Not sure about upgrading set up

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firerescue712
firerescue712 Solar Expert Posts: 95 ✭✭
in Solar Beginners Corner #1
I am fiarly new to solar. This forum is a terrific place for information. There are several here who excel in knowledge. I need some advice. I have four sets of the 45-watt Harbor Freight panels. There are three panels per set. I know...Harbor Freight (yucky). I am a noob and was lured by the sale ads and local availability. Now, i want to upgrade to better panels, but keep the HF ones for a while. The HF sets are wired with the three panels in the set in parallel. They are set up with a Rogue 3024 running 12-v to a 12-v battery bank. I am ready to move up to 24-v for future off grid uses. Can i take two set (3-panels in parallel at 12-v) and run the lead wire from one set to another set via positive to negative and safely make the two sets a 24-volt system? Or would i need to cut all the panels loose and wire only two panels in series? Also, it seems I would have to buy a 24-v panel that is putting our 35-v vmp +/- 10% to tie in with the current HF sets? Thank you for your inputs.
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  • Cariboocoot
    Cariboocoot Banned Posts: 17,615 ✭✭✭
    #2
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    Re: Not sure about upgrading set up

    If you have three low-power panels in parallel you can wire that group in series with three more of the same in another group. Essentially each group of three "behaves" as one larger panel, with the same Vmp as an individual panel but 3X the Imp. You can not wire only one of these panels in series with three others that are in parallel: the Imp difference will be a problem.

    I wouldn't be too keen on mixing the HF panels with other types, as it seems their specifications are bit "optimistic" compared to the reality of their output. In other words I wouldn't trust their Vmp & Imp rating to be accurate.
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  • firerescue712
    firerescue712 Solar Expert Posts: 95 ✭✭
    #3
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    Re: Not sure about upgrading set up

    Thank you for the quick reply. I was thinking the same, but wanted an expert opinion. I guess a Morningstar MPPT for the cheapos, and let the Rodue run the new ones. I am leaning towards the Kyocera KD-235GX from Arizona Wind & Sun. I am constantly checking for new threads and responses on the forum. I have seen you recommend Kyocera, so I know they are a good brand to use. I will series the HF sets of 3 paralelled to give 24v. I was thinking the HF specs, although not accurate, at 24v would run about the same as the Suntech STP280-24-VD. I wish I would have found this forum before I got into the HF panels. Again, thank you.
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  • Cariboocoot
    Cariboocoot Banned Posts: 17,615 ✭✭✭
    #4
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    Re: Not sure about upgrading set up

    Now we get in to the fine details.

    I wouldn't bother spending the money on an MPPT controller for 180 Watts of HF panels. If you want to keep them in the mix, use an inexpensive PWM controller. It is unlikely they'll produce more than a few Amps of current (180 / 24 = 7.5) so attaching them to a controller capable of handling 45 or 60 Amps is a waste of money. All these panels together add up to barely one "real" panel.

    Another thing is that the Vmp on the Kyocera 235 is only 29.8 Volts. You will have to put at least two in series and run them through an MPPT controller in order to have enough Voltage to charge a 24 Volt system. In this configuration their Voc will be too high for the Rogue controller.

    And here we have another lesson in how hard it is to expand a system. :cry:
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  • garlic
    garlic Solar Expert Posts: 43 ✭
    #5
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    Re: Not sure about upgrading set up

    "I guess a Morningstar MPPT for the cheapos"

    A $20 saddle on a $5 horse IMO.How about instead,wire the hf panels
    in 6 pairs connected together in series and the whole lot wired in parallel
    feeding into a Morningstar SunSaver 20?You'd save $100 on the controller
    that would buy you well into a nice panel for your Rogue.After a year you
    wont get more than 2 amps per set of three hf panels anyway,and then
    if you came across a good deal on an odd 24v panel you could add it to
    the pwm array without the worry of mixing panels on a mppt conroller.

    I have a c35 set up just for the purpose of using orphan panels,while
    my tristar mppt 45 is the main bread winner.
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  • firerescue712
    firerescue712 Solar Expert Posts: 95 ✭✭
    #6
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    Re: Not sure about upgrading set up

    So it is best to start with a seperate set up. For setting up all 120-volt circuits in a residence for off grid, and leaving the 220 on grid, what configuration would you use? 24v? 48v? Why? What panels? What Controller(s)? I want to use agm for simplicity. What brand and size? I am taking it all in, so let me have it. Thanks, guys.

    I know the number of panels and batterues will be determined by the load, just need your input as to the equipment to build this system on.
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  • firerescue712
    firerescue712 Solar Expert Posts: 95 ✭✭
    #7
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    Re: Not sure about upgrading set up

    I missed the set up equation....120 v for the battery system, with the 220v tied to the grid. I do not plan on tying to the grid at all. I just want separate power systems for the different voltages. After a few years, i want to go completely off grid. I live in the boonies of Arkansas. Occassionally you can hear the dueling banjos long the river bank.
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  • garlic
    garlic Solar Expert Posts: 43 ✭
    #8
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    Re: Not sure about upgrading set up

    the higher the system voltage you use the less copper you have to buy,and
    the less power you turn into heat through voltage drops.I like a 24v system
    because of there are a greater variety of inverters available,it's a good
    compromise between a 12 and 48 volt system that is 2500watts or less.

    AGM might be more simple,but flooded lead acid will last longer,is cheaper,
    and you have a hands on interaction with your storage that is to the benefit
    of both your knowledge and batteries.I've been into Crown batteries as of late,
    after a bad run of Trojans.GC2 golf cart size is the best bang for the buck till you
    start hitting the $4000 mark then industrial batteries that last 20+ years start kicking in.

