possible solar and wind hybrid system problem

readyforshtfreadyforshtf Registered Users Posts: 7
First of let me say I have enjoyed this forum and the information found here for quite a while but never found a reason to become a member until today. I need some help with a problem I believe I'm having. I have a small solar system of 400 watts that I have used to charge 8 deep cycle batteries for several years. I wanted a faster charge and power production for cloudy days as well so I put up a homemade wind turbine. The motor is PMM rated at 2000 watts but more realistically puts out 600 watts in normal wind conditions. I am using a sunforce controller for the solar setup. The wind turbine is connected to the battery bank with a blocking diode in-line. I also added a xantrex charge controller set to dump mode to protect the batteries from over charging when the wind turbine was installed. I have checked power output from the wind turbine and it easily reaches the 13-14 volts needed to charge the batteries. The amps put out are between 1-6 depending on wind speed. So with all that said here is my question. I am not seeing very much battery charging difference with the wind turbine installed. Is it possible that the power from the wind turbine is kicking out the solar charge controller? Any help or advice is greatly appreciated:D

Comments

  • mike95490mike95490 Solar Expert Posts: 9,358 ✭✭✭✭✭
    Re: possible solar and wind hybrid system problem

    13 - 14 volts is not enough to fully charge the batteries. The input to your wind controller needs to be in the area of 17-19 volts. Even if that "controller" is a blocking diode.

    What is the dump load on the xantrex ?

    Generally, this stuff needs to be designed as a system, with good understanding of how changes will affect all the other things present.

    I'd also be wary of the batteries, you've not had enough solar to properly charge and de-stratify them.
    Powerfab top of pole PV mount | Listeroid 6/1 w/st5 gen head | XW6048 inverter/chgr | Iota 48V/15A charger | Morningstar 60A MPPT | 48V, 800A NiFe Battery (in series)| 15, Evergreen 205w "12V" PV array on pole | Midnight ePanel | Grundfos 10 SO5-9 with 3 wire Franklin Electric motor (1/2hp 240V 1ph ) on a timer for 3 hr noontime run - Runs off PV ||
    || Midnight Classic 200 | 10, Evergreen 200w in a 160VOC array ||
    || VEC1093 12V Charger | Maha C401 aa/aaa Charger | SureSine | Sunsaver MPPT 15A

    solar: http://tinyurl.com/LMR-Solar
    gen: http://tinyurl.com/LMR-Lister ,

  • BB.BB. Super Moderators, Administrators Posts: 32,006 admin
    Re: possible solar and wind hybrid system problem

    1-6 amps at 14 volts is ~14 to 84 watts of charging energy into your battery bank.

    That is actually pretty typical output for smaller wind turbines unless they are on a 60+ foot tower during a wind storm.

    Other that revisiting the design/installation of your wind turbine and your average winds--I am not sure there is any cost effective way of increasing your power harvest.

    In theory, a MPPT type charge controller could increase your output (out putting 6 amps at 60 volts = 360 watts) can be a big help... But MPPT controllers are not cheap and a generic solar MPPT may not work well for the application. And a "real" MPPT Wind Controller setup will probably cost you north of $1,000 for the hardware (SWAG). Probably not cost effective for your present installation.

    See www.midnitesolar.com for their "Classic" MPPT controller configured for wind (with dump load) for details.

    One person here (Wayne) is pretty happy with a MorningStar 15 amp MPPT charge controller on his water turbine--but you have to be very careful you do not exceed the input voltage limits of the charge controller. (experimenting on your $$$$).

    -Bill
    Near San Francisco California: 3.5kWatt Grid Tied Solar power system+small backup genset
  • CariboocootCariboocoot Banned Posts: 17,615 ✭✭
    Re: possible solar and wind hybrid system problem

    First thing I see: 400 Watts of panel on eight batteries. Unless those batteries work out to <300 Amp hours @ 12 Volts they've been chronically under-charged and are probably no good anymore.

    Second thing I notice: a charge controller on the wind turbine and a blocking diode? A charge controller should be all that's needed, and the typical wind controller set-up is to run full DC power to the batteries and dump any surplus Voltage. What is the output of the turbine? As Bill noted, your figures don't come close to 600 Watts; more like 60. Perhaps the turbine's Voltage is too far above the battery bank's and all the power is being lost to heat.

    What Sunforce controller do you have? A quick look didn't show me any unit that would be suitable for wind applications in the manner you describe. A solar charge controller should not "kick out"; they will reduce power from the panels as per the batteries' needs (or perceived needs). A few Amps from the turbine would not significantly affect the panel charge rate.
  • readyforshtfreadyforshtf Registered Users Posts: 7
    Re: possible solar and wind hybrid system problem

    Ok lets see if I can answer all the questions.

