Solar panels direct to batteries??

[newhaul]

Originally Posted by faa50

Before dropping the folding green stuff for a couple of 120 KW solar panels, you may benefit from learning about the new 345 KW solar panels available for marina use. Nearly the same size the output from two of these panels is nothing short of remarkable. Info is available at SunPower 345W X21/345 Solar Panel, Mono/Black | ACOSolar.com. A system consisting of only two panels coupled with the Mustang MPPT/Charger is capable of restoring on average 255 amp hours daily in the tropics. For most sailing cruisers that fulfills the hunger energy needs of their boats. No need to crank the iron horse or her mate the jenny.

One learns quickly, that an MPPT is as critical if not more when it comes to solar panels and their ability to replenish amp hours to battery banks. Solar panels can be finicky in how they generate power (angle to sun, any shading to the panel itself even if only a small portion can greatly reduce energy generation. A well designed MPPT can rectify many of these issues when coupled with a similarly well designed charger. This link provides you with beneficial information of the current advancements in this technology and show how to significantly improve replenishment of amp hours to the yachts battery banks: http://www.amazon.com/Morningstar-TS...r/dp/B007NMVL7

Those panels are really nice looking however they are really expensive IMO give me 4 100 watt panels of the cheaper new like windy nation or renogy and I can get plenty of solar power add an mppt controller and I would get more power for less money than just one of the panels you recommend
( are you sure your not a vendor your other post today is for a specific wind Genny)

[newhaul]

Originally Posted by faa50

Before dropping the folding green stuff for a couple of 120 KW solar panels, you may benefit from learning about the new 345 KW solar panels available for marina use. Nearly the same size the output from two of these panels is nothing short of remarkable. Info is available at SunPower 345W X21/345 Solar Panel, Mono/Black | ACOSolar.com. A system consisting of only two panels coupled with the Mustang MPPT/Charger is capable of restoring on average 255 amp hours daily in the tropics. For most sailing cruisers that fulfills the hunger energy needs of their boats. No need to crank the iron horse or her mate the jenny.

One learns quickly, that an MPPT is as critical if not more when it comes to solar panels and their ability to replenish amp hours to battery banks. Solar panels can be finicky in how they generate power (angle to sun, any shading to the panel itself even if only a small portion can greatly reduce energy generation. A well designed MPPT can rectify many of these issues when coupled with a similarly well designed charger. This link provides you with beneficial information of the current advancements in this technology and show how to significantly improve replenishment of amp hours to the yachts battery banks: http://www.amazon.com/Morningstar-TS...r/dp/B007NMVL7

Sorry but just to let you know the link you posted for the morningstar controller is bad. Here is the corrected link Amazon.com : Morningstar TS-MPPT-60 TriStar 60 Amp Charge Controller 12-48V : Renewable Energy Charge Controllers : Patio, Lawn & Garden

[Empty Pockets]

Originally Posted by newhaul

What I see here with your proposed scenario is that you are using the battery bank mostly as a buffer between the panels and your constant load a low cost pwm would still, be a good item to have to regulate the voltage spikes that may and will occur if nothing else to protect your computer and other electronics and as far as being waterproof place the controller in a location that would not be subjected to near constant immersion in water and if submersion is a possibility I would be more concerned about the batteries you do know that when fla batteries are subjected to sea water they die a horrible death and it makes large quantities of chlorine gas.

Are all the punctuation keys on your computer broken?

[Mirage Gecko]

Ok thanks to all I now have the info I needed.
Chris

[newhaul]

Originally Posted by Empty Pockets

Are all the punctuation keys on your computer broken?

