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Portable Solar Power For Portable Hardware?
Tjeerd writes "Because the 'green revolution' is accelerating, I felt it was time to get involved. Last week I started with buying a portable solar energy charger for my mobile phone. But soon I was thinking of also recharging my Asus Eee netbook with a portable solar energy recharger. I found things like the Portable Power Pack, Foldable Solar Chargers, and the Solar Gorilla. The Solar Gorilla looks quite interesting and might be able to recharge my netbook and fits nicely in a rucksack. But I would like some real-life feedback. If you have experience with these or other portable solar devices, what has worked for you?"
Solar has a lot going for it as an alternative power supply for portable items. The problem is that many of those items aren't exposed to sunlight for enough time to actually charge the reserves.
That's why I use a hand-crank as my primary source of alternative power to my portable items. Especially in the winter time when sunlight is at a minimum, good old elbow grease is always there.
I looked at the solargorilla but could not find any information about how much energy I need to generate with this device to reach the green break even - to offset the environmental cost of making this device. Anyone knows this information?
I'm still waiting for the first netbook or laptop to feature solar cells in the lid, instead of the stupid logo they put there now.
Come on, it can't be that hard? And don't tell me I'm the first to think of this?
While the sentiment is admirable, please don't use 'going green' as an excuse to buy more toys; just buy the toys. Realistically, the power ranges you are talking about are in the 50-100W range for portable solar charging. In comparison, a typical 100 horsepower car is using around 75KW. (1HP=750W), so the power savings possible by simply traveling less dwarf anything possible via solar.
If you are _really_ concerned about going green, the biggest (and likely simplest) impact you can have is to never have children, especially in the developed world where per-capita energy consumption is highest.
"I bless every day that I continue to live, for every day is pure profit."
Or if you use it only to heat water. And live in a sunny, hot place. Why the hell do you need to heat water when you live in a sunny, hot place?
In my experiences dealing with photovoltaic power supply systems of all sizes, I've become convinced that solar panels are currently not a viable solution for powering mobile devices for a few reasons, mainly cost, unreliability, and inefficiency.
First of all, look at how much these things cost. the Portable Power Pack retails online for 420 pounds, or about $660. You could buy more than a dozen eeepc batteries for that much and just keep them stocked in your car or rucksack or whatever. LiIon batteries aren't terrible for the environment, and you won't even need sun to use them...
Speaking of the sun, I live in beautiful southern California, where one can definitely count on the sun 99% of the time. But most parts of the world aren't that sunny, and even if the sun is shining there's bound to be a tree/building/civilization in the way just when you need it most. You're not going to walk or drive around the city looking for a nice open space to sit in for an hour and roast while you check your email, just so you could feel good about spending $600 on a solar panel, no matter how good your intentions are.
so how do you charge your devices with a solar panel while actually "on the go"? you can try to drape it over that rucksack of yours while you're walking somewhere, but if the panel isn't facing the sun directly you won't get anywhere near the peak power output advertised. Instead, you need to find an open space and lay out your few-square-foot mat-- and then you're tied to the ground.
And what about that generous peak power they keep advertising? solar panels output their peak power when they are laid out flat, directly facing the sun, on a completely clear, sunny day. I know from personal experience with small panels that small deviations from the sun-facing angle mean big drops in power.
So alright, let's say that you bought a 30 watt panel and it's noon on a clear, sunny day, so you're getting 30 watts out of it. Please correct me if I am wrong, but I believe that EeePCs use 36 watt power adapters. How do you plan on charging and using your EeePC on less than 36 watts WHILE charging your phone and whatever else you have plugged in? all you could possibly do is increase your battery life considerably-- which might be great, but i'm not sure it justifies the costs and the effort involved.
Here's my suggestion: Save the money you were going to spend on that portable panel. Use a little to buy extra batteries for your gadgets, and put the rest in a savings account. Save up for a large, multi-kilowatt solar system for your house, which will save a lot more greenhouse gas emissions per dollar you spend than one of these portable things. Use that home solar system to charge your batteries, and you're gold... er, green.
