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Solar PV Performance Thread - Post your monthly output

  • 02-02-2020 11:43am
    #1
    Registered Users Posts: 5,130 ✭✭✭ championc


    I think it would be very useful to post Solar PV monthly generation figures. Not only could it highlight a problem further down the road, but there many be many owners who are getting far less than they expected (or promised by an installer) and would welcome feedback from other owners.

    Of course, there are so many factors involved. Your location in the country (or abroad for our international boardies), your array size, your array direction and the panels mounting angle.


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Comments

  • Registered Users Posts: 5,130 ✭✭✭ championc


    garo wrote: »
    January
    Predicted: 81.5 (without taking shading into account)
    Actual 71.0 - 4.8kw East/West - Dublin
    handpref wrote: »
    January - 83

    5.4 East/West
    Jan 158kwh produced, 20kwh exported

    6kwp south facing - east cork
    joujoujou wrote: »
    82.4 kWh produced in January. :)

    4.3 kWp, facing SSW.

    January - 75kw

    2.7kw South Facing - South Dublin - 22 deg slope


  • Closed Accounts Posts: 18,961 ✭✭✭✭ Shefwedfan


    So for Jan below are figures, it only started on evening of 24th

    PV Generation this Month 36.10 kWh
    Battery Throughput this Month 36.30 kWh
    House Consumption this Month 232.10 kWh
    Grid Import this Month 206.30 kWh
    Grid Export this Month 4.10 kWh
    CO 2 Saved this Month 0.036 T

    19 x 330w panels SW facing


  • Moderators, Category Moderators, Motoring & Transport Moderators, Regional East Moderators Posts: 58,884 CMod ✭✭✭✭ unkel


    Shefwedfan wrote: »
    19 x 330w panels SW facing

    I am glad to see you did go with a very large system as I recommended :)

    "Wind is Ireland's oil" - An Taoiseach, 25/05/2022



  • Registered Users Posts: 205 ✭✭ spose


    80 from 4.7 e/w in Cork


  • Closed Accounts Posts: 18,961 ✭✭✭✭ Shefwedfan


    unkel wrote: »
    I am glad to see you did go with a very large system as I recommended :)


    I started at 12 and just as it got closer I kept putting more on.....in the end I wanted more than 19 but they said it was the max allowed:P


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  • Registered Users Posts: 1,835 ✭✭✭ garo


    Might be an idea to also mention tilt as a panel on a 20 degree tilt will give less than one on 40. Mine is 24 so not great. But I wasn’t going to raise the roof angle!


  • Moderators, Category Moderators, Motoring & Transport Moderators, Regional East Moderators Posts: 58,884 CMod ✭✭✭✭ unkel


    Shefwedfan wrote: »
    I started at 12 and just as it got closer I kept putting more on.....in the end I wanted more than 19 but they said it was the max allowed:P

    There's no such thing as a max allowed number of panels or wattage of the panels. But yeah, your inverter is not allowed to be more than 6kW :)

    "Wind is Ireland's oil" - An Taoiseach, 25/05/2022



  • Registered Users Posts: 8,832 ✭✭✭ markpb


    46.8kWh the second half of January (new install)

    We’re in south Dublin, with a 3.1kWp install. We have 5 panels on the side (hip roof facing SE) and 5 at the back of the house (facing SW). The website says 26 degree tilt but that’s probably only correct for one set of panels.


  • Registered Users Posts: 1,389 ✭✭✭ MAULBROOK


    System 4.8kw SE north Wexford

    2020
    Jan 130.6 kw

    2019
    December 94 kw
    November 120.8 kw

    Getting 3 more panels added at the end of Feb.
    The company are adding them for nothing as a thank you for some good sales leads.


  • Moderators, Category Moderators, Motoring & Transport Moderators, Regional East Moderators Posts: 58,884 CMod ✭✭✭✭ unkel


    Temporarily down to 2.9kwp and spotted today that I generated 5kWh yesterday and 6kWh today. Not so bad. South Dublin, south facing 2.9kwp

    Cut the grass today from my off grid PV system in the shed. While my grid tied PV system was providing enough electricity for the house and the thirsty condenser dryer while the sun was out

    "Wind is Ireland's oil" - An Taoiseach, 25/05/2022



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  • Closed Accounts Posts: 18,961 ✭✭✭✭ Shefwedfan


    Best day yet, 9.2kWh generated......as nobody in house battery filled up quickly and a huge amount dumped to grid :-(


  • Moderators, Society & Culture Moderators Posts: 31,297 Mod ✭✭✭✭ Gumbo


    3kW system in Dublin 11.
    South facing.