Sorry about that. I was up all night with my kid she has epilepsy. Sometimes the words just flow from my brain to my fingers. I do tend to forget to place periods in my posts. However most people don't seem to mind. They can still get the idea and understand my pearls of wisdom. Thank you for pointing out my failings and errors. Cheers Rob

[Empty Pockets]

Originally Posted by newhaul

Sorry about that. I was up all night with my kid she has epilepsy. Sometimes the words just flow from my brain to my fingers. I do tend to forget to place periods in my posts. However most people don't seem to mind. They can still get the idea and understand my pearls of wisdom. Thank you for pointing out my failings and errors. Cheers Rob

Sorry, Was just kidding. I need a sarcasm smiley...

[newhaul]

No worries. I don't take offense to much around this big blue marble. Look at my byline on sailnet will tell you a lot about me

[faa50]

Nope I'm not a vendor, although I can see that someone may draw that conclusion. I was unaware of these products until other sailors offering assistance passed along the information and their experience with these systems. For that I indebted and very appreciative as they are not easily found let alone obtaining reviews by actual users.



I'm currently in the process of purchasing an Island Packet 445 and plan to equip it with both solar and wind to provide daily replenishment of approximately 450 amp hours to several battery banks and prior to purchasing have conducted extensive research.

I'm looking for a solar panel solution that is reliable, produces the largest amount of energy possible within a very limited space, and what will fulfill our boat's needs on a daily amp hour basis. Not really interested in turning my sailboat into a solar panel array field, so trying to avoid hanging panels on the stanchions, arches, bimini top and anywhere else there is a spec of "free" space. Our goal is not to use the engine nor genset for power generation - we prefer the being self-sustaining, meaning reducing our need for fossil fuel and avoiding the expense , weight and maintenance of fossil fuel systems. This approach allows us to deploy a smaller genset than otherwise required. This cost reduction more than offsets the cost of two panels.



I totally agree that there are less "up-front" expensive panels and these panels which I encourage folks to investigate for themselves may not be well suited to ever cruiser's need or budget. However, up-front cost do not always equate to "lower" total operating cost per amp hr for the life of the system.

Part of the reason I thought folks might like learn of these solar panels - which technology has just enable them to become available February of 2015 - is that I see a large number of yachts typically carryng 120 KW or !40 KW panels which seems to have been the best available solution over the past decade.

Now for the same amount of space of 120/140 KW panels - and space is usually at a premium on a sailboat especially when factoring in placement out of shade - one can nearly triple energy output. Dollars is less of an issue than space, for some - and with increasing electrical loads being desired/required by cruisers this offers a viable option.

[newhaul]

May I ask two questions. first do you actually mean 120 kw or do you mean 1.2kw ie1200 watts as upposed to 120k which is 12000 watts. The second question is are you sure about 450 ah that's really a lot energy. On our Spencer even with a refer running we use under 40 paper twenty four hour all supplied by a pair of 100 watt mono solar panels running thru a pwm controller. Haven't had the battery charger on for a month, haven't even needed the engine for charging. What does your power budget look like?

[noelex 77]

Originally Posted by faa50

Now for the same amount of space of 120/140 KW panels - and space is usually at a premium on a sailboat especially when factoring in placement out of shade - one can nearly triple energy output. Dollars is less of an issue than space, for some - and with increasing electrical loads being desired/required by cruisers this offers a viable option.

The high efficiency panels are certainly worth considering on a boat where space is often a primary concern.

Sunpower panels have been popular for this reason. Be aware that some models require a positive ground system which is problematic on a boat. In some geographic areas buying these panels is difficult, as they only sell via licensed installers. Both these problems can be overcome, but it takes a bit of persistence and research. There are other makers of high efficiency panels such as the Sanyo HIT series, as an alternative.

The main advantage of these panels is you can pack more watts into the same space. However, the advantage is unfortunately not 3X.

The Sunpower 345w provides 212w per square metre. As a comparison, a similar sized Kyocera panel is about 152w per square metre. As you go to smaller panel effeciency drops off, but the shade tolerance with multiple smaller panels improves slightly. A 140w Kyocera panel is about 140w per square metre.

