diy solar

diy solar

Family in high-rise building, no panel(s) allowed, 72 hour backup plan

A friend of mine in Pakistan has very unreliable grid power. He charges a battery bank when power is available and most 240v appliances run from an inverter
 
If this is a hi-rise building, know where your stairwells are, and if you are worried about loss of power, get comfortable going up and down the stairs 3 times a day. Know emergency exit plans, especially for those in need.
 
1. Hang portable solar panels in the window.
2. Buy a small inverter generator and keep it in your car. Once a day, take the solar generator downstairs and recharge it Outside.
3. have a 12v to 24v or 36v converter installed in your vehicle and once a day recharge the solar generator with your car.

Delta pro is the best choice but a real PIA to move around. Bluetti needs a cart of some sort. Anker 767 is very portable but only supports 1 expansion battery. What’s the budget here?
 
Before everyone want to carry things, remember the family at point of this thread lives on the top floor.
 
So far, 25 states block hoa from disallowing solar...

A bill is presented to make it all 50...

Screenshot_20230721_112002_Chrome.jpg
 
sol said:
Not permitted by HOA governance laws
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I would like to see the wording on this. You are not wanting permanent. Just oh shoot coverage.

If on top floor run long cables and lay them on the roof. Chance of them going by by though.
 
A home refrigerator uses roughly 2 kW-hr per day. On a hot day more, or if it runs a defrost cycle.

That is per my own testing, as well as if you look at the energy label at them, this is what it takes (on average )

Most off the shelf power stations on the market have 1 - 2 kW-hr batteries. So 1 day of power and another day of coasting along on no power if you will.

An example nominal 12 volt x 100 amp-hr LiFe battery has ~ 1 kW-hr of usable power stored in it.

( not precisely but close enough to show a rough budget of what is involved here ).

If they buy one of the ultra efficient refrigerators like a sun dancer or similar, the power usage drops dramatically. Refrigerators like this are super insulated and optimized for ultra low power use. They also run on 24 volts DC so are easy to back up with battery packs.

I believe that the power use per day is roughly 1/3 of a typical home refrigerator - obviously they are smaller inside as well.

Downside - I don't think that they have defrost.

SunDanzer | Household - 12/24V DC Refrigerator and Freezer

SunDanzer's household products offer cheap, reliable, user-friendly 12 and 24 volt DC refrigerators and freezers. designed for off-grid solar homes.
sundanzer.com
 
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I had similar concerns, so I adapted a 36" chest freezer to utilize as a refrigerator. It draws 75w every 40 minutes and cycles between 35 and 41 degrees. Works perfectly and in the event of an outage we will move the contents of the fridge to that special freezer. Right now it just holds the beer.
 
HarryN said:
A home refrigerator uses roughly 2 kW-hr per day. On a hot day more, or if it runs a defrost cycle.

That is per my own testing, as well as if you look at the energy label at them, this is what it takes (on average )

Most off the shelf power stations on the market have 1 - 2 kW-hr batteries.

An example nominal 12 volt x 100 amp-hr LiFe battery has ~ 1 kW-hr of usable power stored in it.

( not precisely but close enough to show a rough budget of what is involved here ).

If they buy one of the ultra efficient refrigerators like a sun dancer or similar, the power usage drops dramatically. Refrigerators like this are super insulated and optimized for ultra low power use. They also run on 24 volts DC so are easy to back up with battery packs.

Downside - I don't think that they have defrost.

SunDanzer | Household - 12/24V DC Refrigerator and Freezer

SunDanzer's household products offer cheap, reliable, user-friendly 12 and 24 volt DC refrigerators and freezers. designed for off-grid solar homes.
sundanzer.com
Click to expand...

Middle of the road option is a smaller fridge. We have an "apartment fridge", which is much bigger than a dorm fridge, but smaller than a full-size regular fridge. In an 85F camp trailer (50F at night), we use an average of 1.2kWh. Add some extra insulation on top and the back (heat is exchanged out the sides on this model) and you could reduce power consumption considerably more. Street price is about $600, ($459 at home depot) but we paid about $250 (scratch and dent model). It has an auto defrost. Possible could be used as a second fridge but then the main one during outages, if space is available for it. I had a friend who lived in a 1000sf apartment and she had two full size fridges there. One in the kitchen, the second at the edge of the living room, which was adjacent to the kitchen (no wall between them). Didn't look too out of place and they loved having so much more food storage space.
 
sol said:
During hurricane season, power is often lost for up to 7 days, sometimes more.
No solar panels are allowed on exterior surface of building by HOA rules.

I recommended they get a Bluetti, EcoFlow, Anker Solix based on a suggestion on a power forum.

