Help Please - Miami Condo Hurricane Prep

[alfaeric]

Welcome to the party!


The problem there is she has 2.4 kWh power need and an east facing balcony with 12' of space. Let's see... in an earilier post it was estimated that 100 watt panels were just over 2' wide, so you could have 5. Assuming you get between 20 and 50% of the insolation (given the east facing and stormy weather) that's roughly 500 to 1000 watts per day as a rough guess.

The Nomads are 20.5" wide, so you could get 7 at a cost of $2800. They're 5' long...so, if you slid them out somehow at 45° , At 5' tall they'd hang down about 42" which is just at the upper end for the height of a railing. So that's good, they wouldn't hang below into the downstair neighbor's air-space. 700 watts of panels at 20 to 50% the insolation would be 630 to 1575Wr/d. So, still not enough watt-hours and that would 71 lbs down plus windage forces... a lot of force on the railing. Easy to see why the first couple of pages are pointing to a propane generator (which we don't know if it'll work or not - depends on the trailer/garage ideas).

One thing to note- while I've not been directly in a hurricane, I have paid attention to post ones- for the most part, after the hurricane passes, the weather (read that as sun) is really quite good. So the sun may not be blocked as badly as you might think.

Also, thinking about it, in the immediate aftermath of the hurricane- call it the first 8-10 hours post shut down, the most important item is the CPAP machine, it seems to me. Then some time cooling the fridge down enough to be safe again. Extended power cuts will be a problem, for sure.

Still, the idea of finding a way of hanging enough panels appears to me to be an interesting path to follow. Even w/o DIY, one should be able to find a fabricator that can make a very effective system that will come super close to meeting the requirements.

Although, it would be good for the building to plan for this.... Not sure how, but a whole building system supplying everyone would be pretty smart.

 

[svetz]

...for the most part, after the hurricane passes, the weather (read that as sun) is really quite good. So the sun may not be blocked as badly as you might think.

It's hard to guestimate that. The 50% in the 20-50% range is from 50% as she's on the east side of the building, so 50% insolation is the best she can do as they'd fall into shade just after noon. The 20% really should be 0% as the worst case, but assumes at least 40% solar energy through any sort of clouds. Most buildings aren't true east, so if it faces ESE she'd do better, ENE worst. If the bottom of the panels can be pushed outwards she can do a bit better.

 

[John Frum]

If the building has an elevator they likely have a generator to power essential systems.
This often means certain outlets in common areas will have power.

 

[Brewman]

When we are talking hurricanes, all bets are off. Been in the Miami area 23 years now.

 

[Bob142]

The problem there is she has 2.4 kWh power need

Yeah, sorry, I was operating off of your revised 1kWh from post #64. The OP needs to get their energy consumption during emergencies down as low as possible. That's true even with a propane or gasoline solution, as those won't provide indefinite runtime either. If they can achieve the level you outlined, the GZ plan or similar plug and play solar with lighter weight flexible panels might give them a fighting chance at lasting through a many day outage in the condo setting (weather permitting).

Haven't heard from the OP in a long while...

 

[Forbisher]

Wind is not looking good for low elevations... found a Miami wind speed chart at 10 meters altitude above ground (~3rd floor):

That 10 meters or 30 feet above ground means unobstructed wind flow on a freestanding pole or tower Not on a balcony of a wind blocking building where you would not get any wind power at all. Even a turbine on top of a 30 foot building would not equate to that chart.

 

[svetz]

Just learned here that there are chest freezers (which can also be used as refrigerators) that are very efficient, as low as 1.84W/cuft for a 21.7 cuft and 2.66W/cuft for 8 cuft; based on EnergyStar data. This article claims you can find a cpap machine for 40 W. From EnergyStar, a fan that consumes 35W.

So let's look at those numbers again assuming some appliances were replaced with very efficient ones:

Device	Watts	number of hours needed/day	watt-hours/day
C-pap machine	40​	6​	=6 x 40 = 240
fan	35​	6​	=35 x 6 = 210
frig	23​	24​	=23 x 24 = 552
cell	20​	1​	=20 x 1 = 20

So a total of 1022/d. So, that makes a lot more things possible...for example a bluetti 2400 would last a couple of days and five 100W panels hanging from the balcony rail might be enough to repower it each day.

