Wind System add on the right way to proceed?

InCogKneeToeInCogKneeToe Registered Users Posts: 67 ✭✭
Hi People.

Newbie Also here (well somewhat).

So my Scabbed Together System.

4, 100 Watt Coleman (Sun Force) 12v Panels. Roof Mount, West Facing, 4.5 hours/day area
4, 105Ah Deep Cycle LA 12v Batteries,
1, 30a PWM 12v Charge Controller.
1, 1000 watt Pure Sine Wave Invertor. (never over powered even with Freezer Starting)
1, 30A Multi Stage Charger tied to Generator (run 1-3 hours per evening). With a Manual Equalization Mode.



This system does most of what I need. Usually Weekends, Stereo, TV, DVD, and such. It is on 2/3 weeks off time, when a 5.0 cu/ft Freezer (1.2A/ 218 kwH-year) is added, that in the Mornings show 11.5-12.5V Yellow Warning on my Charge Controller. 

So, I have to start the Generator for an hour to get the batteries back over 13Vs.


I do get plenty of Westerly Wind, so in thinking, I could harness some of this at night (well most nights), plus maybe 2 more Batteries (for a total of 630 AH). This will help on cloudy days also and Winter, when I might not be able to clear the snow off of my panels for months. Keeping a Charge in the Batteries where temps can reach minus 40F.

Looking at the 4 day History, wind speeds have been averaging 9 knots. I have a West View Lake Frontage, with 3 miles of unobstructed Prevailing Westerly Wind.

I was planning a 400w Coleman (Sun Force) the same as the rest of my stuff, available locally at Canadian Tire. With an extra Charge Controller in parallel, but any Wind Generator suggestions would help.


Hoping to avoid, Morning top up with the Generator.


Ultimate, would be only needing the Generator for Vacuuming, power tools and such.

Thanks in Advance.

Comments

  • BB.BB. Super Moderators, Administrators Posts: 31,143 admin
    Just to be clear--Personally, I am not a fan of small wind systems... Hopefully some members here can recommend units and/or provide a review of the Coleman 400 Watt system.

    From this website:

    https://sunforceproducts.com/products/400-watt-12-volt-wind-generator/

    I did not find any performance charts... So, no idea how it performs (or anything you could hold the seller to for xx mph wind and yy amps of current, etc.).

    I would be wanting to see something like this:

    https://www.solar-electric.com/lib/wind-sun/Air-spec-sheet.pdf

    If you notice, there is very little power generated at 9 knots/10.3 MPH.... Most turbines in this class need around 25-32 MPH wind for "optimum output". And I did not see any other "technical specifications" like "swept area" or "blade diameter".

    Note that wind turbines output power to the cube of the wind speed... I.e., (10 mph)^3 = "1,000", and 13^3="2,197" or ~2.2x more power at 13 mph vis 10 mph... So wind measurements (as well as tower location/height) are critical to getting good performance.

    We have had a few posters here trying to get their turbines to generate power--And we could not really help them much. It is not always be clear if the problem is the design or the installation (tower height, clear of obstructions, non-turbulent air, etc.).

    Just guessing, but many times these small wind systems only generate around 1-3 amps or so (at ~14.x volts or ~14 to 42 Watts roughly, in typical conditions).

    If you can find somebody (hopefully) that has installed this turbine (or other turbine brands/models) near your location and see if you can get their daily/monthly performance numbers.

    Regarding your battery bank size--A 12 volt @ 420 AH is a bit on the small side for running a refrigerator.... You say the refrigerator is 1.2 Amps--Is that at 120 VAC or 12 VDC?

    If you can get 6 volt @ ~200 AH golf cart batteries, I would suggest this (2 in series x 2 parallel strings) is a "better battery bank" for various reasons vs your 12 volt @ 105 AH battery bank. It is usually better than two many 12 volt batteries in parallel. And 6 volt GC batteries are usually among the least expensive you can find.