For example, this one from Home Depot

They have a small apartment, top floor of building and only want power for refrigerator, LED lights and laptop&modem, total power use typical max in this configuration is less than 5.5 amps and of course refrigerator and laptop are not drawing power continuously.

Anything else I can suggest?
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Buy the panels …..diguise them as art… deceive the landlord…
Supervstech said:
Heck...
Most HOA violations have a 15 day grace period...
So...
Unless the power is out a LONG time...
You should be fine with temporary use.
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Ducktape the HOA members to the front of 450 watt panels … let ‘em stew on it a bit… most of those losers are the same people who always volunteered to be the hall monitor in high school.
 
If this is Florida, hurricane season is mid summer thru fall. And it's hot in Florida during that time. If there's no power, there's no air conditioning. That means the inside temperature will be about the same as outdoor temperature. If it's 90 or 100 F degrees, the refrigerator compressor will run much more often and you can throw that 1/3 power estimate out the window. It would be closer to 2/3 or more.
 
So let's assume for the moment that:
- They really cannot have any viable amount of panels mounted outside
- They may not be home when it happens but still want the fridge to keep running and not have a mess
- Let's assume that they don't want DIY batteries either
- For simplicity, let's make it a 24 volt DC power system as that can be built up by anyone.

One option is to
- buy 14 each, 100 amp-hr LiFe batteries or their equivalent
- either a 1 or 2 kW inverter
- 120 vac charger

Have a marine electrician build it up for them so that it is essentially a UPS for the refrigerator.

It would take up roughly a small closet in space and cost < 20K including parts and labor if they hired it done using premium components.

My guess is that people here on the forum can suggest ways to bring this cost done to much less using specific brands so let's see what happens next.

______________________

If they are actually home, then it might make sense to consider:
- Having a similar concept - but smaller battery pack
- Some 5 gallon propane tanks and a generator out on the balcony to run once a day for an hour to re-charge the batteries
 
My upright freezer sips the power once things are frozen. One could store ice in one and then place the ice packs in a cooler.
 
MPP2724 $642 at Maximum solar, same price from Ian at Watts247 & get his help if you need it!
DIY 304Ah 8S battery pack with JK BMS $1200 OR EG4 200Ah 24vDC rack - $1359 (stand it up in the closet)
Hang it in the back of a nearby closet/cabinet (it may all fit in a cabinet above the fridge, and plug into outlet for the fidge)
plug the MPP AC input into 15A 120 volt standard wall outlet.
plug the Fridge into the side of the MPP2724 - this inverter has outlets built into the left side of the AIO case, as well as USB chargers for your devices.

Total plug and play cost, 200Ah capacity $2000, (add a second rack battery for 400Ah capacity for additional $1359).
Likely get rebate on the equipment price from local and federal tax programs.
Take it with you camping, or if you move. Portable folding PV optional for additional cost.
 
Mattb4 said:
Those power packs are not going to run a refrigerator for long enough to make that a worthwhile endeavor. The best suggestion I can make is they find somewhere else to stay during a long power outage.

Your example power pack has a 2000wh battery rating. Likely usable amount is closer to 1500wh. That is about the amount 1 refrigerator will consume in a day.
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Yea not with portable panels. You need to over panel. I power my cabin at our property with an Ecoflow but I also run 4ea 340 watt panels. I don't think you would get away with those panels if you are restricted...
 
OffGridForGood said:
MPP2724 $642 at Maximum solar, same price from Ian at Watts247 & get his help if you need it!
DIY 304Ah 8S battery pack with JK BMS $1200 OR EG4 200Ah 24vDC rack - $1359 (stand it up in the closet)
Hang it in the back of a nearby closet/cabinet (it may all fit in a cabinet above the fridge, and plug into outlet for the fidge)
plug the MPP AC input into 15A 120 volt standard wall outlet.
plug the Fridge into the side of the MPP2724 - this inverter has outlets built into the left side of the AIO case, as well as USB chargers for your devices.

Total plug and play cost, 200Ah capacity $2000, (add a second rack battery for 400Ah capacity for additional $1359).
Likely get rebate on the equipment price from local and federal tax programs.
Take it with you camping, or if you move. Portable folding PV optional for additional cost.
Click to expand...
Also:
I have a MPP2724 Inverter (for RV and mobile set up) using the 304Ah EVE cells,
It will start and run a standard Fridge, I calculate run time with some losses = 3 days for one 200Ah rack battery, 4.5 days for 300Ah 6 Days on two 200Ah rack batteries, based on my fridge (and P3 kilo-watt tester data)
No PV needed, this would basically be a big UPS for the OP in a highrise, portable and low cost, take an hour to set up with server rack option.
 
Here’s a thought. Petition the HOA management to have backup generators. If it’s a big enough building they probably should already have backup generators to begin with.
 
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