I wouldn't go for the fancy laptop bags with solar panels... Maybe they work well, but if you're a real geek why not build your own? To run a regular 15-24v input laptop for 6 hours a day you'd need:
2 x 30W Mnocrystalline Solar Panels
1 x 6amp Charge Controller
1 x 85 Ah Deep Cycle leisure Battery
1 x Cigar to Crocodile Clip Adaptor
1 x Universal Laptop adaptor
At least that's here in drizzly old england. Comes to around 250 pounds in our drizzly english money.
Carbon costs and payback aren't everything: computers today aren't green and aren't sustainable but don't just get sad and do nothing :)
Using solar panels for this means microgeneration and helps promote use of decentralised, off grid energy which I consider a positive social change towards green-ness, and it will help you in particular if you live in a place with frequent blackouts (i.e not the UK!). Think of it as a ticket to a cheap shed-studio setup, or temporary remote setups like at festivals or camping, and once it's all wired up and charging a battery, I can plug it into loads of other kinds of things.
Ale
The foldable you mention is from PowerFilm. They make many different devices as well as components for building your own. http://www.powerfilmsolar.com/products/portable%20and%20remote/index.html
I went the build-your-own route using their thin-film cells. I needed a power source for a laptop in the field, so I put one together that I could epoxy to the laptop lid. It's still on duty 4 years later. I also needed a source on board the ultimate portable device -- a rocket weighing less than 2kg total and capable of handling a vertical acceleration of 20 G to Mach 1+, supplying constant high grade power to the recording altimeter that also controlled the parachute ejection system. That system has flown over 20 times. I put their stuff through some hellacious stress testing and the only failures I've had were my fault.
"I may be synthetic, but I'm not stupid." -- Bishop 341-B
Rubbish. How many 10year old devices are you using? Even if the real lifespan of the device is actually accurate, the real world lifespan is much shorter. Technology moves on, different devices with different requirements come into vogue etc. For the type of portable devices in TFA, the chances of them being still in use in 10 years is minimal. Moreover, they are in many cases going to be occasional-use (the odd hike or trip) rather than daily use. It's not even worth doing any finger-in-the-air math to refute your claim, it's so obvious. You might possibly have a case for permanent photovoltaic panels on houses/buildings etc.
Oh no... it's the future.
I found a cheaper solution to charging my iPhone by solar. I use two solar arrays, very similar to those found here for $23 each: http://www.batteryjunction.com/12vsopabachs.html They deliver 150 mA max, but I've found they can easily deliver 175 mA each, and not even when angled directly at the sun. I use this with a simple car power inverter that has a USB charger port on it, but you can always make your own 12V to 5V regulator with a 5V regulator from Radio Shack, see here: http://www.radioshack.com/product/index.jsp?productId=2062599 I've used this with my iPhone a couple times and found that it is able to charge my iPhone. There is one trick though, the iPhone is picky about its power supply, and so you need to trick it by making a simple circuit with two resistors. See the post below for instructions (you need to scroll down a bit in the post to get to what I'm talking about, it involves making a voltage divider on the data channels): http://forums.macrumors.com/showthread.php?p=5447947&posted=1#post5447947 Also, it charges the iPhone even while playing music. The first time I tested these was in my car, and I had the panels directed in the windshield. After driving for 3 hours it charged my iPhone from about 60% to 90%; and this was with the panels not angled towards the sun. I haven't taken account of how it charges since, but know it does. Also, if ever the power goes out for several days, you can always pull the battery out of your car when needed (or buy another car battery specifically for this use), and use the power inverter (if it has a USB port) or the 5V regulator to charge your USB electronics. You can then keep the car battery charged with these solar cells, so you don't need to waste gas running the car to charge the battery back up.
If your laptop isn't charging with the smaller power supply, I suspect it is a bit too low voltage, not current.
Bruce Perens.
Those products are a rip off. The price for what you are getting is beyond all reason. Check our solar cell products and make your own connectors to suit yourself. You should be spending about 10% of what these jokers are asking.