Exepcted solar output in norther winters?

[sailcrazy]

Can't support it with a reference, but I've been told several times that panels deteriorate over time making the age. as well as the surface cleanliness, the panel temp, and the SOC of your batteries all play a significant role in panel output. We have 4-80watt fixed panels installed; when we sailed in the Philippines some 10 years ago (approx15*north lat), we typically saw 20 amps or more at high noon. Now, here in the Caribbean (18* north lat)we're lucky to see 7 amps max output. FWIW

[StuM]

Originally Posted by sailcrazy

Can't support it with a reference, but I've been told several times that panels deteriorate over time making the age. as well as the surface cleanliness, the panel temp, and the SOC of your batteries all play a significant role in panel output. We have 4-80watt fixed panels installed; when we sailed in the Philippines some 10 years ago (approx15*north lat), we typically saw 20 amps or more at high noon. Now, here in the Caribbean (18* north lat)we're lucky to see 7 amps max output. FWIW

The usual term for loss of output over time is "degradation".



Here's Sunpower's take on it:


https://businessfeed.sunpower.com/ar...el-degradation

[Chotu]

Just don't forget to shovel the snow off.

That will drop your output. Lol

[GRIT]

I have noticed a drop in output when the panels are covered in the white stuff. I'll try wiping that stuff off.🤣

Thanks.
Paul.

[GordMay]

Greetings and welcome aboard the CF, Don L.

[CatNewBee]

Originally Posted by sailingharry

On our new-to-us Saga 43, we have 4 Solbian 90W solar panels. This past summer (we bought the boat in July), I was not feeling very good about charging sources (Alternator, Solar, Wind, and Watt & Sea), but our only measurement tool is Link 2000 that tells total current. To make matters worse, all those terminate under the quarter berth, making it a nuisance to get in there.


So, this winter, I have bought several individual ammeters. Cheap Hall Effect ammeters, probably not terribly accurate but useful indicators. https://www.amazon.com/gp/product/B07STHDKSH
I've hooked them up, and am starting to get information even though we aren't using the boat. We are on shore power, but I can pull the battery down significantly by running a space heater on the inverter.


So here's my question. There are 4 Solbian 90W panels, going through individual Genasun MPPT controllers. We live in Annapolis, latitude 39N. I was on the boat on Dec 22, one day after the shortest day of the year. It was 1PM, an hour after noon. My solar was putting out about 5A, evenly distributed across all 4 panels. A naive newbie would say "well, 4 90W panels is 360W, at 15V is 25A, you have a problem." I'm not so sure! Is 5A about all I can expect from a 360W array with the sun so far south this time of year, an hour after noon? I did look at the sun, and it surely isn't overhead! Math says it is 50 degrees lower than it is on June 21.



Thanks for thoughts.


Harry

1/3...1/5 of A output at the same time of the day and 1/4...1/10th of the Wh per day because of shorter daylight of what you get during the summer.

[El Pinguino]

No mention yet of temperature ..
These people do a better job than I could... https://sciencing.com/solar-panel-st...cold-8161.html
High latitudes, clear skies, and trim-able panels?... heaven...

[hpeer]

Originally Posted by sailingharry

Bill, I'll go look up your other thread. Our first big test of the boat systems will be 2021 when we do "the down east loop" including PEI, Newfoundland, etc. Definitely high latitude solar!

Great trip. We took it to get to NL. And I’ve separately come back so I’ve done the whole route in pieces.

I recall Nigel Calder doing a speech at the Annapolis SSCA gam a few years ago where he touched on this. He was comparing solar to wind power and his opinion was that even in Norway solar was superiors to wind.

Here in the Caribbean we have both good solar and good wind. But even at that you get the odd day, not often, when the batteries get down. A heavily overcast day with no wind that turns into night.

On the flip side ask what your power consumption is. That’s generally the easier side to deal with. For us our ONLY significant consumption, when on the hook, is the reefer.

[sailingharry]

Originally Posted by hpeer

I recall Nigel Calder doing a speech at the Annapolis SSCA gam a few years ago where he touched on this. He was comparing solar to wind power and his opinion was that even in Norway solar was superiors to wind.

You touched on part of the reason for investigating my power generation. My wind generator naturally shades the solar at times. And wind, while looking productive, really doesn't do much at all below 10kts.

It is rated at 400 Watts (about 30A) at 32kts of wind -- but 40Watts (or about 3A) at 10kts. It's not common to see more than 10kts at anchor in many parts of the world (low islands in the trades are an exception).


I hope this summer to figure out if the wind makes enough to offset the loss in solar production.


Also on the list of objectives is to determine if moving the radar from a post on the arch (where the solar is) to the mast would be worth the effort and expense.

[hpeer]

LOL, I just moved my radar from the back of my arch to the front for a variety of reasons among which was to reduce shade. Here in the Wast Carrib with the prevailing Easterlies it works better that way.

[tmw]

This is a little bit old for the reply but I put 2 @160 watt flat on our hard top last summer and the worked great for our daily loads. When we pulled the boat for Winter, for I re-connected the panels under the white shrinkwrap cover and I consistently get 2-4 amps at peak with a load, in Connecticut at Lat 41. This is way more than is needed for self discharge. I have a Victron battery meter and I run my wifi connection and stereo while I work on the boat and the panels supply all the power. I leave the boat after several hours with zero amp hours consumed. All under the cover. So your number seem just fine to me.