Help Please - Miami Condo Hurricane Prep

[svetz]

...my balcony is enclosed w sliding doors so the railings are outside the doors so there is no deck area...

No deck?
Hmmm... that does complicate things and probably kills the generator idea.

...What about if I hang the solar panels from the railing so they face the sun directly and therefore no shadows from the railing poles?

I think you can get this to work, let's see how much power you can gather. Probably the next thing we need to know is how much weight you're comfortable lifting since you'll need to move/mount them. You need to not only be able to lift the panel, but also control it in case of a wind gust. Here's some examples:

20W panel: 6 lbs, 16.7" x 19.8" x 1.97", $10/W​

50W panel: 10 lbs, 26.5" x 22" x 1" , $1.58/W​

100W panel: 16 lbs., 40.2" x 26.4" x 1.4", $1.50/W​

From an earlier post you wrote:

... i have direct sunlight [from the] east [through] ... about 12 ... feet of ... glass doors. And then I have about 40” high railing with 6” opening between each rail.

The bad news is east facing, the good news is you have 12' of space. Each 100 watt panel is 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. That's just a rough guess... if you let us know at what time of day the southern edge of the railing starts to fall into shadow and the time of day the northern edge of the railing falls into shadow we can probably get you a closer number.

So, let's talk about mounting the solar panels and your situation.

First, the railing needs to be super-strong to support the weight of the panels and the forces from the wind blowing on them. Do you feel like the railing can support your weight both downwards and outwards? Five 100 Watt panels and mounting is probably going to exceed 100 lbs. With wind forces that gust to 50 mph (to be clear, don't put these out until well after the hurricane passes) could easily be a few hundred pounds laterally. If the railing is not super strong either make it so, or abandon this idea.

The nice thing about the 100W panels is that they're made for RVs so there is a wide variety of mounting options. You will need some sort of strong mounting, otherwise wind gusts will bash them into pieces in no time.

If the panels were south facing you can push the bottom of the panel away from the railing with the mount, you'll get a lot more power than having them at 90°. Even east facing you'll get more power with the bottom tilted away a bit. Commercial racks look a bit like this, instead of the pole you'd mount the top the railing. You could probably build something with angle iron if you're handy.


Finally, there will still be rain and the glass sliding doors will need to be open a crack to let the wiring through.

 

[Supervstech]

No deck?
Hmmm... that does complicate things and probably kills the generator idea.



I think you can get this to work, let's see how much power you can gather. Probably the next thing we need to know is how much weight you're comfortable lifting since you'll need to move/mount them. You need to not only be able to lift the panel, but also control it in case of a wind gust. Here's some examples:

20W panel: 6 lbs, 16.7" x 19.8" x 1.97", $10/W​

50W panel: 10 lbs, 26.5" x 22" x 1" , $1.58/W​

100W panel: 16 lbs., 40.2" x 26.4" x 1.4", $1.50/W​

From an earlier post you wrote:


The bad news is east facing, the good news is you have 12' of space. Each 100 watt panel is 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. That's just a rough guess... if you let us know at what time of day the railing falls into shadow we can probably get a closer number.

So, let's talk about mounting the solar panels and your situation.

First, the railing needs to be super-strong to support the weight of the panels and the forces from the wind blowing on them. Do you feel like the railing can support your weight both downwards and outwards?

The nice thing about the 100W panels is that they're made for RVs so there is a wide variety of mounting options. You will need some sort of strong mounting, otherwise the wind will bash them into pieces in no time.

If the panels were south facing you can push the bottom of the panel away from the railing with the mount, you'll get a lot more power than having them at 90°. Even east facing you'll get more power with the bottom tilted away a bit. Commercial racks look a bit like this, instead of the pole you'd mount the top the railing. You could probably build something with angle iron if you're handy.
View attachment 15619

Finally, there will still be rain and the glass sliding doors will need to be open a crack to let the wiring through.

I cannot imagine this would be possible to have panels in place DURING the hurricane... best to build a mount that can be set in place in calm weather, and removed easily. Still must be secured top and bottom though...

 

[svetz]

I cannot imagine this would be possible to have panels in place DURING the hurricane... best to build a mount that can be set in place in calm weather, and removed easily. Still must be secured top and bottom though...

It's for after the hurricane passes and things return to normal, except there's no power.

