John Sheridan
Member
Have been looking for some and seem to be as cheap as 200 to 400 plus for a 200 watt panel.
Would like to get at least 6 of them maybe 12, but have no real idea what brand would be best or what price to pay.
Also no idea what wattage is the best value for money, 100,150,200,250,300, best nage for buck.
At this pint in time whats going on.
Thanks.
Get 260watt 37V with a FM80 regulator.
Or if you want to run one 600volt string. Get the new schneider regulator. And run 12panels in one string.
Yeah, why 12volt?
John Sheridan
Member
Because 12 volt is best.
Bushwalker
Member
And '12 volt is best' because???
Oilburner
Member
I am looking for some odd panels to muck around with and I don't recall seeing any 12V specifically. They are all 18v or something above 12v Which you would need if trying to charge a 12 V system which would require up to 15V to charge properly.
Wouldn't matter much what the output was, you just use a regulator/ inverter that takes whatever voltage and rectifys it to the output you want. Higher volts are converted to higher amps. It all works on watts not volts anyway.
Is 12V just a terminology for lower voltage panels or do they make them specifically in 12V?
Lance
Key Master
Standard 12V panels have a max power point voltage of around 17 to 18 volts, for the purpose of covering charging loses etc. A regular charge controller will not increase current, you need a max power point tracking charge controller to do that, although they are a lot cheaper than they used to be. Of the cheaper MPPT controllers, really only the EP Solar Tracer series are worth looking at, see http://www.futurlec.com/MPPT_Solar_Charge_Controller.shtml
wlb
Member
John Sheridan said:
Because 12 volt is best.
John, you need to go back and re-read all the advice that's been given to you over the past 6 months or so before you go off and spend any more money. It is completely pointless designing your system and buying panels and other components while you still don't quite grasps the basics. You have a fixed idea of what you want and all you have been doing is asking for others to confirm it.
wlb
Member
Oilburner, you will learn something from experimenting with a few solar panels and you will probably find it quite interesting. However, don't spend any money or too much time until you've read a bit about basic electricity principles, otherwise you will waste your time, and not really learn anything.
Oilburner
Member
wlb said:
However, don't spend any money or too much time until you've read a bit about basic electricity principles, otherwise you will waste your time, and not really learn anything.
Hmm, You mean basics that would let me build my own 7 phase axial flux alternator, rewind F&P smartdrives, Build 3 phase to single phase rectifiers, set up 3 phase motors as induction generators in star, delta and C2C configurations, Use said induction generator to feed a DIY 3 to single phase, AC to DC rectifier to power a solar inverter to back feed to the grid or just play around with the circuitry of car alternators and by pass the regulators and rectifiers for higher outputs and manual control?
Something like this? https://www.youtube.com/watch?v=HUE1RQRAXlg
or this: https://www.youtube.com/watch?v=SBC2re80yF4
Yep, Might be OK with that! :0)
wlb
Member
My apologies.
Something very odd is going on here. Are you sure your forum account hasn't been hacked? Because if you've built all those things, and you understand how they work and you weren't just following a set of assembly instructions, then your previous post was written by somebody else.
Oilburner said:
Wouldn't matter much what the output was, you just use a regulator/ inverter that takes whatever voltage and rectifys it to the output you want. Higher volts are converted to higher amps. It all works on watts not volts anyway.
Oilburner
Member
What I said is correct.
If you have a panel or a generator Putting out say 28 Volts@100W, you can use an inverter or whatever the correct term is to reduce that to 14V volts at 200W ( less losses) to charge at and it converts the higher voltage input to the lower voltage at higher amps.
Solar inverters work the same way. I was running the one in the vid just under 500V. The unit itself will take up to 600V and output that at grid voltage of 200-260V, whatever the line voltage it is connected to is running at.
The inverter takes that 400V at say 10A and converts it down to 240 at say 16A ( depending on efficiency and losses and feeds it back to the grid.
