It’s hump day! And so begins the third day of my off-grid blogging in observance of Earth Week here at DVICE. Translation: no wall sockets or municipal juice for me until Saturday.
Due to rain yesterday, I had to forgo plugging my laptop into the Solar PowerPac II, my big solar-rigged generator. Though the battery status lights indicate it’s at half capacity (thank you, sun-kissed Monday), I can’t risk sucking my main power source dry. Hear and see how a bit of aerobics can jump-start a laptop after the Continue jump…
Yesterday I mocked the weather forecast. Bad idea. By noon, a wave of clouds rolled into San Francisco and those “chances” of April showers became imminent. Losing charge time wasn’t part of my plan, so I opted to conserve the Solar PowerPac II. After a couple hours of working straight from my MacBook’s 55-watt battery, the computer puttered out late yesterday afternoon. Inevitable bummer. And unfortunately, we’ve got patchy clouds this a.m., and I’m just not convinced there’ll be enough sun to offset any charge-time from the generator (remember, I gotta make it to Friday).
Enter the FreeCharge, Weza’s $300 “portable energy source.” Translation: a 7-amp-hour lead-acid battery that powers up as you step down on a lever. Interesting factoid: Weza (pronounced Way-zah) derives from Swahili for “heart attack” …OK, it means “power,” but no joke, I can no longer deny I am one out-of-shape blogger.
Around 7:35 a.m., I plugged a 12V inverter into the Weza’s DC output (max output is advertised as 120 watts, though step-charging only generates between 25 and 40 watts) and connected the MacBook’s 60W adapter to the inverter. Now, I had assumed the Weza would be completely discharged out of the box. I must confess it did not; it registered half full. It was a wonderful surprise, but I concede this does put me in close proximity to the grid. Then again, keep in mind that even pocket-size solar chargers require or recommend a full wall-socket charge before first use. So I digress.
And Presto… the Mac adapter’s light powered on red. So far so good. After a few minutes of hot steppin', I tried powering up the MacBook: 1% battery! However, the screen started to bug out and the Mac’s battery status read "not charging." Conclusion: do not attempt to work on laptop while charging. So I shut down and continued cranking, leaving the laptop’s charge cord in place.
After 20 minutes of huffing and puffing, I wasn’t optimistic. I had no clue how much power would get lost in the inverter on its way to the computer. I left the Weza hooked up and took my dog for a walk. At 9:40 a.m., when I unplugged the computer and powered it up, I couldn’t believe it. The battery was back up to an astounding 52%!!! And after 15 minutes, it was down to 43%. How this might affect my battery long-term, I don’t know (if you do, please drop some knowledge in the comments… and yes, I backed up my hard drive last week just in case this somehow fries my Mac). Still, what I do know is this: I managed to squeeze in enough time to quickly whip up this post!
OK, I’m heading out for a little field trip. I don’t want to say too much, but check back in tomorrow for my attempt to deliver a few portable solar chargers to the masses.
Oh, and here’s a video of the Weza in action. The faster the stepping, the better the charge. When the noise gets high-pitched, my step input registered a 5 out of 6 according to the charger’s indicator lights. Tiring, but satisfying.
Off the Grid, Part 2: Do watched solar pots ever boil?
editor@dvice.com
By Bob at 6:31 PM ON 04/23/08
Way to go Steve! It took me awhile to find parts 2 and 3 (they didn't show up on the DVICE site until late this afternoon. Anyway, glad to see you are up and blogging. I'm loving your experiment. By the way, I built a solar oven that I ran in Alabama (where I was living at the time) and got it to over 400 degrees in the winter (temp was below freezing at the time). A bent 4x8 foot sheet of aluminum backed foam board was used as the main mirror - which I positioned by hand.
By Bob at 6:45 PM ON 04/23/08
Lets say that your Weza power meter is accurate and you really had 3.5 Amp-hours of 12 volt power in your system. That amounts to 12 * 3.5 or about 40 watt hours of power. Inverters can be pretty inefficient (especially cheap imports), but figures of 80 % or so aren't too far out of the park. So that gives you about 30 watt-hours of power in you Weza. Sure enough, when you took your dog for a walk, that was enough to charge your MacBook to about half capacity. I bet your Weza is dead now, right? Anyway, all you need to do is keep stepping on your Weza for about 6 hours continuously and you will have produced enough power to fully charge your battery.
As for your MacBook battery health, a reasonable life expectancy is 500 full charge/discharge cycles. You used up about half a cycle. Figure on needed a new batter every 1 to 2 years if you keep cycling it daily (as you would in an off-grid world, charging it during the day and running it at night).
By TheAdlerian at 10:12 PM ON 04/23/08
Way to go?
