Are mono panels significantly better than Poly for the price?

[THECHEMICALS]

I bought a 15 watt solar panel to start experimenting with solar energy (+solar charger, inverter, marine deep cycle 160resere amp). It took about 2 weeks to fully charge my 160amp battery which i didnt use at all, just took it home and installed it to the panel/charger. Im guessing it was drained from the store. I orderer a 2nd panel 15 watt to have a total of 30watts.<br><br>My question is if Mono are significantly better than poly. I researched them both fully and the numbers all show mono being better but is it really? *For the price you pay for a mono being 30-60 more than a poly of the same wattage?<br><br>Seems to me like&nbsp;mono could just be an "on paper" winner over poly, and that both function about the same. Ive heard as much as 10% better power than a poly but thats jut 10 cents on a dollar if you understand what im trying to get at here. <br><br>The same problem happened to me a few years back when ddr2 ram for computers were said to be obsolete versus ddr3 ram so i went ahead and got me the newest ram and guess what.....the difference was hardly noticeable-- im thinking this be might the same isue with mono and poly and even amorphous.<br><br>Anyone have experience with different panel types?<br>

 

[Simran]

I've been researching the same comparison. What I've been able to come up with is that, more than anything, mono-crystalline panels will last longer and are more rugged as well. <br>Using my van the way I do (for work &amp; living; I work on a lot of rural country roads and frequent fields and wooded trails); I'm leaning toward the mono variety.<br>I think your argument concerning output is a valid one, however, I've made my decision based on the other variables above.<br><br>gus<br>

 

[akrvbob]

I haven't directly compared them, but I am of the opinion that the difference is mainly theoretical. I'd buy whichever I could get the cheapest. However, there is a huge difference between them and the amorphous panels. I wouldn't want one unless it was given to me for free. Bob<br>

 

[slakrboy]

A general rule of thumb is 1 watt for every 1 AH of the battery.&nbsp; While this is not necessarily true for every case, it is a good starting point.&nbsp; A better measure of power is a watt (thats why the power companies charge you by watt hour or Kilowatt hour.)<br /><br />A 15 watt solar panel can put out a maximum of 15 watts, under perfect conditions.&nbsp; Your 160 AH battery can store approximately 2000 watts, about 1000 of which are usable.&nbsp; Divide 1000 by 15 and you get 66 hours of daylight to charge.&nbsp; Since there are approx. 12 hours of sunlight, it would take 5 and a half days to charge a "dead" battery. <br /><br />In order to have a system that is really useable, you want to have enough wattage in the panels to charge your battery in one day, plus maybe a little extra.<br /><br />Every system is different however, and YMMV.<br /><br />Back to your original question: Mono or Poly (or even Amorphous).&nbsp; Mono crystaline panels are more efficient by 5-10% (depends on panels) but also more expensive (work a little better in non-perfect conditions).&nbsp; Polycrystaline panels use the same technology as mono, but the solar cell is made of different crystal wafers instead of cut from one, and they are not as efficient but they are cheaper.&nbsp; Keep in mind that us under perfect conditions.&nbsp; In general (again depends on brand) mono panels are smaller.<br /><br />Hope this helps

 

[SoulRaven]

When talking solar panels and living off the grid you will need a 160-200W panel with at least a good set of Trojan 6V batteries... as for mono and poly, like Bob said buy the best value available to you... do not forget the needed MPPT controller to handle you wattage of the panels you bought...

 

[Simran]

slakrboy,<br />Thanks for putting up some technical data on the subject. I stil haven't made a decision on panels as it is a significant investment.<br />I havve around 280 amp hours of AGM batteries in my van. I'm leaning towards the mono variety as I've just installed a 12V refrigerator with a freezer in my van and will need to squeak out all the charging power I can muster.<br /><br />This refer would not work for everyone but will work good for me as I use my van at work everyday and will do much of the charging with the alternator. My van probably runs an average of 3 hours in the course of a normal work day. The refrigerator is made by Norcold for the trucking industry and says Volvo all over it; but that's another thread.<br /><br />Anyway, the guideline you have laid out here will go along way toward figuring out what size panels will work well for my situation.<br /><br />gus