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Here! Someone hold my (root) beer!
4 years ago
General
Warning! Nutcase with an 'idea' - do not read if you wish to stay sane!
Some of you may be aware that last February there was a bit more winter than some were expecting and there a lot of power problems/outages as far south as Texas (depending on which report you read/believe, the Texas electric grid almost went completely down - something that would have taken weeks if not months to bring back up if nothing big was damaged by the crash.)
Then there's the rising cost of power (seems someone in DC wants us completely 'green' without first building/installing enough green to cover for the gas/oil pipelines they're trying to close/cancel.)
So this nutcase in question is thinking about power.
There's grid-solar, where you have panels on your roof and it feeds any excess to the grid (and you get 'paid'/credited for it), but if the grid goes down you're dead in the water - even with the sun shining brightly.
Tesla has a power-wall, but that's out of my price-range.
So, the rough idea is to throw some panels on the roof to feed a controller that feeds the juice to a bank of batteries, which then feeds power to an inverter - which feeds power to the house.
For those about to squawk, yes, the mains breaker gets popped/tied-off before the inverter's breaker (yes - that gets protected as well!) is engaged.
Current plans are:
A dozen (may got to 16) 210 Watt panels (in the yard propped on a sawhorse I'm seeing around 170W on a bright day) feeding an:
80 Amp MPPT Solar Charge Controller, which will charge:
Eight (may go to 12) 12.8 volt 100Amp-Hour LiFePO4 Lithium Iron Phosphate Batteries which will power a:
120/240 VAC Split Phase,Continuous 6000 Watt low frequency pure sine power inverter Peak 18000 watts off grid solar inverter
(To reduce wire gauge/cost, the DC side is a 48 volt system, so panels and batteries will be set up in groups of 4.)
Only thing not tested as yet is the inverter, maybe this weekend (dang thing weighs 33kilograms, the batteries are only 10.43Kg each, the solar panels 11.1Kg each.)
Comments are welcome, but the power-bench is taking shape!
Some of you may be aware that last February there was a bit more winter than some were expecting and there a lot of power problems/outages as far south as Texas (depending on which report you read/believe, the Texas electric grid almost went completely down - something that would have taken weeks if not months to bring back up if nothing big was damaged by the crash.)
Then there's the rising cost of power (seems someone in DC wants us completely 'green' without first building/installing enough green to cover for the gas/oil pipelines they're trying to close/cancel.)
So this nutcase in question is thinking about power.
There's grid-solar, where you have panels on your roof and it feeds any excess to the grid (and you get 'paid'/credited for it), but if the grid goes down you're dead in the water - even with the sun shining brightly.
Tesla has a power-wall, but that's out of my price-range.
So, the rough idea is to throw some panels on the roof to feed a controller that feeds the juice to a bank of batteries, which then feeds power to an inverter - which feeds power to the house.
For those about to squawk, yes, the mains breaker gets popped/tied-off before the inverter's breaker (yes - that gets protected as well!) is engaged.
Current plans are:
A dozen (may got to 16) 210 Watt panels (in the yard propped on a sawhorse I'm seeing around 170W on a bright day) feeding an:
80 Amp MPPT Solar Charge Controller, which will charge:
Eight (may go to 12) 12.8 volt 100Amp-Hour LiFePO4 Lithium Iron Phosphate Batteries which will power a:
120/240 VAC Split Phase,Continuous 6000 Watt low frequency pure sine power inverter Peak 18000 watts off grid solar inverter
(To reduce wire gauge/cost, the DC side is a 48 volt system, so panels and batteries will be set up in groups of 4.)
Only thing not tested as yet is the inverter, maybe this weekend (dang thing weighs 33kilograms, the batteries are only 10.43Kg each, the solar panels 11.1Kg each.)
Comments are welcome, but the power-bench is taking shape!
The batteries have some built-in protection, 50 amp max charge rate, 100 amp max draw.
If the inverter is supplying the full 6000 watts, that'll be a 137.5 amp load - thus the need for at least two battery banks. (only 90% efficient so figuring 6600 watts battery draw.) Not that I want to draw that much, it'd drink those 8 batteries dry in just over 90 minutes!
I did look at some micro inverters, but the only ones I saw would only work with an active grid.
Shading isn't too much of a problem, I just have to mount the panels on the eastern end of my south-facing roof - too bad where the power is going is to the west side of the house! (Or convince my neighbor to go solar so he'll have to cut down that tree of his that blocks my late afternoon light! )
I hadn't thought of used industrial sized UPS units, might have to see if they might be better than the inverter (and whether they'll play nice with Lithium Batteries, as most were set up for the older lead-acid batteries.)
Inverters, get ones that put out a smooth sinewave of current - some of the inexpensive ones were odd - tended to ruin computerized equipment like modern appliances - sold appliances for a while and we had issues with folks off grid with cheap inverters that were screwing up the circuit boards in fancy stoves. I overhead a customer arguing with the repair manager and I chimed in with that info when they mentioned their power supply
They also offer this sort of thing commercially. I've seen it advertised on television.
V.
I went with lithium (already bought at this point) for several reasons.
One was 3 - 5 times the life of the lead acid. This single point actually made the lithium batteries cheaper in the long run, so I looked into them more.
Two was the often need to check/top off the lead acid batteries (charging/discharging creates hydrogen/oxygen) , the lithium doesn't vent and has a Built-in BMS (Battery Management System) to protect the cells from damages like: overcharge, over-discharge and short-circuit. The BMS also helps keep the battery cells balanced.
Three is that most lead acid cells can be damaged/ruined if discharged too deeply (from what I've read beyond 50% of their rated value) whereas the lithium can be discharged much deeper (98-99% and the BMS will cut the battery out to prevent damage.) So I'd need twice the number of lead acid batteries to have the same usable kilowatt hours of stored power.
We'll see how it goes.
V.
Removing the ones involving accidents, most of the others seem to center around them being possibly rapid-charged (fire right after stopping at a light suggests regenerative braking may have just dumped a load of power into the batteries.)
How often do Teslas burst into flames?
“From 2012 to 2020, there has been approximately one Tesla vehicle fire for every 205 million miles travelled. By comparison, data shows that in the US there is one ICE [internal combustion engine] vehicle fire for every 19 million miles travelled,” Tesla's 2020 Impact Report claimed.Aug 24, 2021
And I remember Ford having some major recalls after a problem in their steering columns had parked Fords burning down a few homes. Yes, not a battery issue, but batteries aren't always the greatest risk.
https://www.powerstream.com/LLLF.htm has a few things about the LiFePO4 types I'll be using.
I will be careful of my handling and wiring of these batteries (I've been playing with electricity/electronics since the early 70s and I still don't liked getting shocked/burned/or having the magic smoke suddenly escape.) I won't be dealing with anywhere the power those cars have, and both the batteries and other equipment have current limiters that should make any overheat/fire issue hard to create.
While I will happily take all the luck I can get, I'll also do my damnedest to outwit Murphy!
V.
Hope you have an aux generator as well, as a JIC.
As to the project, much easier than overhauling one of Folly's warp cores!
I'll let you guys know how it works out.