    Jan 2020 - 114.18 kWh generated.


  • Registered Users Posts: 418 ✭✭ _dof_


    4.3kWp system in the midlands, SSW facing, no shade problems.
    Jan 2020: 136kW generated


  • Registered Users Posts: 418 ✭✭ _dof_


    Shefwedfan wrote: »
    Best day yet, 9.2kWh generated......as nobody in house battery filled up quickly and a huge amount dumped to grid :-(

    8.5 generated today :), but 4.5 donated to eirgid since I fully charged the battery last night:(


  • Registered Users Posts: 1,835 ✭✭✭ garo


    _dof_ wrote: »
    8.5 generated today :), but 4.5 donated to eirgid since I fully charged the battery last night:(

    Ouch. I suppose the time has come to check the weather before setting the battery to charge. Or possibly switch night charging off altogether.

    Today was my best day of the year with output over 5kWh. I put the dishwasher and washing machine on timer before I left so my battery never got full and I exported very little. Currently restricted to 500W max charge to the Pylontech 2000 due to temperature so I am exporting unnecessarily. Charge is limited to 10A when battery is colder than 10C.


  • Registered Users Posts: 5,130 ✭✭✭ championc


    garo wrote: »
    Ouch. I suppose the time has come to check the weather before setting the battery to charge. Or possibly switch night charging off altogether.

    Will your system allow you to maybe charge the batteries up to a specific SoC level, which would leave room for solar excess.


  • Moderators, Category Moderators, Motoring & Transport Moderators, Regional East Moderators Posts: 58,884 CMod ✭✭✭✭ unkel


    garo wrote: »
    Charge is limited to 10A when battery is colder than 10C.

    Out of a max 25A for a single Pylontech US2000?

    That seems very restrictive. Where did you get those settings from and what way have you staggered them? Something like 0A below 0C, 5A up to 5C, 10A up to 10C and 25A above?

    "Wind is Ireland's oil" - An Taoiseach, 25/05/2022



  • Registered Users Posts: 418 ✭✭ _dof_


    championc wrote: »
    Will your system allow you to maybe charge the batteries up to a specific SoC level, which would leave room for solar excess.

    Yeah, I've been playing the "guess-tomorrows-sunshine" game each night to try to decide the level I should charge the battery at night, it's a bit of fun:) The goal of the game is to have the battery full at sunset, but feeding in the absolute minimum to the grid.

    I'm truly hopeless at the game though, on days I expect sun and only pre-charge to a low level, the sun fails to co-operate, so then I end up using more day-rate grid.

    On days where the forecast is dull, and I fully charge, the bloody sun spends the whole day laughing down at me.

    The met eireann app is useless too by the way for this sunshine forecasting, it's the one leading me down the wrong path....

    I'll stop playing that game once the days get longer though, I hopefully won't need to charge at all at night.


  • Registered Users Posts: 2,442 ✭✭✭ wexfordman2


    _dof_ wrote: »
    Yeah, I've been playing the "guess-tomorrows-sunshine" game each night to try to decide the level I should charge the battery at night, it's a bit of fun:) The goal of the game is to have the battery full at sunset, but feeding in the absolute minimum to the grid.

    I'm truly hopeless at the game though, on days I expect sun and only pre-charge to a low level, the sun fails to co-operate, so then I end up using more day-rate grid.

    On days where the forecast is dull, and I fully charge, the bloody sun spends the whole day laughing down at me.

    The met eireann app is useless too by the way for this sunshine forecasting, it's the one leading me down the wrong path....

    I'll stop playing that game once the days get longer though, I hopefully won't need to charge at all at night.

    I have heard that some manufacturers are testing automating that feature, would be interesting to see it working.


  • Registered Users Posts: 11,213 ✭✭✭✭ KCross


    I have heard that some manufacturers are testing automating that feature, would be interesting to see it working.

