Adding Wind to Solar - What's Needed?

[Ndavies]

Hi
I currently have (in thoery) 275W of solar panels connected to a Bluesky Solarboost 50 MPPT controller. I am looking to add a wind generator and have coflicting advice no how to wire this up. Bluesky produces a replacement controller that has inputs for wind and solar. Another supplier suggested using an air-breeze genrator with internal controller connected directly to the batteries.

Does anyone have advice on how to do this? I typically run a fridge and freezer, so could use these as a load to prevent overcharging. I will likely not leave the wind generator running unattended. I also have 510AH of AGM batteries with a SALT TM500 monitoring system.

Any advice appreciated - especially from anyone who has already solved this puzzle!

Thanks!

[barnakiel]

I have used both systems (combo controller and each wired via its own) and can't say which one delivered best. I can say when the combo controller packs up, you find yourself WITHOUT sol/wind for a time.

Now you do not need this or that wind as any will work if wired independently either.

b.

[ka4wja]

Ndavies,
See below for answers....
1) But first off, I'm happy to see someone else with a SALT TM500 battery system monitor!!!



I have mine monitoring:
1 - the main battery bank
2 - the output of my Blue Sky MPPT controllers (fed from my 520 watt solar array)
3 - main engine alternator

4 - 90 amp IOTA charger (fed from either shore power, or 6kw genset)
4- towed-water-generator (with its own current meter)
(these last two share one channel / one "SALT loop", as it's very unlikely that I'd ever being using the "charger" AND the towed-water-generator at the same time...but even if I did, channel #4 would just show the combined net of the two...)

{BTW, I also have a spare TM500 and two spare loops..although doubtful I'd ever need 'em, I thought best to get 'em before they're all gone...}

See other photos of it here:
AIS Transponder
Nav Station




2) Secondly, I ALWAYS recommend adding more solar, rather than a wind gen!!! (there are some exceptions of course...such as those doing out-of-season high latitude sailing, and/or those sailing where overcasts / multiple cloudy days are common....)

In almost all cases, more solar will produce significantly more energy than the addition of a wind gen...(ask those that have done this, as well as those who have removed a wind gen and added more solar....95% of the time, solar winds hands-down...and the other 5% it's a tie

In addition to the shading that the typical wind gen adds to most solar installations on-board (which REDUCES the energy you get from your solar array), you also have the "space" taken up by the wind gen (space you could've used for more solar), and the noise / maintenance issues associated with wind gens!!

Not to mention that "where" most cruisers anchor, they're not likely to get winds sufficient enough to drive the wind gen to any significant output....remember that most of your time is spent at anchor, etc. not at sea, so it is the wind speed inside the anchorage that the wind gen sees, not the winds out at sea...(if you're like me, more of a voyager, then a towed-water-gen might be a choice to consider, only AFTER increasing the size of your solar array!!!)

Many folks see wind gens spinning around and assume they're charging batteries, but many times in winds 10 kts or less, they are spinning, but not producing much (if any) charge current...
(Just a quick example, I saw a guy with a "air breeze" in the Bahamas a couple years ago....and it would spin up in a "gust" of 10 - 12kts or so, and put out 1 amp, and then idle down to ZERO as the wind was puffing along at 5 - 8 kts...the thing was still turning most of the time, but not actually charging the batteries much....)

Bottom line:
When solar was expensive, using a wind gen was a bit more economical....
But, now that solar is pretty cheap (heck, I see the Kyocera 140 watt panels now about $2/watt...and their larger/higher voltage panels even less), it make little sense to spend even $1 on a wind gen, until you've filled up all your available space with solar!!!




Yadda, Yadda....
But you didn't ask about the above...so how about I actually answer your questions???


3) As for your specific questions...