Her idea is the solar generator is charged and ready to go. At some point the power fails, possibly for days. Because it's charged she has enough power for the first day. While it is too windy, she can place the panels on the floor inside in the sunlight. She'll get some power, but not much. Once the storm has moved far enough away and the breeze is manageable, she can put the panels outside to gather more power. When the power comes back, it all goes back into storage.

 

[svetz]

The problem is the power budget is ~2280 Wh/d, but with solar from the post above she can only get 500 to 1000 Wh/d.

Here's another crack at the budget with some adjustments....

Device	Watts	number of hours needed/day	watt-hours/day	Notes
C-pap machine	70​	6​	=6 x 70 = 420
fan	20​	6​	=20 x 6 = 120	Switch to a low wattage DC fan like this?
frig	40​	12​	=40 x 12 = 480	Get a low wattage DC mini-fridge like this? See Will's video.
cell	20​	1​	=20 x 1 = 20

That get's it to just under 1000 watt hours/d... possibly others will have some ideas on this? For example, when you know there's a storm coming you can freeze large blocks of ice, putting them in the fridge keeps the fridge duty cycle lower.

 

[svetz]

I was watching Will's video on the refrigerator's, the information might be out of date now that there are inexpensive knockoffs of the Arb and Dometica. For example the 45W 42 quart 12V Alpicool is $320, about twice the price of a dorm fridge. The Energy guide on a $200 dorm fridge is about a kW/d, which is what the Alpicool would be if ran 24x7.... saw an Amazon comment that it consumed 552 watts per day. Moot in the OP's case as she doesn't have space for more panels.

 

[svetz]

The OPs original idea was to get a solar generator and recharge it with solar panels. But it doesn't look like there's enough solar to recharge per day with her setup. From the earlier analysis she needs less than 500 Watts inverter.

Two days is probably the average maximum power outage, the earlier table showed about 2280 Wh/d needed per day, so around 4.5 kWh?

Let's start assuming no solar recharging. You could add solar later as discussed here. Any solar power would extend the duration of the system.
For example, from the previous post, assuming we can get 500 Wh/day, then over two days we'd only need 3.5 kWh of battery storage. But, for the numbers below we'll assume no solar for a worse case scenario.

Off the Shelf
The simplest way is to have two days worth of power all wrapped up and ready to go. I don't have enough knowledge to recommend any of these, it's just a paper analysis to get some rough numbers (but I bet Will has videos on these).

Bluetti EB240 2400 Wh, need two Cost: $3800

Lion Safari LT 450 Wh, $585 Need 10, so cost is $5850.

With multiple solar generators I believe you can either swap them out when one runs out of power, or plug the input AC of the second into the output AC of the first unit.

Solar Generator with External Batteries?
Will just reviewed the Bluetti AC200, the cool thing about it was that you could hook up external batteries. So it provides a nice hybrid between a compact package with everything you need plus the lower cost of an add-on battery. Not sure if the AC200 will recharge the external battery.

The Kodiak Inergy (due out in October) is $1350 for 1000 watt hours, three additional batteries would be + $2700 for ~$4000.

Point Zero Energy Titan is overkill in terms of the inverter, 4 kWh $4,390.

The Goal Zero Yeti Tank Expansion Battery looked promising ($1200 Yeti 1000 Li Power Station, $400 Goal Zero Yeti Link Expansion Module), but the manual says it requires ventilation ... so bad for a condo.

Both the Jackery 500 and Rockpals 500W solar generator ($450 - 500W/540Wh) say they can be recharged from a 12/24V DC input and include a cigarette adapter. Could it be connected to a couple of battleborn's in parallel to extend the watt hour capacity? Then you'd just need a charger for the external batteries? Anyone know for sure?

Update 2: The jackery FAQ says all but the explorer 160 support pass-through charging. The Rockpals FAQ seems to indicate the 500W does support pass-thru charging, although it's worded as: all Rockpals portable power stations, except Rockpals 300W/500W, don't support pass-through charging.

Update 1: The Ecoflow Delta 1300 has 1260 Wh for $1400, so would need another 3240 watt hours of external batteries. Will has a video that confirms it can charge and discharge at the same time, see the video for pros & cons.

DIY Options?
Based on comments from the OP, she's probably not interested in this, but thought I'd include for the more adventurous.

A DIY option is like Will's latest video (he has a lot of these showing how to build a DIY solar generator). The main components are:

• Battery
• BMS if using lithium
• Inverter
• Charger

There's a number of other sub-components for which there's a lot of leeway: e.g., mounting panel, fuses, wire, gauge, etc. Didn't consider any of those additional prices. There are a number of systems members have build that list costs if you want to get a better idea; but figure you'll add 10 to 20%.

