Solar Panels

Zakarume

I know everyone has there favorites, but what i am looking for is a good 24v solar panel between 200 - 250 watts. I dont want an expensive panel nor do i want a cheap panel. Want to stay around a mid range price. I heard Kyocera panels are good

BB.

Re: Solar Panels

Kyocera has good panels and when there was a problem many years ago, they stood behind their warranty.

Regarding the panels... Are you looking for Vmp~35-40 volts (true "24 volt panels" for charging batteries) or the "GT Solar" type that are usually around Vmp~30 volts or so?

In the end, there are few "true" 24 panel out there. You end up (usually) with a choice of Vmp~30 volts (at roughly $1.00 per watt), or Vmp~17.5/35.0 volt panel at near ~$2+/- per Watt.

Today, as Marc/Cariboocoot will point out, many times you are better off with "cheap" GT panels and a good quality MPPT controller vs "expensive" "12/24 volt panels for battery system" and a "cheap" PWM controller.

Also--If you are adding panels later--Many times it is easier to find Vmp~30 volt (60 cell, or sometimes 72 cell) panels to add to your system later. It has been difficult to find cost effective true 12/24 volt panels to match with your existing array.

-Bill

Zakarume

Re: Solar Panels

Looking for a good 24v for battery charging and also the panel that the Midnite Kid CC i have now will handle. If it helps i was looking at this http://www.solar-electric.com/solar-panels-mounts-kits-accessories/solarpanels/kyocera-solar-panels/kyocera-kd250gx-lfb-250-watt-polycrystalline-solar-panel.html

Photowhit

Re: Solar Panels

That panel is not designed for 24v charging. If you want to use the new panel with your old panels. you will want to use 2 of the 100 watt 12 v (nominal) panels in series with the new panel. Most true 24 volt panels, made currently, are in the 250+ watt range. This has to do with them having 72 cells vs the 60 cells in panels like the one you linked to.

Your looking for panels that the VMP is within 10% of 2 of your 12 volt panels in series, 2x their VMP.

Zakarume

Re: Solar Panels

I will be eventually getting rid of my 12v panels. And hopefully installing 24v panels for charging batteries. But first need to get someone over to look at my roof first and see what needs to be done to be able to put theses panels up there. I am just jumping ahead first and looking first for panels

ZoNiE

Re: Solar Panels

Just get good low cost GT panels and spend the money on a good MPPT charger. JWID.

Photowhit

Re: Solar Panels

Zakarume wrote: »

I will be eventually getting rid of my 12v panels. And hopefully installing 24v panels for charging batteries. But first need to get someone over to look at my roof first and see what needs to be done to be able to put theses panels up there. I am just jumping ahead first and looking first for panels

Just understand that you will need strings of 2 or 3 of those panels you linked to, to charge 24 volt battery bank.

zoneblue

Re: Solar Panels

Youll be doing yourself and other newbies around here a favour if you avoid the phrase 12/24v panels. PV are current generators, their voltage has little bearing on what they do. A better way to reference PV panels is by their Vmp, or their number of cells.

If you want a module that will charge a 24V battery using PWM, then you need a 72 cell panel. These are almost without exception in the 300W range. They are becoming more common, and more or less price equiv to 60 cell panels. The downside is freight wise they are unweildy.

There are also now some exotic modules appearing in odd Vmps.

Photowhit

Re: Solar Panels

zoneblue wrote: »

Youll be doing yourself and other newbies around here a favour if you avoid the phrase 12/24v panels. PV are current generators, their voltage has little bearing on what they do. A better way to reference PV panels is by their Vmp, or their number of cells.

If you want a module that will charge a 24V battery using PWM, then you need a 72 cell panel. These are almost without exception in the 300W range. They are becoming more common, and more or less price equiv to 60 cell panels. The downside is freight wise they are unweildy.

I would just like people to use the phrase correctly. I'm pretty frustrated with Zakarume since he actually asked for them correctly, since he would be able to use them with his 100 watt panels with little loss, then says he'll switch to all these so he acts like it doesn't matter. But of course he's on a budget, and this will all take time. I've actually explained this several times and even found him a local source.

