Will a 100 Watt Solar Panel Cover the Following?

[LBW399]

*Laptop (will not be on continuously)
*Led Lighting
*Re-charging Ipad
*Possbily might splash out on a little portable 12V cooler to be used only in hot climates when I feel like a cool drink.
- That's it.
Sailboat is a 26 footer, no inboard diesel (outboard motor). Only one crew (me) and plan to cruise full time.

Thanks in advance for any input.

[CSY Man]

You should get 6 amp hours X 6 hours per day = 36 on a sunny day.

MPPT highly recommended.

[xymotic]

nope. well, sorta.

The cooler will kill it greatly (probably depending on brand)
As will the laptop.

HOWEVER, it also depends on what you mean by cover it... In bright sun it would probably power those items directly, but it won't have much left to charge a battery.

A 100 watt panel can put out 8 amps of power (in a perfect world)
my engel uses 2 and my laptop about 5 I think most coolers will run 5 or 6 amps though.

Also, it's not a perfect world

[noelex 77]

Laptops vary considerably in power consumption. About 3.5A is average, if you mean say 4 hours a day that's 14AHrs.

I still have not measured my IPad carefully, but I think about 0.5A so say 5 hours a day is 2.5AHrs.

Lighting say 0.3A for 8 hours is 2.4 AHrs

This gives a total of about 19AHrs. It's always a good idea to add about 10% for charging inefficiencies and some contingencies, so I would call it 25AHrs.

The output of a 100w solar panel is very dependent on location. Say 15 to 50AHrs. An average is about 30AHrs.
These estimations show you will be just OK.

The 12v "coolers"use a lot more power than the compressor based 12v fridges.
A small one will be about 5A. So there is not much power left for this other than the good days/seasons when you will get a couple of hours to cool a drink down.

[LBW399]

Originally Posted by xymotic

nope. well, sorta.

The cooler will kill it greatly (probably depending on brand)
As will the laptop.

HOWEVER, it also depends on what you mean by cover it... In bright sun it would probably power those items directly, but it won't have much left to charge a battery.

A 100 watt panel can put out 8 amps of power (in a perfect world)
my engel uses 2 and my laptop about 5 I think most coolers will run 5 or 6 amps though.

Also, it's not a perfect world

Heh heh yep you are right it not perfect world...well sometimes it is.

So, what then - 150-200 amps. Then I will need two batteries maybe?
Hmmm, maybe you can tell bit of novice when comes to solar.

[LBW399]

Originally Posted by noelex 77

Laptops vary considerably in power consumption. About 3.5A is average, if by continuously you mean say 10hours a day that's 35AHrs.

I still have not measured my IPad carefully, but I think about 0.5A so say 5 hours a day is 2.5AHrs.

Lighting say 0.3A for 8 hours is 2.4 AHrs

This gives a total of about 40AHrs. It's always a good idea to add about 10% for charging inefficiencies and some contingencies, so I would call it 50AHrs.

The output of a 100w solar panel is very dependent on location. Say 15 to 50AHrs. An average is about 30AHrs.
These estimations show you will be short. Using the laptop less ( maybe ipad more as a replacment) would make a big difference, otherwise you need more solar.

The 12v "coolers"use a lot more power than the compressor based 12v fridges.
A small one will be about 5A.

Hmmm interesting.

Laptop will be (if I indeed get one) will be on less than an hour per day coastal, maybe even less when on passage offshore. In fact - I am not even sure I will bother with a laptop as you might see from another post about electronic charts, they are SO much CHEAPER on an Ipad using Inav software nav.

Will use Handheld GPS and Ipad mostly for nav.

I can do without the portable cooler - was just a luxury that I probably don't need - but if I did have it, it would be for in port now and again, more usage in hotter climates, maybe not at all in temperate to cold climatic parts.

[noelex 77]

With the laptop for only 1hr a day you should have plenty of power. Don't forget things like navlights etc and do a proper consumption budget.

[LBW399]

Originally Posted by noelex 77

With the laptop for only 1hr a day you should have plenty of power. Don't forget things like navlights etc and do a proper consumption budget.

Ok, thanks, I will.

