Hi, I am looking to use a stock tank heater over winter for my cattle. However the tank is out in the pasture and I would like the de-icer to be solar powered. I have a 1250 watt and 10.4 A de-icer. What do I need to keep the de-icer running? What would be the set-up? What do I need to run this during the cold winter months?
Stock Tank Solar Power
- Thread starter jlink295
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pollenface
Solar Addict
How much power do you need?
schmism
Solar Addict
If you want it to run 24/7 your need to make 1250w*24hr*1.2 (conversion losses) = 36kwh
you need to collect 36kwh from the sun while its shinning. normal napkin math says the pannel will make the pannel sticker wattage for 5hrs a day, but that's summertime sun, not winter sun. your likely to get half the sun in the winter as you do the summer, so lets cut that number in half, you
need to make 36kwh in 2.5hr = 14kw of solar pannel.
you have to store the other 21.5 hrs of sun in a battery or you'll need a 33kwh battery or 690ah of 48v battery
project cost, north of $10K
you need to collect 36kwh from the sun while its shinning. normal napkin math says the pannel will make the pannel sticker wattage for 5hrs a day, but that's summertime sun, not winter sun. your likely to get half the sun in the winter as you do the summer, so lets cut that number in half, you
need to make 36kwh in 2.5hr = 14kw of solar pannel.
you have to store the other 21.5 hrs of sun in a battery or you'll need a 33kwh battery or 690ah of 48v battery
project cost, north of $10K
It's tough to estimate, because we don't know the cycle rate, or temps...
But roughly at 50% cycle, a 1250W heater would use 15kWh of energy in 24hours...
If you can gain 3.5hours of solar daily it would need a little over 4kW of panels... 10 440W panels should do it, but you would need about 12kWh of batteries to keep it powered.
But roughly at 50% cycle, a 1250W heater would use 15kWh of energy in 24hours...
If you can gain 3.5hours of solar daily it would need a little over 4kW of panels... 10 440W panels should do it, but you would need about 12kWh of batteries to keep it powered.
schmism
Solar Addict
now that you've seen the reality check of trying to run normal restive heaters for de-icers for livestock water, you might see how most people choose to use an air bubbler or pond pump that my draw something like 100w continuous.
Might be interesting to see if a heat pump deicer could be used... I bet the livestock would destroy it though...
rancher1913
New Member
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i just bust the ice and refill the tank. my pasture solar "bleeds" back into the well so the piping above ground does not freeze, i just turn the switch and as long as the sun is up it pumps and refills the tank
Where do you live? In eastern WA, and S.Dakota, without floaters, the troughs would freeze solid...
If I need to get 36kWh of solar energy today where I live, I would have needed ~137kW of panels.
iwasforcedtopickausername
New Member
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- Oct 13, 2022
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If it's just a resistive load, you could probably just hook up any solar panel directly to it.
To actually get those kind of figures, it's going to need a lot of power/panels. But depending on your winters, a couple panels directly wired into a heating element sort of deal could work fine. I don't know how big these stock tanks are. Are they facing south and getting as much natural light as they can?
To actually get those kind of figures, it's going to need a lot of power/panels. But depending on your winters, a couple panels directly wired into a heating element sort of deal could work fine. I don't know how big these stock tanks are. Are they facing south and getting as much natural light as they can?
ianganderton
Auckland, NZ
Where are you ?
Nobodybusiness
Solar Sponge.
Yikes!!
OzSolar
Whatever you did, that's what you planned.
How far from the nearest power source? You could run wire in conduit several hundred feet for a fraction of the cost you can do it with solar.
MarkSolar
Solar Enthusiast
I went through this exercise with our horses and goats, they're out all the time. We live at the same latitude as Chicago in Illinois so it frequently gets -20F in winter. I used a killawatt power meter to measure performance of different solutions, here's the short version.
- Duty cycle in our climate ranges from 100% at -20F on windy nights to 20% during a sunny day at +20F. So a good seat of the pants number for total power required is 50% duty cycle during January-February.
- Most of the heat goes out the top. I switched from 150gal tanks to multiple smaller tanks and put piece of wood on top of the unused tanks to insulate them until they're needed. I also made a plywood top that's just big enough for the horse to stick their nose through and drink. Having mutliple watering tanks made it easier to clean tanks and also helped prevent dominant horses doing resource guarding. Don't know if cattle do that.
- A lot depends how hard it is to refill the tanks. Our filling process is labor intensive so I needed as much water storage as possible to avoid the labor of refills. If you have a freeze proof water source near your tanks, you could increase the frequency of filling tanks and reduce the water volume you have to heat.
