A portable wind turbine the size of a water bottle
singularityhub.com
singularityhub.com
https://www.omnicalculator.com/ecology/wind-turbine
You see that at around 0.2m blade length a HAWT will generate 40W at 28 mph wind. 28 mph is "Strong Breeze", according to the National Weather Service and in which you probably really don't want to be camping.
Strong Breeze = "Large branches in continuous motion. Whistling sounds heard in overhead or nearby power and telephone lines. Umbrellas used with difficulty."
But when you get down to 15 mph (moderate breeze) it's only making 6 watts, and at 8mph (gentle breeze) it's making 1 watt.
That is assuming steady wind to think you will get that continuously, derate accordingly.
I suspect there will be some gap between expected and actual performance for many people.
If you’re going to use a longer pole, portability goes out of the window, as the pole will have to be stronger, too.
Then, you might as well get an even stronger longer pole and increase the turbine diameter. Micro wind turbines rarely make sense.
My ideal combination to cover about 80-90% of power needs whilst camping/hiking/cycling would be a combination of water turbine (for rivers or tiny streams) and solar.
In case I'd be hiking in an area with no water supply, I'd consider something like a wind turbine. Yet, I wouldn't know why I would want to hike in an area with no water supply ;-)
You're not gonna power a heater or aircon through body movement, but devices should be fine.
1. https://www.reddit.com/r/theydidthemath/comments/693daq/comm...
A Calorie is slightly more than a watt hour.
It would be charging itself all day and all night at a couple of Watts. Then when you come back to camp you speed charge your phone at a full 50W.
12,000 mAh internal battery
There's no mention of voltage but it looks like it uses USB connectors, so let's assume 5v. This turbine running at full-load (with NO losses)
40w @ 5V = 8A (maximum theoretical)
8A * 1.5hrs = 12,000mAh (1.5hrs minimum theoretical time needed for a full charge.
Now divide everything by 1/3rd for better 'real-world' (aka pessimistic) numbers.
13w average output
13w / 5v = 2.6A
2.6A * 4.5hrs = 11,700mAh
So really not that bad, but most of the time I'm camping the trees block 95% of the wind. On the other hand that other 5% does seem to happen more then 5% of the time. =)
Here's the fundraiser site where it gives more details: https://www.indiegogo.com/projects/shine-a-wind-turbine-that...
I would be willing to bet that 8mph wind only gives you ~500mA of power (which is what USB v1.1 operates on), and that fancy internal battery is probably using off-the-shelf circuits so that you can charge phones.
This product sells* for $400+ CAD. You can buy several 10,000mAh battery packs for that amount of money, and probably have a lot of juice left over at the end of your camping trip. [Note: I just did some searching and an Anker 20,000mAh powerbank can be bought for $33. So I could buy 10 of them for less cost and probably not need to charge them for a couple of months.]
I'm kinda/sorta intrigued. The fundraiser page looks scammy IMHO, and is full of marketing fluff. I go bike-camping. Something like looks less practical then a 100w solar panel, but also more compact. Full sunlight is rare when/where I camp, I'm usually under tree-cover. That makes the solar panel weep, and is practically useless. I have to make compromises to make use of it. (i.e. the edge of a farmers field)
This turbine might require different compromises, but the best thing it has going for it; time. I could leave it operating for 2 days giving me 48hrs of charging time, compared to the 3hrs of direct-overhead sunlight I might get while camping. That's 16x the amount of time for 'energy generation'. Even at less then my 1/3rd rate of power, that might charge all of my battery banks.
I will wait for them to be built, and field tested by others. I'm not in a rush.
*Not shipping yet, but we promise soon! /sarcasm
I wonder if the turbine could be attached to the bike in a manner that would generate electricity while you ride.
I'd wager it's the airfoil and/or the blade construction.
Sure, I could also just plug in to their el, but where's the cool in that?
> 8A * 1.5hrs = 12,000mAh
This assumes the battery is 5V, but lithium-ion batteries are typically counted as 3.6V.
40W / 3.6V = 11.(1) A
12000mAh / 11.(1)A = 1.08h
Adjust the rest of the calculations accordingly.
The voltage before the energy enters the battery doesn't change the calculation of battery capacity (and its time to discharge) anyway.
EDIT: now I noticed that the calculation is about charging, rather than discharging. 4.2V makes better sense in that case.
A local neighbour has 4 small turbines (the kind typically used on boats) mounted atop 14m masts, and they make a hell of a racket when the wind is strong enough to make them generate reasonable (read: rated) amounts of power (which is pretty seldom around here.)
Frankly I doubt whether this machine is nett energy win over its lifespan. To me it looks more like a virtue-signalling device than something seriously meant to generate energy.
[1] https://www.tesup.us/product-page/atlas20-48v-2kw-wind-turbi...
It's possible to sell consumers ad-hoc designs that are unnecessarily inefficient just because they look cool.
Using the existing principles of tensegrity applied to self-supporting tents, this could have enough surface area to run the generator at maximum in a gentle breeze, with some possibility of trimming in actual wind.
It would be a completely different product but it's not an implausible one.
Edit: I'm thinking vertically mounted with three 'jib' sails which are constrained on (let's say) the clockwise side, these would take turns catching the wind, then relax into the leeward and snap over onto the bar when returning to windward.
The other thing is it doesn't say how noisy it is - bet you it's pretty annoying if it is making 40W, probably even at 15-20W.
BUT in a secluded camping spot, I'd bet it's quiet noticeable. (Compare a quiet conversation in a house to a quiet conversation in a library.)
If you normally camp near running water, you are more accustomed noise and might not even notice it. I once camped near a small stream, just wide enough that you could jump across it; it was shallow, and had a very calm 'babbling brook' sound during the day. Wonderful and calming. By bedtime this peaceful flow was an utter torment, and much too loud.
It's heavy for most recreational activities, but it might be great for expeditions. If it could be made very durable, it could be beneficial for superdeep cave exploration. In such environments there is no light, but often there is rushing wind and water. There is also a critical need for power to keep lights running. While charged batteries can also be brought in from the surface, they have a limited lifespan in the cave, and an expedition therefore needs a continuous supply of fresh batteries to continue.
I guess you would often get closer to the true output of the 20+W solar panels, at least during summer daytime.
I haven't done extended hiking or similar, but I expect "phone off" (and maybe a usb battery) is pretty competitive as a solution, with charging when it happens to be available.
Neat idea but unless you are within 3 miles of the coast you're unlikely to see wind speeds above 6mph in your area for any sustained period of time.
Windiness, as you say, is indeed correlated with exposure. The top three ways of exposing oneself are: ocean (or the next best thing for land lubbers: coast next to ocean), mountain, and wide open space.
I live about 100 miles from the coast, and the number of days I can remember having an easy time of it is of the order of five in a given year.