Turn Fire Into Electricity

Oh my... that's the type of online store in which I could bankrupt myself.

Agreed shiney
For price and output solar is way better
Also in a shtf or survival situation you have to light fire for other to work
If your injured etc the solar can still work even if you stay put in one spot

Ahh, that's a good question. Best I give you some examples for items to help you see it.  The panel works much like your wall charger, so plug it in, charge unplug device when you like. 

iphone 6 - 6.9Wh
UV-5R - 13.3Wh
You can work out how many Watts by multiplying Amps x Volts. There are 1000mAh = 1 Ah.

Now in terms of how long, it depends on many factors, such as is the solar panel pointing 'north' at a slight angle, is it cloudy etc.  If you lay it flat you'll get 10-20% less energy for instance.  The angle makes a difference though you will get power if the panel has light on it, it's a matter of how much. Having said that, lets get to some approximate figures based on average sun and a 7W panel.  10W is about a 1/3 better, so it will charge 1/3 quicker.

Winter = 17.5W/6 hours of usable sun. = about 2.9W/hr.  The actual production curve will peak in the middle of the day, though this gives an idea.
Summer = 42W/8hrs of usable sun. = about 5.3W/hr

iphone from flat = 2.4hrs winter, 1.3hrs summer
UV-5R from flat = 4.6hrs winter, 2.5hrs

It's worth noting that Li-ion batteries are designed to not go completely flat because it can kill the battery if they do, so the figures will be a little better on average.

10W and 7W fordable panels with USB charger are pretty compact and cheap and they're good size for radios/phones and if you're hiking/bush-walking you can string them to the back of your pack and charge things [at a reduced rate] whilst you're moving.   I've not experimented there, so have no real world data, though as I said, if there's light on the panel, you'll put some juice in it.  If you have a spare battery, you might charge that whilst using the unit, which is what I do and have a kit for every portable CB radio I own. 

There are many solutions to this 'problem' but I seem to be missing the point.

How many electronic devices do we really need when hiking or bugging out? You can carry a lot of batteries for the weight and bulk of a solar pannel. A phone is for emergency use, if you get bad battery life ditch the smart phone and get somthing cheap and simple that'll hold a charge for ages.

For a half kg pannel you could pack 20AAs or 30 if you go lithium. Most radios/gps devices can take battery adaptors and this eliminates constantly trying to charge the devices. A map is a simpler solution than a gps anyway.

Anyone else see this as a solution to a problem that doesnt exist?

Dont get me wrong, i have many solar panels from 300mW to 200W... Very very useful but I'd never be taking one with me in a bugout or camping situation. Good thing about solar is you can cut them up and re-wire them to suit application so modular!

In my mind a good collection of recharable batteries and power generation at the base/homestead is the best way to do it, keeps weight to a minimum. As to the device in the OP I'd be interested in a larger scale stationary system for the homestead, makes a lot if sense but trying to make something transportable and lightweight is never going to be efficient.

I agree with a lot of the points being made. I keep three external battery chargers for my phone, a solar panel for topping off small electronics and chargers, and have a couple crank/discharge devices to give my phone a few % if all else fails.

That said, I'm still thinking about picking up a BioLite as another redundancy- boiling 1L of water in 3-4 minutes is fairly appealing.

Zig. For sure, there's horses for courses and you're correct, if you're boiling the water and want to do a little charging at the same time then awesome. Hopefully the sums, gives people perspective and info for what works best for their application.

Myrrp. A thermister is a resistor that changes resistance depending on temperature, typically used as a temperature sensor for a thermostat/thermal cut off etc. You're close though, it's called a Peltier and they're pretty cheap to buy smaller ones if you're so inclined to try it out.

[ramble]
Whilst I've not done it, and haven't looked up performance versus size etc, what I do understand is the theory and you'd want to create as big a heat gradient as you can between both sides as you can. So a large heat sink with lots of air flow on the colder side is a good plan as that will get you the most current [charge rate].   They also don't like too much heat either, so you need the water in the pot or similar or place them near a heat source that isn't over 150C or else you'd kill it.   An idea along these lines is to use a widely focused lens or mirror making sure you didn't create too much heat and use it to convert the sun's energy into electricity.  It's not going to be very efficient [solar is far better] though it would work.  Another is to use solar hot water as your heat source [assuming it's not pressured which might raise the temp] with a heat sink in the air and you'd have some power that way.  You might attach it to a chimney that's hot but not too hot with a heatpipe running to a heatsink outside for winter electricity generation.  The wood stove might be on for cooking/heating anyhow, might as well use the heat running up the pipe for something and in winter, if you can get the heatsink outside, you'll have a great gradiant difference.  Is it going to make much energy,... probably not a lot, though perhaps enough to keep low energy lights on, for no more energy cost [normally wasted going up the chimney.   There's lots of places where such devices could be used, particularly with wasted energy such as a car engine in which we typically use water to take away the heat or on the exhaust of a hybrid and could be pumped back to into the batteries.  It's not free energy, it's using the heat that's usually vented.
[end ramble]

It all depends on application and whilst there might be better ways to make power [solar in my opinion] we are preppers and options can be interesting and may serve multiple purposes.  

Or, if you just want to build a cheap MIDGE gasifier campstove for a few bucks:

www.instructables.com/id/MIDGE-gasifier-campstove/

Used to see larger commercially made versions of these everywhere in China (made from steel buckets) until about a decade ago. Not sure where they were made, but were a popular heater for security guards in crappy draughty guard boxes outside carparks and the like. I reckon with all the recently enforced rules about smoke pollution etc, they're probably not widely used anymore. I guess there would be plenty of old codgers around who remember them and could build one in an emergency though.