What about can I expect from panels on a cloudy day?

[Mike90250]

Using a recycled metal plate as a electrical mounting surface is a poor choice, IMHO.

[solardreamer]

EPever controller or others. Once the charger is in float, is that it for the day? In other words battery charges up and is full by noon but then I decide to blow-dry my hair with a 1500 watt dryer for 20 minutes and I deplete the batteries a bit, will the charger kick back into boost mode or is it a 1 time per day thing?

You should check the EPEver docs but the ones I have used have a time limit (many hours) for float phase and various voltage thresholds including one to restart the charge cycle. I remember battery voltage has to fall below certain threshold to restart the cycle.

[Ampster]

EPever controller or others. Once the charger is in float, is that it for the day? In other words battery charges up and is full by noon but then I decide to blow-dry my hair with a 1500 watt dryer for 20 minutes and I deplete the batteries a bit, will the charger kick back into boost mode or is it a 1 time per day thing?

You asked about others so I will tell you what my Skybox will do. My charge controller does not use the term boost. Normally my charge settings stay in float for the rest of the day so I can enter the evening with a full pack. I do have a setting for rebulk and that can be adjusted. If it is set too close to the Absorb voltage it will cycle too often. Your charge controller may be different.

[SunEagle]

EPever controller or others. Once the charger is in float, is that it for the day? In other words battery charges up and is full by noon but then I decide to blow-dry my hair with a 1500 watt dryer for 20 minutes and I deplete the batteries a bit, will the charger kick back into boost mode or is it a 1 time per day thing?

I would think the charge will go back to full input if the sun is available and the batteries need to be filled. Although you may not have enough time for a full charge to get to float stage.

Of course an EPever CC may act different but you certainly can test it to see if it starts the charge all over again.

[chrisski]

Also just noticed you're in the Pacific Northwest. I recommend reviewing the sticky here:

Solar Off-Grid Battery Design - Solar Panels - Solar Panels Forum (solarpaneltalk.com)

Because of your shorter days and cloudy weather, you may need a system 4X my size and 5X the cost to make the same energy I do in Tucson AZ.

[chrisski]

MT50

Tracer 100 amp

2 Centennial 8D 240 amp hour batteries


Debating whether or not to put the batteries in a case and venting that outside.

If they are flooded lead acid I recommend a vent. I did one and not an easy task.

In my RV, my batteries don’t bubble unless I turn the equalization on, and it bubbles so much sounds like a river. On my charger in my house my the same batteries bubble a little.

[chrisski]

Sometimes the most efficient route for charging with the charge controller may not be the best to maximize production.

IME with my RV setup, there may have been a 10% difference between parallel panel output and series panel output, but I did not notice. What it came down to me, is I am “over-paneled” which means I will be done charging by noon. So. Whether it’s in a series configurations or a parallel configuration would mean a real difference of 30 minutes to 1 hour of charging time, which I’m done before then.

One of the sets of panels I have is 600 watts of panels set up 3S2P. For my Victron SCC, the max volts is 100 and max amps is 60. At max production, I have around 54 volts, which is a little much for “ideal” production, but at a loss of about 10%. What had me set them up 3S2P was wire size, voltage loss, and distance. The MC4 plugs I used had a max ampacity of 30, which all 600 watts of panels in Parallel would exceed. Another limit of my MC4 cables were the 10 gauge wire. The next thing I ran into, I wanted to limit voltage loss to 3%, so when I measured how long my runs were and still eating to use MC4 and no thicker than 10 gauge wire and a 3% voltage loss, that forced my setup to 3S2P. With six panels, 6 in series would have meant exceeding the voltage of the charge controller. At no point was the 600 volt rating of my wire ever an issue.

That was the plan. When I installed the panels, I have never received the max 36 amp production from the charge controller to the battery I expected, and that was because of shading. I got around 20 amps tops, and because these panels were flat, not very much at sunrise, but peaked an hour or two before noon and an hour or two after noon.

Shading was a bigger issue thanI thought with the panels. I have a set of portable panels, four 100 watt panels I turn towards the sun through out the day. Since the panels are in parallel, if wiring on one panel goes bad, which it has, the other three panels operate. I was also surprised when I do testing, that when I use my head to shade the panel, even though the rest of the panel is in the sun, the panel output will drop from five or six amps to one amp.

Because of tilting and facing the sun, the portable panels produce max power an additional hour or two before and after the flat panels.

For panels in series, I thought they were limited to the lowest wattage of the one in the series, to include the one shaded in the sun, but it may not be as extreme as I thought. Never tested it.

