Just seen this on facepage, god knows whether it's real or not (or in production) but if the claims are true it woudl be good for you expedition types maybe?

https://www.facebook.com/TechExplorers/videos/595445817299848/

There are a lot of players on this: just google portable hydro generator. And a lot of things appear. Like http://www.coolthings.com/blue-freedom/

But they will not easily load my drill batteries
another example : http://www.powerspout.com ( this is however not really backpak portable 😄

It's also not particularly difficult to make something, any "tinkerer" should be able to knock up something that is easily capable of charging lamps and mobiles.

MJenkinson said:

Just seen this on facepage, god knows whether it's real or not (or in production) but if the claims are true it woudl be good for you expedition types maybe?

https://www.facebook.com/TechExplorers/videos/595445817299848/

Click to expand...

This thing looks shite, the simple reason being that you will really struggle to get any meaningful power out of it.  The swept area of the blades is tiny and will not manage to harvest barely any of the waters power. 

The maths is really quite simple

P= ? x ? x Q x g x h
where
P is power in watts
? is the dimensionless efficiency of the turbine
? is the density of water in kilograms per cubic metre
Q is the flow in cubic metres per second
g is the acceleration due to gravity
h is the height difference between inlet and outlet in metres

so for this, lets be optimistic and say its about 70% efficient.
the flow Q is the tricky one to determine, again lets be optimistic - 50 litres a second or 0.050 Cumecs.
and the real flaw on the plan, the height drop - 1 cm? In a levelish river, the water is not really falling at any gradient.

so we've got 0.7 x 1000 x 0.050 x 9.81 x 0.01

34 Watts  ... Hmmm - a person pedaling a bike will give out about 100W

Leclused said:

another example : http://www.powerspout.com

Click to expand...

This is more like it! - You could realistically set this up to generate 100W of constant output.  A 15m or more drop, potentially much more if in a vertical cave entrance could net you some proper power.

"we have created a light and sustainable turbine, which generates over 5 watts of electricity; enough to charge smart device"

see http://www.energynomad.com/ and a kickstarter project https://www.kickstarter.com/projects/hyerinster/estream-a-portable-water-power-generator-fits-into/posts/1650339

Well if nothing else I have learned somethings!

I can still see flaws..

fast moving water tends to be shallow, deep water moves slowly - as demonstrated in the film, whats to stop the thing snagging on the river bed all the time, its going to take some luck in finding somewhere 'just right' to set it up.

Your only ever really going to be able to charge a phone from it.  Is that much cop on an expedition. Perhaps sea kayakers touring might use it off the back of their kayak.  Charge their phone each night after a days kayaking. 

With no apparent way of stopping the body rotating (fins/vanes?) the "towing line" will be made of ?????.  Stop your kayak and a nice birds nest forms in a very convenient and readily accessible location 6' behind the paddler?