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24V is better match for 315w 60 - 72cell solar panel voltage without requiring more expensive MPPT controller vs. PWM.

How much do you owe them? Is it less than cost of new inverter and installation? Then write to them and ask for payoff amount.

75 mix has very sharp absorption at 2 Mhz for small cores and 1 Mhz for larger cores with multi turn windings. Good for AM broadcast band filtering. But I found mix 31 to be more broadband, especially good from 0.5 - 5 Mhz with 10 - 20 turns.

Not to mother earth but to the inverter neutral wire which would complete the short circuit current path and trip the breaker or the inverter (with the assumption that ground and neutral are bonded somewhere).

Yes I think so. I run my Victron smart solar 75/15 from 44V 630Ah battery bank connected to PV input via 5A fuse. It never failed.

Is that a 48V inverter? Those IRF2907Z are 75V MOSFETs. Interesting that 1st tier brand would leave so little voltage headroom.

$46 x 4 = $184 for 4 cells shipped. One $150 BMS for all 16 cells. Not one BMS per 4 cells.

Good point. Air will be hottest under top panels.

Don't

Why should private entities be required to spend money on winterizing if they are not compensated for it? Altruism does not write checks. People in Texas vote for cheap power prices and that's their choice. Besides, 2021 Texas was not a total blackout but a load shed event of 20GW out of nearly...

If you are careful not to export significant amount I think you will be ok. I backfed 488 kWh worth of energy into my house wiring with only 1.5 kWh exported to grid by mistake. I used Enphase micro inverters fed from my 44V battery but I bricked 3 of them making this exercise cost me more than...

I suspect this is what's happening right now with no NG bond at the loads panel inside. He's measuring 7 volts N to G at loads panel unbonded. This could mean that there is current on the ground wire going out to the NG bond at the pole and returns via N wire. Could be due to miswired appliance...

Try shutting off breakers one by one while observing that 7 volt N-G voltage. Also you could try measuring N-G resistance at that 7 volt point but only after de-energizing the whole house and solar system. It could reveal loose or corroded connection.

I'd say not worth the trouble (and job risk) trying to "rehabilitate" these. They are most likely process testing cells or rejects. I'd definitely keep a couple in my office as paper holders.

“ageless” and "life cycle" in the same sentence :fp2

Might be easier to use dedicated low power 48V to 120Vac inverter for lights only.

Not sure without knowing what voltage potential your array will be in relation to earth ground. You'd have to probe PV- and PV+ to ground during operation and during idle (night) using high voltage capable oscilloscope and probe. Non-isolated grid inverters can bias PV inputs to 600V peak...

Is there a reason why you cannot irrigate during sunlight hours only?

Yes if you ammeter is peak reading, not true RMS type.

Very nice! At todays FPL rates (15c/kWh) this array would pay for itself in 1.7 years.

I meant 84% efficient 48V DC to 120Vac inverter I use to power it from my battery. So far it seems OK keeping condenser outlet tubing dry. But I would not be able to detect slight cooling efficiency loss anyway.

Your are correct. I was thinking about loose interconnects arcing. If PV wire rubs and shorts to grounded metal raceway then inverter can trip open that PV string and remove pathway to ground. If both + and - of the same string short to ground then inverter cant break the circuit.

Yes resistors look good. Here is David Poz hard switching 90Vdc without precharge into 250/100 although not from battery but from rectified AC generator, capacitor smoothed.

For lowest cost you want something that will backfeed your house AC grid with zero export limiter. Something cheap like this EGCSolax 6.2kW AIO can do grid backfeed but not sure if it supports zero export.

Melting 1 ton block of ice will absorb 92.8 kWh of energy. Same is true for freezing water into ice. COP of ice freezer is around 2 meaning it takes at least 46.4 kWh of electrical energy to freeze 1m³ of water. You can do same amount of cooling using efficient mini split air conditioner at 3.5...

By the way, what do you think of this DIY grid tie inverter project? https://jamesfotherby.com/index-page/600w-grid-connected-inverter-v5/ I am thinking of building one to learn about inverter design and couple it with very cheap 12c/w used panels to save money on power bill (for a friend). This...

In Minnesota at 22deg sun angle? Hmm maybe W/m2 data I found was for horizontal tilt collector. Need to check that. Source: http://www.somnwx.com/pages/station/climate.php?var=S

I did not at first. I saw it up to 200A part. That cell is weak but all that boasting and incorrect testing method is LOL. And his insistence that he is testing the power a cell can provide is a fail.

A team at Dalhousie University with Jeff Dahn have identified modified NMC Li battery that can last 100 years and beat LiFePO4 in both efficiency, longevity and energy density. Full paper here: Li[Ni0.5Mn0.3Co0.2]O2 as a Superior Alternative to LiFePO4 for Long-Lived Low Voltage Li-Ion Cells...

Current shunt is a resistor of very low value. For example 500A 50mV shunt = 0.0001 ohm. Making such resistor without error is difficult. That's why shunt error needs to be calibrated inside measuring device.