Greetings from sunny Miami! I need help to determine what is the best system to buy so I can sustain myself on my condo should we lose power during and after a hurricane. My needs are: For health reasons I would need to power a C-pap machine, small portable AC or fan, and mobile phones. For convenience reasons I would want to keep my refrigerator running. I am considering the Lion 500 for the health group and if the solar panels work well on my balcony then I may buy the Bluetti for the fridge. Which version should I buy? Please feel free to chime in w advice. Thank you so much !!!
Help Please - Miami Condo Hurricane Prep
- Thread starter Ann
- Start date
svetz
Works in theory! Practice? That's something else
Hi Ann,
Welcome to the forums!
Sometimes the device will say directly on it how many watts it consumes. If not, watts can be calculated as amps x volts. For example, if a charger says it's 12V at 2 amps, that's 12x2 = 24 watts. Sometimes, especially for things like refrigerators, you can get the information from the manufacturer based on the EnergyStar sticker (there's a database of devices so you might be able to look it up). If all else fails or you need more precise numbers there are meters you can measure it with. A refrigerator might consume 160 watts while running, but even though you want it cold for 24 hrs/day, the compressor might only run 7 of those hours.
So, from there you create a table, the table below is meant to be an example and has random numbers for the watts column... you'll want to use your actual value for watts and number of hours:
Sum up the right most column, multiply by the number of days backup with no sun. From there you might find these threads useful:
When selecting an inverter keep in mind that inductive loads (like the refrigerator) can have high startup loads, so the inverter you pick must be able handle it's maximum draw for a short period...when you get that far let us know what your top picks are and see if anyone has any advice on them.
Welcome to the forums!
To answer your question you need to know how many watt-hours you need to right-size the system. You've got a great start with a reasonable list of devices. The next step is to determine how many watts each device draws, how many hours per day you'll use it for, and how many days of backup you need.
Sometimes the device will say directly on it how many watts it consumes. If not, watts can be calculated as amps x volts. For example, if a charger says it's 12V at 2 amps, that's 12x2 = 24 watts. Sometimes, especially for things like refrigerators, you can get the information from the manufacturer based on the EnergyStar sticker (there's a database of devices so you might be able to look it up). If all else fails or you need more precise numbers there are meters you can measure it with. A refrigerator might consume 160 watts while running, but even though you want it cold for 24 hrs/day, the compressor might only run 7 of those hours.
So, from there you create a table, the table below is meant to be an example and has random numbers for the watts column... you'll want to use your actual value for watts and number of hours:
| Device | Watts | number of hours needed/day | watt-hours/day |
|---|---|---|---|
| C-pap machine | 70 | 6 | =6 x 70 = 420 |
| fan | 120 | 6 | =120 x 6 = 720 |
| frig | 160 | 7 | =160 x 7 = 1120 |
| cell | 20 | 1 | =20 x 1 = 20 |
Sum up the right most column, multiply by the number of days backup with no sun. From there you might find these threads useful:
When selecting an inverter keep in mind that inductive loads (like the refrigerator) can have high startup loads, so the inverter you pick must be able handle it's maximum draw for a short period...when you get that far let us know what your top picks are and see if anyone has any advice on them.
Last edited:
mandrews44
Solar Enthusiast
- Joined
- Jun 9, 2020
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- 246
To be safer, I'd estimate refriderators at a 50% duty cycle instead of 33%. During a power outage, AC's are no longer keeping the indoor temp cool and in FL, we need fans 24/7 without AC. Unless you have a generator, I would not count on an AC after a hurricane. To make matters worse, most devices only report WATTS, not VA. VA is Volts * Amps = POWER required by the inverter to run the device. For example, my fridge runs at 115 watts while running. If I also include the Power Factor, it requires more like 160 watts to run off of a battery due to the power factor of the compressor.
You mentioned a balcony - if that is your only area to place solar panels, it may be the limiting factor for your watt-hours available. If you can determine a maximum square feet of panels that will fit there, and the number of hours of sunlight per day that falls on the area, that will help us. You may have to depend a lot on battery storage rather than power generation.
Especially permanent mounting DURING a hurricane!
D
Deleted member 1888
Guest
We don't know all the specifics of your location but if you only have a balcony to work with you may not be able to do it.
Is the balcony facing the optimal direction for max sun?
Can you fit several large 300w solar panels on that balcony?
Is the balcony clear of obstructions like trees, building, or other balconies?
If the answer to any is NO then this will not work for you, and you may just need to get a small propane generator and a few pounds of propane. If you only need it during a hurricane then you can save the propane as it never degrades. The propane can sit there for 50 years until you need it.
This is nothing agents solar as I love solar and have a 1200w system but it takes up a good bit of space. You need to pain things out before you start and if you don't have the right conditions(example: your balcony has another right above it that will block sun) then solar is not for you.
Is the balcony facing the optimal direction for max sun?
Can you fit several large 300w solar panels on that balcony?
Is the balcony clear of obstructions like trees, building, or other balconies?