 

[100LastGoodNerves]

Just learned here that there are chest freezers (which can also be used as refrigerators) that are very efficient, as low as 1.84W/cuft for a 21.7 cuft and 2.66W/cuft for 8 cuft; based on EnergyStar data. This article claims you can find a cpap machine for 40 W. From EnergyStar, a fan that consumes 35W.

So let's look at those numbers again assuming some appliances were replaced with very efficient ones:

Device	Watts	number of hours needed/day	watt-hours/day
C-pap machine	40​	6​	=6 x 40 = 240
fan	35​	6​	=35 x 6 = 210
frig	23​	24​	=23 x 24 = 552
cell	20​	1​	=20 x 1 = 20

So a total of 1022/d. So, that makes a lot more things possible...for example a bluetti 2400 would last a couple of days and five 100W panels hanging from the balcony rail might be enough to repower it each day.

Thank you for the info. Have you supplemented with folding Goal Zero, Ravpower and Anker portable solar panels? I realize most cannot be chained or dumped into a charge controller

 

[ianganderton]

Gravity Generator – Just for fun
I doubt this is really practical, but after the recent slew of potential energy generators on youtube figured it would be fun to run through the math to get a feel for it. Or, it could be I'm delaying doing some yard work.... ?

So, let's assume you're on the 9th floor (you'll see why in a bit). The mass to get 2 kWh with a 90' drop is about 27,000 kg. That's hard to move around in a condo, might even fall through the floor. But... sometimes even though the power is out, the water will be on (It’ll have a boil order on it usually).

How many 5 gallon buckets with 4 gallons of water would you have to drop from the 9th floor to recharge 2 kWh, how much would the water cost, and would you flood the ground floor?

Costs are easy, for Miami it looks like $53/6000 gal [ref].

A gallon of water weights 3.78 kg/gallon, so 15 Kg for 4 gallons. The weight of the upwards empty bucket would cancel the weight of the downwards bucket.

The potential energy of 15 kg dropped 90 feet is 1.12 Wh [calculator]. Assume 90% efficiency in conversion and it’s 1 Wh per bucket (had to work the math to get the number of floors to match to 1 Wh/4g ).

So, you’d need to drop 2000 buckets, or 8,000 gallons, at a cost of $70. That's just over 1000 cubic feet of water.

Your typical bathtub spigot is 4 to 7 gpm. In 24 hours there are 1440 minutes and we need 8000 gallons, so to generate 2 kWh/d the faucet would need to run at ~5.56 gpm. Probably faster than that, it'd take a few seconds for the bucket to fall to the ground and tip.

Given Electricity in Miami is $0.1142/kWh normal recharging from the grid would have been about $0.23 per day compared to $70 of water. Of course, if water is included in the condo costs (i.e. no charge for extra usage) ...this might not be so bad!

Left field idea - Would a water turbine be possible?

ive not thought this through properly, just wondering and typing at the same time

So a water turbine uses the potential energy stored in water and gravity so is basically a gravity generator isn’t it

If mains water is on would it be possible to just attach a turbine to a tap and recharch a battery that way?

Depends on how much water there is available. Somewhere like Miami after a hurricane I can imagine it could be wasteful in the extreme

-off to search the inter web for info ?-

 

[ianganderton]

Here you go 120W every time you turn a tap on

Generate Electricity Whenever You Use Water at Home With the Vortical Tech Hybrid Tesla Turbine

/PRNewswire/ -- Vortical Tech LLC, developers of eco-friendly technology, announced today the first prototype of their turbine which generates electricity...

www.prnewswire.com

Interesting idea

 

[John Frum]

Left field idea - Would a water turbine be possible?

ive not thought this through properly, just wondering and typing at the same time

So a water turbine uses the potential energy stored in water and gravity so is basically a gravity generator isn’t it

If mains water is on would it be possible to just attach a turbine to a tap and recharch a battery that way?

