Laptop vs. Small Desktop: Best Bang Per Watt? 526
Deagol writes "Tomorrow I take possession of a remote, wooded lot with a cabin. 15 miles to the nearest utility pole, my electricity options are limited to those I can generate myself, solar being my primary goal. I'm sitting here staring at my power meter, seeing my desktop & monitor draw about 250W -- a non-trivial amount to generate over a 8-to-12 hour workday. I'd be happy with equivalent computing horsepower (1.4GHz T-Bird, 512M RAM, though more is always better). Should I get a small PC with an LCD monitor, or should I get a laptop? Will laptops draw less power (in general), and if so, will losing the modularity and lower cost of commodity PC parts be worth it? I'd love opinions from those who have been in a similar situation."
Whiskey. Tango. Foxtrot. (Score:5, Funny)
Re:Whiskey. Tango. Foxtrot. (Score:4, Funny)
And that raises the age-old question: If a computer is switched on in the middle of the woods, does it consume any power?
Re:Whiskey. Tango. Foxtrot. (Score:4, Funny)
Re:Whiskey. Tango. Foxtrot. (Score:5, Insightful)
I think the laptop would be the better idea. Gasoline is costly. If you could get one with a seperate battery charger, and get two or more batteries, you could leave the used batteries to charge at a friend's house or your work and swap them whenever you're out. I have uncertainties about being able to use the solar power for your laptop, depending on your setup.
Re:Whiskey. Tango. Foxtrot. (Score:3, Informative)
[warning, american centric prices]
Is Gasoline costly, vs power directly from the grid? Not to put to fine a point on it, but based on my observations.... the fuel bill for something like fuel oil, which is diecel #2 floats at $1.50 a gal... and is also on par with what I use, propane heat also at about $1.50 a gal.
I burn roughly 100 gal a year at a cost of $150 for heat and stove. While I don't have an accurate price estimate of what I was consuming with electrisity for the heaters.
Re:Whiskey. Tango. Foxtrot. (Score:5, Informative)
Keep in mind that while chemical-to-heat reactions can be made over 90% efficient, chemical-to-heat-to-motion reactions in a typical portable generator are more comparable to car engines - 30-40% efficient (non-portable large-scale multi-stage turbine generators can do more like 60-70%). If you're storing the resulting electricity in a lead-acid battery, that's only 70% efficient.
Assume that you have an average 35%-efficiency generator charging lead-acid batteries. That system has an efficiency of 24%.
Given that gasoline stores about 130 megajoules of energy per gallon [hypertextbook.com], and you can recover 31MJ of that (same as 8.61kWh), and it costs you $1.50, then the break-even point is $1.50/8.61 (or $.174) per kWh. If you're not charging batteries, then the break-even point is $.118/kWh.
For me at least, the grid is significantly cheaper. As it should be.
Also, if you need the waste heat from the generator anyway (and can rig up a way to exchange it without dying from carbon monoxide), that could make generation a lot more worthwhile.
Re:Whiskey. Tango. Foxtrot. (Score:3, Insightful)
Via Epia Stuff Works Nice (Score:3, Informative)
Any rivers? (Score:5, Interesting)
- you have daylight
- the river is flowing
- there is a breeze
If all of the above fail, you have 2-8 hours of UPS power (depending on how big and how many UPSs you get), and 2-3 hours of battery in the laptop (make that 4-6 if you get a spare battery). You could make it through a frozen, long, dark, and still Alaskan night with that setup. You'll be set...and still nerdyRe:Any rivers? (Score:3, Interesting)
Home Power is primarily concerned with photovoltaics, but have articles on a wide range of home power alternatives. Eachs article has a schematic for the system they're presenting. This is what I want to do. I don't want to pay the Man anymore. I don't want to damage the environment, but I don't want to have it damage me.
Re:Any rivers? (Score:4, Funny)
* there isnt a meltdown
* the EPA doesnt shut you down
* terrorists dont blow it up
If all the above fail, you have 2-8 hours of UPS power (depending on how big and how many UPSs you get), and 2-3 hours of battery in the laptop (make that 4-6 if you get a spare battery). You can hopefully complete your program long before you die of nuclear exposure.
Re:I know why he's doing this (Score:3, Funny)
--Mike
laptop (Score:5, Informative)
Re:laptop (Score:5, Informative)
You will be generating solar power through out the whole day, and I assume that it stores it overnight, so if worse came to the worse and you ran out of power at 4am, the battery(s) on the laptop would have enough power to take you to sunrise, assuming that you stay awake for that long
Most laptops these days have one of three types of chip in them, Celeron - low cache, but low power consumption, Desktop processor - high power consumption, good performance, and Mobile processors - best of both worlds.
