A little music for us today.

Had a conversation with a group member today about an issue he's having with his solar that reared it's ugly head after he had the utility remove power from his house. He has two separate hybrid inverters that are completely separate from each other. Each one feeds a different part of his house, each one is connected to half the solar panels on his roof, and each one is connected to two proprietary HV batteries. For the sake of simplifying this I'm going to make up some parts of this to make it more clear.... one inverter runs 20% of his house but the loads it does run are high power loads. The other inverter runs the rest of the house, 80% of his daily usage. Two separate systems feeding two separate load centers.

I need to go off on a tangent for a moment to make sure that everyone is up to speed.... When a hybrid inverter wants to connect to the grid to export power, it will monitor the grid for 5 minutes for stability, then at the last instant it will come in phase with the grid and connect. It's not like DC where it can just connect any time.... the incoming utility grid and the inverter's grid frequency, voltage and phase must match precisely for the connection to work. Once connected the inverter can import or export power to/from the grid..... back to the post.

How it worked before.... the inverter that runs 20% of his house only gets a workout when the hot water and the clothes dryer run (I'm making this up as I go). So each day, it begins with full batteries and starts selling to the grid. The other inverter has run the house all night and it's batteries need charging. So it charges batteries from solar and also connects to the grid. In reality, it's importing 240v from what the other inverter is exporting. This exchange happens within his house and never makes it to the grid despite both inverters being actively connected to the grid. But each inverter must see a pilot signal of 50/60hz steady state before it will connect to what it calls "the grid". Once connected , one of them is exporting and the other is importing. They are sharing each other's solar panels.

How it works now..... The inverter that runs 80% of his house wakes up in the morning with a low battery and uses half the solar panels on the house to charge the batteries. The inverter that runs 20% of his house wakes up with a full battery and charges for a few moments and stops using solar. There is no grid for it to synchronize to, so it has nowhere to export power.... so it just sits idle. So now we have one inverter that's trying to charge a battery with half the panels for 80% of his daily usage. As you can imagine this is no beuno. The 80% loaded inverter can't call for help because there's no grid for it to connect to... so neither of these inverters is able to connect to each other because there's no grid for them to sync with.... and that "grid" connection is their lifeline to each other. No grid, no connecting together.

The installer says these two inverters cannot be "stacked". This is crazy to me because even "chinese" eg4 and growwatt inverters can be stacked. So there's no way to combine these two 5kw inverters into one "super inverter". I suggested he bridge the two batteries together but otherwise leave the two systems separate.. then atleast they could share power thru the battery bussbars instead of the "grid connection". Any of this will void the warranty from his installer.

Sadly, his solution is to spend about $2500 and get a 10kw inverter to replace the two 5kw units.

Moral of the story.... do like MasterBrains says.... kill your main breaker for a weekend and see what doesn't work. A plan that has not been tested is no plan at all. Something will always come out of left field and smack you in the head.

Make time for what's important.

someone near here has been preparing a house site for a few months... and finally I drove past yesterday and half of a double wide house trailer is parked on the side of the road waiting to go in to that property. I could NOT resist... I pulled along side the crew and said "you can't park here" and grinned. Told them I'd always wanted to say that.... lol.

Holy fragile solar tracker..... yikes.

Got a couple short sections of fencing up today behind the greenhouse and installed a 12' gate. Tried to repair my father in laws old fertilizer spreader and the gear box has siezed and it's rusted beyond repair. So got a new one from agrisupply.

I did this to my shop due to the outrageous price for labor. I bought (2)55 gallon drums. One drum is the activator, the other drum is the foam. It requires a fairly large compressor to be able to keep up the pressure, but they provided the spray gun and the hoses and 100 tips. If you stop for 20 or 30 seconds you must change out the tip because it already starts to harden. I set up some scaffolding with boards across the top and had my son pushed me around. Total cost was around $2200 in 2019. They wanted over 7000 to do it.

Small, closed foam Cell is all you want.

Just to give you an idea.

I petted the nicest good boy today in tractor supply.

biggest system for home use I've ever seen. Either bitcoin mining or growing pot. 138kw of panels (252 panels), 72kw of inverters

https://www.youtube.com/watch?v=vca6uxzgBsY

I bought this all on on pH and moisture meter and it sucks. When i turn it on the analog meter goes full scale and bsck... ok. Then never reads again. Here i have the probe stuck in muddy soil and its reading 0% moisture.

Got stung on my electric bill this month. I actually made more power than I used so that's good... but... the power company credited me for power delivered to the grid but they charge a "demand fee per kw" during the hours of (6a-9a winter) and (6a-9a and 6p-9p summer). So they billed me not for the energy I used but the fact that it was pulled from the grid between 6a-9a... so the demand fee was $28 in total, a completely separate fee than the value of the energy I exported. To add insult to energy, this is the first bill since the new rate plan and it came in over a week later than the old bill so they dinged me for an additional week before I knew.

I've programmed all teh cars to never charge between 6a-9a and 6p-9p no matter what. And the charger that daughter uses has been programmed to not permit charging at those same times. The carport is my only direct connection to the grid.

Honestly I dont know how people without batteries can avoid these penalty fees.

Three ways to clean a crab:

🄳🄾🄾🄼🄿🤖🅂🅃🄸🄽🄶

VERTICAL LFP battery box
I had previously published a cut sheet for an LFP battery enclosure. These newest 314ah cells are slightly thicker than the 280ah cells, so I added 1/8" to the height of the enclosure. One sheet of plywood makes two boxes.

HORIZONTAL LFP battery box.

yes, this is in german, but hte pictures tell the tale. Also I would beef up the bottom of the case with maybe a double layer of plywood or some ribs. I have no evaluated this one for how effectively it uses one sheet of plywood. The vetical one above has been optimized for a 4x8 sheet of plywood.

https://www.youtube.com/watch?v=rpjJvAe6pR8

A buddy here has 3 of these in parallel and they are good. Price drop.

What is your impression of this?