Depends on how much water there is available. Somewhere like Miami after a hurricane I can imagine it could be wasteful in the extreme

-off to search the inter web for info ?-

Yes that should work.
Not sure of the economics if your water is metered.
How big is your mains and at what pressure?

 

[ianganderton]

This article discusses some of the economics

Statoil BrandVoice: Can You Turn Your Home Into A Hydroelectric Plant?

By New Scientist, An Energy Realities Partner Nobody has all the answers to the world’s energy questions, so New Scientist teamed up with Statoil to search for solutions from New Scientist’s audience. The question posed was: How much electricity could be generated if you attached a turbine to...

www.forbes.com

I like the idea of harvesting that bit of energy each time a tap was turned.

I also like the idea of also harvesting the energy on waste water. In a tall apartment building that has got to add up plus with the height the potential energy would be better.

It would be very satisfying to know when you flushed the toilet it charged your batteries a bit ?

 

[Forbisher]

42" pipes and they say the pipes have to be downhill coz it takes power to pump that water.
And is this project still working and a success?

Portland Now Generates Electricity From Turbines Installed In City Water Pipes

Water flowing through the city’s pipes will generate electricity like a dam with none of the environmental consequences.

www-good-is.cdn.ampproject.org

 

[Supervstech]

This article discusses some of the economics

Statoil BrandVoice: Can You Turn Your Home Into A Hydroelectric Plant?

By New Scientist, An Energy Realities Partner Nobody has all the answers to the world’s energy questions, so New Scientist teamed up with Statoil to search for solutions from New Scientist’s audience. The question posed was: How much electricity could be generated if you attached a turbine to...

www.forbes.com

It would be very satisfying to know when you flushed the toilet it charged your batteries a bit ?

I’m not servicing that turbine when it breaks down...

 

[dmholmes]

Just learned here that there are chest freezers (which can also be used as refrigerators) that are very efficient, as low as 1.84W/cuft for a 21.7 cuft and 2.66W/cuft for 8 cuft; based on EnergyStar data. This article claims you can find a cpap machine for 40 W. From EnergyStar, a fan that consumes 35W.

So let's look at those numbers again assuming some appliances were replaced with very efficient ones:

Device	Watts	number of hours needed/day	watt-hours/day
C-pap machine	40​	6​	=6 x 40 = 240
fan	35​	6​	=35 x 6 = 210
frig	23​	24​	=23 x 24 = 552
cell	20​	1​	=20 x 1 = 20

So a total of 1022/d. So, that makes a lot more things possible...for example a bluetti 2400 would last a couple of days and five 100W panels hanging from the balcony rail might be enough to repower it each day.

Might not be big enough, bu how about a Road Pro or O2Cool DC fan? I've seen the RP go as low as 4 watts, the O2Cool 10 watts.

 

[Ann]

Thank you for this update. After much thought now I’m thinking I should get a small backup for the CPap. And get the Bluetti for a portable AC whichever you all recommend and not worry so much about the fridge. The CPap and AC are the most important for my health issues. Do you think the BLuetti 2400 and several solar panels would be enough? Has anyone heard about the “patriot”solar generator? Thoughts on that? THANK YOU FOR THIS FORUM!

 

[Forbisher]

Thank you for this update. After much thought now I’m thinking I should get a small backup for the CPap. And get the Bluetti for a portable AC whichever you all recommend and not worry so much about the fridge. The CPap and AC are the most important for my health issues. Do you think the BLuetti 2400 and several solar panels would be enough? Has anyone heard about the “patriot”solar generator? Thoughts on that? THANK YOU FOR THIS FORUM!

Patriot generator is Overpriced and marketed to people who know nothing about much.

Bluetti 240 and a few panels will not run an air conditioner for very long or at all. Only a 1000 watt inverter.
You will not be able to run an air conditioner in your limited situation.

 

[Ann]

Can you recommend any small AC ? Like tiny? For my face? ???

 

[Supervstech]

Can you recommend any small AC ? Like tiny? For my face? ???

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