For example, the new AMD Mobile Processors can drop down to nearly 300mhz when running of battery to peserve power.
I would say laptop, although having used one for nearly 3 years, I would say this view is slightly biased.
NeoThermic
Re:laptop (Score:4, Insightful)
just pointing that out.
Re:laptop (Score:5, Informative)
If you set it to sleep automatically when you close the lid (impossible under linux right now) and set the backlight to turn off ASAP
I also suggest that you look at using only compact flouresent lamps for lighting.
One way to save a few watts is to charge/power your laptop off of 12 volts. and tap off a pair of the batteries in your array instead of using 110VAC that is converted from your 48volt battery array... (or what ever battery storage configuration you have.)
Re:laptop (Score:4, Informative)
Kris
some numbers (Score:4, Informative)
The "highly efficient" Luxeon star white led will produce a mighty 25lumens/watt.
A boring hardware store compact flourescent will produce 55lumens/watt or better.
Re:some numbers (Score:3, Informative)
Obviously the standard ballast in the fixture will have to be replaced, as it expects 120V AC input. I don't even know if low-voltage DC ballasts are available (although I'm sure they are). An LED based system might have an *overall* higher efficiency if if allows you to avoid transformer / inverter losses. You can't just look at the light bulb -- you have to take the entire system into account.
Re:laptop (Score:3, Insightful)
Florescent bulbs are a proven, mature tech, that work well. White LEDs are newer, with the costs of bleeding edge tech, but offer longer useful life and more flexible installa
Re:laptop (Score:3, Informative)
High voltage AC is much less lossy if you are transmitting it several miles. In a cabin setting, I doubt there will be any cable runs longer than 50 feet, so a predominantly low-voltage DC system would be highly
Re:laptop power modes (Score:5, Informative)
When they are plugged in they speed the CPU back up and brighten the display - consuming more power since it is available. I think I would probably recommend a laptop, and a few spare batteries. Then you can charge on someone else's power and bring it back home with you.
Since your laptop will use less power when running off battery you should always use your laptop on battery power. Then when you shut it off you should charge the batteries. Make sure you get a laptop with two bays.
If you go with a PC get a variable speed CPU fan with a sensor. Then it can slow down when it is not needed, saving you some juice. Since I am assuming you would be building your own system then evaluate the watt consumption of each component, and add it up getting a good quality (expensive) power supply that meets your needs without exceeding them astronomically. When possible use one component instead of two (Optical drives, hard drives, memory modules, etc.) Two will consume more juice then one (obviously) when you can get a single hard drive that is big enough to do the job.
Display brightness has a huge impact on battery life. Whatever you go with make sure your display is as dim as possible. Put your computer in a dark room.
Also, don't run SETI@Home, GIMPS or one of those other background processing systems. Those really increase your machines power consumption, as do games!
Another must have would be a good UPS with a power conditioner. Brown outs are very damaging to your computer hardware. Not that I doubt your ability to build your own power grid, but wouldn't you hate to loose your PC because of a brown out?
Re:laptop power modes (Score:4, Insightful)
Slashdot gets the best guest writers (Score:4, Funny)
Get a Laptop.. (Score:5, Funny)
wtf (Score:2, Insightful)
Re:wtf (Score:3, Insightful)
Perhaps Telecomute [n/t] (Score:2)
Re:wtf (Score:3, Insightful)
Re:wtf (Score:2, Funny)
What if he doesn't know how to be outdoors and he needs the internet for survival tips?
Re:wtf (Score:5, Insightful)
Solar is the big price factor, not the computer (Score:4, Insightful)
Solar power is not cheap.
laptops have batteries (Score:5, Insightful)
Re:laptops have batteries (Score:2, Funny)
Wait a minute. What solar system is this poster in? He said he was only 15 miles from a power pole.
Re:laptops have batteries (Score:3, Informative)
Somebody else mentioned that laptops usually have DC going into them (external converter). A very few take DC direct in, and that would be bad for you. If you can do direct DC->DC conversion to whatever
One word: Batteries! (Score:4, Interesting)
Another option is get a UPS for your desktop. You can run the machine off of that when the power goes out, night, etc. and they are relatively cheap...if you get a 4 hour one... and can power other devices. The laptop and the UPC will trickle charge while juice is flowing, so you can be pretty sure that when the sun does set, you won't miss a beat with your tech.
