How to choose a better solar panel?

bobby, linbobby, lin Registered Users Posts: 8
It is my first time to purchase solar panel and need your help or recommendation.

Is there anything I should pay special attention to?

such as safety, price, quality,etc.

Comments

  • BB.BB. Super Moderators, Administrators Posts: 29,523 admin
    Re: How to choose a better solar panel?

    I guess you are in Taiwan...

    It is very difficult to know these days what company(ies) is making reasonably reliable solar panels these days. Some of the major companies have the history of providing support for their products... But even good companies have been known to turn out bad panels at times.

    In general, if you want panels that will last a long time. Suggest that you get glass panels with crystalline (mono or poly) cells.

    Plastic/flexible panels many times will only last a few years.

    Thin film panels typically only last 5-10 years (although, there are newer panels that should have better life).

    In the US/North America, we usually look for NRTL (National Recognized Testing Labratories) approved panels (Like UL/Underwriters Laboratories, ETL, TUV, etc.). These panels should be marked with the NRTL mark. NRTL testing is expensive (>$50,000 USD last I read a few years ago)--So any company that takes the time an money to do the tests is usually a serious manufacturer. NRTL testing does not really mean the product is "good quality"--But for solar panels, part of the testing is testing in harsh conditions--So if the panel pasts the testing, there is a good chance it is a good panel.

    CE (European) mark usually does not mean too much.

    Otherwise, you need to pay attention to the Vmp and Imp of the panel (to match that to your battery / controller combination). There are several rules/conditions you need to check to ensure that everything plays well together.

    My recommendation:
    1. Measure your loads (and conservation--For solar power it is almost always cheaper to conserve than to generate power)
    2. Design the battery bank based on your loads (Watt*Hours per day, peak Watts, battery bank voltage, etc.).
    3. Define the solar array wattage based on size of battery bank.
    4. Define the solar array wattage based on Watt*Hours per day load and minimum sun (compare 3/4 to pick "optimum array")
    5. Start picking hardware that will support your above design (do several designs, confirm meet requirements and costs).

    -Bill
    Near San Francisco California: 3.5kWatt Grid Tied Solar power system+small backup genset
  • bobby, linbobby, lin Registered Users Posts: 8
    Re: How to choose a better solar panel?

    I like to know how you know I am from Taiwan, is it my poor grammar shows you that? hahaha

    Thank you for your suggestions and I think I should evaluate many things and investigate before buying it.
  • nielniel Solar Expert Posts: 10,311 ✭✭✭✭
    Re: How to choose a better solar panel?

    he can see and look up your ip address.
  • BB.BB. Super Moderators, Administrators Posts: 29,523 admin
    Re: How to choose a better solar panel?

    The sad part is from my poor English grammar, you can tell I am from the US. :p:roll:

    -Bill
    Near San Francisco California: 3.5kWatt Grid Tied Solar power system+small backup genset
  • bobby, linbobby, lin Registered Users Posts: 8
    Re: How to choose a better solar panel?

    i see, but how do u know Taiwan, i thought Taiwan is not that famous.
  • bobby, linbobby, lin Registered Users Posts: 8
    Re: How to choose a better solar panel?

    haha sorry for my poor grammar, where do u learn about Taiwan, Jeremy Lin? or Taiwan student protest on CNN news.
  • BB.BB. Super Moderators, Administrators Posts: 29,523 admin
    Re: How to choose a better solar panel?

    My wife is from Taipei.

    Google Translate is the extent of my foreign language skills.

    谷歌翻譯是我的外語能力的程度。

    -Bill
    Near San Francisco California: 3.5kWatt Grid Tied Solar power system+small backup genset
  • bobby, linbobby, lin Registered Users Posts: 8
    Re: How to choose a better solar panel?

    what a small world, so do u came to Taiwan before? i wish i can go to California too
  • BB.BB. Super Moderators, Administrators Posts: 29,523 admin
    Re: How to choose a better solar panel?

