Adding solar to an old on grid homestead

[UrbanHunter]

Thinking about it a little more, if you are only powering your wifi Router you may be able to address your needs with a simple UPS device. I have one for my router and it does okay. The nice thing about a UPS is it has a built in battery, charger, and automatic transfer switch: https://www.amazon.com/APC-Battery-...&hvlocphy=&hvtargid=pla-4583932713467616&th=1

They have about 200 watt-hours of storage, so if your load is less than 20 watts it can cover about 10 hours.
I use one for my router

I tried to use one for the wife's CPAP machine (72 watts) and it was able to work for 3 hours and died. As a temporary solution I used a 12 volt 100 Ah battery and a 300 watt inverter, which could provide coverage for 2 nights, the inverter had USB charge ports, so we could charge a phone off it too.

Her oxygen machine draws 450 watts and the unit in the picture will only cover that for 1 night (10.5 hours) before depleting the batteries.

A single circuit automatic transfer switch adds about $80 a system.

I like measuring my energy consumption using a kill-a-watt type inline meter as part of my system sizing exercise.

 

[Magpie]

Thank you for all of your thoughts - Have to admit I couldn't remember what thread I used to ask! I meant to say I can buy a solar panel for it also, but you probably saw that.
I'll look into the smaller back ups too. So difficult to find that stuff here at a decent price.

 

[UrbanHunter]

So I need to give an update (~2 year anniversary of being fully operational), my system has been working fine, but I have been increasing my loads to get the maximum utilization out of the system. It works okay, but I smoked an ANL Fuse...

This has got me to thinking that I would have been better off to go with a 48 volt system, the amperage would be reduced by 4X and would greatly reduce the size of the wires required. I would have to replace the inverter and low voltage relay controls, but it would not be as expensive as I originally thought. I could reuse all my batteries, heavy duty wires, and the charge controllers can operate on 48 volts. As for inverters, Many of the 48 volt units offer a 120/240 volt option, which would allow for some interesting opportunities.

I know hind sight is 20/20, but I wish I had a clearer plan 2 years ago...

My general observation is that for systems under 1500 watts (delivered power) 12 DC systems are okay, once you break 2000 watts you are better to plan on going with 24 or 48 volts.

This has been a hobby project and my systems' maximum output went from 200 watts, to 1000 watts, and is now at 4000 watts. That last jump requires way too much amperage (~350 amps, Max) for a 12 volt DC system to supply in a reliable manner. A 48 volt DC system could meet that demand with only an 85 Amp draw. Lesson learned. As a stop gap measure, I plan to limit my total system output to 1800 watts Max.

 

[viking]

We ran our motorhome 120 VAC 2,000 inverter/charger on 12 VDC, it was basically a test set up for going to our solar backup system, which runs on 24VDC, we bought the Magnum Energy 4,000 watt pure sine wave inverter because it could be stacked with other same type 4,000 watt inverters but as it turned out that one inverter serves all of our needs, it's also 120/240 VAC, I figured that if I ever had to run a deep well pump this type of inverter could do the job. UrbanHunter, you're really on the mark in going to a 48 volt system, even though I went to 24 volts the feed wires are very large, which equates to much more expense per foot, the prices of copper wire have really gone through the roof, just seeing the price of a 250 foot roll of 12 ga. Romex is enough to give you a heart attack.

 

[Magpie]

Well I finally got round to buying this- it was on sale, so what I was saving covered the solar panel. I plugged it initially and it charged quickly.There's tons of leads and the solar panel is huge, but has a case for storage, so thats neat. I'm setting it up in my work room for now to practice using it, seeing how long things take to charge etc.

 

[Aerindel]

Today I just added the smallest model jackery and 100 watt panel to my war wagon, these 'generators' seem like the ideal solution for small solar, compared to wiring in a permanent battery, charge controller ect.

 

[SoJer]

...these 'generators' seem like the ideal solution for small solar, compared to wiring in a permanent battery, charge controller ect.