Now... how exactly are you going to get on the net? Satellite? Pigeon?
Re:One word: Batteries! (Score:5, Informative)
Err, carr batteries are designed for short heavy loads - starting your car in the winter. You can run them all the way down and recharge them a couple times but then they're cooked. Substitute "marine" deep cycle batteries - the ones people use to power bass boats - same 12v lead/acid battery but the plates inside are designed for complete discharge.
Re:One word: Batteries! (Score:3, Informative)
Being a person who has worked with many lead acid batteries, I have to disagree with you. A lead acid battery is at its most efficient when the load is the least. Under very heavy loads a lead acid battery will generate high heat and release alot of hydrogen. The only components that are really suited for short heavy loads are capacitors and inductors. The reason that you can use your car battery to start your car without damaging it is b
Re:One word: Batteries! (Score:3, Interesting)
If you use a standard 12V lead-acid battery in a location where it
Re:One word: Batteries! (Score:3, Interesting)
So far as lead-acid batteries go, the best bet (given the remote location of the original poster) would be something like a Hawker Genesis EP-series valve-regulated gas-recombinant pure-lead-plate battery. Or maybe even a PowerSafe. http://www.hepi.com. The nice thing about Hawkers is that a. they are gas-recombinant, so unlike regu
Marine batteries are a ripoff (Score:3, Informative)
As always with batteries, you pay for better quality, and just because lead ain't cheap either.
You are not supposed to run these dry too, discharging till 50% gives a much longer lifetime.
Re:One word: Batteries! (Score:3, Informative)
Is this a trick question? (Score:5, Informative)
However, be aware that some laptops are really just mobile desktops, in that they're fast, hot, and hungry.
There are plenty of good low power laptops out there. Just start by looking at battery life.
"Small PCs" are not necessarily better for power consumption than big boxes. It all comes down to the CPU and graphics cards, mostly. OTOH, I can attest that a lovely little Shuttle XPC with a big fat P4 will probably be enough to heat your cabin thru the coldest winter. Mine was like a hairdryer permanently on.
Re:Is this a trick question? (Score:2)
Power consumption (Score:4, Informative)
For the VIA EPIA type desktop systems with the right LCD displays you can get the power down to about 55W including monitor (thats a real configuration EPIA M6000, Keycorp K57H + 12.1" TFT display, 256Mb, and a disk)
Laptops take you a little bit lower and you get the benefit of the battery being pre-fitted of course. That means looking for real low power laptops - crusoe, anataur, maybe PIII-M as well as making sure they have good power control in your favourite OS and preferably suspend to disk so you can kill the drain entirely when its off.
The CPU is critical, you can get "micro" P4 boxes but they still burn the same power, just in a smaller space. Large boxes can actually use less power because you need less fans!
low power possibilities (Score:2)
Here is a good sample machine for you [dell.com], customize it as desired.
Good ole 12volt hardware (Score:2, Interesting)
There are many different alternatives. Yes, using a laptop is much more power-efficient, and you can get yourself power-adapters to convert DC to DC current to charge your laptop from a 12v battery car.
However, there is also a Mini-ITX [mini-itx.com] form-factor system, to which you can find cases with built-in DC switching power supplies.
I think the solution is to stay native to DC current, and then convert as you see fit. So, all you need to have is a set of car batteries, connected to solar panels (for charging purp
+5 Insightful (Score:2)
similar situation? (Score:5, Funny)
Error: division by zero
Solar PC (Score:4, Informative)
Try looking at what they have here: solarpc [solarpc.com].
They even have a complete turn-key squeak [squeak.org] system (it's at the bottom of the page): here [205.147.44.194].
Return To Civilization (Score:2, Insightful)
Power Meter link (Score:4, Informative)
If you're just running 3-4 PCs, what's the point? Get a Belkin (cheaper) or APC (better Linux support) unit and get the same digits.
Laptop is best choice (Score:4, Informative)
Laptops make perfectly good computers, except as very high-end workstations/gaming machines. I have not owned a desktop machine for at least the last ten years. The small amount you are behind in terms of graphics processor or CPU is more than made up for by the ability to take the thing with you.
John.
Re:Laptop is best choice (Score:2)
Apple's (Score:2, Informative)
If you have no religious preferences about computing then the Apple will give better power performance. The G3 iBooks are coming in cheap now. Especially, refurbed. Then you can save money for the solar setup that is going to hurt more.
