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  • FIRST POST
    • Kernel Sanders
    • By Kernel Sanders 15th Mar 12, 11:06 PM
    • 3,480Posts
    • 1,417Thanks
    Kernel Sanders
    Renewables: "talking 'bout my generation"
    • #1
    • 15th Mar 12, 11:06 PM
    Renewables: "talking 'bout my generation" 15th Mar 12 at 11:06 PM
    Please forgive the corny thread title inspired by The Who, but this post on the bloated 'how do I make the most of it' thread prompted me to initiate a new one...
    Hi Everyone,
    I haven't been here for a while, and am interested to see discussion of how much is being generated, rather than what to do with it.
    Originally posted by old grouser
    Well, there was yet another misty and bleak start in North Notts today (Thursday), but my SSW 3.92 kWp system was generating around 3kW for just a few minutes between 12.15 and 13.00, but enough to get the immersion heater hot enough for a shower. It seems to drop below that figure before it reaches 13.55 (optimum orientation). Final figure was just over 14kWh.

    BTW, there was an item about solar generation in Germany on the radio today; you can stream it here:
    http://www.bbc.co.uk/iplayer/episode/b01d2rvn/PM_15_03_2012/
    Just click on the speaker symbol on the left, then drag the time cursor at the bottom to 25mins 30 secs then release.
    Last edited by Kernel Sanders; 19-12-2012 at 6:01 PM.
Page 1180
    • Martyn1981
    • By Martyn1981 18th Aug 19, 8:52 AM
    • 9,217 Posts
    • 14,144 Thanks
    Martyn1981
    That's correct & what Mart was saying - 1% reduction in output for every 4C increase in temperature. Black panels suffer the most....and yours are very black!
    Originally posted by 1961Nick
    @mrmmhf, think black car in the sun, the panels get very hot very fast. On a long sunny day, with little to no wind and perhaps 30C air temps, don't expect more than 80% of kWp rating.

    BUT I also have a Solaredge HD wave inverter and they are top notch, so anything is possible.


    Boring bit - but many years ago, probably 6(ish) one poster was convinced that undersizing an inverter was dangerous, but he was conflating issues with having too many panels on an unsuitable inverter which could lead to too high a voltage, which in turn would damage the inverter.

    It got so bad I eventually copied the thread to SMA the manufacturer of the Sunny Boy range he was talking about and mentioning 'exploding inverters'. They suggested litigation might happen if he continued.

    The issue there is that a suitable inverter needs to be chosen, and the strings set out correctly to match voltage limits. [Note you and I have single strings thanks to the Solaredge power optimiser technology.]

    But from there I started to here about side by side tests of what at the time were seen as the best of the best inverters, SMA SB TL's.

    They found that 4kWp of identical PV generated slightly more over a year when connected to a SB3600TL, than the SB4000TL. Plus the smaller model was around 100 cheaper at the time.

    But don't worry about my posts, nor my pedantry, be it a 5kW or 6kW inverter, your system looks great, and not only will the difference in generation be small (if there even is one), but you'll never know anyway!

    Oh, last thought, the 6kW model can cope with up to 9.3kW of DC generation, so ....... and this is where I usually waffle on and ponder away ..... but if in the future you decide to add more PV, then given the Solaredge tech allows you to mix any panels, orientation, pitch etc etc, then you are in a perfect position to do so.

    Perhaps some very steep (50-60d) south facing panels to aid winter gen, or perhaps that should be SSW, to compliment your current shallow to average pitch panels.

    PV is addictive, car ports, pergola, shed rooves ...... someone stop me for the love of sanity!
    Mart. Cardiff. 5.58 kWp PV systems (3.58 ESE & 2.0 WNW)

    For general PV advice please see the PV FAQ thread on the Green & Ethical Board.
    • mrmmhf
    • By mrmmhf 18th Aug 19, 9:24 AM
    • 42 Posts
    • 59 Thanks
    mrmmhf
    Should that be 3.46 O's?
    LOL. No, we had a monster day yesterday: 36.6 Os.
    • EricMears
    • By EricMears 18th Aug 19, 10:02 AM
    • 2,513 Posts
    • 4,374 Thanks
    EricMears
    LOL. No, we had a monster day yesterday: 36.6 Os.
    Originally posted by mrmmhf
    That seems an exceptionally large figure from a unit system that is supposed to level out reports from different sized installations.

    So what is the size (kWp) of your system and yesterday's generation in (kWh) ?
    NE Derbyshire.
    4kWp S Facing 17.5deg slope (dormer roof).
    • mrmmhf
    • By mrmmhf 18th Aug 19, 10:07 AM
    • 42 Posts
    • 59 Thanks
    mrmmhf
    I can't seem to upload images on this forum.

