My Off Grid Solar

[Proton]

I started my first system with junk like this about 14 years ago

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I then moved to SMA 4000TL-US 4KW grid Tie inverter. Very efficient but not hybrid. SMA like Nokia did not want to change with times and was left behind.
In Europe Victron is a very good company but they are still behind to the Chinese hybrid inverters. They are just now cathing up.

At this time I also built my first 4 solar pannels. Took 8Hours /panel to solder all cells. by the time I was done with the 4 solar panels the solar pannels in the stores got cheaper , so that was a waste of time.

I think Almost 7 years ago, I moved to Solark 8K inverter and this was a game changer. It runs my whole house. ** If I manage the loads.
My Battery = 93KW.
Solar = 8.4kW

For my hot water heater I removed the 4500W element and changed it with a 1500W element.
Stove uses 2400W, AC uses 2500W, Owen uses 2400W.
So I can use the Stove, Oven and AC at the same time.
2400W + 2400W + 2500W = 7300W.

I can use up to 12kW because I still have a GRID connection but I manage the loads to use my own power because I have too much power.
Here in Georgia, in the summer AC runs all day long From June to September. I had 11 panels Down on the ground and afternoon some shade from a power pole was cutting down my production. Also chickens were pooping on the solar panels and I was washing them 2 times a day. This year I got tired and moved them up. Now there is no pore dirt on the panels and no more shade afternoon. So production went way UP.

I built this solar carport for $1080 and was a lot of work. The metal poles are 4ft in the ground in concrete.

In the spring I was able to produce 50kw /Day. But that was only after few cloudy days when the battery went down to 50%.

Right now I can produce more but I do not know exactly how much because my batteries are full by noon and the inverter stops producing power. I need to have the battery down to maybe 60% and then I need a full sunny day to see how much I can produce in the summer.


This image show the how much my house used this year. Not what the system can produce, because I can produce a lot more.

July is the hottest Month and will probably know if my panels produce enough power.
When I will start charging the battery for the car I will know exactly how much I can produce.

Here I was guarding my solat panel on the ground. we had high winds that were picking up the solar panels and I had to move the cars around.

Here is the new solar carport.

[jrbe]

I've been eyeing a Sol-Ark for a few years. Is your inverter new enough that you can add another in parallel or add microinverters on the switched input/output of you wanted to?

[Proton]

I've been eyeing a Sol-Ark for a few years. Is your inverter new enough that you can add another in parallel or add microinverters on the switched input/output of you wanted to?

I do not want to parallel my inverter. I want to by a 15k when I have some money and keep this one for backup.
the inverter uses 60W/h. At 24 hours that is 1.4Kw which means you need an extra 400W solar panel to cover that. if you have 2 inverters in paralell you are using 2.8Kw/day which translates in 2 solar panel extra. you also need 1/4/2.9 kW of extra batteries.
So it is better to use a bigger inverter and have an extra one for backup.


Micro controllers or any other version of grid tie inverter are garbage, specially these days.
1. power goes out they stop producing power.
2. expensive. lets say you have 30 solar panels 30 x $180 = $5400 just for the micro controllers. if power goes out you go out.
3. you cannot connect batteries or store power overnight.
4. power companies now do not want to pay anymore for the home solar.

in my area I have to pay $10 if I want to export and anything I export they pay me 5cent/kW. This is theft.
I chose to cancel my grid tie agreement after I got the hybrid inverter and batteries.

[jrbe]

The Sol-Ark becomes "the grid" in an outage and the microinverters help support it on the generator input / aux input. The grid disconnect switch likely would keep the system and microinverters producing in an outage.
I don't have the experience with this but it seems the US inverter options are not great vs a Sol-Ark.
Are you sure a 15k will support all your loads? Our split phase power means we use a lot more current on stoves, dryers, water heaters, chargers, etc. vs the sensible areas with 3 phase.
A small East/West bifacial solar fence would cover the inverter(s) power draw and give you some extra system flexibility. Not telling you what to do, was just what I bumped into planning.

[Proton]

AC coupling with solark is possible but only is you have a very big battery, otherwise you do not have where to store that extra energy. Personally I am not going to use microinverters ever, under any circumstrance. Cant stand them.

Solark 15 K puts put 15 k continous.

Stove 2400W AC 2500W, Hot water 1500W, fidge 400w, Freezer 150W, Computers, monitors, Modem, Firewall etc 400W.
All these are 7350W.

with the dryer 6000W is 13350W.

you need to change both water heater elements from 4500w to 1500W.

MOst of the time my house is arounf 400W. Goes up only when I start a big load.

[Proton]

after I tested the Solar production in march and I got 50Kw, and because today is the longest day of the year I wanted to test again the solar production.
TO drain the battery for today yesterday afternoon I turned of the switch from the solar panels to help discharge the battery and last night I did 5 loads of washing and drying and managed to drain the battery to about 68%.
surprise is that the production was only 54.8kW, only 4.8kw more compared to the spring test. I was expecting over 60kW. I guess that heat indeed has a big effect on the solar panels. today we had 34C and indeed was very hot. AC ran nonstop from 11 AM to 7-8 PM

I forgot to check if the 10 panels on the roof of the house are clean, but I can check that tomorrow.

Also the battery showed 100% around 4 PM but according to the production curve I do not think I lost any production.

[johu]

I guess that heat indeed has a big effect on the solar panels

Yeah it does. It was 30°C here yesterday and my system peaked at 1070W. On sunny cold days 1250W

[Proton]

So, it looks like the solar panels on the roof are less efficient that the solar panels on the Carport which have a lot more airflow.
M1 Roof are 79% efficient, probably because of the hot roof.
M2 Carport are 84% efficient probably because there is more air flow underneath.


