Solar Power for Emergencies

 

I had a friend in Puerto Rico who is still dealing with the power outages & recovery from their hurricanes. He said that the only way he could reliably charge his mobile phone (after the mobile phone towers came back up) was to use a folding portable photo voltaic (PV) solar panel. In his configuration, he had a folding solar panel rated at 12 volts and 20 watts, putting power into an auto 5V USB adapter rated at 2.1 Amps.

The solar cell, will put out more than 12 volts (up to 21 volts), but most USB 5V adapters are rated at 12-30 volts.

Here is an estimate of the minimum power needed from a solar panel to charge one mobile device (with a solar cell rated at putting out "12 volts" :

Current needed to charge phone: 2.4 Amps @ 5 volts
Power needed from 5V adapter: 2.4A X 5V = 12 Watts

Doubling the above requirement to account for the adapter to bring the PV cell voltage of 12-20 volts down to 5 volts, clouds, and overly optimistic manufacturer's clams, results in a "real" PV output requirement of 24 watts.

I was wondering if anyone had experience with these, and could recommend a good reliable solar power unit for under $100.

Thank You,

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GO

Here's a Possible Option...

Sorry for the folks in PR, it's an absolute disgrace that our leaders in D.C. are neglecting fellow Americans in need...

Anyway, here's a possible option for your friend:

https://www.amazon.com/Anker-Charger-PowerPort-iPhone-Galaxy...

Hope this helps...

Shame on leaders in Washington, D.C.

Best wishes for Puerto Rico fast recovery. Puerto Rico needs help to recover with dignity.

Still Applies Today.....I Guess!

....."On March 2, 1917, the Jones–Shafroth Act was signed, collectively making Puerto Ricans United States citizens without rescinding their Puerto Rican citizenship. ... He declared that "if the earth were to swallow the island, Puerto Ricans would prefer American citizenship to any citizenship in the world."

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If the only tool you have is a hammer, every problem quickly resembles a nail. (Maslow's Hammer)

I hope we never grant them Statehood

They spend as if there was no end, they are bankrupt and want us to take care of their debt and pay for their services. With 26% unemployed they should have plenty of labor available to take care of all the storm damage. What are "They" doing to help themselves as the People of Florida, Texas and now California and other places are doing to recover???

Maybe ....

windwalker wrote:

They spend as if there was no end, they are bankrupt and want us to take care of their debt and pay for their services. With 26% unemployed they should have plenty of labor available to take care of all the storm damage. What are "They" doing to help themselves as the People of Florida, Texas and now California and other places are doing to recover???

Strategic Patience?

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If the only tool you have is a hammer, every problem quickly resembles a nail. (Maslow's Hammer)

Power

I appreciate the suggestion - following the link, I also see Anker has some nice 20+ AH batteries that would work with the solar panel. It appears that the USB 5V is becoming more prevalent than the 12V auto cigarette lighter solution, but from the sounds of it, the USB C standard is creep9ng the voltage up from what had been the solid 5V standard.

Anyone remember when cars used to run on 6 Volts?

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GO

USB Type A Output

I don't have any personal experience with these solar chargers. However, my brother gave me an Anker portable battery pack/charger few years ago, and it seems to be well made in terms of design and capacity compared with other portable batteries. You may want to check the specs and reviews of other brands too for the most reliable option.

With 12VDC output solar panels, then stepping down to 5VDC with an auto charger, there's an extra level of power conversion inefficiency and power loss. Most standard USB chargers on the market today are still using the USB Type A connector as it's so universally prevalent worldwide. USB Type C will likely become the future standard, but for now these solar chargers' output is USB Type A.

Another Option

During an 8 day power outage after hurricane Sandy in 2012, I used this $13 device to power my iPhone.

https://www.amazon.com/Verbatim-Power-Bank-Charger-97928/dp/...

After I used up my household supply of AA batteries, I drove some distance to a Home Depot that had power. There was literally not a single battery in the store! Surprisingly, there was a supply of these, on sale for $39 no less:

https://www.homedepot.com/p/Hampton-Bay-Solar-Brushed-Nickel...

I placed the 10 solar lamps along my driveway and let them charge during the day. At night, I took the AA rechargeable batteries from a few of the lamps and put them in the Verbatim charger to power/charge the iPhone. As a bonus, I used the extra lamps to provide house lighting and to power my emergency weather radio.

The lamps worked well for the duration of the power outage and are still lighting my driveway today.

Resourceful!!

bdhsfz6, I like this... very clever and resourceful!

Generators and Alternatives

As others have mentioned, using a power bank in conjunction with the solar panel is probably the cheapest and best bet for a SHTF scenario. The power bank can continue to provide power to your cell phone even on a cloudy day. When the sun comes back out, the power bank gets topped off again.

Personally, if I lived in an area that was likely to get hit by floods, earthquakes, tsunami, etc, then I would likely also invest in a portable generator and a large-ish gasoline can. Using Stabil and refreshing the gasoline supply on an annual basis should be enough to keep you safe for some time. I would imagine that the folks in the NE USA probably know all about portable generators with their awful winters.

How much gasoline would you need to power the generator? There are large swaths of Puerto Rico still without power months later, so I think there is no amount large enough to plan for an emergency such as this.

Realistically...