Originally Posted by Ndavies

I currently have (in thoery) 275W of solar panels connected to a Bluesky Solarboost 50 MPPT controller. I am looking to add a wind generator and have coflicting advice no how to wire this up. Bluesky produces a replacement controller that has inputs for wind and solar. Another supplier suggested using an air-breeze genrator with internal controller connected directly to the batteries.

Does anyone have advice on how to do this? I typically run a fridge and freezer, so could use these as a load to prevent overcharging. I will likely not leave the wind generator running unattended. I also have 510AH of AGM batteries with a SALT TM500 monitoring system.

a) The Blue Sky Solar Boost 3024iL DUO is a great controller, and it world work fine for you in this application....but, might not be / probably isn't necessary...

b) Although I use a towed-water generator to supplement energy needs on cloudy days, when on passage....the principle is the same, as if using a wind generator....
And, after a diode pack and current meter, my Hamilton Ferris WP-200 towed-water-gen is connected directly to the house battery bank....no "divert-load", no controller at all...

c) Although a wind gen is different, in that someone is of course on-board all the time you're using a towed-water-gen, but that is NOT always the case with a wind gen...
Assuming that you size your wind gen for the expected winds on your area / along your route, and that you do have an adequate load on your batteries (which you seem to have, with a fridge and freezer running on a 510 A/H battery bank), you'll probably have NO issues at all simply connecting the output of the wind gen to your batteries (assuming a cut-off switch, etc. is standard), with NO "divert load", nor "wind gen controller" necessary...
Although, if you do decide on installing a wind gen, I would recommend that you monitor your battery voltages during peak sun angles and steady wind, to see how YOUR system, on YOUR boat, with YOUR loads and YOUR specific needs, fairs...


d) A bit further detailed explanation:
With the batteries in need of charging (say early AM), assuming you have it programmed/customized to your specific needs/application, your present Blue Sky MPPT controller will be in "Bulk Charge" mode (providing the most charge current possible into your batteries), until your "absorption voltage" is attained and then it will hold that "absorption voltage" for the prescribed period of time ("absorption mode") before moving to "float" (although on-board energy draws and passing clouds, can mean that sometimes you never stay at that "absorption voltage" long enough to ever get to float!!)....

Years ago, I also was questioning what my Blue Sky MPPT controllers would do, if I was also feeding the batteries with the output of my towed-water-gen at the same time...
And, after realizing that most of the time this would be happening I'd be in "Bulk" charge mode, it became clear (thanks to a knock on my brain by Evans, jolting me out of a "senior moment"!!) that the batteries will only accept the current that they can accept!!! No more, no matter how much "extra power" you may have at your disposal!!
So, with that information as a given, then it becomes clear that if the batteries can accept/use the current from both sources, they will....and if not the solar MPPT controllers will "throttle back" and adjust their charge accordingly....
And, without a "charge controller" on the my towed-water-gen (or someone's wind gen), it's either in the water spinning and generating power, or it's not.....so, it's the solar charge controllers that adjust to the needs/demands of the batteries...
(With a wind gen, you'd have an ON / OFF switch, and/or ON / BREAK switch, etc....which allows you to simply/easily switch it on/off to your liking...)


e) Bottom line here:
--- Using the info you provided, you are unlikely to ever have too much alternative energy available, and when you do, you can switch off the wind gen (or for that matter, switch off the solar, if needed)
--- The Blue Sky Solar Boost 3024iL DUO is a great controller, but using the info you provided, probably not necessary....
--- One last piece of the puzzle (which I usually mention right up front) is WHERE are you sailing/cruising, and what time of year, etc....and can you possibly fit more solar on-board?? (without knowing these things, I can only be general in my recommends..)




4) Have a look at some of my energy systems...
Solar Panels
Towed-Water-Generator
Battery
Nav Station

They've all still working great after many years, and 12,000+ miles offshore with some significant weather over the years (across the Atlantic twice, multiple full gales, 3 days sailing thru a tropical storm, etc..)


I hope this helps....

Fair winds and sunny skies..