    If you choose to add more batteries, you probably want to look at adding more solar panels too... 5% rate of charge can work for weekend/summer usage... For more full time off grid, 10-13%+ rate of charge would be better long term (happier batteries charged at 10%+ rate of charge, especially for daily use):
    • 420 AH * 14.5 volts charging * 1/0.77 panel+controller deratings * 0.05 rate of charge = 395 Watt array minimum
    • 420 AH * 14.5 volts charging * 1/0.77 panel+controller deratings * 0.10 rate of charge = 791 Watt array nominal
    • 420 AH * 14.5 volts charging * 1/0.77 panel+controller deratings * 0.13 rate of charge = 1,028 Watt array "typical cost effective maximum"
    Adding refrigeration to an off grid power system--That is generally the load that takes you from a "small" to a mid-size power system.

    If you were to go with a larger battery bank (630 AH) and a 10%+ rate of charge:
    • 630 AH * 14.5 volts charging * 1/0.77 panel+controller deratings * 0.10 rate of charge = 1,186 Watt array nominal
    And lets guess you are around Fort Frances ON, Canada, fixed solar array facing south:
    http://www.solarelectricityhandbook.com/solar-irradiance.html

    Fort Frances
    Average Solar Insolation figures

    Measured in kWh/m2/day onto a solar panel set at a 41° angle from vertical:
    (For best year-round performance)

    JanFebMarAprMayJun
    2.42
     
    3.66
     
    4.54
     
    4.98
     
    5.03
     
    4.88
     
    JulAugSepOctNovDec
    5.02
     
    4.89
     
    3.97
     
    3.11
     
    2.45
     
    2.01
     

    And lets guess at your power needs... 1,000 Watts of power usually does OK for lights, radio, LED TV, laptop computer, cell phone charging (pure starting guess--If you have "real numbers", always helpful). And your 218 kWH per year fridge/freezer:
    • 218,000 WH per year * 1/365 Days per year = 597 WH per day
    • 597 WH per day fridge + 1,000 WH per day rest of cabin = 1,597 WH per day
    Tossing the bottom three months (not there, snow covered panels, etc.) gives us October at 3.11 hours of sun per day as "break even" month:
    • 1,597 WH per day * 1/0.52 off grid AC system eff * 1/3.11 hours of sun per day = 988 Watt array October "break even"
    So if you went with the 12 volt @ 630 AH battery bank (I would prefer 2x 6 volt GC batteries in series * 3 parallel 210 AH string for your 12 volt @ 630 AH bank). With a 1,186 Watt array (nominal 10% rate of charge)... That would not be a bad system.

    Obviously, with the larger array, you would need a 2nd charge controller (or bigger controller and new array, etc.)...

    And if you decide to add wind--And it worked out for you--That would be icing on the cake.

    Of course, there is always the cost tradeoffs between a wind turbine & tower/wiring costs, vs just adding more solar panels.

    Your thoughts? And any questions on the solar design side?

    -Bill
    Near San Francisco California: 3.5kWatt Grid Tied Solar power system+small backup genset
  • InCogKneeToeInCogKneeToe Registered Users Posts: 67 ✭✭
    edited April 14 #3
    Thank You for the guidance Bill!

    You Nailed my area Fort Frances and Rainy Lake btw.

    Yes I follow, the AH storage as being larger than can be supplied by the array, but that was weekend idea, now with the Wife getting 5 weeks of holidays/year and Propane Shipping to an island sketchy, 120v refrigeration has become the nemesis. Turning Afternoon Tunes into a small part of our needs.

    The 1000 watt inverter is the Max Load with the Freezer, well plus 12v stereo/Cell Charging. So I am thinking 1000-1100 WH/Freezer Day. Freezer on 120v.

    Your thoughts? And any questions on the solar design side?

    -Bill 

    Yes, Where would you go with this? Wind was a thought for me for Winter Months to keep up on unattended Battery Charge and location with an abundance of wind available.


    or, Doubling my Array plus 50% more storage to maintain and restore my usage daily, with some Generator top off (if needed) on cloudy days?

    Thank you again for So Much understandable information.

    Bob
  • EstragonEstragon Registered Users Posts: 4,478 ✭✭✭✭✭
    I'm not far from you (LOTW, east of Kenora), also facing west with a ~5mi fetch across the bay, and likely similar terrain.  I haven't tried the kite thing but I'm pretty sure the rise and trees to the east behind the cabin makes the wind turbulent enough for a turbine at the shoreline impractical.  Maybe you have swamp or more lake to the east?

    Getting propane is a pain for me too.  I've used a tracked SxS in the past but ice conditions were sketchy this winter so I ended up buying a ski-doo and boggan and hauling one 100# at a time.

