0.02% of sales in the domestic automotive market. There Mr Diess....
  3. An Inverter is a current source, for it to act that way it needs to draw current from somewhere. The design, apart from Grid-tie String inverters, are to work from batteries. Most inverters will not work with no batteries, or should not be connected with no batteries. There are exceptions.... C rate in Amp hours and Watt hours. C rate is the rate of discharge (or charge) over time based on capacity of the battery. The example here, Pylontech US2000C, is 50Ah based on 2400Wh capacity at 48Volts. Design specification is below. The manufacturer indicates a 0.5C (25Amp) normal discharge and charge rate per module. The max rate is 1.0C or 50Amp at nominal voltage, ie 48Volts. The design capacity of the Inverter dictates its current draw, ie a 3000W inverter is designed to draw from battery or Solar 3kW nominal. from Solar the amps will depend on string voltage, the OEM will specify the max for each. From battery systems the current depends on battery voltage. But 3000W is 3000W at any voltage, ie the current will be determined by the battery or Solar string voltages. The inverter will draw 3000W to supply the 240V 3000W that it's nameplate specs indicate. The inverter is designed to supply nameplate capacity to its output. Now imagine having to supply 3000W to the output, for whatever reason, from the battery. After sunset, during blackout or someone stole the cable or the Substation blew up or whatever... This will draw 58Amps from said battery at 52 Volts. If the battery was designed to deliver 25Amps at 52 Volts (48Volt nominal), you will overload the battery. You may kill the battery as you are exceeding it's design specs. Pylontech US 2000C specs for a single unit: Voltage: 48 V Nominal Energy: 2400 Wh (50Ah) Continuous Discharge Rate (Normal Use): 1200 W (Indefinitely until discharged) or 25Amp Maximum Discharge Rate (5 Minutes): 2400 W (The oops I forgot rate) or 50Amp Surge Discharge Rate (15 Seconds): 4320 W (Strictly for startup of an appliance rate) or 90Amp Maximum Charge Rate (5 Minutes): 2400W (1C or 50Amps) You want to boil a kettle at 2000W you can, but just, as it should boil 1 Liter water in less than 5 minutes. But you are still exceeding the normal use rate and barely fall within the Max discharge rate. Add a few lights, a TV and cell charging, it's already exceeding the Battery design capacity. 3000 Watts, or really anything above 2400Watts, are a no no as it's or startup only. When you loose Utility grid or mains or loose Solar due to clouds while using the inverter, it will use the battery. Losing any of the other supplies will switch to battery, basically UPS the thing. Designing the system, especially the battery, to cope with Inverter capacity is good practise. It will make the battery last and not endanger the warranty. Even a 3kW inverter needs a battery that can supply 62,5Amp, and then we discount the losses of the system when we should actually include such losses and increase the Battery C rate.
  4. Yes it does indeed. The problem however is production priorities. All OEM Car manufacturers have multi year contracts with Battery OEMs and will get production priority according their contracts. Whatever production capacity is left over, will go to stationary use for Grid scale deployments, and what's left after that, if any, will be for residential. Politically, with the centralised command and control of our beloved CancEr government, nope. And I have worked at the Utility for many years as a consultant, so have some insights here. Just look at the state of management of the generators, the mess with the IPPs and residential Solar..... If you were in Herbert's shoes, he is German, would you want to do that? They have the Unions and Government to deal with in Deutchland. They already have the Zwickau plant for EV production and next will be the rebuild at Wolfsburg. A direct quote, and no mention of Aus, ZA etc.... "By investing in its German sites, Volkswagen, as one of the country’s largest industrial players, is contributing to a strong German economy,while continuing to push the country’s transformation into a more sustainable and more digital future with long-term job security. After Saxony, Lower Saxony will become Germany’s second center of electric mobility." Now peruse this chart, especially considering that to date, we have ever sold 1500 EV's in SA. The quality of journalism is mind-blowing.... Never mind finding Africa let alone SA mentioned anywhere. We not even a blip when it comes to global manufacturing or sales.
  5. I would not know a thing about Johnson or his truth. I was referring to the Oil and Gas industry, and specifically about their lack of investments.
  6. Well, consider this. The normal dinosaur juice based fuels (its called Fossil fuels for reasons) you have to pay for in perpetuity. Its consumption based, you pay to consume. With RE types you pay for the infrastructure, the energy is essentially a free byproduct You pays, your choice when and for how long....