John
s/v Annie Laurie

[s/vPainkiller]

I can’t add anything to John’s advice above. I also have a wind generator and solar panels. My panels are controlled by a Blue Sky solar boost controller. The Air Breeze, as has been noted, has no external controller. On the recommendation of Bob Williams at SALT Service in Marathon, FL, it is connected directly to the batteries.

The solar boost will automatically reduce output to match the battery state. The internal controller on the Air Breeze will cause the unit to brake when it senses battery voltage above the cutoff point. Between the 2 there is not much concern about over-charging. When we are going to be away from the boat for a while, I do manually set the brake (which basically shorts out the unit) and tie off the blades just in case there is a big storm before I can get there. This is just a fail-safe since a large wind can overwhelm the electronic brake and cause the blades to turn damaging the unit.

You can use a dual controller for both wind and solar, but unless you just want to spend the money, it is not required.

Hope this helps.
Scott

[Ndavies]

Dear all:
First let me thank you for such excellent and informative replies. John - you certainly put a lot of effort into this, and I really thank you for all the information provided. You must be an engineer! Your response has given me much food for thought. Definitely the things that hit me in the head are your comments about wind (or lack) in an anchorage, and the fact that although wind generators may be spinning they may not be actually producing a whole lot of power.

Your response has certainly led me to the conclusion that I need to do a little more investigation into the system on my boat before I jump to wind to increase my power input. First, I don’t think I am getting the full potential from my existing solar. I mentioned that I have 275W installed. This consists of 3 x Siemen’s SM55s mounted horizontally behind my arch (my boat is a center cockpit); and one SM110 which is on the davits and can be tilted. On a good day, I seem to get about 7 amps from this which is far below the rating. I have read “rules of thumb” saying that real output from solar is typically about 50% of the rating? But I am still below that and have not fully investigated why this is the case. I am not sure of the age of the panels – so there could be some voltage loss there, but more likely, I suspect some cabling is undersized. Anyway, on my next trip to the boat, I think I will try to do some checks with a voltmeter to see if I can ascertain each panel’s output and see if I can find a significant voltage drop anywhere on the wiring runs. Because of this low output, I am typically not charging when I run my fridge and freezer, and my thought/hope is to add more power – either wind or solar so that I can get to a positive mode with both running. I don’t see a lot of scope for adding additional area for solar. I have not checked to see if there are now more efficient panels available, but that may be an option. Going over the Bimini may be an option to add an additional panel, but I suspect I may run into clearance issues – especially if the boom were to drop. Right now, if I lower the topping lift, the boom sits on the arch and is held slightly above the existing panels. Anyway, I think my first step is some trouble-shooting and/or optimization of what I have. I will be taking the panels down to transport the boat in December, so this will be a good time to run new cable if that is an issue.

If I do decide to add wind, both you and Scott have re-assured me that I do not need to change out my Solarboost control panel. For what I am trying to do, a unit such as the Air Breeze directly wired to the batteries may be a way to go.

By the way John, the last piece of the puzzle – location. We are getting ready to do our first cruising trip. We are moving the boat to Brunswick, GA and plan to sail to the Bahamas, then return up the west coast of Florida and possibly take the Tennessee River system up to Chattanooga – basically the bottom portion of the Great Loop. We are taking a “sabbatical” from work for several months, but hope it will be the first of many future trips.
Again – thank you all for your input. Very helpful information. Any further comments of course appreciated.

Neil

[barnakiel]

Originally Posted by Ndavies

(...)

275W installed

(...)

On a good day, I seem to get about 7 amps,

(...)

7A is not enough, I think. We get more from a 150W package.

Test on a well discharged battery or else with with plenty of consumers running - with initial voltage well below 12.5 (some regulators re-set to full charge only if a specific low voltage point is met).

b.

[sailinglegend]

Originally Posted by s/vPainkiller

.....You can use a dual controller for both wind and solar, but unless you just want to spend the money, it is not required.