Re:Laptop is best choice (Score:2)
No brainer, laptop (Score:2, Informative)
Plus, Thoreau, you can take a bag of batteries over to your moms there and charge them up.
What will you use the computer for out there? Reply.
not sure if this will help? (Score:5, Informative)
might even come in handy in new york next time the power goes out.
Re:not sure if this will help? (Score:3, Interesting)
I was in Mexico this past summer and went on a a tour of the Mayan ruins at Coba with these guys [alltournative.com]. (highly recommended, BTW). On part of the tour, they had kids from a local village taking pictures of the tourists with a digital camera. Then, when we got back to the village you could buy a picture of yourself looking foolish.
The kids had a laptop and an inkjet photo printer inside a hut with a line run outside to a solar panel. These folks
Pentium M laptop (Score:2, Insightful)
Steam power rules! (Score:5, Funny)
Laptop, no question about it (Score:5, Informative)
- can pre-charge the batter elsewhere when possible
- has built-in "UPS"
- is specifically designed to use as little power as possible
- if you later get a generator for the rainy day, the battery gives you time to start the generator without hibernate/shutdown
- if you want the comfort of separate keyboard, bigger LCD, real mouse etc, you can still get them for laptop too (and getting that 2nd LCD may give you dual screen as a bonus) and still use less power
Re:Laptop, no question about it (Score:3, Interesting)
Laptops get hot when plugged in because of cheap regulator circuitry at the power input. Remember, there is no incentive to be frugal with power there because you are plugged in and have lots of chunky KWH coming out of the wall. My Powerbook gets very warm on the rear right corner, where the power cord plugs in, when it is plugged in. Definitely a voltage regulator mod
Desktop Replacement Laptops. (Kinda) (Score:4, Informative)
I chose a laptop over a small, quiet PC mostly so I could take it to Tafe, Uni, LANs, etc on public transport, which doesn't sound like it will effect you much.
The point is, that it is quite possible to get a laptop to replace your desktop, especially since your computing power requirements seem to be similar to my own.
Personally, I managed to find a nice looking (Mac design clone) laptop with plenty of power for my needs. I was set back $2,600 Australian dollars for a Pentium M 1.5ghz, 512mb RAM, 40gb HDD, Geforce FX5200 Go and a 15.2" widescreen LCD (just as wide onscreen as my 17" CRT, slightly less tall.) Expansion wise, there is the one PCMCIA card and the internal MiniPCI slot which came with an 802.11b card inside.
My needs were also based around portability, and being a thin and light, this notebook weighs 2.7kgs. However, since you'll not likely be walking to the nearest LAN party from that location, I do think a laptop designed for good battery life will obviously use less power. Between the slower hard disk, powersaving, speedstepping CPU and powersaving motherboard, you could be using far less power than all but the best designed MiniPC. Another advantage to the laptop is that you get a few hours battery life in case your power dies or runs out of juice. Perhaps you could even take it out roaming your property if you're into that kind of thing.
Think I've rambled on a bit, but hope it's been helpful.
Easy solution... (Score:5, Funny)
Great Solution! Here's the plan. (Score:4, Funny)
Lets see, you should ideally keep your voltage drop under 5%, and this 250 Watt computer will draw about 2 amps of current.
120V * 95% = 114V, so we need to keep it above 114V, therefore we cant drop more than 6 volts total on the extension cords themselves (or 3 volts per wire, since the current is bidirectional.)
Thats 3V drop per wire at 2 Amps, so resistance of each 79,200 feet of wire should be lower than:
3V / 2A = 1.5 ohms
OK then.. we need three wires, each 79,200 feet and with less than 1.5 ohms per wire. That's 18.9 milliohms per thousand feet. Well, they do make wire that big, but you cant buy it at any Home Depot. So, we'll make the extension cords from the biggest wire you can get at Home Depot. Aluminum 4/0 wire, typically used for 200 amp service entrance condutors.
Unfortunately, using a single cable of 4/0 would drop almost 9 volts in each direction across this long a run at 2 amperes, so we're going to have to use ALL the conductors in an entire four conductor 4/0 cables for EACH conductor of your power cord to get the resistance low enough for your application. That will get us right at the maximum 6 volt drop at 79,200 feet out.
So, we need two 79,200 foot long 4/0 Aluminum SE-R cables, one cable for hot and one for neutral and we'll assume you'll drive a ground bar yourself since you're 15 miles from the 120V receptacle.