This sounds like a horrible fail in the making.
It seems to me that "green tech" hasn't improved since I was a child, in the 70s, as is just another marketing fad.
By chexxer at 10:07 AM ON 04/24/08
Some exercise bikes have a alternator built in to create the resistance, Maybe you could modify one to charge a battery to achieve the same solution and get a better CV workout !!
By Bob at 10:32 AM ON 04/24/08
Well, let's see...since the 70s (a decade after I was a child), the efficiency of solar cells has gone up by a factor of 5, and the costs have gone down by over a factor of 100. Nah, that's just another "Green" marketing fad.
Meanwhile, your old, reliable, oil based economy is gasping for breath now. Electricity that sold for 3 cents per KWh is not 15 cents, gas that sold for 75 cents a gallon is now $3.60 and climbing. But hey, that's just another marketing fad too.
Keep you head in the 70s if you want, after all it was a great decade -- America was on top of the world, life was simple. However, the rest of the world has moved on. China and India now want the same oil that we do, so prices are going nowhere but up. Meanwhile we still run an oil based economy that is far too dependent on sources we can't control. We saw that coming in the 70s and did nothing to stop it.
Change is inevitable. People who insist on reliving the past are the biggest impediment to change. Too many tightly held and false beliefs.
By yeLLowfLash4 at 12:18 PM ON 04/24/08
Owned.
By TheAdlerian at 10:10 PM ON 04/24/08
Owned?
Hardly, I've been interested in this kind of stuff for decades and it really doesn't work. I had high hopes for hydrogen, but it doesn't work either.
Our culture is like something out of Star Trek. We've a technology which evolved from one substance, and supposedly that substance is threatened, now almost every product made is threatened. So far there is no technology or substance which will bail as out. This "off the grid" experiment is a small bit of proof.
If we truly run out of oil, we'll join the rest of the world in 18th century living, count on it.
Fad:
I've been following stock market shows and whatnot for years. The big complaint is that the consumers in our consumer economy, have stopped consuming so much. The "Green" fad is the answer to that.
Anxiety and guilt are being used to convince consumers to totally replace (re-buy) all of their stuff with "Green" products. This stimulates the economy, and has even created a Green Stock index for investors. Meanwhile, huge amounts of resources are being used to make 18 different type of Green Shower Heads and a mountain of other crap. Less energy would probably get used if we strapped a diesel engine to our shower heads.
This another business cycle in the capitalist system, and it's You who will get owned---again.
Fantasy sells.
By Bob at 3:02 PM ON 04/26/08
It isn't fantasy at all, my doubting friend. Today in Hawaii, residential customers pay over 45 cents per KWH and the price is going up daily (almost all their power is oil based and all of that is shipped in). A 1KWh off-grid solar system with 6KWH of storage is $7500. Such a system produces almost 3000 KWh of power, and pays for itself in three years. That's current retail prices, no rebates or subsidies. It occupies approximately 10x10 feet of roof space.
Under what critical system of reasoning is that a fantasy or failed experiment?
Moving to the mainland USA, the electrical rates are 1/3 of course, so the payback is about 3x. That is still less than 10 years. If you also switch to grid tied, you eliminate the storage system, and you are now talking about a 5 year payback on a system with a 25 year life.
Keep pushing back, but this isn't the case of a bunch of sheep following a green trend. Solar PV works today, and is going to look darned great when your residential electrical rate goes up by a factor of 3 to 10 in the next decade.
By JP at 11:48 PM ON 04/28/08
I'm really glad this guy (Steven, is it?) is doing this experiment, I came across his blog by Googlating "weza output", and though arguing about the grand ideas of 'the green economy' is find and good, I have a direct question to Steven: is the Weza something you may keep and use every now and again to charge any of your devices after your 5 days is over?
I've been thinking about not necessarily focusing in "getting off the grid", but to simply get power to my devices in as an efficient way as I can. I figure a lot is lost in the AC to DC conversion (wall warts) that all these devices have to do, to take wall-power (AC) and convert it to battery (DC); so I'd like to stay DC, in as many cases as possible... if anyone can let me know if I'm off-base here, and that DC-DC stepping/conversion is even less efficient, than please let me know.
Anyway, back to the simple question for Steven: should I get a Weza (and accompanying XPower PowerSource type devices, or even just simple 12v DC -> USB adapters for the small devices, and Kensington/iGo car-adapters for the laptop/big-draw devices)?
Heck, what are everyone else's thoughts on this?
By tang at 8:30 PM ON 06/09/08
a good read !
By laptop battery at 5:33 AM ON 10/13/08
If you are not going to use laptop for few days, then discharge the battery fully and disconnect it.