    Outback,Midnite Solar,Rogue,and Morningstar all make excellent controllers.
    The larger you go,the more you can grow.Between my C35 and mppt 45 I
    have around 2300 watts of panel potential at 24v.

    Panels,buy a reputable brand,buy what you can afford,or somewhere
    between;) Those Kyocera panels would do nicely.

    Your 240 loads are going to be either some form of heat or water pumping.
    the heat part you can switch to propane,wood,or solar.I do all three.As for water
    pumping there is many variables depending on your terrain and situation.

    "Occassionally you can hear the dueling banjos long the river bank. "

    I'm a backwoods boy that is off grid and I'm a logger so I don't have to go to town very often,so I know where you're headed.
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  • Cariboocoot
    Cariboocoot Banned Posts: 17,615 ✭✭✭
    #9
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    Re: Not sure about upgrading set up

    As always it comes down to loads. First you determine how much power you need, then you find the way to supply it.

    In this case you're looking at about household worth of kilowatt hours, so you're likely to want a 48 Volt system. If it were small scale off-grid cabin, maybe not. Not sure why you want to go off-grid anyway, as it is nearly always much more expensive than utility power (usually by a factor of 10).

    As for doing the 120 VAC circuits first ... Most households have 240 VAC split to two 120 legs. Supplying one side only or putting both sides together is probably not a good idea. Coming up with "low Wattage" 240 VAC is not that difficult, as both Xantrex and Magnum make 240 VAC inverters and now so does Outback (Radian).

    Figure out what you want to do before you do anything. That includes both short-term and long-term. You'll need numbers for kW hours and maximum Watts and a darn good justification for spending the money it will cost to get them.

    You've already had a taste of the problems of starting small and trying to expand later. Nearly always you end up scraping everything and starting over instead.

    As for hearing banjos .... unless the bears start taking music lessons I guess I'm safe from that.
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  • firerescue712
    firerescue712 Solar Expert Posts: 95 ✭✭
    #10
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    Re: Not sure about upgrading set up

    Thank you, thank you, thank you. I finally too the plunge. I added a Trina 185w module to my HF kits. WOW!!! It makes the HF kits look like they are not even running. I am SO glad for all of you that share your vast knowledge. As time goes on, I presume the urge will overtake me again and another upgrade will occur. The Train is on sale for $309. I could not turn that down. I was just a tad over $500 with shipping and an adapter cord so it would wire into my current configuration. I am looking into buying cheap 6v gc batteries to venture into the 24v battery bank. I have 12v run throughout the house powering the modems, routers, fire department scanners, LED lights that replaced the night lights. It is so good to know the lights will always be on. Now, I want to get like the rest of you and cut the electric usage and build a system to become greener and more self reliant. Again, thank you all for sharing your ideas and knowledge.
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  • Cariboocoot
    Cariboocoot Banned Posts: 17,615 ✭✭✭
    #11
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    Re: Not sure about upgrading set up

    Good to see your next solar adventure was a happy one. It's so easy for it to go the other way. :roll:

    Just have to say the reason I have an off-grid system is because the nearest electric lines are fifteen miles down the road. It's hard to beat BC Hydro's $0.10 per kwh. The per kwh power cost for my system (based on purchase price and expected longevity) is about 15 times that. :cry:
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  • Gregmik
    Gregmik Registered Users Posts: 19 ✭
    #12
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    Re: Not sure about upgrading set up
    firerescue712 wrote: »
    . The Train is on sale for $309. I could not turn that down. I was just a tad over $500 with shipping and an adapter cord so it would wire into my current configuration.

    If you would not mind my asking, where did you find them on sale?

    Thanks,
    Greg
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  • firerescue712
    firerescue712 Solar Expert Posts: 95 ✭✭
    #13
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    Re: Not sure about upgrading set up

    It was not bought from NAWS. Can I post the distributor? NAWS does not sell Trina modules.

    Cariboocoot, thank you for explaining why your are off grid. Although we have power at the house, it sure would be nice to have everything on the battery bank when the power is out. I have a 20kw Generac, but it would be cheaper and wiser to make the propane last longer for the larger electric appliances. We changed all our lighting over to fluorescent a few years back, and are now changing over to LED. Our electric bill shows our usage is going down. I am on the local volunteer fire department. We had a major ice storm in 2009. No one had power for 7-10 days. I want to set my house up as the neighborhood emergency shelter. We live in the country 10 miles from the town. Very rural and very densely populated. Again, your advice is always welcome and valued.
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  • Cariboocoot
    Cariboocoot Banned Posts: 17,615 ✭✭✭
    #14
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    Re: Not sure about upgrading set up
    firerescue712 wrote: »
    It was not bought from NAWS. Can I post the distributor? NAWS does not sell Trina modules.

    Yes that would be all right. And good of you to ask first. :D

    Been through a couple of ice storms myself. Misery when all power is out everywhere for weeks. Makes you think about just how electric-dependent most folks are.

    Emergency power is one thing: you have to know that's going to cost a lot.
    Going off-grid because it will "save money on the electric bill" is sheer folly. :roll:
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  • firerescue712
    firerescue712 Solar Expert Posts: 95 ✭✭
    #15
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    Re: Not sure about upgrading set up

    I guess I worded that wrong. I want to free myselp for total reliance upon the electric cooperative. At least be able to run self sufficient for a few days in case we have the "big one" when the earth starts to shake. Here is where the module is on sale... http://www.oynot.com/trina185wattsolarmodule.html.

    You opened my eyes and showed me there is life beyond Harbor Freight. Now, I am contemplating selling all my HF panels and replacing them with 6-7 of the Trina panels. Again, thank you.
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