I think that cable is about $2.90 a foot last time I looked, so we need $459,360 worth of cabling. Probably best to buy in 1000 foot spools, but then you'll need hundreds of split bolt connectors and miles of electrical tape. (The good kind, not the cheapo electrical tape.)
Anyway, it is doable. Pulling the cable could be a real bitch. And keep in mind you're not allowed to suspend cables from trees anymore according to 2002 NEC. But then, you cant really use SE-R cable as outdoor extension cords, I'm just trying to keep this affordable for you.
Regards
you gotta consider... (Score:2)
why is this even an option? (Score:3, Insightful)
Or: 600$ for the desktop/LCD combo, with no APM/ACPI, with minimal/no real power management, vs. a compact and portable laptop that can have function outside of the woods in real life in addition to its getaway use, and a shitload of solar panels (or just a few and a large number of car batteries to store the power over time - still a large expense).
I'd personally suggest, that, given your desires and requirements, that you go with a low-power laptop (such as a Fujitsu or IBM thinkpad X31 - I love my X30) and one or two solar power cells: however many it would take to continually charge a 12V car battery or two. That way it can charge while you're gone, and you'll slowly wear down the charge while you're there over a period of a weekend or so. If you go there less frequently, but for longer periods, just get one or two cells, and half a 12V batteries - it'll provide power for a desktop for a day or so, your laptop will be set (especially if you come with a 5hr charged battery at the onset, and you run off the batteries after the laptop battery is used).
Personally, though, I think you're bloody nuts. You've got a nice cabin out in the woods, away from modernization and electronics - what in the world are you thinking, bringing a laptop with you to compute while there? What about spending the time to let your soul relax, to do something different? Why not go out back and chop wood for relaxation? Why not read a book by the fireplace at night? Why not go hiking with a sack lunch, with no descriminate plans for the day?
To behave in such a way as you're considering, in such an environment, is a shame. It's no small wonder that our rainforests are being destroyed, the environment is being poluted, and people still don't give a damn.
Re:why is this even an option? (Score:3, Insightful)
(( Warning for those who are unused to sarcasm: SARCASM AHEAD ))
Since you are obviously so concerned about the environment, and just trolling, have you considered that a low power consumption setup would result in less damage to the environment?
Here are some ideas (Score:3, Interesting)
Very durable, small -- won't take up that much space in your cabin
12" screen, more than adequate for general purpose computing, plus the smaller backlight mean considerable power savings in the long run.
Get yourself a couple of deep cycle marine batteries. 1 to use, the other being charged.
Do you want to build your own windmill [otherpower.com]? Looks like fun project.
P.S. I don't know how remote your cabin is, but if you get yourself a Proxim/Orinoco WiFi card (these have external antenna jacks) and build/buy from a ebay a hi gain 2.4 Ghz yagi antenna, you might be able to hit someone's WiFi AP. It's worth a shot/ fun to try.
If you do by any chance get WiFI with this setup, update your journal and let us. It would be cool to know how you accomplished it.
--
3-5 hr battery life depending on usage.
To invert, or not to invert, that is the question. (Score:4, Informative)
If you start with a laptop, preferably one whose input voltage is the same, or lower, than the voltage of your storage cells, you will make a more efficient use of your power system.
-Chris
Re:To invert, or not to invert, that is the questi (Score:3, Informative)
If you use solar pannels with the standard laptop power supply, you are seriously wasting lots of electricity in the form of heat.
Also watch out. if you are
fuel cells (Score:2)
Take a look at the AirGen.
http://fuelcellstore.com/products/coleman/airge n
http://fuelcellstore.com/item/393
The website says that only the industrial version is available. I contacted them and the commercial version has been available for several months. The residential version may be available now as well, I would suggest contacting them if you are interested.
The cost of the AirGen is $5995.00, which may be too high for a 1KW fuel cell. The AirGen is very similiar
Buy the right laptop (Score:2)
Feathery goodness (Score:2)
Both have big energy loss (Score:5, Insightful)
What you should do is get yourself a computer with a 12VDC power input. They sell power supplies that take in 12VDC and have standard motherboard power connectors (although the last time I shopped for one it was using AT connectors). They work well for computers used in cars and boats. A little more expensive, but they basically take the power in and put it right to the motherboard and components.
Speaking of cars, will you have one? Why not use that as the power source? Get a laptop with a ton of extra batteries and keep three or four charging from car adapters wired into the car's trunk or something. If you get a laptop with a mobile processor that sips power, you should have well more than enough power. I work with a Dell Inspiron 600m and I ususually get 3-4 hours per battery. I have two spares I can hot swap so it is easy for me to go an entire 9 hour day running off of batteries.
