Solar kit

[mike]

I am sure this has been asked a million times but, I looking into a small kit that would help me learn and expand. I was thinking of something that might run a few lights in the chicken coop. I am really new to this but want to learn and at least have another way to power items in the future. So I am looking for any help you are willing to give to someone who knows just enough to get into trouble. It does not have to be a kit if there is a better way to go. Thanks!

[wy_white_wolf]

First thing I'd say you need to learn is how much solar power you have available. Visit Here and find the location nearest you. Look at the insolation hours on one of the charts. With off-grid you need to plan for the worst case so pay particular attention to the winter numbers.

Report back with what available to you.

WWW

[SolarGary]

Hi,
You also need to decide whether you want to do a grid-tied or off-grid system.
The chicken coop lights sound like an off-grid, but I'd think about what you eventually want to do for the house. There are now some ways to start a grid-tie systems small and grow it over time.

Gary

[mike]

Originally Posted by wy_white_wolf

First thing I'd say you need to learn is how much solar power you have available. Visit Here and find the location nearest you. Look at the insolation hours on one of the charts. With off-grid you need to plan for the worst case so pay particular attention to the winter numbers.

Report back with what available to you.

WWW

WWW, thanks for the reply. I really have no idea how to get that info for you. Nice charts but no idea what i am looking at. Sorry.

[mike]

Originally Posted by SolarGary

Hi,
You also need to decide whether you want to do a grid-tied or off-grid system.
The chicken coop lights sound like an off-grid, but I'd think about what you eventually want to do for the house. There are now some ways to start a grid-tie systems small and grow it over time.

Gary

Yes coop would be off-grid, and yes a grid-tied system is what I am thinking of but working toward as little use of the grid as possible.

[mike]

I looked on another site and what I got a low of .094 in December and a high of 2.39 in July. Hope that helps.

[SolarGary]

Hi,
Just going back to your basic goal: -- to help you learn about solar electric.

You could just go ahead and build something similar to one of these small systems:
Solar Photovoltaic Projects Systems
They all consist basically of a PV panel(s), a battery(s), a charge controller, and (optionally) an inverter.
I'd just pick one of the smaller one, and go ahead a build it.
It may not end up fitting into your long term plan, but it you would certainly learn a lot doing it, and the system will always be useful for something.

Gary

[wy_white_wolf]

If you don't want to post the nearest city to you than PM it to me and I'll get the info for you. The numbers you posted don't quite look right. The summer number is way to low. Even foggy England has higher summer numbers then that.

WWW

[nadja]

Well, the first thing you would need to do, is to formulate some sort of a plan. In other words, try and determine how big or what you would want to start powering up with. If you just want a learning experience for knowledge in the future, just build your own. Much cheaper and far better then these so called kits on the market.

If your start up kit is something you would like to grow to power more things as most of us did, then there are different ways to go about it. So, please be more specific on your needs and goals

[mike]

My idea is to start with a simple system that would run a few lights, I would like to use this project to learn the basics so that I could then keep adding to that system or build a different one that would be larger and most likely be a Grid-tired system. In the long run if I could keep adding to a system over time to be totally off-grid, I would. That would not be the case for a long while.

[wy_white_wolf]

Her's the numbers I was looking for.

They represent the amount of solar power available on a daily basis and is is used as the number of sun hours available. As you can see the winter numbers are real low. Summer isn't to bad.

Insolation, kWh/m²/day
Jan - 1.37
Feb - 2.22
Mar - 3.27
Apr - 4.29
May - 5.10
Jun - 5.67
Jul - 5.66
Aug - 4.73
Sep - 3.74
Oct - 2.39
Nov - 1.43
Dec - 1.15

Now that we know how much power is available we need to calculate you load. Unlike the getting power from the grid, in an off-grid system if you don't get a full calculation for power needed you either end up in the dark or pay way more for your system than needed.

So, what do you want to run fro a light in the chicken coop and how many hours a daily (most) will it be used?

WWW

PS - growing a system like you talk about is not really a good idea. many things that work great on a small system don't work on larger systems.

[mike]

We currently have 2 13-watt CFL bulbs and 2 50-watt heated dog dishes.
The lights are used mostly in winter and would be on max 4 hours a day, the dog dish would be on all the time in the winter. I understand the dishes may be a bit much so they could be left out if a small system could not handle them.

[Jim-mi]

Do the math on those heated dog dishes . . . Times 24hours . . that puts a big hurt on a solar system . . .in a big hurry.

Consider the far far more efficient LED lamps

[Alaska]

get the catalog from backwoods solar. All the crew there is very helpfull and live with alt energy so they have first hand knowledge. backwoodssolar.com

[PD-Riverman]

Originally Posted by mike

We currently have 2 13-watt CFL bulbs and 2 50-watt heated dog dishes.
The lights are used mostly in winter and would be on max 4 hours a day, the dog dish would be on all the time in the winter. I understand the dishes may be a bit much so they could be left out if a small system could not handle them.