Most of us will never experience a power outage on the scale of that in Puerto Rico. Planning to provide whole house power for an event of that scale would be both expensive and impractical.

There are many low cost solar solutions for low power devices like cell phones, lighting, laptops, portable radios, etc. Providing whole house power during an extended outage is a different story. As Poibb suggests, portable generators or permanently installed emergency units are the best option for relatively short power outages.

Running these generators for an extended period however creates a fuel supply issue. Gas cans or a 300 gal. propane tank will power most sizable generators for perhaps a week. After that, the question becomes do I siphon gas from my vehicles or drive a considerable distance and chance finding an open gas station.

After lessons learned during Hurricane Sandy, I decided to take advantage of my 1000 gal. fuel oil storage tank used for my home oil heating system. I bought a $3000 trailer mounted generator and connected it to my diesel yard tractor. Using fuel oil from the storage tank will power the tractor / generator for almost 2 months.

Sorry for getting a bit off topic here but whether you elect to use solar, wind or fossil fuel options for emergency power, consider your fuel source, storage capability and most importantly the expected lifespan of the system you purchase.

if using generator, don't forget about the oil

If you're looking at using it for an extended time, you'll want to have oil for it BEFORE you need it. After hurricanes down here, you might be able to find gas but not 30W oil.

Tariff

A 30% import tariff is being imposed on Chinese solar panels due to the Chinese government subsidizing their manufacturers and accusations of product dumping. Last week I purchased 350 watts of USA made panels for my camper van, although like nearly all panels made here, some components are imported.

Great thinking- very

bdhsfz6,Great thinking- very resourceful!

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Maps -> Wife -> Garmin 12XL -> StreetPilot 2610 -> Nuvi 660 (blown speaker) -> Nuvi 3790LMT

An interesting impact of the Puerto Rico disaster

Hospitals scramble to avert saline shortage in wake of Puerto Rico disaster
https://www.washingtonpost.com/news/to-your-health/wp/2017/1...

Another Clever Product

Although not solar, this product uses cordless tool batteries to produce 120 v 60 hz house current:

https://www.amazon.com/DEWALT-DCB1800B-Portable-Power-Statio...

According to the product reviews, with the proper batteries, it will power an average refrigerator for 3 - 4 hours. It also does double duty as a battery charger.

This particular unit is made by DeWalt but other cordless tool manufacturers have similar products.

For those, like myself, who have a number of cordless tools and batteries, this could be a useful thing to have during short term power outages.

For multi day outages, the unit could be charged by generator at night when the household electrical load is reduced. Then, during the day, it could be used to handle peak loads for items like TV's, PC's, radio's, etc. effectively increasing the capacity of the generator.

Emergency Radio

An emergency Radio such as the Eton FR370 are also a good choice. I haven't had to use mine during an regency, but it has a solar cell and hand crank. Also has a USB Port to charge cell phones plus emergency weather, AM/FM Radio and LED flashlight.

Hand cranking takes awhile but at least works at night.

Good luck getting power restored.

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NUVI2555LMT, NUVI350

Teen Delivers Solar Lamps to PR

beware of gasoline

poibb wrote:

...Personally, if I lived in an area that was likely to get hit by floods, earthquakes, tsunami, etc, then I would likely also invest in a portable generator and a large-ish gasoline can. Using Stabil and refreshing the gasoline supply on an annual basis should be enough to keep you safe for some time. I would imagine that the folks in the NE USA probably know all about portable generators with their awful winters.

How much gasoline would you need to power the generator?...

My area is the Northeast US. Superstorm Sandy here on Long Island caused power failures for hundreds of thousands of people for days to many weeks.

I watched with dismay people buying large quantities of gasoline that they stored on their property, many in an attached garage.

There is no gasoline can that will contain the fumes because its vapor pressure is so high. All containers are vented, or they would fail. This not only is bad for us to breathe, but also increases the chance of a nearby source of ignition causing a fire.

As a firefighter, I can tell you that a plastic gasoline can will fail almost immediately in a fire. Just one gallon of gasoline will produce a roaring fire that can destroy a house before any fire department can get there.

I agree with Bdhsfz6 that a small generator will use at least 5 gallons per day lightly loaded. Storing more than this safely is impossible. It should be in a shed or outbuilding. During a widespread power failure, most service stations will be unable to pump gasoline, so buying more becomes a problem every passing day.

Remember the carbon monoxide problem. Never operate a generator inside a building of any kind!

I am glad gordyo brought this issue up. I think it is a good idea to use solar panels just to charge your cell phone. The next step up is a bigger panel with a deep cycle marine lead-acid battery the size of a car battery.

Many of my neighbors have large solar systems in order to save electricity, but these also operate in a power failure. With the use of a large battery bank and an inverter, 120v AC is produced.

dobs108 smile

Another thought: Cordless

Another thought:

Cordless drills are DC motors,run them backwards and they become DC generators:

They don't generate much power, but could possibly charge a phone from found objects in the garage (you have a lot of free time when the power is out.)

https://hackaday.com/2014/12/06/cordless-drill-turned-into-b...

To paraphrase one of the above's commenters it reminded me of Edward G. Robinson in the movie "Soylent Green."

All I ever needed to know about urban survival I learned from watching Charlton Heston Movies circa 1968-1976.

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GO