If the answer to any is NO then this will not work for you, and you may just need to get a small propane generator and a few pounds of propane. If you only need it during a hurricane then you can save the propane as it never degrades. The propane can sit there for 50 years until you need it.
This is nothing agents solar as I love solar and have a 1200w system but it takes up a good bit of space. You need to pain things out before you start and if you don't have the right conditions(example: your balcony has another right above it that will block sun) then solar is not for you.
For instance, I have a condo with a first floor patio, it faces south, and has decent sun 2/3rds of the day, trees obstruct morning, and evening sun.
I have a 300WATT panel, and have the panel tilted towards noon sun.
I get about 350Wh a day...
So, unless you have a LOT of sun view it won’t amount to much output.
I have a 300WATT panel, and have the panel tilted towards noon sun.
I get about 350Wh a day...
So, unless you have a LOT of sun view it won’t amount to much output.
WOW!!! Thank you so much for your help!!! I will calculate all the watt hours I need to determine the number of watts I should get. Regarding sunlight, i have direct sunlight facing east to about 12-16 feet of uninterrupted glass doors. And then I have about 40” high railing with 6” opening between each rail. I was planning on fastening the panels against the rails with over half the panel above the rails which would receive direct sun from sunrise to before sunset and below the railing the panels would be blocked by the vertical rails but the 6” opening would allow sunlight to hit it. no one in my building can see that side of my apartment. Therefore I am not concerned about my building. Unless someone in the building across the way (far away) decides to use a telescope and spy on our building.
However I am concerned about the number of panels I have to buy to recharge the equipment and how long does it take to charge one 100 panel.
I was thinking Of buying the
Lion Energy LT Off-Grid Kit which
Features:
However I am concerned about the number of panels I have to buy to recharge the equipment and how long does it take to charge one 100 panel.
I was thinking Of buying the
Lion Energy LT Off-Grid Kit which
Features:
- Safari LT Solar Generator With 500W Continuous Pure Sine Inverter and 450Wh Internal Energy Storage
- 140W MPPT Charge Controller built into the LT - Kit includes a 100W Folding Solar Panel
- 25' Extension Cable To Connect The LT To The 100W Folding Panel
- 3 LED Lights That Are Powered By The LT Through One Of The USB Power Outputs
- Fast Charger Included For Rapid Charging From Your Wall Outlet
I do not plan to install permanently on a wall. Only pull them out as needed.
THANK YOU FOR THE INFORMATION!!!
THANK YOU VERY MUCH FOR ALL THIS INFORMATION!!! I answered below before I understood that I could answer to each comment individually.
Thank you
Wait from what you are saying about the hours I appears that I could only use the 500 watt battery for the CPap machine! Wow. Basically i would charge during the day and use the battery during the night. And that is assuming that the sun comes out after the hurricane and all it’s banda leaves our county. So then I guess I would need a smaller device for cell phones. And forget the fan :?. Does they sound correct to you?
Thank you for all the detailed info. I gave a more detailed reply in a separate comment. I think I’m ok w the amount of sun access. I’m not sure how many panels I need or how long it will take to charge up. And it sounds like I need to choose between the CPap and the refrigerator cause I can’t do it all if I get only the 500 watt battery. If I get the Bluetti 1200 I’m not sure I would be able to charge it up all the way every day. Thanks again
svetz
Works in theory! Practice? That's something else
It depends on the power consumption of the devices and the length of time you use it. That's why I like to stress the power budget first, it's important to understand watt-hours usage vs. battery supply. Because the inverter is typically only 90% efficient you have to multiply the battery watt-hours by that efficiency to get closer to the real-world hours.
Exactly! As I'm sure you know, during and right after sunlight is sketchy at it's best. To make things worse, a solar panel only gets it's rated output near noon, before/after is less... so a 100 watt panel with a good half-day of sun might only generate 200 watt hours.
For a condo, @PsychoticEpisode's suggestion might be the best:
So let's look at those numbers again:
| Device | Watts | number of hours needed/day | watt-hours/day |
|---|---|---|---|
| C-pap machine | 70 | 6 | =6 x 70 = 420 |
| fan | 120 | 6 | =120 x 6 = 720 |
| frig | 160 | 7 | =160 x 7 = 1120 |
| cell | 20 | 1 | =20 x 1 = 20 |
First you'd need to know how much power the generator would need to supply. If you were to run all of the devices simultaneously, you'd add column two. But if you only ever run the fridge and one other device you'd only need 280W. I doubt they make generators that small, so probably not an issue for a fuel-based generator, but it might be with a solar generator.
I don't know anything about propane powered camping generators, perhaps someone can recommend one?
I spotted one on Amazon for $300. It say's it'll run for 9 hours at 50% load (600 watts) with 1.3 gallons of gas. So, five gallons of gas you pick up before the hurricane would last about 34 hours. Plus, it's dual-fuel, so if you've a 20 gallon propane tank for the grill on your patio you can use that too. Seems kinda big and noisy... I bet if you research what folks use for camping you can find something better.
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