FWIW - there have been 24 volt nominal panels made in many sizes over the years, It has more to do with the larger sizes of cells they are making now, I have some Suntech 24 volt nominal panels in my closet now that are Suntech STP 185 watt, made just 3-4 years ago. There are Topoint 190 watt panels available from NAWS that are true 24 volt panels. They are out there...

Zakarume

Re: Solar Panels

Sorry but i am getting alot of confusing answers. Just FYI i now have the Midnite Kid Charge Controller. When i am finally done with system i would like to have anywhere from 800 - 1000 watts of solar and be able to charge a 24v battery bank. Some of you are saying get cheap panels and but good MPPT. Some are saying get the true 24v 72 cell panel and a PWM Charge Controller. I just want a good panel to be able to charge the battery bank with the KID

Zakarume

Re: Solar Panels

Photowhit wrote: »

I would just like people to use the phrase correctly. I'm pretty frustrated with Zakarume since he actually asked for them correctly, since he would be able to use them with his 100 watt panels with little loss, then says he'll switch to all these so he acts like it doesn't matter. But of course he's on a budget, and this will all take time. I've actually explained this several times and even found him a local source.

FWIW - there have been 24 volt nominal panels made in many sizes over the years, It has more to do with the larger sizes of cells they are making now, I have some Suntech 24 volt nominal panels in my closet now that are Suntech STP 185 watt, made just 3-4 years ago. There are Topoint 190 watt panels available from NAWS that are true 24 volt panels. They are out there...

I am still learning. you dont need to bash on someone that is still learning

Cariboocoot

Re: Solar Panels

Generic terms and cell counts do not matter. Specifications matter.

The array configuration has to have high enough Voltage to charge the batteries. For a 24 Volt system this means an array Vmp of 35 or more, higher Voltages needed for overcoming wiring losses. The array must also produce sufficient current to charge the batteries.

PWM type controllers limit array configuration to the 'primary' Vmp, and the current is merely Imp * the number of parallel connections.

MPPT type controllers increase the array configuration possibilities because as long as the array Vmp is high enough the power output is a function of the array Watts.

Basic explanation: http://forum.solar-electric.com/showthread.php?16241-Different-Panel-Configurations-on-an-MPPT-Controller

Zakarume

Re: Solar Panels

ok so going with http://www.solar-electric.com/solar-panels-mounts-kits-accessories/solarpanels/topoint-solar-panels/topoint-jtm-190-72m-solar-module.html. Would be good?

Photowhit

Re: Solar Panels

Zakarume wrote: »

ok so going with http://www.solar-electric.com/solar-panels-mounts-kits-accessories/solarpanels/topoint-solar-panels/topoint-jtm-190-72m-solar-module.html. Would be good?

To expand on what 'Coot said, the problem with going with the often cheaper, lower voltage(22-31 volt), panels is you will need 2 of them to reach the charging voltage for a 24 volt system.

You could use the panel you linked to this time with the 4 panels you have now, you would need to run the 4 panels you have now in strings of 2 so that their voltage matches the 24 volt panel you linked to. It will not be exact, but they will work fine and give you very close to the maximum output from all the panels, old and new.

This is a forum, I might be 'bashing' a little bit, but I believe I have repeated the point, and provided links to other learning material, to the extent that this should be basic information at this point.

Cariboocoot

Re: Solar Panels

Yes: their Vmp is 36.5 so it is sufficient for a 24 Volt system as-is.

How many you need would depend on the battery bank capacity. For example the Imp is 5.2, so if the batteries are 220 Amp hours and you want roughly 20 Amps you need four such panels (4 * 5.2 = 20.8 ). The actual current output expected on an MPPT controller would be (4 * 190 * 0.77 / 24) 24 Amps. They could be configured as all four in parallel (fuse or breaker per panel), or two parallel strings of two in series (no fuse or breakers needed). The output would be the same.

Photowhit

Re: Solar Panels

Please note that you are framing a choice here. You can go with the lower voltage panels and they are likely to be more available, but as I said you would need 2 of them now to add to your system, and you would largely want to sell the current 100 watt panels now, you could get some effective increase by using them in a string of 3 or 4, but it would likely NOT be an effective use of them.

I think I would check with the guy in Springfield, I think I sent you a link in the past, something odd like he's in Springfield but posted in Kansas City's Craigslist. Shipping will be a very large expense for single panels! and he was reasonable in price.

