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Showing content with the highest reputation on 14/05/2018 in all areas

  1. 3 points
    This has been done before by people much smarter than me; Fixed Adj. 2 seasons Adj. 4 seasons 2-axis tracker % of optimum 71.1% 75.2% 75.7% 100% The table above shows that there is hardly any value at all in adjusting panel tilt each season over a fixed tilt array, however there is a very real advantage to a 2axis tracker over fixed array. The above numbers don't really tell the whole story - for a fixed array to theoretically match the annual output of a 2axis array you would need to add 40% panel capacity, but the larger fixed array would still give low output in the morning and evening with a huge output in middle day, whereas the 2axis array would give a much smoother output throughout the day. This smoother output would deliver significant benefits in real life over the simplistic result of math on a piece of paper showing equal annual output. To have your output pick up quickly in the morning and extend PV output late into the afternoon would have significant benefits in an off grid situation (and most other situations as well).
  2. 2 points
    ebrsa

    Cape Town Water Crisis

    @plonkster I am glad that you pointed out the flaws in your proposals of government involvement in business activities, The main problem is not lack of accountability but lack of the discipline of the market. SAA would be long gone if it was a non-government company. Neither does the suggestion that a loss making airline could be beneficial to the nation hold water. Why should taxpayers subsidise a financial disaster of an airline so that shareholders of hospitality businesses can make money. Given the total incompetence of governments in general, there is no assurance that they will make a success of mining . Govenment is in any event a freeloader on the backs of shareholders of mining companies given the company and mining taxes they confiscate without contributing one cent to the capital investment. The only viable answer that makes sense to me are to be found in Austrian School economic theory or Libertarianism if you like. That is after all based on freedom of the individual with peaceful exchange of goods and services without coercion by government. Some time ago, when suggestin to our municipal manager that services should be privatised, he told me of an occasion where he requested a quote from their own civil engineering department to move some goods from one location to another and it was in excess of R3000. Then he requested one from the private sector which was around R1200. So this is just one small example why small government, doing the absolute minimum, should be the objective if the citizens are to prosper. It also supports the proposal that bulk water supply should be a local matter and ideally privatised.
  3. 1 point
    Obviously having a bad day, I think I need a whisky
  4. 1 point
    That I dont know, will need to check with @Coulomb. Maybe it is because you have 1450W coming into a 3kW MPPT. My PV indicator is either on or off, maybe the Aussies got smarty and added power level indicator.
  5. 1 point
    That is an ICC thing and not to do with the update, if you have a dual MPPT inverter then you will see [MPPT 2] come alive. I have 2 Axpert in parallel and still no [MPPT 2] numbers on this screen, howver you can view them in the [INVERTER CLUSTER VALUES] tab, which is also only available if you have parallel inverters.
  6. 1 point
    plonkster

    The future in inverter software

    Us whities very often have daddy issues. Which is not to say that there is or isn't such a thing... just... saying.
  7. 1 point
    gabriel

    The future in inverter software

    elon musk, their ceo, is south african by birth. he still has family here BUT not only did his schools take advantage of him [one of which pretoria boys high], also the government - he has no interest in sa. i can't blame him, with a ever so wise government* with a culture of disregarding innovative ideas, why should a self made multi billionaire whizkid be the exception? apparently he has plans which could rescue our power chaos, but so has this forum, but it seems eskom will not or can not apply their mind [?] to any equitable solution. *one of the reasons he left sa was military service under the nats
  8. 1 point
    viper_za

    The future in inverter software

    Talking about this
  9. 1 point
    ebrsa

    Cape Town Water Crisis

    @gabriel Iam afraid he did not say and I thought the point had been made. Unfortunately municipalities are too scared of the trade union concerned to privatise services and would rather take the easy way out and let the taxpayers, who actually pay their accounts, bear more of the burden. Swartland Municipality, mail about 24,000 accounts per month but around 8500 of those are receivers of subsidies. @plonkster what I am hoping for is that the combined intelligence on this forum may come up with some workable solutions for sustainable water supply, other than looking hopefully at the winter sky which today is nice and sunny. At least my PV panels will save me some money before their viability is taxed into oblivion together with the capital that we were so enthusiastically encouraged to invest. Maybe the one snowflake that precipitates the avalanche will come to light.
  10. 1 point
    gabriel

    Cape Town Water Crisis

    that's 'a bridge too far'
  11. 1 point
    plonkster

    The future in inverter software

    I'm not sure I saw that bit :-) But about scheduled charging and discharging, some have it already, and planet blue is getting it real soon. I'm not sure if the other guys -- you know the ones who cannot even properly fix a charge bug in their firmware -- if they will get it anytime soon.
  12. 1 point
    Coulomb

    Patched firmware based on version 73.00

    So you have performed an update successfully now? Re the scary moment: you have to remember that during reflashing, the main software is completely disabled; you are talking only to the boot loader. With a successful download, all that usually happens is that the LCD and LEDs merely freeze at whatever they were displaying last; you might not even notice that anything is different if you weren't looking for it. But when a reflash has comms errors or doesn't start properly, it can be in a sort of limbo between normal operation and normal firmware updating, so that neither the Reflash tool nor the LCD seems to respond. That's when you need to keep a clear head and figure out how to rescue the operation. The other thing to keep in mind is that there is only one serial port that talks to the outside world. So if you have ICC talking away on the USB port while you are trying to update via the RS232 port, the two sets of serial data are going to get badly intermingled; they might even wire-OR and mingle at the bit level, I've never sorted that out.
  13. 1 point
    plonkster

    Pylontech US2000B Plus

    I really think more needs to be done to educate people about that. The Lithium sellers are all like "oh, you only need a third of the capacity compared to lead acid", and then you have people who install a 7kw PV array, 5KVA inverter and a 2.5kwh LFP battery (the exact reverse of what you'd do in lead acid territory). "Because I want to use that power during the day and have some left to charge the battery". And then they also want to keep the battery completely full most of the time, and sometimes feed the excess into the grid too. And then on top of that there are sometimes feed-in limits imposed as well (eg no more than 3.6kw on many single phase installations). It's almost as if people lost all common sense now that the batteries are better :-) Isn't 52V a tad low? I believe they want to float at 53V? On the other hand, I did note that the Pylons have a somewhat high float and absorb voltage. For example, a BYD wants to float at 55V and it has 16 cells, so that's around 3.45V per cell. Transferring that over to Pylon territory should mean 52V, but I'm sure the spec sheet calls for 53. 52V is probably fine though. Good batteries. First, they are 16s vs the 15s of the Pylontech, so for comparative purposes one must always take that into account as well. They have a wider voltage range to work with (possibly because of the relatively lower float voltage and the extra cell), which makes life a tad easier at the top end. But I think the Pylontech has the better BMS, from a functionality point of view. The BYD publishes a static charge voltage of 56.5V. But you can get nowhere near it, because the BMS sends the stop charge signal at 55V and only reactivates charte at 54V. It's like a hard limit, it produces this beautiful sawtooth figure that nobody likes to see. So you essentially have to ignore the charge voltage info from the BYD BMS. The Pylontech, as far as I've seen (I haven't seen that many) has dynamic voltage control, in other words, if there is a high cell, it can lower the charge voltage to compensate for it. Proper dynamic voltage control works much better than attempting to regulate the charge current, or that has been my experience at least. So my opinion, the BYD is possibly a slightly better battery, but the Pylon has the better BMS. That is, let me stress again, an opinion only.
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