One of critical issue with an AC coupling system is happening when battery has fully discharged.
There is no way to recover back.
So, I decide to install an addtional DC coupling
Two panasonic HIT340 module on the shed at my back yard.
2 pannels are connected in series, it can generate 680W. (practically, it can generate 760~780W).
I have installed cheap MPPT charger,
Actually, this model can support 190V input, and working up to 160V.
When I make 2s 96cell module, Voc is around 130-140V. and Vmppt is around 120V.
It is too hard to use a generic 150V charger.
but, this MPPT controller is perfect in my case.
This is final connection,
I have installed 200W 48V to 12V DC2DC for Mini-computer (monitoring), NAS (Data storage & Web Server)
and Wireless Router (to keep on an in-house network).
I have installed 30kWh battery power
The useable capacity is around 24~25kWh. and, It is enough to supply 24 hours full power usage.
or 2-3 days limited power usage at my house.
Really, simple information but hard to find
Recently, I have just updated little bit..
Add an accmulating graph, It can make me easy to read how much power has generated/used easily.
Around 50 yard in front of my house, there are some big trees.
I make some shadow on my house now.
Power gain is not even, and, drop power at end of day ~
actually, the shadow is not much horrible to reduce the power to the diffusion power level.
but, It is a problem with solar power generation.
I hate the trees, but, I can do nothing ~ because it is not belong to me.
When install a solar system, need to consider more carefully,
The top-left panel are shaded, just little bit, What will happen ? just guess ?
Yea, lost 1/2 energy. Technically, solar panel is not working like that..
(1) 20 cells are in a string, and
(2) 3 strings in a panel (that is why there are three by-pass diode)
If half of one cell is shadowing, the cell will generate much lower current and/or voltage drop.
those string will makes much weak power such as 10-20% (power base on the diffusion light)
The other two strings will generate the power normally, so, it will generate 100%.
100% * 2 strings * 2/3 = 66.7%
10% * 1 strings * 1/3 = 3.3%
so, finally, the power generation should be around 70%, BUT, Enphase inverter has a problem in MPPT.
They track the lower peak instead higher peak in this situation. and generate 3.3% * 3 = 10% intead 70%.
by the result, just 50% of power can be havested in this situation.
This kind of problem is happening with a full sun-light condition also. when three string show full power,
but, there are some cell mis-matching. it will generate 2-3% flatten peak points near highest power point.
Enphase inverter is detecting the lowest peak one, instead highest one also. and, it can reduce the power by 2-3% also.
You can observe the discontinual highest power peak when shutting by cloude. because, when shuttering, this inver can find the highest point, but by time, keep going down, and stay at the lowest-peak power again.
Due to the tracking problem, Enphase Micro-inverter can not havest 100% enery, if they fix it.
The power yeild can be increased 1-2% for the good sun-light condition, and by 5-30% for the shading condition.
First, I do not know, it has been caused by an Inverter or a Panel,
but, I am suspecting that the problem is happening by The Inverter.
Everybody know the shadow can reduce the power gain from Solar Panel,
What will happen there is very small shadow 1-2 cells in a 60 cells panel ?
Yes, it can reduce the production to 30~60%,
Look at the detail production yield at my house,
Sunlight is coming from Right-Top side and, Dommer at Right Hand Side is making a shadow on Panel #6,
#1, at 09:19AM, half of two cells (right-top side) are shade, power production is just 10% via the other panel.
#2, at 10:23AM, very thin shade on a cels (aroudn 10~20% on right-top side), production is 80% via the other panel.
#3, at 10:29AM, no shades, same power gain via the other panel.
In the solar panel test with MPPT charger, the minimum power is aroudn 60% in #1, 90% in #2
It makes me suspect There is a critical problem in Enphase IQ inverter.
Note. Enphase IQ 7+, LG350N1C-V5
Finally, I have got PTO, and my solar system start to work ~
뉴저지에서 텃밭을 준비하는 시기입니다
상추, 파, 들깨는 3월중순에 영하를 벗어나면 바로 직파를 합니다
모종을 준비하나 아니면 씨앗으로 직파를 하나, 크게 차이가 없었습니다.
고추/토마토/수박은 2월말에 모종을 준비합니다,
고추는 3월중순에 직파를 해도 되지만, 조금 이른 수확을 위해서는 모종으로 준비합니다.
그리고 고추/토마토는 4월말에 정식을 해도 되지만, 수박은 조금 늦게 5월초에 하는 것이 좋은 것 같습니다,
올해는 매운고추/파/토마토를 충분하게 냉동 저장해서 내년까지 먹을수 있도록 해야 겠습니다.
수박은 8개 정도 거둬볼 계획입니다, 작년에 5개는 조금 부족한 느낌이었습니다.