..'Economy of Scale'...

jd

 

[Neb]

I received shipment of a solar generator today.

Limited-time deal: BLUETTI Portable Power Station AC200L with 350W Solar Panel Included, 2048Wh LiFePO4 Battery Backup w/ 4 2400W AC Outlets (3600W Power Lifting), Solar Generator for Camping, Home Use, Emergency https://a.co/d/igVPVrk

I just finished reading the manual. I am excited about getting it set-up. It has more capability that the Amazon page didn't mention. If I understand what I read I can set it up as a UPS for my critical loads... freezers, internet, furnace. I can connect it up to my transfer switch using the same cable I would use for my generator. So it is basically plug n play at this point. Installing the solar panels and running the wires aside.

If it works as hope, we will be adding the expansion batteries.

Excited!

Ben

 

[Hardcalibres]

I received shipment of a solar generator today.

Limited-time deal: BLUETTI Portable Power Station AC200L with 350W Solar Panel Included, 2048Wh LiFePO4 Battery Backup w/ 4 2400W AC Outlets (3600W Power Lifting), Solar Generator for Camping, Home Use, Emergency https://a.co/d/igVPVrk

I just finished reading the manual. I am excited about getting it set-up. It has more capability that the Amazon page didn't mention. If I understand what I read I can set it up as a UPS for my critical loads... freezers, internet, furnace. I can connect it up to my transfer switch using the same cable I would use for my generator. So it is basically plug n play at this point. Installing the solar panels and running the wires aside.

If it works as hope, we will be adding the expansion batteries.

Excited!

Ben

When you trial that plugged into your transfer switch, let us know how long it will run those loads - with and without the solar topping it up..

 

[Neb]

When you trial that plugged into your transfer switch, let us know how long it will run those loads - with and without the solar topping it up..

Solar panels have not shown up yet. It will be a while before I get those installed because I am in an arm immobilizer.

Once installed, it charged to 100% faster than I could get it registered and the mobile app installed.

I had to order an adapter to convert the tt-30p of the generator to l14-30r. The transfer switch is set up for 240 split phase from my gas generator. The solar generator produces 120v 30 amps. The transfer switch completely isolates the critical loads so shouldn't be an issue. The adapter is due tomorrow.

The app includes logging of all inputs and outputs.

Ben

 

[Neb]

I had a bit of excitement. The type that is seldom welcomed.

A soon as I plugged the transfer switch into the solar generator the circuit breaker on the service entrance tripped. I will spare you the trouble shooting but turns out the outlet was wired backwards!

So I have a refrigerator/freezer and a chest freezer running from the solar generator. Drawing about 220W.

I ordered 2 expansion batteries to get them while on sale. And as was typing, the solar panels were delivered.

Ben

 

[Neb]

I had a bit of excitement. The type that is seldom welcomed.

A soon as I plugged the transfer switch into the solar generator the circuit breaker on the service entrance tripped. I will spare you the trouble shooting but turns out the outlet was wired backwards!

So I have a refrigerator/freezer and a chest freezer running from the solar generator. Drawing about 220W.


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I ordered 2 expansion batteries to get them while on sale. And as was typing, the solar panels were delivered.

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Ben

After reading the fine print on the solar panels I learned they are " portable" and not intended for use in the rain.



So no permanent install! Bother.

I have 4 panels stashed that I will use instead.

I am quite enamored with the Bluetti app for my cell phone. I can check the history performance and status with having to run down to the basement.

I love it.

Ben

 

[Neb]

We added two expansion batteries to the system. I am running a test now that looks it will power the refrigerator/ freezer and the chest freezer for 2 days. I will try just the chest freezer next. I suspect the defrost of the old fridge is using most of the energy.

I will also figure out how I can route some conduit to where the solar panels will be mounted.

Ben

 

[Neb]

We added two expansion batteries to the system. I am running a test now that looks it will power the refrigerator/ freezer and the chest freezer for 2 days. I will try just the chest freezer next. I suspect the defrost of the old fridge is using most of the energy.