For the numbers below I'll use the first inverter/charge I came across, the $400 MAGNUM pure sine wave 600W, 12V INVERTER/CHARGER. It's a bit more expensive, but has a built in automatic transfer switch so devices like the CPAP machine could switch to battery automatically in the event of a power outage.

DIY LiFePO4 Fortune 120Ah Cells @ $135 each. Using a 90% Depth of Discharge (DoD) you'd need: 2280 x 2 / .8 /.9 = 6334 Wh, 6334 / 12V = 528 Ah 528 Ah / 120 Ah batteries (round up) = 5 batteries You need 4 cells to make 12V, so 5 x 4 = 20 cells, so $2,700 You'll also nee a BMS and charger, so ~ $3,300

DIY Sealed Lead Acid AGM Trojan 31-AGM 12V, 100AH (20HR) AGM Sealed Battery @ $313 80% DoD gives 500 cycles (will only use a few cycles per year) 2280 x 2 /.8 /.8 = 7125 Wh, or 593 Ah Cost = 6 x $313 = $1878 Each battery is 70 lbs, and it will need a charger with a trickle function. So ~$2278

 

[RickP]

@Ann, I’ve read through this thread and your concerns on solutions presented. I wondered if your condo provided a garage area where you could store a small generator and fuel. Most solar generators on the market can be charged on a gas/propane generator during the day in order to get you through the night hours when running a generator can draw the ire of neighbors. Some, like the PointZero Titan, allow you to have extra batteries that can be charged away from the main console unit. These extra batteries also increase the load you can power or length of time you can power it.

It is possible a garage area might mitigate your fuel-in-the-house concerns, while still providing a means of charging system batteries with need for a massive solar panel array. How are you set up in that way?

 

[Deleted member 1888]

This sounds like you will have to set up the panels in your house? That will never work you will get so little power out of them that its a wast of money. It make take you several days to a week just to charge your batteries, I don't see how that is going work.

 

[RickP]

This sounds like you will have to set up the panels in your house? That will never work you will get so little power out of them that its a wast of money. It make take you several days to a week just to charge your batteries, I don't see how that is going work.

I’m not sure if that was referring to my suggestion. I’m not suggesting panels be used at all, as it doesn’t appear they will work on her situation. I’m more suggesting a battery backup, charged by generator power (during the day) not stored in her living space, which I surmised she didn’t feel comfortable doing. This would be a solar-capable setup, though wouldn‘t use that capability in her application... at least not until things degrade to a place where you don’t care what the HOA thinks!

Admittedly, a shot in the dark, but something I thought might suit her preferences while providing a solution she could feel comfortable having indoors. All the better if she uses a propane generator, as you suggested, to alleviate concern over stale gas.

Just venturing ideas in hopes she will find a solution she feels comfortable with among all the input.

 

[Deleted member 1888]

This is a long shot but I came up with a way this can work for you. Now this is dependent on 3 factors that you MUST HAVE, if you dont have them then stop reading now.
1. Is your condo on the 1-5th floor (if no stop reading)
2. Is there a parking lot below your balcony (if nt stop reading)
3. Do you have or can you get a full size truck with stranded or long bead. (if no stop reading)

If you have all 3 what you can do is park the truck under your balcony then install solar panels(400w to 800w) on the bed with the batteries IN the bed. Then just run an extension cord down to the truck to get the power up to the condo. This would give you the added benefit that if you needed to leave you take the power with you. Just hook up a trailer and take all you belongings with you.

 

[svetz]

Saw this $3300 Power station, 8,000 Wh, so about 4 days backup with the original numbers, no ventilation required so it could be kept in a closet.
But that got me to thinking, there are a number of AC battery options that might work too (e.g., tesla, Enphase, LG Chem).

Have to admit, I like RickP's solution of two batteries and using a generator in the garage to charge one while you use the other; although you'd need to pipe the exhaust out of the garage.. A lot of the commercial solar generators are really slow to recharge, so that might be a part of your selection criteria.

PsychoticEpisode's above is a good one too. If too high you could combine it with RickP's idea... that is move the battery down to solar panels for recharging. You don't really need a truck/trailer/parking-lot; just a secure place in the sun where they won't be stolen.

