Advertisement
If you have a new account but are having problems posting or verifying your account, please email us on hello@boards.ie for help. Thanks :)
Hello all! Please ensure that you are posting a new thread or question in the appropriate forum. The Feedback forum is overwhelmed with questions that are having to be moved elsewhere. If you need help to verify your account contact hello@boards.ie

Solar for Dummies.

Options
11213151718108

Comments

  • Registered Users Posts: 5,853 ✭✭✭daheff


    Thanks for this.


    EV isn't used as much as it was precovid, so going to night rate doesn't really make much sense.


    I have the Zappi set to charge on the eco+ mode. It does mean that it charges at around 1.2kw/h, so slowly. But it makes better use of available solar. Still rarely charge at more than 40% solar over any period of time greater than an hour.


    To connect the myenergi app to the zappi I think I need to also buy the hub(harvi?)



    Really my array is small, doesn't produce much energy. I think I'd need to put money into it to do it right, but not sure the benefit is worth the costs and hassles.


    Maybe the FIT is the best option to make some benefits.


    I'd nearly be certain that the builder did not register the NC6 with the ESB, but will check it.


    Thanks



  • Registered Users Posts: 12,556 ✭✭✭✭AckwelFoley


    Do batteries for solar need to be the same brand..


    I'm due to get a Puredrive kw battery but of I want to down the line add another 5kw battery, do I need to get the same brand or can I shop around?



  • Registered Users Posts: 2,504 ✭✭✭bullit_dodger


    Typically yes, they need to be the same brand - but not always. It's a good idea though as each battery manufacturer has their own profile. Voltages used, configuration, the BMS (battery management system) will like to see indentical profiles......although it's not 100% necessary.

    Basically while "in theory" you can do what you are suggesting, in reality you'd probably be better off sticking to the one brand or you might run into issues.



  • Registered Users Posts: 12,556 ✭✭✭✭AckwelFoley


    Another quick question.


    I know ow with the glycol solar setup, if one had east west, that when east was working, west wasn't and than it would transfer over when sun hit west


    Is it the same with the PV, when east is generating west is idle. And vice versa or do both generate together albeit one higher than the other



  • Moderators, Home & Garden Moderators Posts: 5,959 Mod ✭✭✭✭graememk


    In short yes. Usually it's on different strings so that it's technically 2 separate/independant arrays and don't effect each other.

    There was a paper out that tested matched east west on a single string and that worked just as well as two separate strings, although I think they needed to be mirrors of each other, eg 6 west and 6 east .



  • Advertisement
  • Registered Users Posts: 21,792 ✭✭✭✭ELM327


    If you get a different but similar battery you should be fine.

    I was looking at this and the likes of dyness and pylontech for instance should (in theory) work together as they are almost the same underneath.



  • Registered Users Posts: 307 ✭✭redmagic68


    So if you’ve an east/west split only one array will generate at a time? I thought if the sun was on both that both would generate for example midday when the sun is in the south and would be shinning on both, only one array will generate even if they are separate strings on the inverter?

    8.4 kwp east/west Louth,6kw sofar, 9.6kwh batt



  • Moderators, Sports Moderators Posts: 18,872 Mod ✭✭✭✭slave1


    In an E/W split the E is String 1 usually and the W String 2, String 1+String 2 = Array 1

    Just a loss in translation, an array is both strings together so the Array will generate off String 1 and String 2 at solar midday

    My stuff for sale on Adverts inc. outdoor furniture, roof box and EDDI

    Public Profile active ads for slave1 (adverts.ie)



  • Registered Users Posts: 1,439 ✭✭✭DC999


    Even when the sun is not on them, they will produce a small amount. So in the morning when West can’t see the sun, there is light bouncing around the sky so they pick that up. Output levels would be like that of a cloudy day.

    You could put them on 1 string like a Fronius whitepaper @graememk mentions. I asked our installer if they wanted to try that with us as a proof of concept. And that they’d change back at no cost if didn’t get the output. They weren’t interested.

    Paper does seem to suggest (from little of it I could understand as it’s technical) that the different between the roof angles needs be shallow. So an Irish roof isn’t typically. Some countries might have flatter roofs. Think they did it in Germany or Oz, can’t recall. But I could well have misunderstood that part



  • Registered Users Posts: 2,504 ✭✭✭bullit_dodger


    Good thing to do is take an actual example of an actual east/west split. This is from my own site and a good day in July last. I'm exactly 90/270 split.

    You can see that the east panels shoot up very quickly when the sun comes over the neighbors house at 6:30am, and they "peak" about 11:30am, while the west facing panels peak about 3:30pm (solar noon is 1:30pm in Ireland in summer)

    But even at 7-8am the west facing panels in the shade of the roof and not facing the sun are still doing "something"......just not a lot :-)



  • Advertisement
  • Registered Users Posts: 8,578 ✭✭✭micks_address


    hey folks - sorry if asked before.. is there generally much difference in solar invertors/batteries from a manufacturer point of view? ive a quote with a givenergy invertor and battery and im not sure if its gen1/gen2.. i'll ask but does it matter?



  • Registered Users Posts: 2,504 ✭✭✭bullit_dodger


    Between the various makes/models, no - they all pretty much do exactly what they say on the tin. Whichever one you get will for most people be perfectly fine. I have a Givenergy one myself and if you are planning on some automation, the remote management of it is 1st rate, probably best in market.

    I would however make sure that you get a Gen2 model. The Gen1 are limited to 2600w charging/discharging rates from the battery while the Gen2 is limited to I beleive 3600w. Makes a huge difference if you are trying to charge a big battery in a short window (for example a 3 hr window at 2am on a smart tariff)



  • Registered Users Posts: 2,330 ✭✭✭robwen


    Do u need a WiFi hub to use the myenergi app, should one have been included with the installation or is it an extra, where do u buy one??



