I kind of feel that keeping chickens is a fairly thin-veil for needing to build things out of doors.  It is an excuse to fire up the earth auger, drill holes into the dirt and put in supports and fence posts.  It is an excuse to use power tools – drills, impact drivers, pneumatic nailers, miter saws, and so on.  In the end, however, we get a nice structure that can be home to a one or a few birds.

To say we overbuilt this coop-addition is probably spot on.  Insulated 2×4 construction, ventilated, concrete floored, and complete with a winch-powered liftable roof.

We never really intended to make another coop structure.  The converted dog house (beyond/next-to this new coop in the photo) was thought to be enough.

Earlier in the year, at the end of spring, we placed our last-of-the-season orders for meat birds.  Along with the fifteen cornish roasters, we added a silver laced polish chick to the order.  Melissa is fond of the white polish we had included with an earlier order of egg layers.  We figured, we would deal with getting her acclimated to the rest of the flock when the time came.  She could be brooded with the cornish roasters in the garage.

A week into September, the silver laced polish, now named Agnes, was injured.  We had introduced her to the greater flock a few days prior.  She is not the most cunning chicken; she ducks her head and runs straight into things — namely, other, larger, more aggressive hens.  She got stuck in the fence once, which resulted in the other hens pecking at her.  By the end of September, she was effectively a house chicken.  We brought her into the house to recover.  She had been pecked on at the base of her tail feathers, and had also gotten cut up by getting stuck hardware cloth covering one of the windows.  Missing lots of feathers, having cuts and pecks all over, she took up residence in a modify dog crate in the dogs area in the house.

Chickens are dusty creatures.  And they poop…a lot.  And their poop smells.  Agnes was on the mend, and we were tired of the dust and smell (even though we cleaned her cage twice daily, the general area still smelled).

### Agnes needed her own coop.

We started with scoping out how to build on to the existing coop structure.  The only free-of-obstruction side was the east side.  The south side has the green roof-covered run area, the west side has the covered run exit into the main chicken yard area, north has the man door entrance to the main coop structure.  East side it was.

Two support posts sunk into the ground, secured with concrete.  The insulated-plywood-on-each-face base was next.  Insulated walls, complete with an opening out of the front for a chicken door, were next.  Tile backer board with concrete poured over the top, then the insulted and hinged roof was built.  Roof vent and shingles followed with cedar shake siding (to match the existing coop) rounded out the bulk of the build.

We could have stopped there, but the roof proved to be a bit over built, and because of the weight, impossible for Melissa to lift.  The roof needs to be liftable to get into the coop for cleaning, and, once Agnes starts to lay eggs, we will want to retrieve them.

I noodled on the problem for a couple days.  Hand crank winch – like the ones used to pull a boat onto a trailer?  No, I need something with a bit more control when letting cable or rope out to lower the roof.  I imagined losing my grip on the crank handle and having it whip around quickly as the roof dropped.

Hydraulics crossed my mind, but, a bit over kill for this project.  I would need a reservoir tank for hydraulic fluid, pumps, and possibly more power than what we have available at the coop (remember, the coop is solar powered).

Garage door springs and other sorts of assists crossed my mind, too.  The winching idea kept coming to mind.  Maybe a 12 volt winch could be a solution.
We started to investigate winches.  Price seemed to be driving factor at first — what’s the cheapest winch on the market that has received decent reviews?  A number of winches fit this criterion.  A bit more reading and research revealed that many entry level winches have power in (pull), but no power out (push).  We needed both power in, to lift the roof, and power out to lower the roof back down.  A bit more reading, and having a brake on the winch would be ideal.  No brake, and the load of the lifted roof might just pull the winching cable back out.

### Brake. Power in. Power out.

These were the must haves for the project.  Superwinch’s UT3000 model fit the bill.  We also probably ended up spending almost as much on random pieces of hardware – heavy carabiner clips and chain for a safety line, threaded long anchor eye bolts, steel quick links, self-tapping lag bolts, a couple pulleys, and so on.

The pulley system we arrived upon puts an anchor near the outer corners of the roof.  Looping through the two pulleys, the end of the winching cable is attached to the existing coop structure just above the east side’s window.  The winch is mounted at the upper, outer corner of the existing coop structure.