That said, I love her idea of using a trailer (clever!). Assuming the condo will let you keep a trailer and you have another parking space. Putting panels on top of an enclosed trailer keeps them out of sight from the ground, not easily stealable, and if above the 5th floor you could put the spare discharged battery inside the trailer while it is recharging to keep it secure. Lot of stairs to go up and down though, be sure the batteries are lightweight enough for you to carry up/down.

You could even have a generator in a trailer for recharging them (pipe exhaust through the flooring?) and the generator being enclosed would help muffle the noise. Or, if your unit is low enough to the ground, perhaps skip the solar and just put the generator in the trailer? Great place to keep all the associated supplies too. Heck, a great place to stash any junk you'd like to get out of the house and cheaper then offsite storage.

Can't imagine it would be hard to find a good cheap used trailer in Miami, but even new they're not expensive if you don't mind a little assembly (e.g., Harbor Freight for $300 to $500 (building one is just a matter of bolting the bits together, although when finished fairly heavy). HomeDepot and Lowes sell them for more, but they might also do the assembly. In Florida, don't buy a used trailer without papers if you want to get a license plate for it.

If you have a garage, the trailers in the Harbor Freight link are fold-up, so you could keep the panels mounted on the trailed folded up and in the garage for storage until you need them.

 

[BoloMKXXVIII]

Svetz, you stated two days of power outage after a hurricane? Have you been through one? I was in Andrew and was without power for weeks. The devastation can go for miles. Electrical crews came from states all over the southeastern region of the country. They worked in terrible conditions, around the clock, for weeks. They did an amazing job but there was so much destroyed and they had to bring everything they needed with them. I am prepared for a minimum of two weeks without power and could probably go a month.

 

[svetz]

...Svetz, you stated two days of power outage after a hurricane? Have you been through one?

Yup, several...and you're right everyone needs to be prepared. I agree the crews that come in are nothing short of amazing. But it's more than power or telephony crews; for example the roads and bridges need to be cleared/safe for them to get in... it's a huge effort from many teams and runs amazingly well. Heroes, everyone of them!

It really depends on where you live and how bad the impact was as to how fast it is restored.

​

Is Two days enough reserve for Miami?
I used two days reserve to illustrate the math as it seems about right for most storms for folks living in a big city like Miami which has it's own nuclear power plant. Hopefully the OP has a good feel for her neighborhood and knows better than me. But yeah, if a Cat 5 hits, you live in a rural area... then your chances of being without power for far longer are far greater. When Irma went through I had one acquaintance who was without power for over a couple of months. A lot of it depends on the water draining out of the area (faster in a coastal city like Miami), how many trees were in the path of power lines (yeah, I know none of them are supposed to be...but I see them all the time) and the roads being cleared of debris.

I live in a more rural area than Miami... but for hurricane preparedness I assume the storm will pass after a couple of days and my system will recharge. It's a rationing plan and includes a gas generator, not business as normal. If I could afford more batteries I'd definitely get them.

 

[svetz]

Stupidly scary Idea?

This is the opposite to PsychoticEpisode's post ... that is might only work if you're fairly high up and the condo is near the ocean.

Idea: Mount a wind turbine after the storm has passed to recharge rather than solar panels (which have bad logistics).

Normally I'm the first person to poopoo wind because most people just don't have enough wind (see: www.solacity.com/small-wind-turbine-truth/)
Certainly, the side of a tall building acts like a wind block... so normally I'd think it plain ridiculous. But, the higher you are the faster the wind is and the closer to the ocean the more you can take advantage of the sea breeze. Plus, at least for a day after the hurricane passes, you might get over 12 mph wind speed so as to actually generate some power.

I suspect the only way to know for sure would be for you to install one of those cheapo anemometers on your rail or just periodically measure the wind speed using a hand tool. Inland Wind at low altitudes is really fickle. But near the ocean there's an effect called a land-breeze/sea-breeze (morning/evening) that is fairly reliable. So be sure to measure your actual wind speeds if you think this might be viable (e.g., always a stiff breeze flowing when you open the doors).

The ratings of a wind turbine are at the maximum wind speed. For example, the graph to the right is fairly representative in that you won't see any power below 12 mph and the rated power around 30 mph. Given the railing is very close to the sliding glass doors, you'd probably also need some sort of "arm" that holds the turbine out from the railing. How big (watts) of a wind turbine would you need? Assuming you need 2400 Wh/d to recharge, and the average wind speed is > 15 mph for half the day, you'd need 2400 / (24 x50%) = 200 watts. From the graph to the right at 15 mph the turbine is producing about 25% it's rating, so 800W. All depends on actual measured conditions and the actual hardware specs of course.

