help required with home solar system

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System
System Posts: 2,511 admin
in Solar Beginners Corner #1
I have 16x12V Mono 85W panels, which I would like to hook up to a 24V battery system ( have a 24V 2Kw inverter). I live in a suburban property, surrounded by many tall trees in neighbouring properties. During the winter months my panels will be shaded intermittently by various trees from mid to late morning, from midday to late afternoon I have full sunlight (Better in summer). Unable to get the trees pruned, or elevate panels. Yet am still eager to continue with the installation, and will just have to work within these boundaries.

Any suggestions about regulating to the battery?
Thought about grouping 2x2 and thus using 4 x (MPPT) regulators, sharing the current.
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  • Solar Guppy
    Solar Guppy Solar Expert Posts: 1,989 ✭✭✭
    #2
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    Re: help required with home solar system

    Normally I would suggest a Xantrex XW-60-150 or an Outback MX-60, but with that much shading potentional, I would suggest the 4X mppt controllers ( I recommend the MorningStar Sunsaver Mppt )

    With shading everyday, using the indivdual controllers is really the only way to maximize harvest, its a bit more $$ wise but I don't really think you have any other options unless you get the chainsaw out
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  • mike95490
    mike95490 Solar Expert Posts: 9,583 ✭✭✭✭✭
    #3
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    Re: help required with home solar system

    Whats the direction your roof faces ? East? south, west northwest ??
    Powerfab top of pole PV mount | Listeroid 6/1 w/st5 gen head | XW6048 inverter/chgr | Iota 48V/15A charger | Morningstar 60A MPPT | 48V, 800A NiFe Battery (in series)| 15, Evergreen 205w "12V" PV array on pole | Midnight ePanel | Grundfos 10 SO5-9 with 3 wire Franklin Electric motor (1/2hp 240V 1ph ) on a timer for 3 hr noontime run - Runs off PV ||
    || Midnight Classic 200 | 10, Evergreen 200w in a 160VOC array ||
    || VEC1093 12V Charger | Maha C401 aa/aaa Charger | SureSine | Sunsaver MPPT 15A

    solar: http://tinyurl.com/LMR-Solar
    gen: http://tinyurl.com/LMR-Lister ,

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  • System2
    System2 Posts: 6,290 admin
    #4
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    Re: help required with home solar system

    The panels will be placed on the north-west side of the house.
    Thanx Gup, will check the specs.
    Thanx
    Mic
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  • icarus
    icarus Solar Expert Posts: 5,436 ✭✭✭✭
    #5
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    Re: help required with home solar system

    Not the optimum direction. Is there any chance of putting the panels somewhere else? Ground mount? Wall mount? Fence mount?

    T
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  • niel
    niel Solar Expert Posts: 10,300 ✭✭✭✭
    #6
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    Re: help required with home solar system

    just to be sure of how he meant that are the pvs facing northwest when mounted?
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  • System2
    System2 Posts: 6,290 admin
    #7
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    Re: help required with home solar system

    Probably more north-north west facing than north-west. As I am on lat. 32S, sun angle (noon) in mid-winter 32deg and mid-summer 81deg. Considerable difference, will tilt the panels accordingly. Have also positioned as high as possible on rooftop. But unfortunately due to lack of yard-space, am restricted to positioning on the rooftop.
    Thanx
    mic
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  • niel
    niel Solar Expert Posts: 10,300 ✭✭✭✭
    #8
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    Re: help required with home solar system

    facing that northerly direction with the pvs will be a waste of the pv's ability to produce power. ideally pvs should face south at an elevation angle to be determined by your latitiude +/-. this might be akin to looking in the wrong end of a telescope, it just doesn't work that well like that.:roll:
    if you have northerly facing roofing then odds are that you also have a southern exposure in most cases. i know there are exceptions so nobody pick on me for it.:p
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  • mike95490
    mike95490 Solar Expert Posts: 9,583 ✭✭✭✭✭
    #9
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    Re: help required with home solar system
    niel wrote: »
    facing that northerly direction with the pvs will be a waste of the pv's ability to produce power.


    This means your 1,360W array will produce about 500W. (facing north) in the summer, and nothing in the winter.
    I hope this is not the case, but my west facing 4.5KW array, when the sun is in the east,
    http://www.mike-burgess.org/images/MB_May-3-2007.htm
    only puts out 1KW, till it gets good sun angle around noon, and continues to gain power till 2pm.

    Please have your installer check to see if your panels will get enough sun to make it worthwhile.
    Powerfab top of pole PV mount | Listeroid 6/1 w/st5 gen head | XW6048 inverter/chgr | Iota 48V/15A charger | Morningstar 60A MPPT | 48V, 800A NiFe Battery (in series)| 15, Evergreen 205w "12V" PV array on pole | Midnight ePanel | Grundfos 10 SO5-9 with 3 wire Franklin Electric motor (1/2hp 240V 1ph ) on a timer for 3 hr noontime run - Runs off PV ||
    || Midnight Classic 200 | 10, Evergreen 200w in a 160VOC array ||
    || VEC1093 12V Charger | Maha C401 aa/aaa Charger | SureSine | Sunsaver MPPT 15A

    solar: http://tinyurl.com/LMR-Solar
    gen: http://tinyurl.com/LMR-Lister ,

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  • icarus
    icarus Solar Expert Posts: 5,436 ✭✭✭✭
    #10
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    Re: help required with home solar system

    Hey guys,,,

    He is at 32 degrees SOUTH!