## Cold Weather, The Coop and Heat Transfer

A few weeks ago, we bought a new waterer for the coop.  There was nothing wrong with the current waterer other than being an energy hog.  Throughout December, we struggled with keeping the coop’s battery charged enough power the waterer.  The waterer’s 100 watt heating element was just too much. Think of it like this: the waterer’s draw (outflow) on the battery is greater than the solar panel’s ability to recharge (inflow) the battery.

$$Outflow > Inflow$$

The new waterer, branded as Cozy Hen Waterer, is from Neora Inventors, LLC. From a cost perspective, it was expensive.  Around $70 for the waterer, a hanging chain, and a heater. The waterer consists of two buckets – one ¾ gallon bucket nested within a larger pail. Inside the larger pail, there is a layer of thin insulation. The outer pail is only used as a convenient way to capsulate the inner pail in insulation. The water, contained in the inner pail, is able to get out to the chickens byway of a chicken nipple (pictured to the right). The other interesting bit of engineering is the encasement of the chicken nipple in an aluminum pipe. The pipe extends into the water pail by several inches. This is subsequently encased in a bit of insulation with an outer shell made of a PVC plumbing part. Finally, inside the water pail, there is a 15 watt aquarium heater. It will keep the water at around 77°F. The aluminum pipe is clever because of what it allows: heat transfer. Although not entirely analogous (it is a pipe and not a rod), you could get a sense of the heat transfer by using a partial differential equation (Partial Differential Equations for Scientists and Engineers is also a good place to look). There are actually several energy-flows going on in these coop-systems if you think about it. The heat is transferred from near the center of the water pail down to the chicken nipple byway of the aluminum pipe. This allows for the nipple to stay mostly ice-free on those -20°F days. If you recall from a previous post, the first-replacement waterer had a thermostatic switch that kept the water at 35°F. In my mind, that seems like a valid temperature for water – it would minimize the energy consumption. The new waterer with the aquarium heater and its 77°F temperature seems, on the surface, like it will use too much energy. But, there are a few things that make the new waterer-system much easier on the consumption of electricity. First, the larger waterer has 1.⅔ times the surface area as that of the new, insulated waterer. More surface area results in faster transfer of energy from the warm water to the cold air. Second, and this is likely the most important factor, the new waterer is insulated. Top, bottom and sides – it is all insulated. The one direct exception is the chicken nipple area, but that has the aluminum pipe to assist with heat loss (with the assumption that the heat transfer from the water + pipe is greater than the heat transfer from the end of the nipple to the air). The more I have thought about the larger waterer and how it appears to be inefficient, the more I kept thinking of its design in comparison to the new waterer. The larger waterer has the heating element on the bottom – the three gallons of water sit on top of the element. This means that only one side of the element in contact with a surface that has water touching it. That other side is hanging out in the air; sometimes, well-below-zero air. What is the likelihood that the thermostatic switch actually switches off for any significant length of time? A better design would be have the heating element have more contact surface with the water. Perhaps, instead of being encased in a disc in the base of the waterer, the element would be a more rod-shaped protrusion from the base into the center of the water reservoir. Secondly, insulate, insulate, insulate. The choice of insulation material is possibly debatable – the new waterer uses foil covered bubble insulation – this might be sufficient; it would certainly be better than nothing. ## Solar Coop – Update II Since writing the first update on the solar panels on the chicken coop, we had quite the cold snap. Along with the persistent cold, there was persistent cloud cover and strong winds. The combination of cold weather meant the battery for the coop had diminished capacity and the cloud cover meant that there would not be enough solar irradiation to fill that reduced capacity. Each night, I would disconnect the battery from the system and lug into the garage; connecting it to a battery charger for the night. We also brought the chicken’s waterer into the house to prevent the need in the morning of having to thaw the water. In addition to the routine changes, I removed two things from the electrical-mix: the electric timer and the ammeter. With the battery’s stored energy being consumed so quickly and the water and battery being brought in at night, it did not seem like the timer was needed at all. The ammeter was removed because it stopped working in