Yes Nav lights, but you can also get them in LED too, to keep power consumption down.

Cheers.

[sailorboy1]

Shop around for panels more. For the price of a 100W unit you can get a much larger one for not much more money, especially if you can pick it up instead of shipping it.

[Pete7]

Kiwi, in good sunshine (UK summer, 50.North) we can get away with 125w of solar with similar demands to you, but would be struggling if it rained for a week. No chance during the winter though. Our fridge is a compressor type btw so uses less than 3 amp hours.

If you could increase the amount of solar it would give you a bit extra for on board without ending up living like a hermit. Could you mount 2 x 80 or 2 x 100 perhaps? a loose mounted panel for use just in harbour might be a solution and one I am thinking about for next year to give us a bit extra.

Worth having a good read back through CF on solar as there is lots in valuable advice on things like MPPT, PWM, shading and parallel or series wiring.

Pete

[Randyonr3]

Its not the solar itself, or the batteries, or the type of controler by themselves, its a complete controled charge and discharge of the system.. and your batteries should only be discharged up to 50% of there value.. for us with "Lifeline" fully charged is at 12.8 and 50% is at 12.2..
you dont have to have masave solar units if the storage is designed right.. Like a barrel of water with a trickel of water going into it.. the rise and fall for water continues but the trickel keeps comming in..
Our Boat, is totally self sufficient, we live on it and are "Off the grid".. and we dont scrimp on power.. reffer, lights, electronics, and the wife has her inverter to opperate the kitchen, toster, coffee pot and the othere day she made a stew in the crock pot which was on for 6 hours.. and from time to time I'll run a power tool off it..
we have two 130 watt pannels but over 2000 amp hours of storage...
Befor you go out and start spending money on panels, set down and design a complete system for the boat, from the panels to the light switch and everything inbetween.

[swisscraft]

Originally Posted by noelex 77

The 12v "coolers"use a lot more power than the compressor based 12v fridges.
A small one will be about 5A. So there is not much power left for this other than the good days/seasons when you will get a couple of hours to cool a drink down.

Yes 100 Watt could make it as previous stated. Just need to stress the "cooler" out a bit more. As said above, you will need a compressor cool box in this config: Engel/Waeco or similar. Any other typ like Peltier will simply not work! Takes to long to cool down and to much power. During my lake sailing time I could perfectly run a compressor box with a small solar panel. Just switched it on during solar peak and then off. On a sunny day it could run almost 24h. No way to do this with the cheap ones. So if you spend the buck choose the right (more expensive on)!

[foggysail]

Originally Posted by Don Lucas

Shop around for panels more. For the price of a 100W unit you can get a much larger one for not much more money, especially if you can pick it up instead of shipping it.

Amazon will ship free............and they offer DM 145 watt panels with prices in the $360 range for a pair when in stock.

[Captain Bill]

I would guess things will be a bit tight. We have 300 watts of solar and the best day I've ever had we made 88 AH. Most of the time it was between 50 and 60. I would guess you'll get 1/3 of that out of a single 100w panel unless it's mounted so that it's inclined towards the sun. I agree with the previous posters that Peltier based coolers will not work. The best ones will suck up anything you can produce. I have a friend that had 220 watts of solar in Florida and the Bahamas with similar power requirements using a danfoss based compressor refrigeration (no freezer, but a well insulated box) and never plugged into the grid. He had a single 8D lifeline that he used for both house and starting. He had about 2 days of cloudy weather capacity without running the outboard to pump up the battery a bit. Since you didn't give your location it's kind of hard to tell how you'll do. The problem is that in the tropics it usually gets partly cloudy in the afternoon so you seldom get good power producing sunshine all day.

[foggysail]

Capt Bill.....and Nolex are correct pointing that getting 100 watts out of a 100 watt panel isn't going to happen. OK--- maybe in a laboratory setting.

I currently have close to 300 watts ( 2 each 145 watt panels) that served me well this last season. Next year I plan to add additional refrigeration, compressor style. I should have no problems with energy storage to meet my expectations because I have another pair of 145 watt panels ready to install next spring. So my solar panel total will approach 600 watts from which I expect to see about 20 amperes flowing during peak sun using a pwm regualtor.