Solar panels in the pacific northwest

[Jared1048]

I'm looking at getting a 65watt panel added to the top side of my deck below the main. I know its not the ideal location but a panel would fit nicely there.

I'm noticing a big difference in the panel prices though- $280 - $800. Are the more expensive panels better suited for the weather patterns in the winter for the pnw? I just got a wallas diesal heater thats using 2.8-3.5 ah through the night and has made my bank barely enough to get through a weekend trip.

House battery bank is 2 85 ah deep cycles in parallel and a 100 ah agm for a reserve. Stock 35(?) amp alternator on 2gm20f.


Thanks!
-Jared

 

[Les]

I had a Hunter 380 for nine years and it had a factory installed solar panel installed right under the boom just forward of the dodger. The solar panel was hooked directly to the starting battery with no connection to the house batteries.

My only problem was that my starting battery went dry more often then the house batteries. My marine electrician says there was no way to shut off the solar panel. Had I kept better track of the water in the starting battery I wouldn't have had any problems but out of sight-out of mind in my case.

Why I didn't put in an AGM battery for the engine I just don't know.... I can be rather dumb at times. That would have solved the problem instead of me buying new batteries every so often.

What size solar panel? No help here except to say the one on my 380 was rather small but it did the job.

I wish you well.

 

[Stu Jackson]

If you have a solar panel, it should be connected to the house bank. Why? 'Cuz the start bank rarely needs to be charged since it only takes 2 amp hours out everytime your start the engine.

If you do an energy budget with that load, you'll find you also need more house bank capacity. You should be able to fit three 130 ah house batteries on a 31 footer, if not at least two 6V golf carts. With 2 85 ah house batteries all you have is 85 ah useable.

 

[Jared1048]

Yeah, I'm finding that I need more battery capacity for the house bank and mabe a bigger alternator. When the battery capacity was low (~70%) and the motor was running, it was only accepting something like 5-9 AH (as observed from that xantrex monitor). I would of expected it to be pulling harder than that on a 180 AH bank. I did have other electronics running (Radar, music, VHF) though which when switched off bumped it to the higher side of 9 AH.

 

[Don12364]

Re: PHIL - Solar panels in the pacific northwest

Phil -
I had two topics open simultaneously. To include an alpha character in an answer to the other topic I used a 'ctrl' function. This closed the current topic and left the previous one showing the reply panel. Not spotting the change I simply retyped the text and posted it.
Now it was on the incorrect topic so needed to be deleted.

If you know a way for contributors to delete this please advise.

 

[Bill Roosa]

You have to understand bulk (0-50% SOC) absorption (40-85%) and float (85-100%). The battery determines the amount of current going into it not the alternator. The max you will ever see is about 25% of the AH capacity of the bank or for a 100 AH bank around 25 amps. That is during bulk charge only. The current RAPIDLY falls off once you get to 50% charged so buying a hunking big alternator only makes sense when you have 400+ amp hours and actually use around 300 before charging. Not many of us do that BTW.
You really can't design a system by just randomly assembling the parts you have look at consumption (how much and when) production (how much and when) and storage (SOC at any given time and total amount of storage available) Then choose the parts to support the load and its usage. The math is easy but gets tedious unless you have some sort of simulator to keep track of things
I built a spreadsheet and found that just altering when I use a load made a big difference in the bank SOC and how much engine time I'd need.

 

[rochesterdriver]

Jared,

If you do a little research you'll find that panels have come WAY down compared to the price you quoted in the original post.

hth,

Jim

 

[Jeff20919]

Jared,

Suggest you look at Northern Arizona Wind & Sun, www.windsun.com
I installed three Kyocera 135 watt panels on my 2006 Hunter 45 CC, with a combiner box with 3 10-amp circuit breakers which allow me to disconnect any one or all 3 of the panels, a Blue Sky Controller. Purchased all components from them. Good luck with your project.

Jeff

 

[ora726]

Hi Jared,
No comment on the price of the solar pannel, but definitely on the location. Read an interesting article the other day on the effect of shade on a solar pannel. The result was that 10% shadow on a solar pannel resulted in 90% drop in output. So if you can find yourself a place for the solar pannel that is not under the main you might need a smaller and cheaper pannel.
Good luck with the installation.
-R