But both lose efficiency in this heat.


Probably next for the sake of science I will disconnect the solar panels on the roof too see if the carport is enough to keep the batteries full in this east coast weather where you have to run the AC 24/7 in the summer.
For a well insulated house like a passive house the 3.1kW panel on the roof should be enough even in the summer.

[Proton]

I just want to mention that in may area there are no rules. I do not have to pay money, get approvals and anything like that.

I other parts of USA is different. Usually Democrat states have more rules and more fees, and more taxes. Republican states have less rules. When I bought this land it was all trees and I went to the county to ask them what kind of rules we have here. they asked me for my address and said "NO rules".

They said that I do not even have to pave the driveway if I do not want to. just gravel is fine.

[johu]

Well I guess that's great but please don't plant the seed to political discussions. There's other places for these.

[Proton]

Today I disconnected the solar panel on the house. will see how many days the carport by itself can sustain the house needs.

[Proton]

So the carport cannot produce enough even on a mostly sunny day. did not wash clothes or cook much today and still not even enough for the AC and the rest of the house.
So for anybody planning for solar this is almost the max a 5.3kW solar system can produce in a sunny day.

ON the carport I have 12 x 485W panels but only 11 are connected in series. with all 12 panels in series I would have too much voltage in the winter when is cold. I could make 2 series of 6 but I need to run another cable.

So for tomorrow I need to reconnect the panels on the house to bring the battery back up. another 3.1kW.

and some potatoes. Need to pland 2nd batch for fall/winter harvest.

[Proton]

So I made it through June with my personal production. 1200kw use for the whole month.
we had a very hot week at the end.
Now in July it looks like all days ave over 31C and in the morning at 7 am the lowest is going to be 21C. that is the reason here on the East coast you cannot live without AC in the summer.

will see if the panels keep UP with July. I also have water batch collector outside that preheats my hot water before it comes in the house. water comes in around 40C in the water heater inside.

[Proton]

Finally end of July and usage was almost 1400kW. this means that only the AC used about 600kW, based on the average of winter and spring months.
About 800kW average. that is no heat at all since I use wood to heat my house.
I can get higher usage only after I start charging the electric car. but for that I need more solar panels. My battery is at 74% right now and the whole month of July was never able to get the battery at 100%. the temperatures are going down a little bit so I will be able to fully charge the batteries next week.

[MattsAwesomeStuff]

usage was almost 1400kW. this means that only the AC used about 600kW

It irrationally irritates me that you have so much knowledge, and yet conflate kW with kWh.

[Proton]

Yeah... People keep telling me about KWh and I keep forgetting. one of these days I will remember to spell it correctly.

[Proton]

[Proton]

I was cleaning my shed and found the old Grid Tie inverter. If anybody wants to pick it up for free let me know. I am in north Georgia.
4kw and 98% efficient. I only used it I think a little over a year.

SMA 4000 TL-US

[tmhb16]

Any chance you'd would be willing to ship the inverter if I covered the costs? I'm in central Alabama and could definitely use it for my solar system

[Proton]

I will PM you. I will be in Birmingham, Alabama Sunday. I will PM you the address.

[arber333]

ON the carport I have 12 x 485W panels but only 11 are connected in series. with all 12 panels in series I would have too much voltage in the winter when is cold. I could make 2 series of 6 but I need to run another cable.

I have found out that using 12 panels in 2x6 cofig makes up for cloudy weather loss. Parallel lines seem to be better at generating SOME amps when series line would dissolve because of cloudy weather. Of course you need to provide inverter which can handle lower voltage from parallel panels.

I use 2x8 configuration so that my inverter wakes up and i still get 25% in cloudy weather as long as it doesnt rain...

[Proton]

I used all 12 this summer when the battery was low, but already disconnected the #12 panel. i am afraid to keep it on. I would have them 2x6 in paralel but then my cable would pass 2x12.4 Amps not sure if that is good for my 10GA cable. I would have to pull another 120ft/30m cable.

[arber333]

I used all 12 this summer when the battery was low, but already disconnected the #12 panel. i am afraid to keep it on. I would have them 2x6 in paralel but then my cable would pass 2x12.4 Amps not sure if that is good for my 10GA cable. I would have to pull another 120ft/30m cable.

10ga is about 5mm2 if i know my US conversion, that should be safe for 50A max. However i wouldnt go more than 25A just because.... You need to use 30A fuse for paralleling that. Also you need to make a good junction. I would suggest not to use chin Y adapters, rather crimp cable shoes to a bolt connection, join the three lines and cover the junction by nylon tube. That way you can take it apart if it gets too hot...

Another question is if your inverter input is up to 25A!

EDIT: Yes i use separate lines from each 400W 8S modules and then i connect the whole thing in one big Y junction to a single line. I have 8S one the south and 8S on the west which gives me really good stretch through the whole day. But from noon till 2pm i get full 6kW then it fades a bit. In clouds i get 2kW still...

[Proton]

Since this is the last year in USA when I can get the 30% tax rebate I bought the Solar 15k. Found it in sale.
It can take 26amps on each of the 3 MPPTs.

[Proton]

I finally had time to install the 15K. Did not connect the Grid back; just the batteries and the solar.


Using 10k right now. Dryer 6 kWh, stove 2.4 kWh, water heater 1.5 kWh, and the rest are small loads.