the sub-zero cold. Subsequent tests, while it has been warmer outside, show that the meter still works; it just does not like the cold. We have since made it through that cold spell, and have been in a pleasant middle ground of nice amounts of sun, above freezing day-time temperatures – several days in a row, and light amounts of wind. With the warmer stint of weather, the battery has been under lighter duty. Even when the solar charge controller has been indicating that the battery is not strong enough to power the inverter, the next day’s sun will be more than enough to give the battery a good charge. Being a curious, amateur scientist, I wanted to know a bit more about why a lead-acid battery appears to be quite poor at being able to provide energy when the ambient temperature is very low. This inability to provide energy is quite noticeable and prevalent in colder regions during the winter. For those who are familiar with starting a car while in the depths of a cold winter – think of how the car’s starter seems to struggle to turn the engine over. It’s a battle between cold lubricants with a higher than normal viscosity and a lead acid starter battery with diminished capacity. But, why does cold cause this diminished capacity. With my day-job being at a university, and I am surrounded by academics and researchers, my first thought was to look into published research on batteries or modeling batteries. The first paper I found was A mathematical model for lead-acid batteries co-authored by Dr. Ziyad Salameh – Dept. of Electrical Engineering, UMass Lowell, Margaret A. Casacca (student), and William A. Lynch (student). The paper was published in the IEEE Transactions on Energy Conversion, Vol. 7, No.I, March 1992. Aside from equations and a mention of a BASIC program that was developed (but this program is nowhere to be found in the paper), the main take aways from the paper are list of five factors that effect a battery’s ability to store energy; for the most part, the list of things is obvious. (1) State of charge, (2) battery storage capacity, (3) rate of discharge, (4) environment temperature, and (5) shelf-life or age. (This list is originally from the Complete Battery Book.) We can say that our battery is fully charged (state of charge is 100% at the on set), has a capacity of 110 amp-hours, the waterer has a draw of at most 10 amps (this is likely not constant as the waterer will turn on when the water is below 35 degrees, and turn off when it reaches a temperature above this), the shelf-life or age is basically “brand new”. Temperature is likely the deciding factor. Looking at how temperature effects capacity, you can see that as the temperature drops, the capacity drops, as well. Assuming this graph is true (there is no documentation or available analysis), at our coldest, the battery is likely to be running at a bit over 60% capacity; meaning, we’ll only get about 66ah from it. The inverter will shut off when the voltage drops below about 12.10V; according to another battery university article, this likely means the battery has about 50% capacity remaining. This could roughly be translated into a capacity of 33ah at our coldest, and about 55ah at optimal temperature (which we won’t have until sometime in late May). Now that I have some numbers that better explain the observation of why didn’t the battery last more than 8 hours on the coldest day, I still want to know why does this happen. Why does ambient cold have such an effect on lead-acid batteries? The short answer is internal resistance. To understand this, you first need to know a bit about how lead-acid batteries work. A course offered at the University of Colorado Boulder‘s Electrical, Computer and Energy Engineering department has a great set of lecture slides (or here) explaining how lead-acid batteries work. The gist of how lead-acid batteries work are electrons drifting or flowing from the negative terminal – most often made of lead ($$\ce{Pb}$$) – to the positive terminal – most often made of lead dioxide ($$\ce{PbO2}$$). The two terminals are submerged in an electrolyte solution. This is usually in the form of sulfuric acid ($$\ce{H2SO4}$$, where, in solution, it takes the form of aqueous ions $$\ce{{H^{+}}+{SO4^{-2}}}$$). As you draw electricity from the battery via the positive terminal, electrons flow from the negative terminal to the positive terminal. How easily or difficult the electrons can move from negative to positive terminals in the internal resistance. I think of what happens with the electrolyte solution and effect of cold temperatures on it is sort of like what happens to honey when it is chilled. It is not quite analogous but I think it gets the point across. If little droplets of honey are running down a piece of glass and you suddenly cool the glass, the honey will begin to run much slower. Similarly, as the electrolyte solution cools, the ability for electrons to drift efficiently to the positive terminal decreases. The decrease in electron flow results in less power to be