HT Power lines don't run at 240 or even 440V they run at tens of thousands of volts or higher to reduce the current and then that voltage is reduced at the sub stations to lower volts and higher amps suitable for the end user.
There are also buck and boost circuits published everywhere that allow you to take a lower voltage and convert it to a higher one but at lower amps than the input voltage.
It is not about voltage or amps it's about the wattage because 1000V @1A can be 500V @ 2A or 500A @ 2V. Same thing. You can slide the scale and expand it anyway you want as long as your volts times amps does not exceed 1000W or whatever wattage you started with.
I won't even try to overwhelm you with multiphase AC to single phase DC increase's, C2C conversions, or how they work. Best you come to grips with the simple stuff first.
If you are not aware of these very fundamental things, it is clearly you that needs to read a LOT about basic electricity principals before you make yourself look foolish. 
wlb said:
My apologies.Something very odd is going on here. Are you sure your forum account hasn't been hacked? Because if you've built all those things, and you understand how they work and you weren't just following a set of assembly instructions, then your previous post was written by somebody else.
wlb
Member
Oilburner said:... Putting out say 28 Volts@100W, you can use an inverter or whatever the correct term is to reduce that to 14V volts at 200W ( less losses) ...
You really need to change your password. They've done it again.
P.S. Inverter, regulator, charger, rectifier, etc. are not interchangeable words.
karmacoma
Member
Sounds like OP wants a simple system i.e. appliances and storage all on same voltage, and unwilling to go to higher voltages for unspecified reasons. Possibly overriding cost advantages of a higher-voltage system. But that's parameters. One man's desire is another's anathema. Funny old world, what can you do?
I've already given a certain company in Preston, Melbourne a free plug on this forum once today, I'll not give another without a sales commission from them, but they have a 200W 12V mono selling for $1 a watt. That's probably the best bang for 12V buck right now.
Other than that, this thread has gone off the rails completely. Oh, and a toast to all the eccentrics here who don't do things the way everyone else does. 
Oilburner
Member
karmacoma said: but they have a 200W 12V mono selling for $1 a watt.
Do these panels deliver 12V open circuit or have a regulator that outputs 12V or 13.8 or some other voltage that is taken as 12V but is actually a higher output for battery charging or the like.
12V Can actually vary. A car is said to be 12V but the battery is above 14.5 when the vehicle is running.
That's why I'm just trying to clarify if in this context it is actually 12V or for a 12V system that operates at an actual higher voltage?
I'm seeing a few people selling panels at under $1 a watt now but I spose it depends if you consider 18V to be for a 12V system?
karmacoma
Member
Oh well, here's a free plug for said company, seems inevitable now its been mentioned:
http://www.ebay.com.au/itm/New-200-Watt-12v-Solar-Panel-Mono-Off-Grid-12V-200W-Pick-Up-/321381293946?hash=item4ad3d15f7a
From the label, Open-circuit voltage (Voc) = 22.3V; Short-circuit current (Isc) = 11.89A; V at Pmax (Vmp) = 18V; Current at Pmax (Imp) = 11.12A.
Pretty cool if you can get panels now at under $1/watt.
My pea-brained understanding is that that voltage is pretty typical of a big "12V" solar panel; as said above, voltage is actually a bit high to provide charging punch for a "12V" battery via a regulator, with component losses, and when the sun is off peak. I guess that even though the battery should really be charged above 12.0V (but less than 14.4 or so volts, to prevent damaging the battery), it is called "12V" because that's the nominal voltage of appliances that run off it. If you tried to charge an "18V" system off this panel, there wouldn't be enough potential difference to fully charge the battery, especially when you haven't got the panel aimed right at midday sun. Anyway, as long as you can run 12V car/caravan/boat type appliances off the nominally "12V" system, all is good. But that's pretty much the full extent of my understanding. I just ask questions here for anything more.