    For unattended winter charging I have small arrays mounted vertically for when the big arrays get shaded by long shadows and/or get snow covered.
    Off-grid.  
    Main daytime system ~4kw panels into 2xMNClassic150 370ah 48v bank 2xOutback 3548 inverter 120v + 240v autotransformer
    Night system ~1kw panels into 1xMNClassic150 700ah 12v bank morningstar 300w inverter
  • InCogKneeToeInCogKneeToe Registered Users Posts: 67 ✭✭
    Yes, I have used 2 40w panels mounted on the west wall for Winter before. This year I didn't. I moved them to the Shed for a small system. (water pump, lighting, and 2000w Inverter for occasional power tool).




    This is the Wind Access. Right about the Tower Position I am thinking of (short run to the Battery Bank). The Red Pine to the left does shade my panels some, but April-May after 5pm.

    I helped a Neighbour add a Wind Generator to their system 25 years ago. It helps them some, but they are still Propane Fridge and Freezer. It tops her system up on Grey Days and last fall it came unhooked, she noticed it absence.


  • BB.BB. Super Moderators, Administrators Posts: 31,143 admin
    Bob,

    For unattended batteries (not being used during winter), fully charged FLA batteries do not freeze until something under -70F or lower... "Completely Dead" FLA batteries freeze at just under 32F.

    https://www.mathscinotes.com/2013/02/battery-freezing-math/ (in degrees C)
    editedfinal

    More or less, an FLA battery that needs recharging about every 30 days @ room temperature (around 25C/75F), when below freezing can go an entire winter without charging... See page 5 of paper in link below.

    https://gelcoservices.com.au/docs/Lead%20Acid%20Battery%20Self-Discharge%20Paper.pdf

    I cannot find a quick reference, but the old engineering rule of thumb for aging is a good start (almost anything from batteries to food), is for every 10C (18F) drop in temperature, the aging is cut by 1/2... From 25C to 5C, that is 1/2 * 1/2 or 1/4 the aging, or 4x life while cold (note, this does not include cycle life calculations--Just battery sitting unused).

    Normally, I use the 30 Days and assume 100% to 75% state of charge--And when the battery falls below 75% SoC, it is time to recharge because the sulfation process (permanent and non-reversible) accelerates.

    Here, I am using the engineering rule of thumb to also model the self discharge process (remember: all models are wrong, and some models are useful)... If your FLA battery will go 1 month between recharging @ 25C, at 5C it should go 1/2 * 1/2 = 1/4 or 4 months between recharging (slower self discharge--Seems to follow the graph above).

    And others here have simply mounted a couple extra solar panels (100+ Watts or so, whatever room and $$$ allows), on a vertical south facing wall (or racking) that stay reasonably clear of drifts during the winter--The small amount of float charging helps keep the batteries up as well...

    Regarding electric cooking... Induction "hot plates" and cooktops are getting popular in the RV market. And they are installing them on some relatively small battery bank (using LiFePO4 banks--Smaller AH capacity, but higher surge/current ability vs FLA).

    Might look at that... Have to get the "right pans" for induction heating. And not expect to use lots of high heat/wattage--I have not seen numbers, but it seems like (a little back of the envelope math, numbers from RV videos) that 350 Watts for heating/simiring for 20 minutes is possible for a small dish for 1-2 people. That can be operated on an off grid solar system. Getting a induction hot plate, pan, and a kill-a-Watt type power meter, and do a little experimentation at home. Very similar to cooking with gas (instant heat response) without the gas flame issues of extra heat in the room (hot weather), or extra humidity/use of oxygen in winter (freezing climates and "sealed buildings"--An issue?).

    My suggestion has always been to do "everything" first with solar panels (panels are cheap, last 20+ years, and zero maintenance/ongoing costs). And a backup genset (smaller, gasoline seems to be a bit easier than diesel, propane, etc. in extreme cold climates).

    For "summer" and hunting cabins... A small solar power system for lights, cell phone charging, running a tablet computer, quite time---And use a genset for larger power needs (well pumping, clothes washer, cooking/microwave). Limit risks and sunk costs for a few hours per week, a few weeks a year --- Vs full time (9+ months) off grid living.