With both solar panels and a wind generator it is often better to use a single regulator with separate wind and solar inputs. If two different regulators are feeding the same battery bank one can get confused by the other and may switch off too early. This is a particular problem in the initial “Boost” stage of charging where batteries will take all the charge they can get. Regulators all work in slightly different ways, but in principle they are programmed to reach a maximum voltage for a set time and then drop down to a float voltage. With wind generators there is not a constant source of power to allow the regulator to stabilise itself. Often there is a huge surge in available current from wind gusts, and then their charge may drop. The wind controller will then still see the high voltage coming from the solar panel controller so it will switch to float. When the wind rises there may be a built-in delay of maybe an hour before the wind controller attempts to charge again and so the cycle continues. The wind generator may be the charge source that could potentially be providing the highest charging capability, but much of the time it has switched itself off so its energy is being wasted.

The simplest KISS principle, which is recommended by several manufacturers, is not to have a regulator for the wind generator but control it manually with a switch or a safe method of tying back the blades when the batteries are known to be 100% charged. This will rarely be needed when cruising with a large service bank, but an unregulated wind generator should not be left running when leaving the boat for an extended period without the risk of overcharging.

For trade wind sailing a towing generator or a DuoGen wind and towing generator are worth considering. A normal wind generator loses efficiency when sailing downwind because of the apparent wind speed.

[noelex 77]

Originally Posted by sailinglegend

With both solar panels and a wind generator it is often better to use a single regulator with separate wind and solar inputs. If two different regulators are feeding the same battery bank one can get confused by the other and may switch off too early. This is a particular problem in the initial “Boost” stage of charging where batteries will take all the charge they can get. Regulators all work in slightly different ways, but in principle they are programmed to reach a maximum voltage for a set time and then drop down to a float voltage. With wind generators there is not a constant source of power to allow the regulator to stabilise itself. Often there is a huge surge in available current from wind gusts, and then their charge may drop. The wind controller will then still see the high voltage coming from the solar panel controller so it will switch to float. When the wind rises there may be a built-in delay of maybe an hour before the wind controller attempts to charge again and so the cycle continues. The wind generator may be the charge source that could potentially be providing the highest charging capability, but much of the time it has switched itself off so its energy is being wasted.

My view is you are better with two separate controllers for wind and solar. For several reasons.
Redundancy
Combined controllers are not very sophisticated especially on the solar side.

Conflict problems between the two charge sources are not common, but it helps if you buy some of the better adjustable regulators that allow variable cut off voltages and time.
In the above examples you give of conflict you need to allow for the fact that the absorption time will only countdown when the voltage is at the absorption voltage. If the voltage drops the countdown stops.

Originally Posted by Ndavies

I seem to get about 7 amps from this which is far below the rating.

Yes that is much too low. A clamp on ammeter makes troubleshooting easy. You can see the output of each panel separately.

[sailinglegend]

Originally Posted by noelex 77

....Conflict problems between the two charge sources are not common, but it helps if you buy some of the better adjustable regulators that allow variable cut off voltages and time...

With two Solar regulators I agree but Wind and Solar are different. If the wind has dropped to Float because of the absorption voltage from the Solar, and the solar output is cut by shade or clouds AND if the wind is blowing then the Wind Regulator may be locked in FLOAT mode for an hour and produce nothing.

On a boat there is rarely a FLOAT situation that operates for very long if the boat is lived on, especially with a BIG battery bank that is NEVER really going to get back to 100%. Loads will quickly drag the battery down to a point when they need charging. Many batteries suffer from Maine Sails "Premature Efloatulation" syndrome so having a wind generator constantly charging when you are aboard can only be a good thing. Set the battery monitor HIGH VOLTAGE alarms to warn you if the battery gets high, indicating it HAS reached 100%.

My DuoGen manual recommends NO regulator if you live aboard the boat. We never leave the boat without locking it OFF.