consumed – in our case, by the inverter and waterer. So, what can be done be to keep batteries from losing their capacity in the cold? Some of the documentation that I read suggested gently warming the battery to keep it from getting too cold. This might be possible if we added another electricity generator – like a wind turbine. We would have to build a better storage place for the battery, too. We can’t really put the battery into the coop (where it is noticeably warmer because of sheltering from the wind as well as the use of deep-litter) because lead-acid batteries generally need venting (there is a small amount of oxygen and hydrogen released from batteries). In addition to the idea of keeping the batteries slightly warmer (which, I will admit, I’m likely not going to do), adding capacity seems like a more viable option. This is done by simply adding additional batteries in parallel. With the idea of adding in a wind turbine, I have already been thinking of adding additional batteries. To wrap things up, I just hope that the recent temperature bounce-near-and-around-freezing continues. The battery likes not being choked by the cold; nice amount of sun – the adequate sun light we have been receiving has had two benefits: the battery is able to be recharged successfully, and, equally important, the chickens have begun laying eggs once again. For a better look at the specifics of the chemical reactions that occur within a lead-acid battery, check out this page. ## Solar Coop: Followup (One) It has been a couple weeks since my father-in-law helped install the solar panels onto the chicken coop. Since then, I have modified a few things, added this or that, or replaced a component or two. The first thing to get replaced was the waterer (or fount). The existing one we had was a carryover from the coop in Proctor; it was not keeping the water free of ice on the two days we have had that were below freezing in that last two weeks. I picked up a new waterer/fountain (I bought the new one at Mills Fleet Farm for much less than what it is listed for on Amazon.com) – this one has a built in thermostatic switch that turns the heating element on at 35° F. Looking at the reviews on this particular fountain, many of the complaints revolve around how the unit is filled. There is a rubber plug on the underside that can be removed or you can simply remove the entire base. I can see where the complaints of having to “flip” the unit after filling are coming from, but this style of waterer is all we have ever used. I went with this model because it was the lowest watt-use fountain (100 watts) that I could find, and it could be hung. All of the metal waterers that I have come across use a heated metal base. I could imagine, with this setup, having ice-free water, but having all sorts of debris in the water from the chickens kicking bedding around in the coop. In addition to the new waterer, I added in an electric timer. This is a bit of an experiment, but my thinking is that water, when surface area is minimized, is a relatively good retainer of heat. If the heated-waterer is adding heat to the water now and again – when the temperature is below 35° F – it will use less of the battery reserve than if only relying upon the thermostatic controller in the waterer. That is my thesis, at least. It is difficult, however, to control variables in the experiment when things like the ambient temperature keep going well above freezing, or there is not enough sun to charge the battery. About a week into the experiment of solar panels on the coop, I noticed the battery was not holding a charge for very long. It was not a new battery, but, I thought it should have been lasting more than 24 hours with little to no draw on the battery. The sun had hardly been seen over this time period, but the solar panel charge controller was registering enough charge from the panels to attempt to charge the battery. I installed a ammeter/watt-hour-meter inline between the battery and the power inverter. I wanted to see if there were phantom load being drawn. With no real sign of phantom loads, I replaced the battery. This will be a bit of an experiment, too. A few of the solar-related forums and articles that I read through had recommendations on using AGM batteries, but the cost – usually two to three times more than a conventional lead-acid battery – is a bit much for me at this point. That last bit of modifications that I have made were to solar panel mounts. I raised the panels to a steeper angle. In my travels around the Twin Cities metro-area, I kept an eye out for solar panels on MNDOT equipment (traffic cameras and information signage, for example) that is located on roadsides and in ditches. The angle that is used on much of their equipment looks to be around 40° to 45°. I raised the height by about 8″ or up to an angle of about 40°. I think all we really need now is freezing weather and some sunny skies. ## Solar Coop For the more pleasant parts of the year, our chicken coop functions quite well without