    Energy is a highly personal set of choices... This needs to work for you and your needs. I like to do things right (a bit on the conservative side). I try to look at risk vs reward side of the issues... A $15,000 solar power system is nice, but a $1,000 solar+battery system (~2-6x 6 volt Golf Cart batteries) + 300 Watt inverter for lighting/small loads--And a $1,200 2 kWatt inverter-generator for the large loads/recharging battery during bad weather + 10 gallons or so of gasoline for a week or two at a time...

    For remote cabins--There is always the issue of theft/vandalism and leaving large/expensive power systems (well pump, etc.) alone for months at a time... A small genset (Honda eu2200i or similar) and 5-10 gallons of gasoline will keep you in "useful" power for a week or two--And much easier to pack up and take home at the end of the season.

    And to clarify... I am NOT a battery engineer. And the closest I get to freezing temperatures is in my refrigerator. Hopefully some folks from our neighbors to the north/mountain regions (Estragon posted just before this post--He always has good information) can add their real life experiences and suggestions.

    With all things off grid--Details matter. Because I have not brought a specific issue up, does not mean that it can be ignored, or there are not other "useful" solutions. Although at times it may look like it--I am not writing a book here  :) .

    -Bill
    Near San Francisco California: 3.5kWatt Grid Tied Solar power system+small backup genset
  • InCogKneeToeInCogKneeToe Registered Users Posts: 67 ✭✭
    Thanks Bill.

    Freezing is just a back thought worry. Discharging over time to a Freeze Point.

    Cooking is covered by Propane. A 20lb lasts nearly a full season with BBQing/Smoker 1/2 the time.

    It is just the Refrigeration part of the equation I have to rework.

    So the way I am thinking, I need more saturation, 5% was ok for 2-3 days light use every 7 days.

    So another 400 watts with another Charge Controler would bring that number up to 10% Correct?

    But then I have a Storage issue (11..-11.5 Volts early AM). So adding 1 or 2 more Batteries 210AH,  would fix that but drop the saturation to 6-8%?.

    Yes I do have a e2200 Honda, but I mostly use a 1250 Champion @ night (again it will handle everything including a 30A Battery Charger and Fridge (that the Freezer is replacing for insulation factor).
  • BB.BB. Super Moderators, Administrators Posts: 31,143 admin
    The 50% discharge level... It is a good point for design theory. But you going down to 20% SoC occasionally, is not going to "kill" a good flooded cell lead acid battery by itself). Mostly, as an example, cycling to 60 SoC 2-3x is roughly equivalent (in cycle life) to taking the bank to 20% once (i.e., the cycle life * depth of discharge is roughly a constant--The proportionally deeper cycle, the proportionally reduction in cycle life--But the cost per AH is roughly the same).

    Or a battery bank 2x larger with 1/2 the depth of discharge will last ~2x longer. Or a 1/2 size AH battery bank will last 1/2 as long, and cost 1/2 as much.

    As long as you recharge the battery bank >80% State of Charge the next day...

    For a daily use system, very deep cycling does shorten the battery bank life... Hower for seasonal/weekend system, the batteries tend to "Age Out" before they cycle out. So--Use the batteries as you need the energy.

    The 50% cycle point is not "obvious" with lead acid batteries. For a resting battery (3+ hours no load, no charging) at room temperature, 50% state of charge may be around 12.4 volts. For a bank under a reasonable continuous load, 50% SoC may be 11.5 volts.

    Regarding refrigeration/freezing... A few folks here have gone to the RV wreckers and purchased a used propane refrigerator for weekend/seasonal use... A 1/2 to 1 lb per day of propane(?), saving on "a larger" off grid power system/more genset use.

    -Bill
    Near San Francisco California: 3.5kWatt Grid Tied Solar power system+small backup genset
  • InCogKneeToeInCogKneeToe Registered Users Posts: 67 ✭✭
    Wouldn't you know it. The Wind Generator I was contemplating, is on Sale this week. $300 off, so $499 instead of the Over Inflated $799.

    Thinking "This is the way Life is suppose to go" attitude, and a $249 to return item at the same Store, "Perfect" I will be into it for $250, worth giving it a try anyways.


    It's more money than some on the Web, but it has it's on Charge Controller and Shut Off, so I wouldn't need an unattended Dump.