    The solar charge controller is a sunforce 60032.

    The solar controller is only on the solar array not the wind turbine.

    The wind turbine is connected directly to the batteries with only a blocking diode between the wind turbine and batteries.

    The battery bank is only used for small loads and emergency power and has almost never fallen below 12 volts.

    The dump load for the xantrex is a 600 watt 12v water heater element.

    The wattage of the wind turbine is determined by wind speed. It maxes out at 2000 but real world is more like 600 is possible.

    The battery voltage clamps the wind turbine voltage so 17-19 volts may not be possible.

    Thanks for the help guys. I do appreciate all the input. Hope I answered all the questions.
  • CariboocootCariboocoot Banned Posts: 17,615 ✭✭
    Re: possible solar and wind hybrid system problem

    Okay, now we're getting somewhere! :D

    Charge controller on the solar panels: all fine.
    But there is still the question of how many Amp hours those batteries are. For instance if they are eight golf cart batteries of 6 Volt @ 220 Amp hours that's 880 Amp hours @ 12 Volts. Far too much for longevity off 400 Watts of panels. 12 Volts, btw, is 50% discharged (roughly). Have a look at the good ol' battery FAQ's: http://www.windsun.com/Batteries/Battery_FAQ.htm
    And of course SOC will have a bearing on the current from either panels or wind.

    Now as to the wind turbine, you bring up a good point with the battery Voltage "clamping" the output. Normally we'd look for around 18 Vmp from panels feeding a charge controller for a 12 Volt system charging at 14.4 Volts. Your wind power measured only in Watts leaves out the potential difference here. If it's supposed to run at 24 Volts, say, and the battery is pulling it down to 14 the turbine may 'interpret' this in a manner that ends up losing power. This is why some wind systems have charge controllers on the generator: as Bill suggested, an MPPT unit that can take the varying output and make the most of it for charging the battery.

    This is where the numbers get tricky, especially with homemade. For instance a 2kW generator feeding 12 Volts could hit 150 Amps. That is a lot of Amps. Running that much power @ 12 Volts all the way down the tower to the batteries introduces the potential for a lot of Voltage (and thus power) loss. On the other hand if it outputs more like 48 Volts that current drops to about 40 Amps and the V-drop potential becomes much less. At 600 Watts the ratios are the same, but the current numbers are smaller.

    What I'm trying to get at here is that it is entirely possible to introduce a wiring factor capable of choking off much of the power. Let's say you have a 'short' run of 50' from generator to batteries @ 12 Volts and expect the low output of 600 Watts. That's 50 Amps of current. Run those numbers through a V-drop calculator and you get a need for 3/0 wire to keep the V-drop to a minimum. That's really big wire.

    This is why wind turbines ought to be high Voltage, in my opinion: it's always a far distance from the generator to the batteries. At least it is if the blades are up a tower like they should be. And if the generator's Voltage is high then you have the problem of the batteries taking it low without being able to gain the power benefit (unless using the MPPT controller as mentioned before).

    It's a balancing act, and not an easy one.
  • readyforshtfreadyforshtf Registered Users Posts: 7
    Re: possible solar and wind hybrid system problem

    This is the motor I'm using.

    http://www.ebay.com/itm/600-WATT-WIND-GENERATOR-TURBINE-MOTOR-PMA-ALTERNATOR-/250919274981?pt=LH_DefaultDomain_0&hash=item3a6bf449e5

    Yes I have considered shortening the run and going to larger wire as well. I did that with my solar also.
  • CariboocootCariboocoot Banned Posts: 17,615 ✭✭
    Re: possible solar and wind hybrid system problem

    Oh boy.
    See, this is where you wanted to do some bench testing before you put it up on that tower.
    If you could spin this thing (which is a permanent magnet motor, and motor are not alternators even if they can be made to work like one) at a controlled RPM you could get an idea of what kind of Voltage it would put out. You could also "load it" and see what kind of current to expect at that Voltage.

    Then there's the whole translating-wind-speed-into-RPM-through-blade-design thing.

    Let's just look at this sentence from the ad: "... this generator will start charging a 12 volt battery bank in consistent 6-8 mph winds."
    Charge how much 12 Volt battery at what rate? Technically putting 1 milliamp into a 1000 Amp hour battery bank is "charging", but it won't do much for it. My point is not to say that it won't work, but to illustrate that the methods used to describe its functionality are rather imprecise. Vague, you might say.

    But if you know the blade design will spin it at 'X' RPM in a wind speed of 'Y' MPH and at that rate it will produce 'V' Volts @ 'A' Amps then you have some figures to work with. As it s you have only the indication that it will produce some power in some wind which will supply some charging. Maybe.