    SolarEdge reads: 34.6kWh - it's a 6.16 kW system, and the panels were in full sunshine, all day.
    • mrmmhf
    • By mrmmhf 18th Aug 19, 10:11 AM
    • 42 Posts
    • 59 Thanks
    mrmmhf
    • 1961Nick
    • By 1961Nick 18th Aug 19, 10:34 AM
    • 810 Posts
    • 3,175 Thanks
    1961Nick
    34.6 Os yesterday.
    Originally posted by mrmmhf
    Thats kWh.

    To calculate Os you need to divide the above by the size of your array...6.16kWp in your case.

    This keeps us on a level playing field for the purpose of comparison.
    4kWp (black/black) - Sofar Inverter - SSE(141) - 30 pitch - North Lincs
    Installed June 2013 - PVGIS = 3400

    Sofar ME3000SP Inverter & 5 x Pylontech US2000B Plus Batteries - 12kWh
    • Martyn1981
    • By Martyn1981 18th Aug 19, 11:15 AM
    • 9,217 Posts
    • 14,144 Thanks
    Martyn1981
    I can't seem to upload images on this forum.

    SolarEdge reads: 34.6kWh - it's a 6.16 kW system, and the panels were in full sunshine, all day.
    Originally posted by mrmmhf
    One last thing* another reason for undersizing inverters relates to the permission required from the DNO when you add a SSEG (small scale electricity generator) to the network. For anything that can (even theoretically) export 3.68kW's or more, you need prior approval from them.

    So, combine this with at the time a FiT tariff that reduced at 4kWp+, and we get an additional reason to keep the inverter at or below 3.68kW. Basically as far as the DNO was interested, you could have as much PV as you like, so long as the inverter wasn't capable of exceeding an AC output of more than 3.68kW.

    When I added to my original 3.58kW system that at the time had two inverters totalling 3.7kW (in this instance the PV being under 3.68kW) I had to get permission from the DNO, and I'm now allowed to have inverters totalling 5.9kW.

    *Obviously I and others love to chat about PV and all the ins and outs, but to prevent too much diversion on this thread, best to choose another, or might I suggest you start one based on your personal set up, as I find it interesting, and my sister has just bought a property with mains leccy and water but no other services, and when she moves in I'm on call to offer suggestions such as heatpumps, PV etc etc.. So the more you can share the better.
    Mart. Cardiff. 5.58 kWp PV systems (3.58 ESE & 2.0 WNW)

    For general PV advice please see the PV FAQ thread on the Green & Ethical Board.
    • JKenH
    • By JKenH 18th Aug 19, 11:20 AM
    • 721 Posts
    • 2,732 Thanks
    JKenH
    Not even a solitary O on Friday, then 4.22 Os yesterday.
    Northern Lincolnshire. 7.8 kWp system, (4.2 kw west facing panels , 3.6 kw east facing), Solis inverters, Solar IBoost water heater, Mitsubishi SRK35ZS-S and SRK20ZS-S Wall Mounted Inverter Heat Pumps
    • mrmmhf
    • By mrmmhf 18th Aug 19, 11:34 AM
    • 42 Posts
    • 59 Thanks
    mrmmhf
    Thats kWh.

    To calculate Os you need to divide the above by the size of your array...6.16kWp in your case.

    This keeps us on a level playing field for the purpose of comparison.
    Originally posted by 1961Nick
    Thanks for the explanation. Got it now.
    • legoman62
    • By legoman62 18th Aug 19, 9:13 PM
    • 2,877 Posts
    • 15,080 Thanks
    legoman62
    4.175 O's here today
    16 Sanyo Hit 250s.4kWp SMA 3.8kWp inverter. SW roof. 28 pitch.
    Minimal shade. Nov 2011 install. N.E Lincs Coast. Hybrid car
    • 1961Nick
    • By 1961Nick 19th Aug 19, 7:02 AM
    • 810 Posts
    • 3,175 Thanks
    1961Nick
    4.3 O's yesterday.
    4kWp (black/black) - Sofar Inverter - SSE(141) - 30 pitch - North Lincs
    Installed June 2013 - PVGIS = 3400

    Sofar ME3000SP Inverter & 5 x Pylontech US2000B Plus Batteries - 12kWh
    • JKenH
    • By JKenH 19th Aug 19, 9:24 AM
    • 721 Posts
    • 2,732 Thanks
    JKenH
    Good day yesterday with 3.80 Os. Beginning to think I won’t see 4 Os again this year as last year the last day I made that was 7th August (although I did have 3 or 4 days right at the end of the month when my system was shut down.)
    Northern Lincolnshire. 7.8 kWp system, (4.2 kw west facing panels , 3.6 kw east facing), Solis inverters, Solar IBoost water heater, Mitsubishi SRK35ZS-S and SRK20ZS-S Wall Mounted Inverter Heat Pumps
    • Coastalwatch
    • By Coastalwatch 19th Aug 19, 12:20 PM
    • 672 Posts
    • 2,827 Thanks
    Coastalwatch
    Been away a few days so now trying to play catch up.
    Figures from the 15th being 3.8, 2.02, 4.68 & 3.99 O's. Currently running at 96% of pvgis v5, an average August day being 3.81 O's.
    East coast, lat 51.97. 8.26kw SSE, 23 pitch + 0.59kw WSW vertical. Nissan Leaf plus one dirty diesel. Still waiting for V2H and home storage to become available at sensible cost.
    • JKenH
    • By JKenH 19th Aug 19, 12:59 PM
    • 721 Posts
    • 2,732 Thanks
    JKenH
    One last thing* another reason for undersizing inverters relates to the permission required from the DNO when you add a SSEG (small scale electricity generator) to the network. For anything that can (even theoretically) export 3.68kW's or more, you need prior approval from them.

