Looking to do a couple small solar projects to help me learn

[Blindsay]

So in a couple years when we build our new house my goal is to do the solar system myself. I have been reading and watching a ton of videos (which is how I ended up here) but I am the type that I need to apply the knowledge in order for me to really remember it.

So that said I had a couple small projects I was thinking of to start working with solar a bit.

1: We had some electric fence for horses that runs off of a SLA battery right now and the battery has to be pulled and charged every couple of weeks. I was thinking of getting like a 50w panel and a charge controller and building a small rig so this could maintain itself (I might downsize the battery a bit once the panel is on to make it a bit more portable, or maybe a lighter battery chemistry). This setup does not have to contend with winter but it does have to be outdoors all the time

2: We are rebuilding a chicken coop. It will need power and wont be attached to the existing electrical. I was thinking of putting a few panels on the roof and then making the coop offgrid. It would mostly be for a few lights, small water heater (like 50w) and then a heat lamp (250w). This would be inside the coop but would have to contend with cold VT weather. I like the combo charge controller/inverters but I havent found any good quality but smaller ones (dont need a giant multi kw one for the coop). I also have an ecoflow Delta max 1600 which i thought about using but the fact it can only charge at/above 32F is an issue. It definitely gets way below that here in VT (But if i kept it in an insulated box I am not sure how much that would help)



The coop would probably be overbuilt but I want to try to simulate how the house would be but on a smaller scale. When we build our house it will be a grid tie in but for now offgrid stuff seemed a bit easier to start with. Also the main house (which is completely separate) already has solar so I know solar is viable for this location. When the chicken coop gets built we will make sure things like the pitch of the roof and direction are optical for solar

Thoughts?

 

[HarryN]

Those are great projects to learn from.

VT weather more or less restricts you to using a lead based battery, such as a flooded or AGM due to how Li batteries behave in sub freezing weather.

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I am not really a fan of the combo units, especially for cold weather conditions.

For the electric fence, all that is needed is a small panel and something like a Bogart engineering charge controller. The temperature compensation is built into the monitor portion, so you will need this to properly charge in cold conditions.

If you were to need a lot more power, then it would make sense to use a higher voltage panel and an MPPT controller, but that only make sense if the panel voltage is at least 12 volts higher than a fully charged battery. The PWM type will be ideal for the low light / overcast conditions.

Probably a small motorcycle battery could make this work.

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The big challenges for using solar to heat the chicken coop are frankly snow, overcast, and you are fairly far north.

Look outside on a winter day and there just are not that many hours of solid sunshine in any direction in January / Feb.

It can be done, but the solar + battery system will need to be able to capture and store enough power in one day to run for at least 3 days to have viable reliability.

( 300 watts) x ( 24 hrs / day ) x ( 3 days ) ~ 20 kW-hrs minimum of storage, and realistically 2 x that.

Just using a battery that I am very familiar with, that is 40 each, size 27, Lifeline AGMs. ( you can of course use other brands )

So very roughly $10 - 12K just in batteries.

In theory you could cut this down by 60% if you are willing to use a generator to do battery charging on overcast days. The bogart unit broadcast the battery state of charge using WiFi, so a pretty decent range.
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I would encourage you to think about a propane approach for the heat if possible, but it does make sense for lights and fans.

 

[Blindsay]

Those are great projects to learn from.

VT weather more or less restricts you to using a lead based battery, such as a flooded or AGM due to how Li batteries behave in sub freezing weather.

____________
I am not really a fan of the combo units, especially for cold weather conditions.

For the electric fence, all that is needed is a small panel and something like a Bogart engineering charge controller. The temperature compensation is built into the monitor portion, so you will need this to properly charge in cold conditions.

If you were to need a lot more power, then it would make sense to use a higher voltage panel and an MPPT controller, but that only make sense if the panel voltage is at least 12 volts higher than a fully charged battery. The PWM type will be ideal for the low light / overcast conditions.

Probably a small motorcycle battery could make this work.

____________

The big challenges for using solar to heat the chicken coop are frankly snow, overcast, and you are fairly far north.

Look outside on a winter day and there just are not that many hours of solid sunshine in any direction in January / Feb.

It can be done, but the solar + battery system will need to be able to capture and store enough power in one day to run for at least 3 days to have viable reliability.

( 300 watts) x ( 24 hrs / day ) x ( 3 days ) ~ 20 kW-hrs minimum of storage, and realistically 2 x that.

Just using a battery that I am very familiar with, that is 40 each, size 27, Lifeline AGMs. ( you can of course use other brands )

So very roughly $10 - 12K just in batteries.

In theory you could cut this down by 60% if you are willing to use a generator to do battery charging on overcast days. The bogart unit broadcast the battery state of charge using WiFi, so a pretty decent range.
____________

I would encourage you to think about a propane approach for the heat if possible, but it does make sense for lights and fans.

Thanks for the reply. Yeah the cold temps really seem to be a hamper for this project (at least when we build our house that wont be an issue).

For the electric fence, that one will be outdoors but only during warmer weather so that is a plus at least (It will be completely outdoors though).

For the chicken coop, I was kind of thinking to overbuild the solar panels a bit so even on light solar days it would be enough to recharge the batteries back up during the day on winter. The main house currently has a couple tesla powerwalls which at least gives me a ton of data so i can see their power production for the past couple years which is cool (we are living with our inlaws until we build our house)

Looking forward to all of these projects, I have always been a tech guy and this is a new fun area to learn/explore.

 

[rhino]

For charge controller for your electric fence a MorningStar SG-4 is high quality, outdoor rated, and handles up to an 80W panel. Just connect two wires to the battery and two to the solar panel.

 

[HarryN]

Thanks for the reply. Yeah the cold temps really seem to be a hamper for this project (at least when we build our house that wont be an issue).

For the electric fence, that one will be outdoors but only during warmer weather so that is a plus at least (It will be completely outdoors though).

For the chicken coop, I was kind of thinking to overbuild the solar panels a bit so even on light solar days it would be enough to recharge the batteries back up during the day on winter. The main house currently has a couple tesla powerwalls which at least gives me a ton of data so i can see their power production for the past couple years which is cool (we are living with our inlaws until we build our house)

Looking forward to all of these projects, I have always been a tech guy and this is a new fun area to learn/explore.

I mostly work with mobile applications vs fixed, so the equipment selection isn't always the same (due to vibration resistance aspects )

If you really wanted to capture 3 days of power in 1 day, that starts to look like:

( 20 000 watt-hr) x ( roughly 50% nameplate generation ) / ( roughly 6 hrs of sunshine) ~ 6 - 8 kW of panels.

That would put you in the heavier duty Victron, Midnight solar or similar units for the types of components that I tend to use.

This forum tends to use some other brands for projects that are different than my usual experience.