Two friends with wind and solar have removed their wind regulator and been eternally grateful for these suggestion.

[donradcliffe]

Been there and done that with solar, wind and water generators. I'd forget the wind generator and put more panels up, especially where you are going. Kentucky Lake is "bake and bob" country.

[noelex 77]

Originally Posted by sailinglegend

With two Solar regulators I agree but Wind and Solar are different. If the wind has dropped to Float because of the absorption voltage from the Solar, and the solar output is cut by shade or clouds AND if the wind is blowing then the Wind Regulator may be locked in FLOAT mode for an hour and produce nothing.

On a boat there is rarely a FLOAT situation that operates for very long if the boat is lived on, especially with a BIG battery bank that is NEVER really going to get back to 100%. Loads will quickly drag the battery down to a point when they need charging. Many batteries suffer from Maine Sails "Premature Efloatulation" syndrome so having a wind generator constantly charging when you are aboard can only be a good thing. Set the battery monitor HIGH VOLTAGE alarms to warn you if the battery gets high, indicating it HAS reached 100%.

My DuoGen manual recommends NO regulator if you live aboard the boat. We never leave the boat without locking it OFF.

Two friends with wind and solar have removed their wind regulator and been eternally grateful for these suggestion.

Good regulators do not look just at voltage, they look at voltage and time. (Or even better voltage and battery return amps, but few regulators do this)

The regulator will only drop to float when the absorption voltage has been met for the absorption time.
Say 2 hours at 14.8v.
If the voltage drops below the 14.8v the clock stops. The batteries have to spend a total of 120 mins at (or above) 14.8v. If the output of the wind generator is fluctuating only the time at or above 14.8 v will contribute to the two hours.

If this criterion has been met the batteries should be dropped back to float it does not matter to the batteries if has been kept at this voltage by solar, wind or a combination.

[sailinglegend]

Originally Posted by noelex 77

Good regulators do not look just at voltage, they look at voltage and time. (Or even better voltage and battery return amps, but few regulators do this)

The regulator will only drop to float when the absorption voltage has been met for the absorption time.....

You are totally ignoring Maine Sail's "Premature Efloatulation" syndrome and not looking at "Real World" scenarios.

My very expensive and correctly setup Victron Multiplus drops down to FLOAT at 85% - according to my very accurate SmartGuage.

If there is any possibility of a wind regulator prematurely dropping down to FLOAT because it is being influenced by my expensive and correctly setup Morningstar solar regulator then why have it if you can easily disable it.

[noelex 77]

Originally Posted by sailinglegend

My very expensive and correctly setup Victron Multiplus drops down to FLOAT at 85% - according to my very accurate SmartGuage.

I am not very familiar with the Victron Multiplus, but if dropping down to float prematurely then by definition it is not set up correctly.
Some equipment has a limited range of adjustment and this may be the case with your battery charger, but perhaps you can explain why you cannot correct the problem with say an increase in the absorption time?

Originally Posted by sailinglegend

If there is any possibility of a wind regulator prematurely dropping down to FLOAT because it is being influenced by my expensive and correctly setup Morningstar solar regulator then why have it if you can easily disable it.

If the regulators are good quality, adjustable and set up correctly this should not happen. In many ways a regulator (ignoring the MPPT function) should do nothing until the batteries are overcharging.
I lived without a regulator on cruising boat for some 10 years, but its less than ideal with at least occasional overcharging even if you are attentive. In addition the charging sources sometimes needed to be turned off prematurely when say leaving the boat for several hours when the batteries were were close to full. With modern good quality regulators this should not be necessary.

The exception is where the output is very low in relation to battery size and a regulator is not needed, or the budget is tight and a good quality regulator is out of reach.

Setting up regulators to automatically achieve reliable charging should not be seen as impossible. It just needs good quality equipment with a reasonable range of adjustment, set up correctly.