    So, combine this with at the time a FiT tariff that reduced at 4kWp+, and we get an additional reason to keep the inverter at or below 3.68kW. Basically as far as the DNO was interested, you could have as much PV as you like, so long as the inverter wasn't capable of exceeding an AC output of more than 3.68kW.

    When I added to my original 3.58kW system that at the time had two inverters totalling 3.7kW (in this instance the PV being under 3.68kW) I had to get permission from the DNO, and I'm now allowed to have inverters totalling 5.9kW.

    *Obviously I and others love to chat about PV and all the ins and outs, but to prevent too much diversion on this thread, best to choose another, or might I suggest you start one based on your personal set up, as I find it interesting, and my sister has just bought a property with mains leccy and water but no other services, and when she moves in I'm on call to offer suggestions such as heatpumps, PV etc etc.. So the more you can share the better.
    Originally posted by Martyn1981
    I have just watched the video which I thought was excellent. I noticed in the video that the installers initially supplied a 5Kw inverter then replaced it with a 6kw inverter. I think it might be worthwhile the OP checking with the installers that they got DNO permission for 6 Kw. I had a system installed last year and when I decided I wanted to add some panels I asked my installer what capacity system had been approved by my DNO. It turned out the DNO application had not gone through even though I had 7.2Kw inverter capacity. Negotiations are ongoing with the DNO but it hasn’t started off well with the DNO only approving 5.9 Kw capacity (which coincidentally is the same as what Mart was offered).

    Apologies for continuing to take this thread off topic but maybe when the OP posts his next video update (which I am looking forward to) it could be done under a separate Home Farm Solar Installation thread.

    Ken
    Northern Lincolnshire. 7.8 kWp system, (4.2 kw west facing panels , 3.6 kw east facing), Solis inverters, Solar IBoost water heater, Mitsubishi SRK35ZS-S and SRK20ZS-S Wall Mounted Inverter Heat Pumps
    • mrmmhf
    • By mrmmhf 19th Aug 19, 2:55 PM
    • 42 Posts
    • 59 Thanks
    mrmmhf
    I've created a new thread here so that we can continue the discussion - this has been extremely educational for me - back to just posting Os here:

    https://forums.moneysavingexpert.com/showthread.php?p=76174802#post76174802
    • mrmmhf
    • By mrmmhf 19th Aug 19, 3:09 PM
    • 42 Posts
    • 59 Thanks
    mrmmhf
    4.97 Os yesterday.
    • Coastalwatch
    • By Coastalwatch 19th Aug 19, 9:34 PM
    • 672 Posts
    • 2,827 Thanks
    Coastalwatch
    4.25 O's for today.
    East coast, lat 51.97. 8.26kw SSE, 23 pitch + 0.59kw WSW vertical. Nissan Leaf plus one dirty diesel. Still waiting for V2H and home storage to become available at sensible cost.
    • legoman62
    • By legoman62 19th Aug 19, 9:40 PM
    • 2,877 Posts
    • 15,080 Thanks
    legoman62
    3.75 O's here. Away for most of the day so nearly all of it went to the grid

    Edit:- I also managed to charge my electric toothbrush for free
    Last edited by legoman62; 19-08-2019 at 10:10 PM.
    16 Sanyo Hit 250s.4kWp SMA 3.8kWp inverter. SW roof. 28 pitch.
    Minimal shade. Nov 2011 install. N.E Lincs Coast. Hybrid car
    • 1961Nick
    • By 1961Nick 20th Aug 19, 7:11 AM
    • 810 Posts
    • 3,175 Thanks
    1961Nick
    4.25 O's yesterday.
    4kWp (black/black) - Sofar Inverter - SSE(141) - 30 pitch - North Lincs
    Installed June 2013 - PVGIS = 3400

    Sofar ME3000SP Inverter & 5 x Pylontech US2000B Plus Batteries - 12kWh
    • Coastalwatch
    • By Coastalwatch 20th Aug 19, 7:47 PM
    • 672 Posts
    • 2,827 Thanks
    Coastalwatch
    The sun has finally set on a very good day here recording 5.4 O's and taking us back up to 99.5% of pvgis for the month!
    East coast, lat 51.97. 8.26kw SSE, 23 pitch + 0.59kw WSW vertical. Nissan Leaf plus one dirty diesel. Still waiting for V2H and home storage to become available at sensible cost.
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