- Switch from metal to rubber/plastic troughs. That adds enough insulation on the side and bottom to reduce power about 10%. I tried making insulated boxes but they got destroyed so fast it wasn't worth the marginal improvement.
- I ended up installing grid tied solar and ran power to the tanks. Problem with heating stock tanks is nearly all the power is needed at night when temps are lowest and sun isn't heating the water, so the battery backup has to be disproportionately large. You can't put the batteries out in the open field or the efficiency drops off in the cold just when you need power the most.
- My inverter is in the barn and panels are next to the barn, I still can't justify the cost of batteries given the net metering deal we have. If things ever change I would install the batteries in our tack room in the barn, it's already heated to stay just above freezing so I don't need to build anything new.
- I looked at all kinds of devices with floating balls, self draining fountains, etc. I think any of them would work if you had a few pet cows. But I didn't see any of those kinds of things working at larger scale out in an open pasture in a cold climate.
The "tank" is a plstic IBC tote that was cut in half and buried into the ground. I believe it was an old "water hole for deer" The nearest power source is close to a 1/4 mile away-hence the solar power. For reference I am located in northwest Wisconsin. Instead of a 1250w de-icer, what about a 100w air bubbler or pond pump? What would I need for batterie(s) and how big of solar panel(s)?
ianganderton
Auckland, NZ
Here are solar irradiance figures for Eau Claire optimised for winter production
www.solarelectricityhandbook.com
Solar Irradiance Calculator
www.solarelectricityhandbook.com
MarkSolar
Solar Enthusiast
That's a good setup, the ground will help you. You can go 2 directions. If you want to stick with the heated deicers you'll need to convert from DC produced by the solar panels to AC, which means you'll have to buy an inverter. If you go with a pond pump or bubbler you can stay with 12v from the batteries and can save the cost of the inverter. I've never seen a 12v deicer, I know they make 12v water heaters for houses but I've never seen anything waterproof.
You could try the progressive approach, get a single panel, a battery management system and a few batteries and see if a bubbler can keep it thawed. If not you can add a panel and a few more batteries until you find the right solution. Are you able to throw a piece of insulation over the tote at night? That would really help reduce the power requirement to daylight hours. Since you're a farm you probably don't need any inspections, you could ground mount the panel on railroad ties to keep the cost down.
I assume you have a backup plan if the solar isn't enough. I have a PTO generator for my tractor, if you have something like that you could park the tractor out in the field for the really cold spells when the solar can't handle it alone.
Thanks for the input. When you say "if you went with a pond pump or bubbler you can stay with 12v from the batteries" What do you mean by that? Could you explain in further detail? Would I need multiple 12v batteries? What would you recommend for a solar panel? Would I then just hook the connections from the solar panel to the battery?
MarkSolar
Solar Enthusiast
You can buy 2 kinds of pond pumps/bubblers. One kind runs off 120v AC that you have in your house, the other kind runs directly off 12v DC that comes from a battery. If you buy the 12v kind of bubbler you need 3 pieces of solar equipment: the panel(s), a charge controller, and one or more 12v deep cycle batteries like you'd use for a trolling motor in a boat. You might also need a Battery Management System at some point depending on how many batteries are required, but I'd forget about that iniitially.
It's hard to guess what size pump you need, I don't know how to calculate it, which is why I suggested starting with something and see what happens. So I would pick out a 12v bubbler, probably as big as you can find readily available, and see how much power it draws. Then we can help you size the panel and battery to make sure it runs for some number of days and nights without sun. The hard part is guessing how many days of shade you'll get, because once the battery goes dead you need a different way to power the pump. The longer you want to run the pump without sun, the more batteries you need to buy. You also will probably benefit from building a little enclosure to protect the batteries from the cold. I have a deep cycle battery I use for my automatic gate opener, I put it in a small plywood box that has open sides in the summer and I close the sides in the winter. It sits in the sun so that helps keep it warm during the winter. If you have a windbreak for the cattle it might be possible to leverage that to build a small box.
If you own a backhoe another option to consider would be geothermal. You could bury a heat exchanger coil and use a pump to circulate the water from the pond through the heat exchanger to warm it up. I have no idea if a bubbler will be able to keep the surface free of ice in your climate, the geothermal would actually help heat the water.
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In western nebraska/South Dakota/eastern Wyo, Waterfowl hunters use exactly that to keep water open on a pond in the most severe conditions. There are ready made rigs to bubble or even floating circulating pumps. Gotta be the best solution to this problem.
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