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?"

Better off with a long extension cable

[Anonymous Coward]

These panels are ridiculously expensive, and produce a pitiful trickle of energy. Save your money and get a long extension cable -- or, if you absolutely need the portability, just get some extra batteries and lug them around with you.

Solar is a great idea, but it's one whose time is not yet come.

How many watts does it produce?

[Joce640k]

I couldn't see a wattage anywhere and that makes me very wary.

If you have to leave it a whole day to get ten minutes of power then it's not much use (and expensive!)

Other locations.

[Gnea]

Frys.com [frys.com] has some affordable solutions. Pricewatch [pricewatch.com] seems to have a scant selection, although very unique.

Solar Power carbon-hostile?

[lkcl]

Before saying "I have found a way to save the planet!" check that the cost in planetary terms of the product is worth it:

http://www.genersys-solar.com/carbon-savings/carbon_footprint_solar-panel_manufacture.asp [genersys-solar.com]

seems to be saying that there's a reduction of the carbon cost when compared to other power-generation mechanisms, over the expected 35 year lifespan of the home-sized solar panels.

are the small, portable solar panels you're advocating as carbon-friendly?

Green Gadget Challenge

[MattSparkes]

I wrote a feature recently where I explored if it was possible to run all of the standard office gadgets from sustainable power - it includes quite a few product reviews [pcpro.co.uk].

Re:Enviromental cost of making the device?

[TheLink]

You can often have a good idea from the price tag if it's close enough to the cost of making it.

While it's not exact, it shouldn't be that far off in those cases.

If a device is priced at USD1000, costs USD500 to make, lasts 10 years and only saves you USD20 a year, it's probably not worth it in terms of the environment.

While it's true that in some places they don't value their environment that much, it's still not zero - even in China they are starting to value it more, and so it will be added to the cost of making stuff there.

Re:Watch out

[dgatwood]

Not nearly twice the consumption to charge. My MacBook has a 60W supply. With a MacBook Pro, that's just enough to run it without charging; the battery won't charge, but it doesn't drain the battery, either. With the MBP's 85 Watt supply, it can do both. The EEE PC draws 24W or so at full tilt, 36W to charge. For an optimal charge rate, yeah, doubling the maximum draw is a good idea, but most laptop manufacturers base their power supply choices on 25-50% over the maximum drain, not double.

On the flip side, this means that even with an ultra-low-power netbook, you're still talking about 4-6 of those panels before you start charging at all during normal use even in full sun. Solar panels on your roof: good idea. Solar panels on your laptop: waste of money, time, and materials.

Back of the envelope...

[Dice]

The power brick for my laptop claims that it draws 65 Watts. The average incident solar power per square meter on Earth is 1000 Watts. If we assume a solar cell with 30% efficiency I would need 65/300 = 0.216 square meters of solar cell for my laptop. That's a square 46.5cm on a side, or around 18.3 inches on a side.

Not too bad, but not something I would carry with me unless I was severely limited in terms of power sources.

Re:Solar Power carbon-hostile?

[dgatwood]

Where did you hear that nonsense? The typical solar panel lifespan is measured in decades. The energy produced does decrease over time, but a ten year lifespan is absurdly short for modern panels. Many home solar panels have a guarantee on their output power for a period of 25 years.... If they only lasted ten, those manufacturers would be replacing a whole lot of panels....

I think you're thinking of the break-even point. Typically you break even cost-wise compared with grid power at about the ten year mark.

Some real life feedback

[dirkjan]

I had a Solio Classic to charge GPS logger and phone while hiking for multiple days. It worked okay, good in very sunny conditions (in northern europe) and not enough to keep up on clouded days. But it was stolen and now I have a Solar Mio 31 which works better, even in clouded conditions. It manages to keep the batteries of a mobile phone and GPS logger charged in average dutch weather, back pack mounted or behind a south facing window. As I also use it at home, I haven't touched the normal chargers in a year...

As for price or "greeness", they won't repay themselves financially or impactwise. But I see part of it as gaining experience with solar cells and it is nice to see your week long treks through nowhere in google earth...

My Bike Trip and Solar Panel Experiences

[SJrX]