    It’s already done. Moixa have it up and running in the UK.

    Energia are running a trial with Moixa at the moment with 20 of their customers.


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  • Registered Users Posts: 418 ✭✭ _dof_


    KCross wrote: »
    It’s already done. Moixa have it up and running in the UK.

    Energia are running a trial with Moixa at the moment with 20 of their customers.

    Yeah I knew about the Moixa smart battery and its machine learning of your usage patterns and its ability to control the charging based on that and forecast sunshine. There's a very interesting interview with the Moixa CEO on the EV News Daily podcast a few months ago.

    I didn't think they were available in Ireland, but I saw here that someone was quoted for a system including the Moixa. I didn't know about the Energia trial though.

    Hopefully my system manufacturer AlphaESS will eventually come out with some software update to provide this smart functionality.


  • Registered Users Posts: 5,130 ✭✭✭ championc


    _dof_ wrote: »
    Yeah, I've been playing the "guess-tomorrows-sunshine" game each night to try to decide the level I should charge the battery at night, it's a bit of fun:) The goal of the game is to have the battery full at sunset, but feeding in the absolute minimum to the grid.

    I'm truly hopeless at the game though, on days I expect sun and only pre-charge to a low level, the sun fails to co-operate, so then I end up using more day-rate grid.

    On days where the forecast is dull, and I fully charge, the bloody sun spends the whole day laughing down at me.

    The met eireann app is useless too by the way for this sunshine forecasting, it's the one leading me down the wrong path....

    I'll stop playing that game once the days get longer though, I hopefully won't need to charge at all at night.

    Have you checked your data in terms of how much power is used to charge your batteries ? Assuming it's night rate and a 2 to 4 kw battery pack, that will cost feck all so realistically, you can therefore afford to charge up fully and if you end up exporting, then so be it. But ever kw you buy at night will still end up replacing day rate electricity one way or another. Up to about 10:00 each morning, I also suspect that you are using more than you generate, so since the night rate finishes at 08:00, you have two hours or so with of stored night rate power which can immediately be used.


  • Registered Users Posts: 418 ✭✭ _dof_


    championc wrote: »
    Have you checked your data in terms of how much power is used to charge your batteries ? Assuming it's night rate and a 2 to 4 kw battery pack, that will cost feck all so realistically, you can therefore afford to charge up fully and if you end up exporting, then so be it. But ever kw you buy at night will still end up replacing day rate electricity one way or another. Up to about 10:00 each morning, I also suspect that you are using more than you generate, so since the night rate finishes at 08:00, you have two hours or so with of stored night rate power which can immediately be used.

    Yeah, it charges 5kWh at 10c night rate, and therefore saves using 5kWh of 20c day rate, so it's saving 50c a day anyway.

    So this time of the year it's always going to be consumed, and it's feck all money anyway, but like I say it's a game, like a little challenge to see if I can predict the right level and see the battery graph rise all day from low to full on the free solar electricity, but if I've overcharged the night before, I end up filling the battery early in the day and then donating the remaining generation for the afternoon.

    I'll probably get bored of the game soon enough anyway, especially since I'm so useless at it :)

    Tonight, I've been optimistic, and decided on 25% charge. Hoping for lots of sun tomorrow :)


  • Registered Users Posts: 64 ✭✭ Zardaz


    _dof_ wrote: »
    Yeah, it charges 5kWh at 10c night rate, and therefore saves using 5kWh of 20c day rate, so it's saving 50c a day anyway.

    So this time of the year it's always going to be consumed, and it's feck all money anyway, but like I say it's a game, like a little challenge to see if I can predict the right level and see the battery graph rise all day from low to full on the free solar electricity, but if I've overcharged the night before, I end up filling the battery early in the day and then donating the remaining generation for the afternoon.

    I'll probably get bored of the game soon enough anyway, especially since I'm so useless at it :)

    Tonight, I've been optimistic, and decided on 25% charge. Hoping for lots of sun tomorrow :)

    Do you have a diverter to boil the tank during the day when the battery is full?


  • Registered Users Posts: 418 ✭✭ _dof_


    Zardaz wrote: »
    Do you have a diverter to boil the tank during the day when the battery is full?