I will also figure out how I can route some conduit to where the solar panels will be mounted.

Ben

I removed the old refrigerator/ freezer from the solar generator. Just running a non-frost free chest freezer. It averages less than 0.4 Kwhr each day. That indicates I can go 16 days without power between charging.

I still have to figure out how to deploy the solar panels.

Ben

 

[Mountain trapper]

Last February I put up a 110 watt solar panel, with a 300 watt inverter and 12 v deep cycle battery, on the chicken coop in order to power a couple of lights.
Everything worked great, for a day or 2, then the inverter had a fault. So I put on a new 300 watt inverter, after a couple days same problem. Next I bought a new charge controller, same problem.
In order for this system to work we have to disconnect the solar panel for a few days, use the lights as needed, then plug it back in to charge the battery until the inverter has another fault.
And suggestions on what could be wrong?

 

[Neb]

Last February I put up a 110 watt solar panel, with a 300 watt inverter and 12 v deep cycle battery, on the chicken coop in order to power a couple of lights.
Everything worked great, for a day or 2, then the inverter had a fault. So I put on a new 300 watt inverter, after a couple days same problem. Next I bought a new charge controller, same problem.
In order for this system to work we have to disconnect the solar panel for a few days, use the lights as needed, then plug it back in to charge the battery until the inverter has another fault.
And suggestions on what could be wrong?

Only common element is the solar panel?

What is the fault?

What is the battery voltage when you get the fault?

I have seen wind turbines switch to a dummy load when the batteries are fully charged.

Ben

 

[Mountain trapper]

Only common element is the solar panel?

What is the fault?

What is the battery voltage when you get the fault?

I have seen wind turbines switch to a dummy load when the batteries are fully charged.

Ben

That's what I was thinking too, but the charge controller is supposed to protect the battery from over or under charge. The charge controller states that it cuts in at 13V and cuts out at 14.2V. When the sun comes out I'll take my volt meter up and check the output of the panel, and the voltage going in to the battery.

 

[Neb]

That's what I was thinking too, but the charge controller is supposed to protect the battery from over or under charge. The charge controller states that it cuts in at 13V and cuts out at 14.2V. When the sun comes out I'll take my volt meter up and check the output of the panel, and the voltage going in to the battery.

You didn't say what the solar panel output voltage is.

Ben

 

[Mountain trapper]

You didn't say what the solar panel output voltage is.

Ben

Its listed as a 110 watt panel. I'll check the actual output when the sun comes out.

 

[Neb]

Its listed as a 110 watt panel. I'll check the actual output when the sun comes out.

The panels that came with my solar generator are rated at about 60v.

Ben

 

[Mountain trapper]

The panels that came with my solar generator are rated at about 60v.

Ben

I've got an 85 watt panel on my lower gate opener.

 

[UrbanHunter]

I ran into a similar problem with my system, everything would go okay and then the inverter alarm would go off and I would have to reset it. What I found was that at night the inverter would drain the battery until it crossed the inverter low voltage alarm threshold, then continue dropping until the inverter tripped off. The inverter would not auto-reset and the next day when the solar came on-line the battery would recharge but the inverter was no longer working. Kind of like when the kids leave the car door open and the battery is dead in the morning....

Based on what you have told me, if you have a 100 watt solar panel and you get 8 hours of good sunlight, that should give you about 800 watt-hours of power. If you have a 12 volt battery, then your system should give you (800/12) 66.7 Amp-Hours of charge each day. Depending on the load you have on your inverter (300 watt) your draw could be as much as (300/12) 25 Amps, and your battery could only support that load for about (66.7/25) 2.7 hours before draining the battery.

I would look at the lights and figure out their wattage, if they are 60 watt bulbs, 2 lights the draw would be 120 watts at the inverter, (120/12) 10 Amp draw at the 12 volt battery, If the lights are on all night ( say 5PM till 7AM: 14 hours) they will draw 140 Amp-hours, if you have a 100 Amp-hour battery it will be near dead at the end of the first night, recharge it with 66.7 Amp-hours of energy from the solar panels, and it will be dead in the middle of the second night.