Mike, think about a solar set-up this way, every how many watts you draw off the batteries has to be put back into them or they fail.
Lets say you start off with a little battery bank with 500 watts reserve and you run those 2 13 watt bulbs for 4 hours per day 2x13=26 watts 26x4hr=104 watts. Now you want to put those 104 watts(+ loss) back into your bank. There is only a few hours in a day that a panel will produce its best output. WWW has a chart with those hours above. Lets go with 4 hours for some figuring. 104 watts/4=26 so you would need around a 30 watt panel to put those 104 watts back into the battery bank. Lets say that it rains for the next 2 days all day and you did not add nothing back to the bank now you got 312 watts you got to put back into the bank on the 3rd day or your bank will stay discharged so now you need about a 90 watt panel so you can make up for the 2 day loss. 60 watts might get you built back up to full charge if it stayed sunny for several days.
Now here is the problem, you plug in those 2 50 watt heated dog dishes--- 2x50=100watts per hour. Now in less than 5 hours you have drained your battery bank empty, so now you got to get a bigger battery bank. 100 watts per hour just on the heated dishes----100x24hr=2400 watts per 24 hrs. Now you want some reserve in case it rains for 2 days straight so lets figure 3 days reserve--3x2400=7200 watts now this means your battery bank has got to grow 15 times bigger to get you that reserve plus enough to run the 2 13 watt lights for 4 hours so now you need to figure 16 times bigger. Now you got about 8000 watts that needs to be put back into the bank on the third day because of 2 days of rain. Yea you might get by with 5000 watts if it stays pretty for several days again, Lets figure 5000 watts to get by cheaper----if it rains/cloudy again in a day or two you can crank up the generator. 5000/4=1250. You will need around 1000 to 1250 watts of solar panels and a 16 times bigger battery bank to keep up with the 2 heated pans and the 2 13 watt lights to give you a couple days reserve.
So to answer your original question, if you will forget the heated pans you can get you a 80/100 watt panel and a charge controller and a couple deep cycle batteries and you should be able to run your lights with no problem.

I am no pro at solar just giving you something to think about.

I will ask WWW how far off am I? Thanks

[mike]

Originally Posted by PD-Riverman

Mike, think about a solar set-up this way, every how many watts you draw off the batteries has to be put back into them or they fail.
Lets say you start off with a little battery bank with 500 watts reserve and you run those 2 13 watt bulbs for 4 hours per day 2x13=26 watts 26x4hr=104 watts. Now you want to put those 104 watts(+ loss) back into your bank. There is only a few hours in a day that a panel will produce its best output. WWW has a chart with those hours above. Lets go with 4 hours for some figuring. 104 watts/4=26 so you would need around a 30 watt panel to put those 104 watts back into the battery bank. Lets say that it rains for the next 2 days all day and you did not add nothing back to the bank now you got 312 watts you got to put back into the bank on the 3rd day or your bank will stay discharged so now you need about a 90 watt panel so you can make up for the 2 day loss. 60 watts might get you built back up to full charge if it stayed sunny for several days.
Now here is the problem, you plug in those 2 50 watt heated dog dishes--- 2x50=100watts per hour. Now in less than 5 hours you have drained your battery bank empty, so now you got to get a bigger battery bank. 100 watts per hour just on the heated dishes----100x24hr=2400 watts per 24 hrs. Now you want some reserve in case it rains for 2 days straight so lets figure 3 days reserve--3x2400=7200 watts now this means your battery bank has got to grow 15 times bigger to get you that reserve plus enough to run the 2 13 watt lights for 4 hours so now you need to figure 16 times bigger. Now you got about 8000 watts that needs to be put back into the bank on the third day because of 2 days of rain. Yea you might get by with 5000 watts if it stays pretty for several days again, Lets figure 5000 watts to get by cheaper----if it rains/cloudy again in a day or two you can crank up the generator. 5000/4=1250. You will need around 1000 to 1250 watts of solar panels and a 16 times bigger battery bank to keep up with the 2 heated pans and the 2 13 watt lights to give you a couple days reserve.
So to answer your original question, if you will forget the heated pans you can get you a 80/100 watt panel and a charge controller and a couple deep cycle batteries and you should be able to run your lights with no problem.

I am no pro at solar just giving you something to think about.

I will ask WWW how far off am I? Thanks

Wow, thanks that is an eye opener. Dishes will not included. Thats sounds like a good small system to at least begin with and learn from.

[mike]

Originally Posted by Alaska

get the catalog from backwoods solar. All the crew there is very helpfull and live with alt energy so they have first hand knowledge. backwoodssolar.com

Thanks! I will check it out.