I had done quiet a few bike trips and generally can't be without my iPod, PSP, and cellphone so I have had some experiance using Solar Panels previously, though never for something as power hungry as a notebook/netbook. Two years ago I purchased the Soldius 1 Solar Charger, seen here: http://www.thinkgeek.com/gadgets/travelpower/7d34/ [thinkgeek.com]. I found that even stationary it really just drained my iPods batteries and made them unusable, as the change in voltages associated with clouds would cause the iPod to constantly redetect that the charging had started and illuminate the screen thus draining more power. I may have only gotten one meaningful charge or two out of it, in the two years I've had it. It also didn't charge some devices, that were USB powered, and seemed very brittle. This summer past, I had taken time off to go cycling for 2 months across Canada, and so invested in another Solar Panel, the SolarFocus SolarMio 31 Solar Charger: http://www.mec.ca/Products/product_detail.jsp?FOLDER%3C%3Efolder_id=2534374302697169&PRODUCT%3C%3Eprd_id=845524442620595 [www.mec.ca]. It was very durable, and I had it strapped on my rear rack, even in the worst rains. It also has a portable battery pack so you can charge during the day, and then have power for later, and it charges relatively quickly. I found that 4 hours would give it a full charge to the battery, (it is probably much better than this, as being on my bike rack and in motion means that it is not really positioned for optimum solar energy collection) and that would charge my iPod to 90%. It also has an external AC adapter to charge the battery overnight, and a USB port for 'most' USB devices. Some draw backs are that it didn't charge my Phone at the time, a Motorola KRZR, and after my trip I found out it doesn't charge my iPhone (which is kinda a disappointment). Another plus is that the battery is detachable, and while replacements/spares are expensive, it made it convient to charge at camping sights. They make an equivilant solar panel for laptops which is a bit pricer at CAD $595: http://www.mec.ca/Products/product_detail.jsp?FOLDER%3C%3Efolder_id=2534374302697169&PRODUCT%3C%3Eprd_id=845524442625524 [www.mec.ca]. Which is too rich for my blood at the moment, but if the quality is anything like this one, I'd definately recommend it. Finally some other words of wisdom: 1) The Solar Device compatibility list actually seems to matter at least for obvious devices not listed, just because it's USB doesn't mean it will charge it. 2) Getting a dead iPod (I had both a iPod 4G Photo and 5.5G Video) to charge is a bit tricky if you are charging straight from the sun in less than ideal conditions, as when it turns on, the screen comes on maximum brightness, and I believe stops charging for a moment, and will cause the iPod to turn off. I found that both the above would eventually charge by just booting it into Disk Mode a few times, eventually it would have enough power to stay on in Disk Mode and charge. Finally after two minutes rebooting it into Normal mode, so that the screen turns off resulted in a quicker charge.

Re:Solar and handcranked are the way to go

[nospam007]

"Are there practical crank chargers out there? "

Tons!

http://www.nextag.com/crank-charger/search-html [nextag.com]

Decomas

[Decomas]

Yes! I actually have that EXACT model from the first link. It is 20 Watts and I run all my usb devices off of it simultaneously. I think I got up to about 7 or 8 devices at once before it reached its peek. It's great, I worked at the beach all summer and carried the panel in my bag every day, only taking up the size of a thin composition notebook. and the great thing is, IT FLEXES like a softback book. So there is no need to worry about breaking the "glass" on the panels.

NOMADIC POWER!

I want to get the Y adapter and bump my power up to 60 watts with a 2nd solar panel. I would suggest E.Bay for some great deals on these panels. such as this. http://cgi.ebay.com/35-Watt-Foldable-Solar-Panel_W0QQitemZ190262865303QQcmdZViewItem?hash=item190262865303&_trkparms=72%3A1205 [ebay.com]|39%3A1|66%3A2|65%3A12|240%3A1318&_trksid=p3911.c0.m14

Re:Wait for Better Solar Panels

[Anonymous Coward]

I have a 75W solar panel for the camping and did some measurements for my U9200 Fujitsu-Siemens laptop (Core2Duo CPU T5450, 2GB RAM). I connected the laptop to solar panel's charge controler via Trust's universal car adapter (http://www.trust.com/14669).

While using default setting for CPU voltage (1.25V), laptop was drawing 3.8-3.9A (46-47W) at full load with the CPU temperature over 70 degrees Celsius and fan on the full speed. Since max. current for this panel is around 5A in ideal conditions, this means there will be not enough power in lower light conditions.

Then I did a CPU undervolting using RMclock program which enabled me to lower voltage in range of 0.95V-1.00V (I was probably lucky with this CPU since most of the folks out there is able to get 1.05-1.10V as a minimal stable voltage). Power consumption dropped dramatically:

- idle - 1.5-1.6A (18-19W)
- normal work with WiFi on - 1.8-2.0A (22-24W)
- full load - 2.9A (35W)
- temperature also dropped dramatically (idle @42C, full load @53C)

With this setting I'm able to go off-the-grid for longer period of time while being able to use my laptop, charge cell phone and the backup battery for night lights - all that off the not-so-big 75W solar panel.

KK

Re:This isn't "green"

[pla]

The CO2 produced by making those things is more than you'll ever get back from using them.

That myth really needs to die, once and for all.

You've phrased it one layer of indirection more than the standard claim (it takes more energy to make them than they will produce over the useful lifetime), but they reduce to the same concept (since virtually all of the CO2 "produced" during manufacture comes from the energy input).


A trivial economic proof should demonstrate this fact - The payback period for wind or solar runs around 10 years on average (a lot less in ideal climates, somewhat more in suboptimal ones).

The expected lifetime of such devices averages around 20-30 years (most importantly, more than the payback period).

It follows, then, that in order for it to take more energy to produce the device than it will generate over its useful lifetime, the manufacturer would effectively need to spend twice as much on electricity as they sell the finished product for... And that ignores other overhead such as labor and raw materials.

How many companies do you know of that sell at a massive loss and stay in business?

Re:Plants

[ShieldW0lf]

Try an onion [youtube.com]

Re:Solar and handcranked are the way to go

[Anonymous Coward]

HA HA Ha if you have ever tried to re-charge your mobile fone using one of those silly hand crank led torches you will know from bitter experience it is a no go job 2 hoyrs of cranking and still not anywhere near charged bit lame as are solar cells the effiencey (SP) of them is poor at best and in the UK well need i say more there is still no NO alternative to atomic power wind farms farcical a friend of mine has one not far from him the noise is to be heard to be believed and so many for such a small amount of power

not really anonymous just sick of the stupid rating system in use on here

Re:How many watts does it produce?

[dajak]

I was also looking for that. The solargorilla spec does list .5 Ah @ 5V (usb) or 20V (power socket). If I understand things correctly, this means that it delivers 10W in ideal conditions if you use the power socket. Not impressive. I'll pass.