    They are not taking Returns during the hole Covid thing. So I went with the "This is the way Life is suppose to go" attitude,

  • InCogKneeToeInCogKneeToe Registered Users Posts: 67 ✭✭
    edited April 23 #10
    BB. said:

    • 420 AH * 14.5 volts charging * 1/0.77 panel+controller deratings * 0.05 rate of charge = 395 Watt array minimum
    • 420 AH * 14.5 volts charging * 1/0.77 panel+controller deratings * 0.10 rate of charge = 791 Watt array nominal
    • 420 AH * 14.5 volts charging * 1/0.77 panel+controller deratings * 0.13 rate of charge = 1,028 Watt array "typical cost effective maximum"
    Adding refrigeration to an off grid power system--That is generally the load that takes you from a "small" to a mid-size power system.

    If you were to go with a larger battery bank (630 AH) and a 10%+ rate of charge:
    • 630 AH * 14.5 volts charging * 1/0.77 panel+controller deratings * 0.10 rate of charge = 1,186 Watt array nominal
    And lets guess you are around Fort Frances ON, Canada, fixed solar array facing south:
    http://www.solarelectricityhandbook.com/solar-irradiance.html

    Fort Frances
    Average Solar Insolation figures

    Measured in kWh/m2/day onto a solar panel set at a 41° angle from vertical:
    (For best year-round performance)

    JanFebMarAprMayJun
    2.42
     
    3.66
     
    4.54
     
    4.98
     
    5.03
     
    4.88
     
    JulAugSepOctNovDec
    5.02
     
    4.89
     
    3.97
     
    3.11
     
    2.45
     
    2.01
     

    And lets guess at your power needs... 1,000 Watts of power usually does OK for lights, radio, LED TV, laptop computer, cell phone charging (pure starting guess--If you have "real numbers", always helpful). And your 218 kWH per year fridge/freezer:
    • 218,000 WH per year * 1/365 Days per year = 597 WH per day
    • 597 WH per day fridge + 1,000 WH per day rest of cabin = 1,597 WH per day
    Tossing the bottom three months (not there, snow covered panels, etc.) gives us October at 3.11 hours of sun per day as "break even" month:
    • 1,597 WH per day * 1/0.52 off grid AC system eff * 1/3.11 hours of sun per day = 988 Watt array October "break even"
    So if you went with the 12 volt @ 630 AH battery bank (I would prefer 2x 6 volt GC batteries in series * 3 parallel 210 AH string for your 12 volt @ 630 AH bank). With a 1,186 Watt array (nominal 10% rate of charge)... That would not be a bad system.

    Obviously, with the larger array, you would need a 2nd charge controller (or bigger controller and new array, etc.)...

    And if you decide to add wind--And it worked out for you--That would be icing on the cake.



    Your thoughts? And any questions on the solar design side?

    -Bill
    Thinking Deeper of your suggestions. And after this Winter's Snow Cover Days (which were New Years Eve-2nd Week of March) without Freeze Up.

    I have decided to Add another Array. Ground Frame, that can be shifted more Southerly for Winter.

    So Questions are (if you care to help)

    2 more 12V DC Flooded 105 A/H, to not Mix and Match my Bank or 2 "for now" 6V Flooded 220AH added?

     And, Is there a Benefit to MPPT over another Identical Digital PWM 30a Controller? Or 1 Controller for Both Arrays? Will I need a Combiner or can I tie them directly at the Batteries? I have the single as far apart as possible + on #1 Battery -on #4 Battery (just reversed)

    The Leads for both will be about each, but from different areas (Roof and Yard) meeting in the Cabin.

    PS. 1000w AC Inverter runs everything, needed. Including, June-Sept are the Freezer Months. 

    Freezer Months don't have the Storage needed, and Generator run time is shorter at night.
  • BB.BB. Super Moderators, Administrators Posts: 31,143 admin
    If you are going to add a southern facing array for winter, do you want to make the frame so that it is adjustable tilt (less tilt for summer, more tilt for winter/better shedding of snow)? Make frame high enough for snow to fall to ground, and/or easier to remove snow from front of array in winter? (I am near San Francisco, so me asking about snow/cold is "in theory" only).

    Regarding batteries, I really prefer 6 volt @ xxx AH batteries. For 12 volt banks, all 12 volt batteries are in parallel, all batteries are at "12 volts". With 6 volt batteries, 2x in series, a simple voltage check will show "unbalanced" battery voltages if you have problems.