[wy_white_wolf]

Originally Posted by mike

We currently have 2 13-watt CFL bulbs and 2 50-watt heated dog dishes.
The lights are used mostly in winter and would be on max 4 hours a day, the dog dish would be on all the time in the winter. I understand the dishes may be a bit much so they could be left out if a small system could not handle them.

Been away at a wedding so sorry for getting back late.

PD pointed out that the dishes are out for a small system. 2.4KW is a mid sized for off-grid.

I'll do the calc but am basing them on an assumption that the 4 hours is to extend the daylight hours so the chickens will lay more in the winter.

First thing I recomend is to look for some 12VDC lights. They would allow the use a o lighting controller in place of the charge controller and eliminate the need for an inverter. 12VDC CFLs can be found on EBAY.

You will have to rerun thes calcs if the new lights take more wattage.

So 2 - 13W lights for 4 hours.

that's 2 * 13W * 4H = 104WH (WattHours) Load

Now we need to calculate how much your panels need to produce. Most will say 104WH but they forget that nothing is 100% efficient. With off grid
about 66% is normal for a PWM controller and 75% with a MPPT controller.

So 104WH * 1.5 (66%) = 156 WH daily average need produced.

Now divide that by the amount of insolation available. Get the lowest number from above which is December at 1.15 hours.

156WH/1.15H = 135.65W You will need a solar panel of at least 135 watts. A little larger like 150W to 165W would be ok just don't go too far over or that may cause other problems. At 135w you will have excess power in all but the winter months. Also you want one with a VMP of 18V +/-1V.

So first calculation on the battery size. a few things to note about batteries with solar is that you shouldn't use more that 20% of there capacity in a day and should never go below 50% discharge. I now in boats people go past that alot but figure they are only using them a few weekends a year where you'll be using them daily. Be nice to them and they will last.

So we need to divide the Daily WH by the battery voltage then muitply by 5 so we only use the 20% a day.

156WH / 12V * 5 = 65AH minimum on the battery. That would give you2.5 days of usage before they hit the 50% level.

There still is one other thing to check on the battery. They have minimum and maximum charge rates. Typically for lead acid they are between C/8 and C/15 with a preference of being close to the middle. C = AH capacity of the battery. Best to check the spec of the battery manufacture.

So what you need here is to take the amperage of the solar panel and divide it into the AH of the battery. So a 135W 12VDC panel would typically have a VMP of about 8A.

So 65A / 8A = 8.125 and 65A / 15A = 4.33. So your within range with a 65 AH battery. Most marine deep cycle batteries are in the 75 to 100AH range so the would work good. But also remimber that if you over size the panel much abover th 135 you will need to go bigger on the battery.

Just a note that AGMs can be charge up to C/4 but I don't recomend them for beginning systems as this is to be a learning experience and you should use a battery that will teach you how to maintain them.

The charge controller need to be larger than the panel output. I usually oversize them by at least 25% to account for any highlight conditions. Solar panels are rated at 75dF and do puty out more power at colder temps.

So right on the edge of a 10 Amp controller being a little to small. If you can't find a 12 to 15 amp lighting controller a 10 amp will work but might get a spare one just in case.

One can put a bypass switch around the load side of a lighting controller to use when you enter the coop and need light besides the time it allows it. This is the style of controller I'm talking about. Other's do make them.

So in review your 3 main componets are:
135W 12V panel (min)
65AH battery (min)
12-15A lighting charge controller

I think one should be able to put this all together for about $400 to 600.

WWW

[PD-Riverman]

Originally Posted by mike

I am sure this has been asked a million times but, I looking into a small kit that would help me learn and expand. I was thinking of something that might run a few lights in the chicken coop. I am really new to this but want to learn and at least have another way to power items in the future. So I am looking for any help you are willing to give to someone who knows just enough to get into trouble. It does not have to be a kit if there is a better way to go. Thanks!

I know we have given you alot of info but let me tell you what is on my chicken coop. Most people do not like these panels but I got a new Harbor Freight 45 watt kit for $125 from a Auction. I use the 2 lights that came with the kit for early AM lights. I also have 2 automatic doors that run off this set-up. The panels are hooked to a 7 amp charge controller that did not come with the kit----you could use the one in the kit but have a spare because I have not seen the ones in the kit last long at all. The charge controller is hooked to 2 Trojan 6 volt golf cart batteries. It has been hooked up about a year and Runs perfect. My lights come on and the doors open about 3 hours before daylight. Here is a picture where you can see the panels.

[mike]

WWW I will have to read you post a few times but I think I understand what you laid out. PD that is what I am looking to do the doors are a neat idea. Thanks to you both for the info. I am sure I will have more questions for you all.