  • Registered Users Posts: 12,556 ✭✭✭✭AckwelFoley


    Another question..


    I'm looking at the tariff that electric are offering. One is the night boost ie 2 hours at a lower rate than regular night.

    If I have a 5 kw battery how long would it take to typically fill its boots with electricity. Would the 2 hours cover it? I'd consider getting 10kw batteries and more panels so less peak grid

    Albeit a good month, the solar has exceeded my expectations, and yes I know December and Jan is going to be poor but I'd like to make best use of battery at that point

    Post edited by AckwelFoley on


  • Registered Users Posts: 327 ✭✭Redlim


    Hi All. Apologies if this has been answered previously. Are there any downsides to using larger panels e.g. 550w/580w panels?

    Assuming the installer is ok working with the larger size, is there anything to consider from the user standpoint? It might work out better for us to use these to get the most out of the small amount of space available to work with.



  • Registered Users Posts: 2,734 ✭✭✭yankinlk


    I fill my battery slowly over the entire night rate by dialing down the amps...but yeah the default setup of solis filled it in 2 hours easily.



  • Registered Users Posts: 74 ✭✭Punchin A Keyboard


    Depending on the size of the panels, you might be able to do some maths and see if you can jenga in more smaller panels which may give a higher overall kwp



  • Registered Users Posts: 8,578 ✭✭✭micks_address


    hi folks -

    talking to an installer today about number of panels on back roof versus front roof of the house.. they recommended putting all on back as the ones on front would drain down the power if they werent getting sun? i thought they'd be different strings so would be independent? ive heard about optimisers if one panel is shaded it can take down the rest to its operating level

    our back of house gets probably 60 percent of sun, with front getting the later afternoon sun..

    Cheers,

    Mick



  • Registered Users Posts: 21,792 ✭✭✭✭ELM327


    You should have string 1 and string 2. Just use string 2 for the front and 1 on the back. That installer is talking through their hoop tbh



  • Registered Users Posts: 8,578 ✭✭✭micks_address


    yeah i think they are more of a diy type outfit.. didnt inspire confidence



  • Advertisement
  • Registered Users Posts: 4,044 ✭✭✭TaurenDruid


    Yeah... wouldn't be using those guys. Definitely want two strings in that situation.



  • Registered Users Posts: 327 ✭✭Redlim


    Cheers, I had been playing around with the dimensions alright and it actually seems to work best with these larger panels. Just not sure if there are any downsides to consider with the much larger panels apart from the Tetris element.



  • Registered Users Posts: 1,439 ✭✭✭DC999


    @micks_address, as others say that's a walk away job. Usual craic that some installers want an easy life (only 1 roof so it's done in jig time) but bad design for you (as miss later afternoon sun).



  • Registered Users Posts: 12,556 ✭✭✭✭AckwelFoley


    This is where "solar for Dummies" was born out of hence why I created the thread because im still a bit unsure


    A string is one loop of panels?

    If you have shading on one one of the loops it effects all the panels on that loop. I have 2 rows of panels 2 x 8 on the one side of my roof south face ..I think..pv1 and pv2


    All strings added together is an array

    Shading only effects the string, not the array

    2 strings can supply different KW levels at the same time if they're in different locations kn the site.

    ...I think



  • Registered Users Posts: 2,504 ✭✭✭bullit_dodger


    On the surface it sounds odd, but it may be just a misunderstanding of wording. Also you haven't really outlined the orientation of the front and back roofs. You mention.....

    our back of house gets probably 60 percent of sun, with front getting the later afternoon sun..

    So, we can guess from that, that the front is west, or "west north west" facing......so the supplier telling you to put most/all of your panels on the more southernly facing roof might not be as bad advice as you previously though? Depends a little on shading, number of panels you want to install, orientation of the roof, any chimneys/trees shading , etc.

    If you give details the folks here will give you options.



  • Registered Users Posts: 8,578 ✭✭✭micks_address


    East west facing.. east at back of the house. they didn't seem to know about having the panels on their own strings..made some sort of joke about it not being a piano



  • Registered Users Posts: 2,504 ✭✭✭bullit_dodger


    Yup - you got it spot on. A string is a collection of panels all hooked up in series. Forgive the crud drawing, but effectively it's like this.

    Don't have to have the same number of panels on both strings (although you do in your case), and neither do they have to be on the same roof. So you could have string 1 on a east facing roof and string 2 on a west facing roof. As a result they will generate different power at different part of the day.

    With both your stirngs on the same roof and with the same number of panels, they should nearly always unless there's some shading from a chimeny or something, be pretty close to each other in terms of power (which they are as it's only 1-2% difference)



  • Registered Users Posts: 12,556 ✭✭✭✭AckwelFoley


    How many strings can an inverter take, is it limited to just 2. For example a solis hybred.



  • Moderators, Home & Garden Moderators Posts: 5,959 Mod ✭✭✭✭graememk


    For residential, it's 2

    Commerical, 3 phase.. depends what you want really, I think there is 3 and 4 string out there, but sometimes it's better just going with more inverters



  • Advertisement
  • Registered Users Posts: 2,504 ✭✭✭bullit_dodger


    And the next question that people ask..."how many panels can you have in a string?"

    The answer is ... "it depends". Usually for reasons I won't go into, your inverter is limited to about 12 panels per string. There's also a power limit, that you shoudn't really go more than 50% higher in the panels than your inverter. E.g. if your inverter is 6Kw, then you shouldn't have more than 9Kw of panels. That's not an absolute rule, but it's the general guideline.

    The 12 panels per string one though is fairly hard rule. You might (might!) sneak in 13, but generally 12 is the limit.



Advertisement