Wind Gen or More Batteries ?

[SimonV]

We are getting ready for the next big trip planning on being away for 2-3 or more years. My power storage at the moment is 400 Ah in the bats, production is by 2x 130W solar, 130 Ah eng alternator and a Hamilton Ferris Tow generator.
I was thinking about adding a wind Gen but the return for $'s spent does not seem to add up. when under way I have full bats thanks to the tow gen @ 1Ah per Knot over 4Kn, so that is not an issue. sunny days at anchor the solar keeps up but the bats don’t go into float so I see 80-90% in the afternoon but by next morning I am down to 65-70%.
I have thought about adding another 200Ah bat giving a total of 600Amps, I have the space for more??

[djmarchand]

Well, it depends on how much time at anchor between passages and cloudy days and whether your anchorage has enough wind to make it worthwhile to add a windgenerator.

I would add another 200 amphours of batteries to carry you through the lulls.

David

[Bash]

I have a similar system to what you're contemplating. 2x 130 watt solar, 100 watt Balmar alternator, 200 watt wind generator, and a 420 Ah house bank.

Couldn't be happier. On my previous boat I went the route of having more batteries, but in the long run that's a more expensive way to get the job done.

[SimonV]

Originally Posted by Bash

I have a similar system to what you're contemplating. 2x 130 watt solar, 100 watt Balmar alternator, 200 watt wind generator, and a 420 Ah house bank.

Couldn't be happier. On my previous boat I went the route of having more batteries, but in the long run that's a more expensive way to get the job done.

But do you get enough power from the wind generator to make the extra expence worth while, I like little or no wind at anchor.

[Bash]

Originally Posted by SimonV

But do you get enough power from the wind generator to make the extra expence worth while, I like little or no wind at anchor.

Yes, but I'm in SF Bay, so wind is something we've got a lot of. The wind gen is well worth its expense in the rainy season, on in fog, or even when there's enough of a marine layer to keep the solar panels from accomplishing much.

Depends on where you sail, and when, I suppose. This past weekend we didn't turn the wind generator on because we had enough sun for the solar panels to keep the batteries topped off. But there have been ample times when the wind generator does the bulk of the heavy lifting.

[Ex-Calif]

I think you are asking the wrong question. Let's say you are going from 90%-65% on a frequent basis -

400 a/h * ((90-65)/100) = 100 a/h

I won't get into why and how you are using 100 a/h a day but your real world consumption is 25% of your battery capacity per day. It's marginal for now IMO as long as your power thirst doesn't keep growing.

The question is - Do I have enough capacity and replenishment capability? My short answer is no on either count.

If I read your post correctly you have enough battery capacity to be on the hook for 2 days without falling below 50% charge state.

You solar is 10A * 8hrs * .6efficiency = 50 amps or so

You need to double your generating capacity and for me if I really was using 100A per day I would go on a power diet and/or add 200ah.

[drinky]

Same story. Since I added fridge and freezer I find my solar doesn't quite meet the demand of them and TV. I am about to add a D400 to the system so I can generate power when the sun goes down cause that is when the batts go down.

[Hampus]

If I read correctly:

If your solar panels can't keep you 400Ah charged, they won't be able to keep your 600Ah charged either. All you will accomplish is to create a larger buffer before you run dry. My advice would be to decrease your consumption (LED lights where possible, better fridge etc.) first and add more charging capacity second. Larger battery bank third.

/Hampus

[sailorboy1]

I think your current system is good. You start the day at 65% and end the day at 80%. So at night the draw is only 15% and the solar keeps up during the day and charges the batteries. Why would you need more battery capacity just to be at 75-85% charge instead. When it's clouding out and the solar can not do it, run the engine. In your case it's going to take like 1500 engine hours to pay for the wind generator.

[SimonV]

I think it will be an extra 200amp house giving 600amps plus one 100 amp batt in the forpeak for the anchor winch to draw on. This batt will be charged from the house bank system with a blocking diode to act as an emergency batt and will always be fully charged. I am leaning towards the AirBreeze wind gen as it seems to be the best price per amp for the overcast and windy nights.

Don, I have read that, the bigger the bank there is a principal (cant think of the name) but the bigger the bank the Use % is less and the Batts wil pick up that % alot faster.

[sailingaway221]

The issue also will be the extra power needed to charge the larger bank. 600 ah bank will take longer to recharge and much longer to float...approx 50% longer. your charging off the solar panel is recharging your house bank to 85-90 % but if your house bank is 50% larger it will take 50% longer to reach that level....I imagine this will equate to you needing to add charging ability anyways. I love my wind generator as long as its windy..say 15 knots or more....Something else to remember is that it is very hard to get that last 10% charge into a battery bank.....not too many boats I imagine get the battery to float using solar and wind unless its really windy. Bigger bank harder it is to fill up all the way.

Simon, all that said if you like little or no wind at anchor, get more solar panels... a wind generator doesn't really do much below 13 knots and works great around 18 -25.....but if the wind is light it puts out less than another solar panel.

[capt_douglas]

It seems to me that increasing the battery bank capacity requires increasing the charge capacity in order to recover the losses and prolong battery life.

It also appears that what you currently have doesn't seem to keep up with your current load. Wind generators seem to do their best work when the vessel's not moving so I doubt you'd see enough to recover the cost underway. Have you considered another solar panel? Do you orient the panels for maximum power collection during the day?

It sounds like you do OK when underway (1A/kt @ GT 4kts) so I'm thinking the problem's at anchor. That means a different set of loads and the best bang for the buck may lie there.

I'd suggest a serious look at your loads and reducing them as much as possible.