diy solar

diy solar

Feast or Famine, The off grid solar dilemma.

I have talked to Texans about this before.

When asking them about rainwater harvesting they laughed.

They said” When we get rain its in buckets all at once”

If I recall , that 94 flood , I believe that was caused by hurricane Opal…it hit us in the blue ridge for days in the fall of that year having come out of the gulf .. it flooded so much in the mountains it drowned cows by trapping them against culverts openings..
it was a slow moving wet storm for sure ….
 

How many kW & kWh/day do your parents use?
Seems like a ridiculously large system for a house, are there other loads on the property?

Generators usually aren't as stable as the grid. Does SolArk have a setting to remain connected and pass through a wider voltage and frequency range when fed by generator? And to limit power draw from grid or generator by supplying from battery, so generator smaller than peak load can be used?
 
How many kW & kWh/day do your parents use?
Seems like a ridiculously large system for a house, are there other loads on the property?

Generators usually aren't as stable as the grid. Does SolArk have a setting to remain connected and pass through a wider voltage and frequency range when fed by generator? And to limit power draw from grid or generator by supplying from battery, so generator smaller than peak load can be used?
They use around 15kw peak, and about 50-65kWh/day on the hot summer days. It's not just a system for a house - they are working on building a house up there and are living in RV's, have been for the last 5 years as they work through the nightmare permitting process with the county.

The Sol-Ark could be adjusted to accept the power, however, when the generator unloading contactor pops open, the sol-ark stays connected for so long after, that any computer or similar electronic device completely shuts off. Every clock looses its time. We have to make the operation window SUPER wide. I wish I had a scope down there for this video to show just how bad the waveform from the old generator has become.

Sol-Ark does have peak shaving, but it does not have what Victron calls "Dynamic Current Limiter" - so essentially whenever their water pump kicks on, the surge is sent through to the generator, causes a sag, and there ya go...back to battery power. Victron's dynamic current limiter feature pulls the loads like this over to battery while simultaneously ramping down charging, so that they can then incrementally transfer the load back to the generator without causing a cut-out. This could have been their saving grace...but I didn't know about it when choosing the Sol-Ark's nearly 4 years ago.
 
50-65 kWh is well within my systems production, on decent days. Which is when I sometimes need A/C, but I don't need to run that through the night like you guys in Texas do. Like them, I've got inverter capacity maybe 2x actual max load, so it is just loafing along.

My Sunny Island also may glitch output when grid input goes down, apparently depends on how it sags vs. being switched off. Tends to reset things. Would be nice if a half-cycle lost was all it took. Connecting to AC input is synchronized in phase, don't know for sure (don't think) it matches voltage, so not sure how big an instantaneous load it throws on the input, but it does detect current and inverter to limit it.

On-line UPS seems to be the way to keep things smooth, at the expense of losses, and not having grid/generator for large surge loads. (If depending on that, you'd want to disable loads beyond inverter capacity when operating off-grid. I plan to pull more wire so some are grid only, some are fed through inverter.)

Separate battery charger is good solution, although might not manage fuel vs. PV well. Of course you're using it prior to having enough PV.
What I would consider is feeding generator or other AC source into AC coupled inverter (rectified into PV/turbine input.) That inverter could be set to curtail at lower frequency, so 100% of available PV is used first. It is still a guess how much PV will come later in the day. With such a large battery bank, when using generator you can probably shut it off leaving battery able to accept any PV so you never waste fuel.

Is the Victron LF? People say HF has more trouble switching between inverting and charging, to deal with load dump. SolArk appeared at a time when most of the market had different needs, could be more optimized for grid-tie or no-generator applications. Trace and then SMA (Sunny Island) were made for people living off-grid with generators, so better optimized for that usage. Most reasonable users won't have the huge generator you do, so just one ChargeVerter and longer run time should do. I assume SolArk sends a signal to start the generator so it is in control.
 
We've talked about putting the freeze drier on solar but in our case we aren't using it that much anymore. We've been freeze drying for I think four years ("we" being mostly my wife) so now it seems to be during garden harvest for a few runs and the occasional batch of skittles or some other treat that the grandkids love. The thing is a kw hog and the cycles are often 48 hours or more so there's a good chance it could push me into bypass at night. That's not in itself a concern but I've had a few things flicker when I go to bypass and if the FD shuts down over that then you're stuck with starting the cycle all over again or worse. Just not worth it to save a couple dollars in power usage. But that's just me. I'm not even suggesting I'm right about it.

The dehydrator, on the other hand, is not a bad idea at all. We have one but haven't used it since we got the freeze dryer but we've talked about some applications where it might actually be better. I'm going put that on my maybe list. Good suggestion.
We too have both... just building a home now & are on of grid solar. We really want to use the FD when compete. With 21kw of bifacial panels I'm not worried about producing enough juice to run it...during the day. I am wondering how much battery storage I'm going to need. I have 4 EG4 Lifepower4's now (NOT enough) & planned on adding 6-8 more...or 2 of the new PowerPros.

Has ANYONE used one of grid? Set up?
Thx
 
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