wind vs solar power generation

[Donald6441]

The cells are in sets of parallel series

Designed to max out output. If 1 cell is shaded in a series, it will drop by 1 volt (open circuit voltage), and so on. Each cell has a diode over it to jump it if shaded. The matrix with the bypass diode was really made for military usage, as they needed a way to array the cells that wouldn’t allow a panel to get disabled if one cell got shot out... With out the diode, the dead cell turns into a resistance unit and kills the string.Anyways, its time for bed for me..

 

[Ed Fluss]

Ok you got me all worked SOLAR-how to install?

Ok so all this SOLAR TALK got me worked up. My general daysailing/weekend sailing generally does not take my two 80AH deep cycles to far beyond my needs.I have the LINK 20 which does a great job of telling me what Im using and how much juice is left.That all said I went and got a 15W 1amp panel and the 7amp regulator.I have it mounted on top of the bimini and well guys what do I do with the wires? Where do I plug this in? I have the standard factory battery charger and two Deep Cycle 24 battery on the standard battery switch.Any diagrams? Instructions?Thanks in advance

 

[Stu Jackson]

Connect them to your batteries

But seriously, Ed, it all depends on how your boat is wired. The instructions for the regulator should be easy. But not knowing how your two batteries are wired in now, I can't tell you. Do you have a PDP and an NDP? Your NDP should connect to your Link, and the shunt shouwld be the NDP. Check the Link instructions for how to install a solar panel in the shunt to have the unit show amps in from the solar as well as amps out when you're using the batteries. One bank or Two banks of batteries. More questions here than answers.Stu

 

[Dan McGuire]

Questions about Diodes

DJCould you come up with a circuit diagram of the diode bypass arrangement? After 20 years in the military and 17 years of aerospace experience, mostly in the battery business, I am still confused.I have never seen a solar panel in a military application where they were trying to protect it against getting shot, but that is certainly possible. In space applications they are worried about meteorite damage and do take some protection.I may have it wrong about what is defined as a cell. My 10W solar panel has 6 squares. I am assuming one of those squares is a single cell. I believe the 6 cells/squares are wired in series. I get over 20V open circuit. Therefore one of those cells/squares is delivering over 3V open circuit, not one volt.If my assumptions are correct, a solar panel is wired as follows: The number of cells in a series determines the voltage. The current capability capability is determined by the square inches of surface area. This can be accomplished in two ways-by either increasing the area of a cell or by adding more series in parallel.As far as the diodes go. There is absolutely no point in putting a diode in series with each cell in order to protect a cell from being shaded. It is possible that they might want to put a single diode on a series string to prevent that whole series from getting reverse flow from the other series and the battery.I will be leaving later today and therefore my ability to respond will be limited for the next few days.

 

[Dan18277]

Found a Link

I found a link which provides a lot of information on solar panels and batteries.I would like to correct some of my own misinformation. The square blocks on my solar panel are modules. The modules are made up of individual cells. There are six modules in my 10W solar panel.

 

[p323ms]

Unit definitions

All of this electrical stuff can get confusing!!! Some definitions seem circular. Such as defining watt as 1 amp/sec or joule/sec or a coulomb /sec. A coulomb for a sec is roughly 6,240,000,000,000,000,000 electrons!!! An amp is also the current produced by 1 volt across a resistence of 1 ohm!!!Red neck definitions using a water hose analogyVolts equals water pressure Amps equals gallons of waterWatts equals gallons of water times pressure!!!When you attach time you get amp hours. And that can be thought of as your water tank. If you have a 100 gallon tank you can take out or put in water at different rates. A gallon an hour for 100 hours or 20 gallons an hour for five hours. For best battery charging you need 14.4 volts at the battery!!!! Think of a siphon hose. It won't siphon up hill!!! Usually when talking about battery size it is amp hours which is a current of 1 amp for one hour. Hope that this helpsTom

 

[ruedi ross]

Diodes

There are 2 types of diodes used on solar panels. Blocking and bypass diodes. a blocking diode prevents reverse current flow at night from a battery to a PV array. Most PV controllers disconnect the array when it's not producing power, making a blocking diode unnessary. Smaller panels that don't use controllers, or cheapo controllers will need a blocking diode. A blocking diode will eat up some effeciency. A bypass diode protects individual panels from damage in larger series/parallel arrays. When one panel is shaded and you have other strings of panels in parallel, the panels that are producing power will force a current flow through the shaded panel(s). This condition can damage the shaded panel(s) due to overheating. The bypass diode will provide a path for this current to bypass the shaded panel. The more panels in series, the more pronounced this effect Most, but not all, panels above 40 watts come with a bypass diode installed. Here's another link with gobs of info about solar.

 

[Dan18277]

Not Necessarily

You don't always need a diode when you do not have a charge controller. Before I installed my 10W solar panel (not a cheapy), I called the manufacturer, Siemens. A diode is generally needed only when the night time or shaded losses will exceed the power loss due to the diode. For a small solar panel, there is little discharge through the panel at night. The loss due to discharge is less than the loss due to the diode.My panel is used with a type 24 battery, about 70AH. If the charge rate is less than about C/50 or the capacity divided by 50, a controller is not needed. My battery is 70AH or C=70. 70/50=1.4A. As long as the charge rate is less than 1.4A, I do not need a charge controller. My 10W panel delivers about .67A at 15V.My boat has running lights, cabin lights, am/fm radio, and fish finder. I occasionally use a trolling motor.I have used this arrangement for about 4 years. The battery is connected to the solar panel 24 hours per day for about 11 months per year. The only time I have got a low battery is when I put the boat in the garage during the annual pull out. Since that happened, I always disconnect the solar panel. This is with a 10W panel without either a diode or controller.

 

[John]

solar power

I have used Two pannels one is a flex pannel that sits on my sail cover the other is a glass covered pannel that rides on a 1" ss hoop that is over my wheel .this is great for shade and rain it is a 70 watt kyoc and is 25" wide and 35" long I thought the 70watt pannel was to big when it was sitting on the coffee table at home but once mounted on the boat You cant see it.It sits flat, this year Im adding one more pannel so Ill have a shade 50 wide by 35 long over the cockpit . I have a full cockpit cover but my wife makes me take it down so she can sun her self.I have around 500amphr gells with a three step smart regulator and 80 amp alt I have plenty of power for TV radio micro wave AB reefer lights and I leve the battreys hooked up all winter to keep them at full charge.The pannels where around 300bucks each In the summer the pannels put out alot more power becouse the days are longer.I think my setup puts out about 10 amps when the sun is high. I think that the AIR X wind generator puts out about 6 amps in 15kt wind but I start to louse sleep when its blowing 15ks and Im always looking for cover when anchoring .I think that a wind generator is a bit of a pain with the blades spining There is nothing easer then a flex pannel over your boom hooked to your battrey with a regulator. Im happy with my solar . my 2cents. John