  7. Hmm C rating..... Let's look at the system level here. The inverter needs to draw Current as it is a current source, the thing that makes inverters work. If we have a 5kW vs 10kW inverter and a nominal 48V battery the 5kW will draw about 96 Amps at 5000W and 52 battery Volts. If you installed a 10kW inverter, double that current draw. At 3000W it's 58 Amps and 2000W it's 38 Amps, not a big load and a kettle can draw that by itself. This is not accounting for any system losses, just theoretical mind you. With losses it's even worse. So C ratings are quite important in sizing a system, especially if you do not want to kill the battery. You have to consider all things battery in terms of what your system is required to deliver and do. C rating will also determine charging time.
  8. Normally, the coldest temps are after Sunrise, it takes a while for Mr Sun to warm things a bit. At my place, using a calibrated weather station, I have seen coldest temps about 1 hour after Sunrise.
  9. There is an Xcell spreadsheet from Victron where you can add your own panel data and simulate the panel voltages with temp. You welcome to ignore the Victron bits, just select something closeish to what your specs are and simply use the sheet to model the panels, temps etc…. Panel calc here
  10. Two lenghts will allow raising by at least 1.5m and brace it properly.
  11. Can you move some of the panels to a new string and position them better perhaps?
  12. ICE car OEMs going bankrupt.... The biggest of them VW group, are loosing sales, and their own internal predictions indicate a loss of 25% of staff by 2030. Wonder what may happen if this snowball hits lesser companies.... Well guess it's predictable, they will collapse under their debt and lack of sales. That will leave us here in SA, and likely the rest of Africa in a real predicament. All the local production for those going bankrupt will close, with a loss a f jobs, and no more exports. Not that any other country would want ICE cars, by then ICE will be banned from imports.
  13. Get rid of the shade, if you can obviously. Move the panels to another position or higher if possible. If you would rater get the extra panels, don’t consider the extra energy as wasted, consider it as shade mitigation, see where this goes….
  14. On the panel Volts, use the highest one of STC or NOCT and base the calcs on VoC. Most panels should have a temp graph, look that up. The colder the temps (winter early mornings) the higher the VoC. This means that the VoC will rise or get more the lower the temps. The graphs are normally based on standard temps, like 25Celsius. Some panels will show VoC for colder temps on the graphs. Use that to see what the VoC will be at say -5Celsiuc for Johannesburg and figure out how many panels will get you at a reasonable voltage, and not to close to max, say max volts minus 5 or 8% or whatever you like for a safety margin. The inverter MPPT cannot withstand overvoltages, so stay well clear of max volts, it will smoke beyond max volts.
  15. Back then, most inverters did not have Voltage control, let alone Export to Utility grid control. These technical issues are not "real" but a smokescreen to protect their revenue. Hence other things like Net consumer, thus basically ensures that, depending on the location, you can only ever sae 1/3 of you bill.
  16. Me thinks you in CoCT? If so, this dastardly deed was done, to the best of my understanding in CoCT, because they calculated when an unacceptable Voltage rise would occur. At the time way back, they calculated that for every single dwelling installing grid feed in systems (that was for all of them at the same time) the limit before this unacceptable rise in Voltage would be this 3.68kW figure. Hope this helps....
  17. This? https://www.sseg.org.za/wp-content/uploads/2019/03/NRS-097-2-1-2017.pdf
  18. That 2kVA unit will roughly get you to 1200 Watts, What is the rated standby time for this unit and do they give the wattage for this time? The lot you mentioned will draw about 100-130 Watts. If we work with 100W draw, that should get you to just about 1:10 min only I recon. BUT, it depends on the time or capacity that UPS specifies, if they do that even.
  19. As per the below, the Firmware enabled the Min/Max cell voltages being sent to the GX from the BMS on 2 Oct. This indicates that the cables etc are working as it should. It is clear that the firmware are causing a lot of voltage variability as per the graphs, from 2 Oct.
  20. It's a pleasure. Sorry, don't know about downgrade capability. You might have to contact Pylontech or a dealer or someone on here may know....
  21. This is what my system's CCL and Bulk/Absorbtion looks like. The BMS asks mostly for a charging current above 0 Amps, in my case 250 Amps. The bulk of the time is spent in Bulk mode, no pun here..... On the Pylontech, after Firmware update, it looks like the firmware logic is inverted.... see bottom image. Inverted logic post red line.
  22. I sent you an email response. You welcome to remove me from the portal.
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