The Solbian flexible panels are also worth considering. The SP series manages 167w per square metre (for the SP 125). The combination of flexibility and the availability of small sized panels that are still efficient means that available space can often be used more easily.

The big question is what will fit in the space you have available. The general rule is to go for as many watts as possible.

[seandepagnier]

Originally Posted by bsurvey

I used to run direct to the batteries from the panel and the batteries over charged sulfated and I had to replace them

normally sulfating is from undercharging. Overcharging will make them go dry.

Originally Posted by newhaul

... be a good item to have to regulate the voltage spikes that may and will occur if nothing else to protect your computer and other electronics and as far as being waterproof place the controller in a location that would not be subjected to near constant immersion in water a...

Why would there be voltage spikes from solar panels? The regulator to my computer takes 8-36 volts input.

In my experience the solar panels last a very long time, the batteries for years, but the cheap controllers break every year or two. I have the same problem with inverters and I solved it by not using them either.

Originally Posted by barnakiel

Wiring directly (without controller) is OK when the panel is small compared to the battery.

Yes.

It is also OK when the panels are big BUT then only when and if the the owner can control the charge (read disconnect at high voltage). This can be done. And I have done it. And it is not efficient. And it IS completely impractical. I would only ever do it again if we lost our controller.

It's actually very slightly more efficient than using a controller because the controller consumes power. It becomes less practical as you have more power input relative to the battery size.

Only in certain situations it makes sense to not use a controller. Another one not yet mentioned is if you had nickel iron batteries.


Another note.. the large solar panels are generally a bad idea on a boat because they have a single circuit (all cells in series) which means they are not good with partial shade. These panels are designed for rooftops which are free of obstructions, not sail boats which have rigs. It is much better to use many smaller panels instead, and also sometimes breaking waves destroy solar panels so it is better to use smaller panels for that reason as well.

[newhaul]

Originally Posted by boat_alexandra

Another note.. the large solar panels are generally a bad idea on a boat because they have a single circuit (all cells in series) which means they are not good with partial shade. These panels are designed for rooftops which are free of obstructions, not sail boats which have rigs. It is much better to use many smaller panels instead, and also sometimes breaking waves destroy solar panels so it is better to use smaller panels for that reason as well.

I agree with you on using several smaller panels for possible damage reduncy. However larger panels are not as affected by partial shading as you seem to be saying. due to a little thing called a bypass diode which allows the part of the panel that is shaded to be bypassed by a the power of the rest of the panel. Our 100 watt panels are decided into three separate sets of cells putting out 18 volts and about 2 amps of power output for a total of about 6 amps to the controller when in full sun and reducing by 2 amps when partial shaded. One last thing to consider is it seems that the breaking point for cost per watt starts to decline is around 100 watts per panel.

[nimblemotors]

Partial shading that drops your output from 6 amps to 2 amps,
I'd call that a huge effect. When a shadow crossing all three sections, the output can drop to 'zero'. These large panels are also heavy.

What other sailors does 'faa50' know that have one of the recommended panels? My understanding is SunPower does not sell 'panels',
they sell 'solar systems' installed on homes.

Originally Posted by newhaul

I agree with you on using several smaller panels for possible damage reduncy. However larger panels are not as affected by partial shading as you seem to be saying. due to a little thing called a bypass diode which allows the part of the panel that is shaded to be bypassed by a the power of the rest of the panel. Our 100 watt panels are decided into three separate sets of cells putting out 18 volts and about 2 amps of power output for a total of about 6 amps to the controller when in full sun and reducing by 2 amps when partial shaded. One last thing to consider is it seems that the breaking point for cost per watt starts to decline is around 100 watts per panel.

[newhaul]

Actually the other way around partial shading drops panel by at the most one third aka 2 amps lower output from 6 amps to 4 amps. My panels are not to heavy only 18 and a half pounds each.

[jkindredpdx]

I didn't see anyone mention isolating... Isn't that necessary to separate your banks?