 

[svetz]

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

The average of mean hourly wind speeds (dark gray line), with 25th to 75th and 10th to 90th percentile bands.​

 

[Deleted member 1888]

Now this is what Will wanted when he made this site, so many good ideas and possibilities. All that is left now is for the original poster to look at each and figure out witch will work best for them.

 

[svetz]

So imagine you’re in a high rise condo and you need to recharge your Bluetti 2400 but the power is out. You have 12’ of east facing glass sliding doors that open to nothing (e.g., just a rail beyond the door, no actual balcony)…. How do you recharge those batteries?

The earlier posts talk about the practical ways to do it with a generator, solar, and possibly wind. What’s left? Recharging it while visiting at a friend's house? A stationary bike (supposedly the average peddler can do 560 Wh/d (8 hrs peddling), or 200W in a hour ref)

 

[Bob142]

So imagine you’re in a high rise condo and you need to recharge your Bluetti 2400 but the power is out. You have 12’ of east facing glass sliding doors that open to nothing (e.g., just a rail beyond the door, no actual balcony)…. How do you recharge those batteries?

The earlier posts talk about the practical ways to do it with a generator, solar, and possibly wind. What’s left? Recharging it while visiting at a friend's house? A stationary bike (supposedly the average peddler can do 560 Wh/d (8 hrs peddling), or 200W in a hour ref)

I know I'm very late to the party but here goes...

I haven't seen a hard budget limit in this thread and it seems pretty clear that DIY isn't the route the OP would be most comfortable with. So in this particular case (and only this case) I would spend a ton of money on Goal Zero gear*. Hear me out on this because I think it could work.

1) Buy a Yeti 3000

Portable Power: Power Banks & Power Stations | Goal Zero

From family camping trips to the most rugged expeditions, our line of portable power banks and small power stations keeps your gear charged and ready. Goal Zero offers portable power supply solutions for any need, from compact to heavy-duty.

www.goalzero.com

2) Buy the fast wall charger to keep it charged up from the grid

Yeti Fast Charge 25-Amp Power Supply

short Recharge your Yeti 1000X or larger up to five times faster with this 25A AC power supply. Note: Compatible with Yeti 1000 Lithium Power Stations and up, Yeti 1000X, Yeti 1000 Core, Yeti 1500X Power Stations. tech CHARGE TIMES Yeti 1000: 4 hours Yeti 1400: 4.5 hours Yeti 3000: 10 hours...

www.goalzero.com

3) Buy six Nomad 100 folding solar panels (dimensions: 20.5 x 59.5 x 1 in, weight: 10.2 lbs) for a total of 600W

Nomad 100

short Portable, rugged, and powerful, this 100-Watt lightweight, foldable panel features built-in charging cables for Yeti Power Stations. Combine multiple panels to maximize solar input on your next overlanding trip. box NOMAD 100 HIGHLIGHTS 100-Watt (14-22V) foldable and weatherproof solar...

www.goalzero.com

4) Buy two of these combiner adapters

4 x 8mm Panel Combiner to High Power Port Powerpole Connector | Goal Zero

Safely ombine two or more Goal Zero Solar Panels with 8mm outputs into an array with a single High Power Port (HPP) connector.

www.goalzero.com

5) Buy a bunch of carabiners

6) Clip the 6 panels to the railing using the carabiners

7) Connect 3 panels together using one of the combiner cables and plug it into the Yeti MPPT input

8) Connect the other 3 panels together and plug the combiner cable into the Yeti PWM input

9) Conserve energy in device and appliance use and hope those east facing vertical panels collect enough energy to keep you going for a while

(A way to angle the panels could be to build a frame out of angle aluminum with some holes drilled into the outward facing side for attaching the bottom of the panels with carabiners. Slide the frame along the floor to push out the bottom of the panels. Build it so that it can't ever slide all the way off the balcony by including some stopper arms that would hit the bottom of the railing. The frame could be disassembled and kept under a bed.)

* I am not affiliated with Goal Zero in any way.

 

[svetz]

...I know I'm very late to the party but here goes...

Welcome to the party!

... six Nomad 100 folding solar panels (dimensions: 20.5 x 59.5 x 1 in, weight: 10.2 lbs) for a total of 600W

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 closer!. Still not enough watt-hours and that would 71 lbs down plus wind 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).

 

[svetz]

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!