    Changes things a bunch for us northern centric thinkers!

    Tony
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  • niel
    niel Solar Expert Posts: 10,300 ✭✭✭✭
    #11
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    Re: help required with home solar system

    so so sorry as i had missed that. you are good to go with that facing north. thanks for catching that tony.
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  • mike95490
    mike95490 Solar Expert Posts: 9,583 ✭✭✭✭✭
    #12
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    Re: help required with home solar system
    micjones wrote: »
    Probably more north-north west facing than north-west. As I am on lat. 32S, sun angle (noon) in mid-winter 32deg and mid-summer 81deg. Considerable difference, will tilt the panels accordingly. Have also positioned as high as possible on rooftop. But unfortunately due to lack of yard-space, am restricted to positioning on the rooftop.
    Thanx
    mic


    Sorry ! If you come to a NA based forum, where most of the members are in NA, and we think the world revolves around us, and you don't fill out your profile as to where you are from [Canberra?], we assume lat 32 = Texas or Florida. we didn't all see the "s" An honest mistake. Now that my world is upside down, things are starting to make more sense.
    Powerfab top of pole PV mount | Listeroid 6/1 w/st5 gen head | XW6048 inverter/chgr | Iota 48V/15A charger | Morningstar 60A MPPT | 48V, 800A NiFe Battery (in series)| 15, Evergreen 205w "12V" PV array on pole | Midnight ePanel | Grundfos 10 SO5-9 with 3 wire Franklin Electric motor (1/2hp 240V 1ph ) on a timer for 3 hr noontime run - Runs off PV ||
    || Midnight Classic 200 | 10, Evergreen 200w in a 160VOC array ||
    || VEC1093 12V Charger | Maha C401 aa/aaa Charger | SureSine | Sunsaver MPPT 15A

    solar: http://tinyurl.com/LMR-Solar
    gen: http://tinyurl.com/LMR-Lister ,

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  • System2
    System2 Posts: 6,290 admin
    #13
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    Re: help required with home solar system

    Sorry about confusing you all, I should have mentioned that I am living down-under (Western Australia). Will add to my profile.
    I have had a single 85W panel on my rooftop over the past year, operating 12V electric gates, security system which has allowed me to gauge some of the benefits of solar, there is still a much more that I need to learn. (Hopefully, I will be able to learn much more from the experts in this forum).
    Unfortunately, home solar is not as popular as it should be in W. Australia, there are only a handful of installers listed in the telephone directory (on occasions information given locally is contradictory). Although Solar electrical systems here are government rebated (Federal and State Governments encouraging installations), homeowners who install solar electrical systems are often at loggerheads with local councils, who are totally blind to the benefits of solar, and governed by tree huggers, who believe that trees should reach into the heavens, in meagre backyards or close to homes on street verges. (I am not anti-tree, nevertheless the shading situation is of great concern to myself).

    My request:"Please lop 2 to 3 metre from the top of street tree, to allow sunlight for solar electrical system, plans as stated"
    Reply from council: "Your request does not conform to council policy, therefore your request is denied. However the council will prune dead branches from street tree"

    With the recent increases in the price of oil and gas, increasing electricity costs, more people will realise the benefits of solar, let's hope councils change their ideas. It would be good to know what the situation is like in the USA.

    Thanx
    mic
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  • niel
    niel Solar Expert Posts: 10,300 ✭✭✭✭
    #14
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    Re: help required with home solar system

    without being able to top off the trees maybe you could devise a way to get the pvs higher. the direction should be good seeing as how the shade is mostly in the morning hours.
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  • BB.
    BB. Super Moderators, Administrators Posts: 33,439 admin
    #15
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    Re: help required with home solar system
    micjones wrote: »
    With the recent increases in the price of oil and gas, increasing electricity costs, more people will realise the benefits of solar, let's hope councils change their ideas. It would be good to know what the situation is like in the USA.

    In the US--the states (are supposed to) have pretty much all of the power to micromanage/write laws on just about anything--the Federal government (Washington DC/Pres./Congress) are only supposed to write laws that affect state to state issues (commerce, foreign relations, military, etc.).

    So, while it is not always true (creeping control and accumulation of power by the Central/Federal government)--it usually means that anything like solar siting issues, shading, permits, etc. are state and local questions...

    So, with 50 states, there are 5,000 laws affecting 300,000,000 residents.