    Been there a 1/2 dozen time over the ~30 years.

    -Bill
    Near San Francisco California: 3.5kWatt Grid Tied Solar power system+small backup genset
  • South AfricaSouth Africa Solar Expert Posts: 295 ✭✭✭
    Re: How to choose a better solar panel?

    My 2 cents.

    I have learned do not buy X panels now with a plan to buy the rest later.

    Turns out that the chances are there that the exact panels may not be available when you have the cash to buy more. And mixing and matching, although it is sometimes ok, can cause a lot of headaches and spare parts. And trust me, once you go for solar, you need space to move for you are going to like ti so much that you want more. :-)

    And panels are getting better and better. More amps for your buck.

    Have also learned, once you have decided what you want to do, get the controller and match the panels to it, not like I did, get the panels and then try and match controllers to them.

    Good idea, for me at least, if you want moving space into the future, get a controller that can take a higher than 24v array, yet can step down to charge a 24v system. They inevitably can go 24v array / 24v battery or 48v array, 48v battery also.

    On the batteries. Try and steer clear of 12v, go 24v or 48v. Only negative with 48v are that batteries are double 24v.

    Moral of the story, in my opinion, leave yourself room to move: The key to that is the controller you get.
  • ILFEILFE Solar Expert Posts: 364 ✭✭
    Re: How to choose a better solar panel?

    Currently, I believe Yingli (Chinese) is the largest manufacturer / distributor of solar panels in the world. They seem to have a pretty good reputation, and have always communicated well whenever I had any questions. I will be buying from them at some point in the future.

    However, I currently use (exclusively), Just Solar monocrystalline panels, also made in China. I am pleased with their performance. (I live in Cambodia and Just Solar panels are commonly sold here.) I have experienced similar communications with Just Solar representatives.

    Either would not be very far to ship to Taiwan, if they are not already sold in Taiwan.


    Off-Topic: If the staff look at my (Dynamic) IP address, my current internet provider will show me as being in Phnom Penh, Cambodia. I am actually in Battambang. At other times, it will show me as being in Hanoi, or HCMC, Vietnam. I have yet to visit Vietnam. Gotta love modern technology. :roll:
    Paul
  • BB.BB. Super Moderators, Administrators Posts: 29,523 admin
    Re: How to choose a better solar panel?

    This is what "IP Addresses" can tell us. For Paul's:

    http://whois.domaintools.com
    inetnum: 42.115.32.0 - 42.115.47.255
    netname: FPTDYNAMICIP-NET
    country: vn
    descr: FPT Telecom Company
    descr: 2nd floor FPT Building, Pham Hung Road, Cau Giay District, Hanoi



    And one of the "geolocation" sites:

    http://www.geobytes.com/IpLocator.htm
    Phnum Penh, Cambodia

    It is not 100%, but usually good enough for one of us moderators to "help" with initial estimates on amounts of sun and where your "local" solar products suppliers may be.

    Of course, there are "proxies"--Sometimes company networking standards (AOL, satellite services, mobile browser like Opera), sometimes folks trying to hide their locations or get around Spammer IP Range blocks.

    -Bill
    Near San Francisco California: 3.5kWatt Grid Tied Solar power system+small backup genset
  • South AfricaSouth Africa Solar Expert Posts: 295 ✭✭✭
    Re: How to choose a better solar panel?
    ILFE wrote: »
    Currently, I believe Yingli (Chinese) is the largest manufacturer / distributor of solar panels in the world. They seem to have a pretty good reputation, and have always communicated well whenever I had any questions. I will be buying from them at some point in the future.

    I google them, and lo and behold, their 310w panels are the closest match I have seen to date to my 310w Tenesol panels!
    And, seems to me they have signed a deal with SA: http://www.reuters.com/article/2010/11/17/ozatp-safrica-yingli-idAFJOE6AG0G720101117

    Now the next trick, to see if I can get them close to my IP address: 105.237.86.162 Then I do not have to sell and re-purchase, can just add.
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