Matching your generation (solar panels), energy storage (battery), and your load (inverter/lights) is the black magic needed to make solar work.

The other thing that people forget is that solar does not work great on cloudy days, planning for that creates a whole other level of complexity.

Depending on what your goal is, 12 volt lights and timers are available that could eliminate the need for an inverter all together.
Because you said chicken coop, I guessing that you are trying to give the birds some warmth or keep their water from freezing.

 

[Mountain trapper]

I ran into a similar problem with my system, everything would go okay and then the inverter alarm would go off and I would have to reset it. What I found was that at night the inverter would drain the battery until it crossed the inverter low voltage alarm threshold, then continue dropping until the inverter tripped off. The inverter would not auto-reset and the next day when the solar came on-line the battery would recharge but the inverter was no longer working. Kind of like when the kids leave the car door open and the battery is dead in the morning....

Based on what you have told me, if you have a 100 watt solar panel and you get 8 hours of good sunlight, that should give you about 800 watt-hours of power. If you have a 12 volt battery, then your system should give you (800/12) 66.7 Amp-Hours of charge each day. Depending on the load you have on your inverter (300 watt) your draw could be as much as (300/12) 25 Amps, and your battery could only support that load for about (66.7/25) 2.7 hours before draining the battery.

I would look at the lights and figure out their wattage, if they are 60 watt bulbs, 2 lights the draw would be 120 watts at the inverter, (120/12) 10 Amp draw at the 12 volt battery, If the lights are on all night ( say 5PM till 7AM: 14 hours) they will draw 140 Amp-hours, if you have a 100 Amp-hour battery it will be near dead at the end of the first night, recharge it with 66.7 Amp-hours of energy from the solar panels, and it will be dead in the middle of the second night.

Matching your generation (solar panels), energy storage (battery), and your load (inverter/lights) is the black magic needed to make solar work.

The other thing that people forget is that solar does not work great on cloudy days, planning for that creates a whole other level of complexity.

Depending on what your goal is, 12 volt lights and timers are available that could eliminate the need for an inverter all together.
Because you said chicken coop, I guessing that you are trying to give the birds some warmth or keep their water from freezing.

The two lights I have are 4 foot LED light bars at 5,000 lumens and 43 watts each. At most they are used about 20 minutes per day, just during feeding time. This time of year we get a lot of overcast days and plenty of snow. But we were having problems all summer too. I installed the panel last February.
I'm planing on buying another kit just like this one to install on the barn to provide lights without having to start the generator.

 

[Aerindel]

As a data point....

My 200 watt panels....generate 1.2 watts on a cloudy day. This time of year we only get about 10 hours of daylight.......so you see how the math works out.

 

[UrbanHunter]

I like the 12 Volt LED light strips designed for RVs and trailers, a toggle switch, some 2 strand 12 volt wire, connect it up to a battery and you are good to go. At 3 watts per foot, 8 foot 24 watts isn't bad for power usage. I think you could get get everything you on amazon for under $40.

Personally, I would add a second 100 watt solar panel.

Come to think of it that is what my first experimental solar array looked like, 200 watts of solar, a small cheap charge controller, 2 old 100 AH 12 volt batteries, a cigarette lighter plug and a cheap inverter... The inverter failed twice, but I learned a lot of lessons. The most important thing I learned was that having a volt meter on the system (or having the ability to connect one easily) taught me a lot about how the batteries were doing.

My first kit was basically this https://www.renogy.com/200-watt-12-volt-solar-starter-kit/ with batteries in a tote, the volt meter and cigarette lighter (https://www.amazon.com/dp/B0B823FZF...zgmBGSsg37eiHAZ53bvh8ZWrVI7dluitxzOKNS3w&th=1 ) attached to the tote, the inverter was inside the tote. Moisture and heat were a real problem for the inverter.