    I don't suppose you want to take it down and do some bench testing? :roll:

    Got an anemometer? Can you check for open circuit Voltage at a given wind speed? In general it's better to let the Voltage be high and the current low to maximize power transmission over distance.

    In short, and this is only my opinion, I think most of your wind turbine's power is being lost to long wires and large Voltage differences.
  • readyforshtfreadyforshtf Registered Users Posts: 7
    Re: possible solar and wind hybrid system problem

    I think you may be correct. I was thinking of changing to a PMA. Any opinion on this?
  • BB.BB. Super Moderators, Administrators Posts: 32,006 admin
    Re: possible solar and wind hybrid system problem

    Be warned, I am not a big fan of small wind... I think it is expensive and high maintenance for the amount of power collected. And most people do not live in areas where there is enough wind anyway... So, here are some links:

    Wind Power Links
    www.otherpower.com (good forum for DIY Wind Power)
    Hugh Piggott - Scoraig Wind Electric site for tons of info (from mike90045)
    www.greenpowertalk.org (added from "russ"--Like here but more wind/less solar)
    Small windpower a scam ? Survey says SO
    Truth About Skystream & SWWP
    Windmax HY-2000 2kW Wind Turbine (apparently, some vendors don't sell spare parts--just new turbines)

    And a general DIY Solar Builder site:

    www.builditsolar.com

    The above is from a Beginner's FAQ Thread.

    -Bill
    Near San Francisco California: 3.5kWatt Grid Tied Solar power system+small backup genset
  • CariboocootCariboocoot Banned Posts: 17,615 ✭✭
    Re: possible solar and wind hybrid system problem
    I think you may be correct. I was thinking of changing to a PMA. Any opinion on this?

    Aside from the links Bill has provided there's not much more to add.
    But I will explain my statement, in that charging an electromagnetic field to push a magnet-laden rotor around is not the same as spinning said rotor to induce a magnetic field in surrounding windings.
    The "car alternator" wind turbines have the right idea, but very poor execution. Wind blades don't usually come up to 2000 RPM, and that right there is a problem. At slower speeds you either sacrifice power production or else you need huge blades to grab enough mechanical power from the air to create usable electric. Just look at those big, slow-moving commercial turbines. It's an entirely different magnet-to-winding ratio thing.
  • readyforshtfreadyforshtf Registered Users Posts: 7
    Re: possible solar and wind hybrid system problem

    Your right car alternators don't work correctly due to the rpm required but when they reconfigure them and turn them into a permanent magnet alternator the rpm issue is corrected.
  • readyforshtfreadyforshtf Registered Users Posts: 7
    Re: possible solar and wind hybrid system problem
    BB. wrote: »
    Be warned, I am not a big fan of small wind... I think it is expensive and high maintenance for the amount of power collected. And most people do not live in areas where there is enough wind anyway... So, here are some links:

    Wind Power Links
    www.otherpower.com (good forum for DIY Wind Power)
    Hugh Piggott - Scoraig Wind Electric site for tons of info (from mike90045)
    www.greenpowertalk.org (added from "russ"--Like here but more wind/less solar)
    Small windpower a scam ? Survey says SO
    Truth About Skystream & SWWP
    Windmax HY-2000 2kW Wind Turbine (apparently, some vendors don't sell spare parts--just new turbines)

    And a general DIY Solar Builder site:

    www.builditsolar.com

    The above is from a Beginner's FAQ Thread.

    -Bill

    I agree that solar produces a more consistant power and I love solar but on overcast winter days you really need an extra source of power. Also wind can charge all night long unlike solar. So they work well together. As far as cost goes my 50 watt sunforce panels sold for 350-400 I think. This wind turbine has cost me 200.00 and if you add the extra xantrax controller and heating element I'm at 350.00. So even at this point I'm still ahead of the game as compared to solar. When I get all these technical issues worked out it will even be that much better.
  • CariboocootCariboocoot Banned Posts: 17,615 ✭✭
    Re: possible solar and wind hybrid system problem
    As far as cost goes my 50 watt sunforce panels sold for 350-400 I think.

    How many 50 Watt panels did you get for $400?
    Just for comparative purposes, a Kyocera 135 Watt is about $325. When you need more Watts the bigger panels become a much better deal.
  • readyforshtfreadyforshtf Registered Users Posts: 7
    Re: possible solar and wind hybrid system problem
    How many 50 Watt panels did you get for $400?
    Just for comparative purposes, a Kyocera 135 Watt is about $325. When you need more Watts the bigger panels become a much better deal.