    So, here is a good place to start--you can look at the east/west coast states for how the more government intensive solutions/laws would look like. And look at the southern US for what a laze-fair attitude would look like.

    http://www.dsireusa.org/

    From the above link, you can look at California for the state of rebates, incentives, and laws around solar / alternative energy systems. For example, state wide "solar property rights:"


    But, just because somebody wrote these laws--it does not mean that things are easy or problems/issues are magically resolved:Solar Panels Vs Trees (Solar won--after six year court battle):
    The law requires homeowners to keep their trees or shrubs from shading more than 10 percent of a neighbor's solar panels between 10 a.m. and 2 p.m., when the sun is strongest. Existing trees that cast shadows when the panels are installed are exempt, but new growth is subject to the law.

    Residents can be fined up to $1,000 a day for violations, though the judge did not impose any fines against the Treanors.
    -Bill
    Near San Francisco California: 3.5kWatt Grid Tied Solar power system+small backup genset
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  • niel
    niel Solar Expert Posts: 10,300 ✭✭✭✭
    #16
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    Re: help required with home solar system

    bill,
    i thought we all realized he is in australia at 23 degrees south. he has no need to see anything about the us government or the states, but i'm sure he has plenty of roadblocks there as we do. the tree issue i guess was one he has to deal with there.
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  • BB.
    BB. Super Moderators, Administrators Posts: 33,439 admin
    #17
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    Re: help required with home solar system

    Niel,

    But he asked for information about what it is like in the states:
    It would be good to know what the situation is like in the USA.

    I assumed he was looking for information from other countries (US in this case) to support changes in laws/attitude/support by his local council.

    -Bill
    Near San Francisco California: 3.5kWatt Grid Tied Solar power system+small backup genset
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  • mike95490
    mike95490 Solar Expert Posts: 9,583 ✭✭✭✭✭
    #18
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    Re: help required with home solar system
    micjones wrote: »
    It would be good to know what the situation is like in the USA.

    Here's a very recent thread about that -
    http://forum.solar-electric.com/showthread.php?t=3069
    Powerfab top of pole PV mount | Listeroid 6/1 w/st5 gen head | XW6048 inverter/chgr | Iota 48V/15A charger | Morningstar 60A MPPT | 48V, 800A NiFe Battery (in series)| 15, Evergreen 205w "12V" PV array on pole | Midnight ePanel | Grundfos 10 SO5-9 with 3 wire Franklin Electric motor (1/2hp 240V 1ph ) on a timer for 3 hr noontime run - Runs off PV ||
    || Midnight Classic 200 | 10, Evergreen 200w in a 160VOC array ||
    || VEC1093 12V Charger | Maha C401 aa/aaa Charger | SureSine | Sunsaver MPPT 15A

    solar: http://tinyurl.com/LMR-Solar
    gen: http://tinyurl.com/LMR-Lister ,

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  • System2
    System2 Posts: 6,290 admin
    #19
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    Re: help required with home solar system

    Thanx BB. That is exactly the case. Appreciate your help.

    At present here, there is zero local council legislation regarding home-owner solar installations and protection thereof.

    As we are pensioners on a tight, fixed income, solar is indeed the best option to lessen the effect of ever increasing household electricity costs.

    As there is a great deal of resistance to home solar installations from local council (increased workload). I need to gather as much information, especially from the USA, where solar is far more popular, in order to present my case and protect my investment.

    Thanx
    mic
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  • BB.
    BB. Super Moderators, Administrators Posts: 33,439 admin
    #20
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    Re: help required with home solar system

    Mic,

    You (and your council) are probably between a rock and a hard place...

    Solar Electric Power (even Grid Tied--without batteries) is not cheap and it really does not generate than much power for the price.

    So, for your council to cut trees (for hundreds, if not thousands of dollars) so you can collect a few tens of dollars of extra power, is a hard sell...

    Even though I have Grid Tied Solar and I am happy to have it--There will be a very long time before it makes true economic sense for me.

    In the end, controlling your power use through conservation (insulation, double pane windows, energy efficient lights and appliances) is usually the best place to start.

    And addressing your heavy power consumers... Replacing a furnace or hot water heater if old and/or inefficient. Using solar thermal for hot water / space heating rather than electric heat is usually a big winner (if you don't have natural gas or other inexpensive heating fuel source).

    Obviously, I don't know your costs or your living requirements (use A/C?) or your utility billing practices (we have tiered rates--the more power you use, the higher rate you pay; also, we have Time Of Use metering available--if we can not use power during summer afternoons or use solar PV to generate during this time, and only use utility power off-peak, we can save another 20% on our bill).

    Being down in Australia, you don't have access to some of the cheaper, mass marketed equipment (Energy Star Appliances, Kill-A-Watt meter to measure individual loads), and many such items (including solar) are more expensive there.

    You can make do with substitutions (such as for the kill-a-watt meter, I got an old electric utility meter and bought a socket for it to wire into an extension cord--and I used it to measure my kWhrs per month for larger equipment).

    In the end, don't fall in love with a solution--do the research and work the numbers (a spreadsheet can be handy) and see what makes economic sense for you and your home. And conservation is a powerful tool... For every watt you save--that is a life time you will never have to buy a watt*hour or pay for solar to generate it.

    -Bill
    Near San Francisco California: 3.5kWatt Grid Tied Solar power system+small backup genset
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