electricity. We can get the coop locked up before sundown or, if we are running late, we can use a flash light. Our old coop, at our previous house, had electricity; the coop was attached to our garage and running power into it was quite easy. Our coop in St. Paul, however, is not attached to any out-buildings. In a former life, our coop was a dog house. Without electricity, the coop has a distinct disadvantage during the winter months: the chicken’s water freezes. We have used, at the depths of winter, a power inverter attached to a deep cycle marine battery. It has worked well enough, but it too has a disadvantage – the battery is heavy and needs recharging now and again. With the winters in the east-central part of Minnesota (where we now reside) milder than our previous locale, carrying fresh, warm water out to the coop each morning is usually not a problem. The only time it proves to be an issue is when we need to be away from the house for an extended period of time. Friends and family tend to be willing to drive out to our house, but we really wanted an option that would let us be away from the house for several days without having to burden those friends or family with chicken-maintenance. Our original plans for the coop that we submitted to the city of St. Paul, included solar power as an option for providing a small amount of electricity to the coop. I really had no idea how many panels we would need, or how much initial capital would be need to get something viable up and running. I waited…a couple years. After getting a bit more serious with the idea over the summer; I did some back-of-a-napkin math with how many watts would likely be needed to power a heated waterer, as well as having a small light in the coop. I came up with a minimum of 200 watts. Heated waterers run between 100 watts to 125 watts (and heat elements exist, too, if you were trying to keep a livestock tank free of ice). Nearly all of the chicken waterers I looked at use alternating current (AC), e.g. they have a two prong plugin like a toaster or hairdryer; using AC power means a power inverter is needed to change the direct current (DC) from the solar panels and battery into AC power for the waterer. In a perfect world with perfect balance, the battery recharge and power consumption and generation would be something like, [consumption] 100 watts per hour for the waterer; [generation] 200 watts per hour being generated by the solar panels; ½ that amount would go to the waterer and the other ½ would go to recharge the battery. It should also be noted that inverters, on average, 95% efficient; e.g. 200 watts DC will result in 190 watts AC. An amount of power would be consumed at night that is less than the amount of power that was regenerated the during the day. There are variables that complicate the situation – persistent cloud cover, snow, freezing rain, and, as we enter winter on December 21, St. Paul receives less than nine hours of daylight. And, so far, during the first part of meteorological winter, we have had fits and starts of abnormally warm weather. A day, two days or even three-day stretches of above freezing temperatures. This simply means we need to be smart about how we use the power; use of a thermostatically controller outlet, for example, maybe helpful. The above freezing temperatures along with the thermostatic outlet would also allow the battery to regain charge quicker without having to warm the waterer. So, what is needed to put solar panels on your own chicken coop? A weekend, a bit of time, some handyman-(or woman)-type-skills, tools, and a bit of money. First, unless you buy used panels or are able to repurpose existing panels you might have and maybe patch to together bits of heavy gauge wire, the whole setup is not necessarily inexpensive. This, of course, also excludes any of the indirect costs, too, of the power tools that were used – like an impact driver, angle grinder (I have two of these, actually), a drill, wrenches, a small propane torch for soldering, pliers, screwdrivers, hammer and, likely, sundry tools that I am forgetting. Here is an almost-complete list of the things (and prices) for this project:  Renogy Solar Panel Bundle, 200 Watt$324.99 BESTEK 1000w/1200w 12v to 110v Inverter Power Supply MRI10011-1 $65.99 Terminal Ring, 12-10 AWG, Stud Size 8-10, Yellow (50 pk)$6.64 Terminal Ring, 6-10 AWG, Stud Size 3/8″, Blue (8 pk) $6.64 Solar Panel Cable 6 Ft – Mc4 Pv Extension (2x)$12.09 Keep It Clean FHC10 10 Gauge ATC Fuse Holder with Cover (2x) $16.72 10 Gauge, Strand, Black- Copper Wire – 50 feet$16.16 10 Gauge, Strand, Red – Copper Wire – 50 feet $16.16 Heat Shrink 1/4″ Tubing$1.97 4.1/2″ Metal Cutoff Blade $5.94 8′ Angle Steel – 1.1/2″ (2x)$37.98 5′ Angle Steel – 1.1/2 $13.78 Carriage Bolts – 3/4″ x 5/16″ – bag, count 39 (2x)$7.56 5/16″ Washers – bag, count 90 $2.28 1/4″ Fender washers$3.49 5/16 Nylon nuts – bag, count 90 $3.49 1.1/2″ Self-tapping polebarn screws$5.29 Electrical 40% tin/60% lead Solder $7.65 Blue 15 Amp ATC Blade Fuse, (Pack of 25)$7.99