    When I bought them last year I got them on a close out at newegg.com and I think I got them for 150-175 each so I bought 2. They were retailing for 300 or 399 IIRC. I remember thinking they were a horrible deal at retail price.
  • System2System2 Posts: 6,290 admin
    Re: possible solar and wind hybrid system problem

    hello-
    my first post here. i don't like the general consensus that small wind is bad, and doesn't work. i fully agree with that statement for UL listed grid tied systems that are installed in all, but the windiest locations, as the costs are astounding. however, for off grid home built turbines, so long as you're in at least a class 2-3 wind zone, wind can save the day when you solar is all but useless. all that said...

    buying any motor from ebay that is advertised as a wind generator PMA or PMM or whatever magic terms they give, and magic number (openV and shortedA) multiplying those numbers to give you a 2000W output is a bunch of junk. any motor that resembles a car alternator in any way is most likely junk for a wind turbine.

    there are small motors like 1/3 and 1/2HP motors for variable rate furnace blowers that can do alright if your target is 100w or less on a regular basis. but again, these are not advertised as wind turbine motors.

    then there's three phase PM servo motors. these can be HUGE producers with the right blade match. i use a fanuc servo with 8.5' blades and have seen over 600w @ 24v going right into the battery bank. many mornings, i wake to see the battery bank at float, something solar will never accomplish.

    readyfor- i think your problem has to do with a poor motor for wind. doesn't sound like your controllers are fighting with eachother. might be time to go back to the drawing board and find a new motor. bench test it first to give you an idea on V/rpm and amps per rpm after cut in. then start trying blades. it's all trial and error with home built, but most anyone with decent skills can build a reliable unit that produces decent amounts of power.

    i hope through my first post, i've not peeved anyone too badly, but i just couldn't stand by with the accusations against home built small wind for off grid applications.

    adam
  • BB.BB. Super Moderators, Administrators Posts: 32,006 admin
    Re: possible solar and wind hybrid system problem

    Not a problem... The right person can build a pretty decent turbine, with the right parts, on the right tower, in the right location, can produce.

    But the same can be said for Solar PV systems too... Need lots of sun, in the right location, with good equipment.

    At this point, solar is a lot easier to predict the output for and verify it meets the design goals.

    With wind, not so much. In fact, many times when I ask people how may Amp*Hours/kWH their system produces per month--I rarely get an answer (except for direct Grid Tied connected systems).

    The other killer is maintenance... If you built and installed your own system, you are pretty much able to do anything you need to keep it operating.

    With commercially supplied/installed systems, there is usually a charge for a crane truck to service the unit (once a year on average?).

    Add lightning into the mix (turbine/tower strikes), it is a handful to keep running.

    Adam, if you wish to document your system and/or point to your system website--Please feel free. We are a big believer in the free flow of information.

    -Bill
    Near San Francisco California: 3.5kWatt Grid Tied Solar power system+small backup genset
  • System2System2 Posts: 6,290 admin
    Re: possible solar and wind hybrid system problem

    BB-
    thanks for the nice reply.

    readyfor-feel free to ask questions as to a new motor. i'm not a perfect person to advise, but have some knowledge of the "good ones" 12v is typically way easier to find good motors for than 24v or 48v.

    i use solar as well as wind out at my ranch. the nearest power poles are ~5 miles away, so i have no choice. didn't mean to downplay solar, as i reap the benefits very often. problem is, there are times when even a Kw of panels do almost didly squat. these times the wind is typically ripping hard, and a decent turbine pulls in the amps when needed most. the reason you rarely see output figures on off grid turbines, it it's kinda hard to measure. most are connected directly to the battery bank which makes metering tricky. a doc wattson meter with mods via a 100A external shunt seem to be the best way to do this, but i've yet to go that route.

    i'm very much a DIY guy and my wiring isn't near as clean as many photos i've seen here, but the connections are all very solid, and wire gauge is typically thicker than needed for 2%.

    my 70' home built tower is tilt over and can be lowered in 5 min. and raised in 15min. proper grounding only takes effort once, during the build, and "should" eliminate lightning strikes. i've got (7) 8' long grounding rods all connected with #4 bare. this is a WAY better ground than most of the UL CE Code inspected homes most of us are sitting in today.

    a well built turbine with heavy steel parts should take very little maint. that's the way i've built mine. some grease on the tower stub, and maybe some touch up paint on the blades each year should cover it.

    i've probably typed too much, and feel like i'm hijacking this thread, but heres the links to my set-up: http://fieldlines.com/board/index.php/topic,145343.0.html

    and http://fieldlines.com/board/index.php/topic,145609.0.html

    adam
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