Zakarume

Re: Solar Panels

I eventually want to get rid of the 100 watt panels. I am thinking ahead on getting new panels. panel i kinda have in mind right now. Is to get 2 http://www.solar-electric.com/solar-panels-mounts-kits-accessories/solarpanels/topoint-solar-panels/topoint-jtm-190-72m-solar-module.html. For now. Get 2 at later date, probably after taxes next year and maybe 1 more. Total of 5 panels. Just checked on the Midnite Kid Sizing. Running 4 panels (http://www.solar-electric.com/solar-panels-mounts-kits-accessories/solarpanels/topoint-solar-panels/topoint-jtm-190-72m-solar-module.html) in parellel is good. 5th panel would make wattage be high

Mountain Don

Re: Solar Panels

FWIW, I believe it is best to hold off on the purchases until everything can be bought at once. That way you won't run into having to find a panel to match up when the ones you bought first are discontinued. I've also seen a few people who started buying pieces spread over time changing their system design and having items that did not fit well into the newly redesigned system. It's only my conservative approach opinion, but until one can buy the whole enchilada at one fell swoop, I think the money is better left in the bank until that day arrives.

Photowhit

Re: Solar Panels

MDon has a pretty good idea, You understand that, if there is nothing wrong with your 100 watt panels they will work with the 2-190 watt panels to give you close to a 800 watt array? They should match up nicely as 2 strings of 2 panels.

zoneblue

Re: Solar Panels

Zakarume wrote: »

Sorry but i am getting alot of confusing answers. Just FYI i now have the Midnite Kid Charge Controller. When i am finally done with system i would like to have anywhere from 800 - 1000 watts of solar and be able to charge a 24v battery bank. Some of you are saying get cheap panels and but good MPPT. Some are saying get the true 24v 72 cell panel and a PWM Charge Controller. I just want a good panel to be able to charge the battery bank with the KID

Assuming quality is there, then the cheap panels are the best ones! You asked for 24v panels so i assumed you were using PWM. If you have a kid, then that gives you lots more flexibility. With mppt you ideally want about twice the battery voltage as the array Vmp. That gives teh best result, but the fact is that a good mppt controller like the kid will likely run ok at anything from maybe 6 volts over the battery voltage right up to the Voc max. Check out the Kid string calculator, for workable combos.

DavidsOM

Better a few 100+ watt solar panels HQST ​​or RockPals, for example https://solwiser.com/am-solar-panel-reviews/  (I think to buy myself these panels).They could be configured as two parallel. That gives best result, or I'm wrong?

BB.

DavidsOM,

You really need to look at what the overall energy needs and system design requirements.

What you are looking at (solar panels vs portable solar panels) are just two wildly different products. One is (usually) permanently mounted to a roof/rack mounts. They tend to have thin tempered glass over panels--Which are pretty strong until you scratch with something sharp or bump up a against a rock--then the shatter into a thousand pieces (the cover glass). The panel then allows water in and flexing of solar cells/wiring--And they are usually destined for the trash can.

The folding RockPals panels--They look fine--But are not intended to be permanently mounted on a roof/racking, and if you did, the "soft materials" will not last very long in full sun/UV.

It also matters what your battery bank (voltage, AH rating) and what type of solar charge controller (PWM or MPPT) you want to use.

Smaller panels tend to run (very roughly) around $1-$2+ per Watt, and larger panels (>200 Watts) tend to run $0.50 to $1.00 per Watt (note smaller panels can be cheaper to package and ship... Larger panels, when ordering 1 or 2 panels, can cost more to package and ship than the panels themselves cost).

I highly suggest that you start from the beginning--How much power do you need (AH @ volts; Watt*Hours per day), roughly where the system will be installed (hours of sun per day), and your overall expectations (home, cabin, RV, camping, hiking, etc.).

You are very welcome to start a new discussion/thread of your own (in Beginner's forum) and we can talk about your system/needs specifically.

-Bill

mike_s

@DavidsOM @BB.

Do you guys realize you're adding to a 7 year old thread?

BB.

I do... Why I suggested our new member start a new thread addressing his questions and system design.

New folks do not always feel "comfortable" starting a new thread. And I then suggest that everyone start new threads for their Q&A--It keeps the discussion focused on their needs vs possibly confusing the Q&A of the original poster.

-Bill