    Also, with 2x 12 volt @ 110 AH batteries--You have 12 cells to check. For 2x 6 volt @ 220 AH batteries in series, you only have 6 cells to check electrolyte levels.

    Lastly, if you are adding array and battery storage--Is a 24 (or 48 volt) bank in your future? My suggestion is if you are looking at >~800 AH @ 12 volt battery bank, might be worth looking at 400 AH @ 24 volts.... Of course, that is at the cost of a new AC inverter, possibly new battery bank for new Series/Parallel configuration, etc... But if your peak loads are not getting larger--Perhaps 12 volts will continue to work fine for your needs.

    -Bill
    Near San Francisco California: 3.5kWatt Grid Tied Solar power system+small backup genset
  • InCogKneeToeInCogKneeToe Registered Users Posts: 67 ✭✭
    Ok, Thanks again Bill.

    Next time I am out of Town, I will pick up 2 6volts. (can't find them readily n town). 

    I am hoping to stay small enough, hot to have to start over. (Panels/Inverter) so staying 12v is most likely my way of the future. Anymore and I would just do Plan B, a 2000watt Inverter Gen, 15 gallon external tank, 12v low pressure pump, 24/7.


    Leave the Solar for Music/Phone Charging during Weekend trips
  • BB.BB. Super Moderators, Administrators Posts: 31,143 admin
    I forgot toanswer another question you asked... If you have MPPT type charge controllers, then each array (that faces a different angle and/or direction, you should have separate MPPT controllers for each.

    If you have one larger PWM controller, they can support different angles/directions.

    MPPT controllers try to "maximize" Vmp and Imp of the array. When you have different arrays pointing different directions, the MPPT controller cannot find the "optimum" (there may be two or three sub-optimum points, and no "perfect" match).

    With MPPT controllers you can run the solar array at higher voltage (higher Vmp-array). And you can use "GT" type solar panels (Vmp~30-36 volt or so large format solar panels which are cheaper $$$/Watt too). That allows you to use smaller AWG copper cables from the array to the battery bank. And to use less expensive/larger wattage solar panels (>~200 Watt panels). Note, large format solar panels typically require two people to safely lift and install.

    With PWM controllers, if the panels are close to battery bank--Then you can use PWM with ~140 Watt @ Vmp~18 volt panels (these tend to be more expensive panels $$$/Watt) all in parallel.

    It is true that MPPT controllers can harvest more energy for solar arrays running in sub freezing climates (something like 10-20% more energy harvest over PWM controller). But it is not a huge increase (i.e., just add another panel to your PWM controller if you want more energy in winter).

    Do several paper designs and see what works best for you. If you need help with the details, feel free to ask.

    -Bill
    Near San Francisco California: 3.5kWatt Grid Tied Solar power system+small backup genset
  • InCogKneeToeInCogKneeToe Registered Users Posts: 67 ✭✭

    Thanks Bill.

    My Panels are 12v and cannot be hook in series, only parrel so I am stuck with a 12v Charge Controller.

    My thoughts right now are 2 12v 150 watt panels (on Sale where I purchased evrything else) Again Coleman Branded, Sunforce.

    I will remove 2 (of the 4) 100 Watt panels from my roof, and add 1, 150 watt totaling 350 Watts. The run is less than 50' and I have 2, 12 guage leads, 1 on the 2 100 watts, 1 for the added 150 watt panel.

    I will build a rack for the other 150 Watt, along with the 2, 100 Watt panels that I removed from the roof. It will be no further than 50' from my bank also, so 2 more 12 guage runs. Another 30A PWM Charge Controller. Then I can watch, which Bank is doing a better job.

    I have found a Local Supplier for 6V 448 minute reserve capacity, 230 amp hour Group Size: GC2 batteries, and will add 2 (for now), and gradually replace my 12v 105A batteries with these.


    Sound sufficient enough? I still will only be running the same amount of power. My deficency was in the Over Night part.

  • BB.BB. Super Moderators, Administrators Posts: 31,143 admin
    Sounds good... Running your system and watching/logging how it performs should give you a better idea of where to head next (more panels, more battery, more genset charging, etc.--Or not).

    -Bill
    Near San Francisco California: 3.5kWatt Grid Tied Solar power system+small backup genset
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