    Not yet, I'll be getting one though.

    Anyway, sorry for derailing the thread, back to people reporting their system's performance :)


  • Registered Users Posts: 2,442 ✭✭✭ wexfordman2


    _dof_ wrote: »
    Yeah, it charges 5kWh at 10c night rate, and therefore saves using 5kWh of 20c day rate, so it's saving 50c a day anyway.

    So this time of the year it's always going to be consumed, and it's feck all money anyway, but like I say it's a game, like a little challenge to see if I can predict the right level and see the battery graph rise all day from low to full on the free solar electricity, but if I've overcharged the night before, I end up filling the battery early in the day and then donating the remaining generation for the afternoon.

    I'll probably get bored of the game soon enough anyway, especially since I'm so useless at it :)

    Tonight, I've been optimistic, and decided on 25% charge. Hoping for lots of sun tomorrow :)

    Even if today is a fantastically sunny day, it will be near 10am before you get any usable production. So if you leave it at 25% charge and your discharge limit is 10%, then you have 9bly 15% available to you before 10am, which is what, 0.750kwh ?


  • Registered Users Posts: 1,835 ✭✭✭ garo


    unkel wrote: »
    Out of a max 25A for a single Pylontech US2000?

    That seems very restrictive. Where did you get those settings from and what way have you staggered them? Something like 0A below 0C, 5A up to 5C, 10A up to 10C and 25A above?

    There seem to be only two restrictions in practice. You cannot charge at over 500W when the temperature is below 10C. And it doesn’t charge at all under 0C. Though it never really gets below freezing where my batteries are stored. It makes sense as you cannot beat chemistry. Link below has more info. You could get a LFP battery to take more charge but then you would be shortening its life. This is a BMS setting but unfortunately the manuals have no mention of this or a temperature defeating chart.

    https://community.victronenergy.com/questions/8827/dvcc-limiting-charging-current-multigrid-venus-mpp.html


  • Registered Users Posts: 1,835 ✭✭✭ garo


    championc wrote: »
    Will your system allow you to maybe charge the batteries up to a specific SoC level, which would leave room for solar excess.

    Yes I have a Growatt inverter that allows charging based on both time and SoC. I haven’t tried night charging as I think the gains are marginal at best. You are reducing battery life by cycling so each battery charge and discharge will cost you something in the range of 5-10c.


  • Registered Users Posts: 5,130 ✭✭✭ championc


    garo wrote: »
    Yes I have a Growatt inverter that allows charging based on both time and SoC. I haven’t tried night charging as I think the gains are marginal at best. You are reducing battery life by cycling so each battery charge and discharge will cost you something in the range of 5-10c.

    I overnight charge to 80% each night and can get all the way to 23:00 the following evening meaning that I'm no longer using any daytime rate electricity :) Of course, it's only possible with my 16.8kw of Lead-Acid AGM"s !!!

    However, batteries will never pay for themselves. I got my batteries for free. Battery technology will change before their useful life has expired.


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  • Moderators, Category Moderators, Motoring & Transport Moderators, Regional East Moderators Posts: 58,884 CMod ✭✭✭✭ unkel


    garo wrote: »
    There seem to be only two restrictions in practice. You cannot charge at over 500W when the temperature is below 10C. And it doesn’t charge at all under 0C. Though it never really gets below freezing where my batteries are stored. It makes sense as you cannot beat chemistry. Link below has more info. You could get a LFP battery to take more charge but then you would be shortening its life. This is a BMS setting but unfortunately the manuals have no mention of this or a temperature defeating chart.

    https://community.victronenergy.com/questions/8827/dvcc-limiting-charging-current-multigrid-venus-mpp.html

    That seems to be a discussion on a Victron forum

    Did you check the manual, or with Pylontech tech support about charging amps at lower temps? 10A at just under 10C seems unnecessarily restrictive to me

    This will kill a lot of your potential on a sunny winter's day where you can easily see say 1300W out of a 4kwp system. With a 300W base load that means that at 10A restriction only half above the 300W will go to battery, the other half will be lost into the grid

    "Wind is Ireland's oil" - An Taoiseach, 25/05/2022



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