For cloudy days, where my 100 watt panels would be making 5 to 6 amps in the sun per 100 watts, I would get 1.1 to 1.5 amps per panel. When I had 900 watts of panels, I produced 10 to 15 amps on a cloudy day, andI’ve went up to 1350 watts of panels. I now hope for 13 to 20 amps on an overcast day. I have 3 SCCs for the three different sets of panels I have. With 1350 watts of panels in the sum, I’ve maximized production with 67 amps, but math not taking into account shading and flat panels should put that closer to 85 amps.

[Mike90250]

With that much panel, you really should be looking at a higher voltage battery bank. Running many batteries in parallel ( since I don't think you are using 2V 400ah cells )

As to your MPPT vs Voltage, you only need 30V of panels to get good MPPT action. Higher voltage just wastes heat in the charge controller, unless you are stuck and can't get all the parallel wire into the conduit.
With more than 2 panels in parallel, you need to have a combiner box, to prevent good panels from backfeeding a damaged panel and starting a fire

I am a bit concerned that you seem to be stating all your panels will be facing west . With several arrays, why not split up the aim and hope some panels get sunlight.

Clouds/fog really cut out the power, if you don't have crisp shadows on the ground, you will not have good harvest. On cloudy/fog/rainy days, my 5kw of panels produce about 300w, so I run my generator then. I do not use an autostart generator.

[Mike90250]

Shaded panels in parallel (or differently oriented arrays in parallel) work with MPPT controllers. You take a small hit in wattage tracking, but the panels in full sun, will still produce close to their normal power
You do NOT want to series a shaded panel with a lit panel, the shaded panel will throttle the output of the lit panel. Bypass diodes in the panel may alleviate some of the issue, but then continued operation cooks the bypass diodes and you have to buy a new panel (most modern panels use chip diodes embedded under the glass) Old school panels use leaded diodes in the J-box. Your single panel has to produce enough voltage for the MPPT to work (usually 1.5x max battery charging voltage of 15V per 12v battery) read the charger data sheet to be sure

[Ampster]

....

In other words my question is, in regards to maximizing power output, especially in shaded conditions, is it better to have each individual panel on its controller.

It is better from a power standpoint in shaded situations to have MPPT at the panel level. It may NOT be cost effective unless you are comparing micro inverters to a string inverter. Even then it may depend the type of shade and the effectiveness of the diodes. It is not a question answered easily on the internet without being there.

[Mike90250]

DIY Auto Start generator ?
I'd like you to read these 2 links and the comments below the articles
Just some points you should be aware of. Be safe - don't burn the genny shed down

https://www.utterpower.com/zachs-remote-start-generator/

&

https://www.utterpower.com/zach-asks-is-your-generator-ready-for-winter/

excerpt:
"It’s often a learning experience what can go wrong and Murphy always finds something that can be wrong! Example: Some operators might purposely close the vent for the fuel tank to keep moisture out and forget.

Murphy takes full advantage of this situation and the power outage arrives right in the middle of family night. You’re all watching a rented movie, eating popcorn, and out goes the lights! You jump to your feet, it’s your first opportunity to be the family Hero, and you strut into the garage, make a flawless transfer to generator power, and return to the family room with a big applause.

The wife hugs you, the kids hug you, the dog even drops by to give you a lick on the face, the kids have the movie back up, and there’s more pop corn going in the microwave and…. and…..the generator dies! You’re back in the dark, you left the flash light somewhere, you were just too excited, and don’t remember. ...."

[chrisski]

Is there lower wattage equip? Perhaps wired cameras IPOe vs WiFi or Bluetooth? Even the night time LEDs add up.

Now that my system is up and functional, I am seeing what I can do to reduce power.

Last discharge was 101 ah. Turns out I left a few things on overnight I didn’t need. The inverter at 1 amp per hour, 10 amp total; a set of outside LEDs at 1.2 AHs, for 12 amp hour total. I needed the fridge, but found out my gas fridge pulls .5 amp in propane mode or 5 amp hours total. That .5 amps is better than the 18 amps on electric mode.

Those 27 ah added up to about a quarter of my usage that day.

[oregon_phil]

Our fires were so bad in Oregon, we went from 50 kwh/day to 4 kwh/day for about a week. It was surreal.

[SunEagle]

Ouch. My plan was to have this keep a battery bank live at a cabin that in turn would power some security cameras. I calculated a constant 50 watt draw 24/7. Amazing that 10 270 watt panels probably won't meet this need but live and learn I guess.

I did get a POE switch and 12-48 converter so I guess I will go ahead and get that up and running just to see what the actual real-world draw will be.

I'll report back. This is in Washington state and we are nearly solstice.

I was a bit shocked to see how much just a bit of smoke from the chimney drifting over the panels diminished their output by about 80%.

How about any smoke from the wild fires up there in WA. They have hurt production at most northern CA sites.

[chrisski]

My Victron controller can power a relay with a low voltage cutoff and energize the relay based off battery voltages. You could build for a day or two of power and that relay would to run it back on once the battery is charged.