The angle steel was used to construct supports for the panels so they could be angled toward the sun.  The supports are two, 18″ pieces at the top of each panel, and two, 8″ pieces at the bottom.

We decided to go with a fixed angle setup.  Fancier installations can have step motors and a pair of light dependent resistors with the panel support structure mounted on turntable of sorts to automatically track the sun laterally intra-day, as well as adjusting the angle of inclination as the sun tracks higher above the horizon during the summer and lower in the winter.

Following the calculations found at SolarPanelTilt.com, the correct angle for our latitude, near 44.9°, the formula is latitude, times 0.76, plus 3.1°.  This turns out to be 37.2°.  I am not sure of reasoning behind the use of 0.76 as a multiplier and then addition of 3.1°, but I will go with it for now.

The roof of the coop is angled at roughly 11°, leaving the panel support angle at 26°.   A bit of dusting off my trigonometric & algebra skills and I calculated the opposite side from the angle to be 28″ from perpendicular to the horizon.  Cutting the triangle with the 11° roof angle and a bit of subtraction, the vertical supports come out to be about 21″ tall.  I ended up going a little shorter than 21″ – due to a transposition of two numbers.  The angle is shallower than ideal for the winter months, but would be great for summer (which would be a pointless time to run a freeze-free waterer).

With the panels mounted on the roof, the wiring fed through into the coop, I got to work connecting the panels’ wire to the charge controller, the charge controller to the battery, as well as connecting the inverter.  The panels are connected in parallel as each panel generates 12 volts and there is only one 12 volt battery.

Following the instructions on wiring, there are several fuses used in the setup.  There is a calculation to get an idea of what size fuses you will need; these two panels needed two, 15 amp fuses; the third fuse is actually built into the inverter.  Check your inverter specs to see if you need to install a fuse before your inverter or if there already is one as part of the inverter.  The first 15 amp fuse is installed between the solar panels and the charge controller.  The second 15 amp fuse is installed between the charge controller and the battery.   Checkout the instructions (above) and consult with friend who is an electrical engineer, if needed.

To the keen observer, a few questions may come to mind; why 10 gauge wire with 15 amp fuses?  It is a bit overkill, I will admit, but the fuses are changable.  If we added two more panels, the only things that would need to changed to handle the 27 amps would be the fuses.

Another question might revolve around the massive 1000 watt inverter.  I mostly settled on the unit I did buy because it had threaded terminal posts as well as a thermo/load-sensor for controlling the cooling fan.  Simple, light loads will not cause the fan to turn on allowing you to stretch a little more out of your battery.

Finally, and possibly the elephant or mouse in the room, the cost-question.  Around \$500 to keep water for a small flock of chickens from freezing.  I look at it as an experiment with a bit of usefulness thrown in. The experiment is that I have never worked with solar on this scale.  It is still small compared to a utility company’s solar array, but it is quite a bit larger than that solar powered set of christmas lights you may have seen at the hardware store.  The experiment part also comes into play for us on two fronts; first, on the family-land north of Hibbing, the nearest electrical pole is a couple miles to the north.  If the coop works out well for us, we could think of solar as an option for when and if we build a cabin.  The second front is closer to home here in St. Paul.  We have tossed around the idea of putting a small array on the house once we put new shingles on the house.  Both of the situations would require more in depth cost analysis to determine the return on investment, e.g. how long would it take to recover the upfront cost of an array.

The final bit of usefulness for us is that we now have a small amount of power at an outbuilding that would otherwise be much more expensive to bring power out to than this project cost.  I won’t be able to lug the 50 amp, 240 volt arc welder out there, but powering a trouble light or recharging the drill and driver batteries is definitely within reason.

We will give give our new setup a trial run on the coop, and we will likely post, again, with what we find.