Also, how much storage do you need? Why not go completely solid state? You could boot from say a CD, load everything into RAM and then power down the CD drive. At that point all you need is a USB key or other flashram to keep your data safe and that should be it. No hard drive, no CD-ROM should mean a lot less power right? Those are both big draws on my laptop.
Those are just a couple thoughts I had...
- JoeShmoe
.
Re:Both have big energy loss (Score:4, Interesting)
This is incorrect. Standard computers use 12v, 5v, 3.3v, -5v, and -12v power. 5v and 3.3v supply the majority of the power used. Additionally the 12v as supplied by cars and boats is not 12v, it can be anywhere from 10.5v (mostly dead) to 14.5v (chargeing). 12.66v is the actuall full charge potential of a lead acid battery. The power from an engine altenator is also not nearly clean enough for use in a computer.
A 12VDC power supply as discussed by the parent is a DC-DC converter. Typically the DC input will be inverted (converted into AC) so that a transformer can be used to generate the various required voltages. After the transformer the power supply is very similar to standard switching power supply found in computers. A good DC-DC power supply will be slightly better then an inverte and standard power supply. Typically either will be equally efficient.
A car is a really terrible generator. Most have trouble keeping their own batteries charged. An inexpensive generator will do far better.
The original poster should really figure out what they plan to do for power first. Depending on the power source they may not have to compromise.
Solar cells sound great in theory, but in practice leave a lot to be desired. Especially if the cabin is not located in a desert with lots of sun. Even if sun is plentifull it is hard to show that solar cells plus a bank of batteries are more environmentally friendly then an old fashioned disel generator running on dead dinosaurs. A properly installed generator running on biodisel with heat recapture, for hot water and heating, would be better. Although expensive a fuel cell generator (as posted elsewhere) is also worth looking at. Again heat recapture can be used. If the fuel cell is the propane type, the same propane can be used for cooking, refrigeration, and additional heating. Hydro is also worth looking into if there is water nearby. Bonus points for useing a windmill to pump water back up to the resevior for reuse.
Re:Both have big energy loss (Score:4, Interesting)
Both satisfied by VIA EPIA and Procase 12V DC-DC converter board (included in their Mini-ITX cases). I purchased a couple of these to play with in designing an outdoor router. (One with a lot more oomph than the commercial alternative, the routerboard)
The DC-DC board presents at one end a 12V 4.5A input, and at the other an ATX power connector and power for 3-4 peripherals (in my case, only one is used to power an IDE-CF adapter)
The only great problem I have is with 12V 5A power supplies - they're damn near impossible to find! (guys at Dick Smith say, "you mean
For starters, dump the I386 (Score:3, Insightful)
Laptop (Score:2)
I then give the 3-yr-old system to a family member, earning many kudos ('sides, that's when the warranty runs out).
Lowest power (Score:2, Informative)
If you can sacrifice a little performance, you will find that a system that uses a Transmeta Crusoe or a VIA Eden CPU will consume far less power than anything from Intel or AMD. There are a few nice Transmeta based laptops.
Both provide good x86 instructions and run XP or linux fine.
As well, going with a small (15"-17") LCD will be a big power saver for a desktop over a traditional CRT.
Use a lower RPM disk, or a laptop drive in your desktop.
On a
Use a DC/DC ATX power supply (Score:4, Informative)
I assume that you use solar power to charge up 12v batteries. Running that power through an inverter only for it to eventually get converted back to DC is hugely wasteful for a variety of reasons(A horrible power factor being one of them).
I just googled around, and found this [rsg-electronic.de] page with a variety of DC/DC PC Power supplies, with a variety of supported voltages.
Now that I think about it, if you have the capability to supply the power supply more than 12 volts(ie: 24 or 48 volts), then that will probably improve your wattage even more(as well as improve your stability if your power is "dirty").
Pair this with a small, power-saving bare-bones PC, and I would imagine you would have a setup that would be comparable in wattage to a laptop. Perhaps even better, considering that you are still using gobs of power from the DC->AC->DC conversion when charging the laptop batteries.
Finding a DC LCD Monitor may be a bit harder, but I'm sure they are out there somewhere. If you are feeling adventurous, you could even modify a monitor for DC...
Re:Use a DC/DC ATX power supply (Score:4, Insightful)
Finding a DC LCD Monitor may be a bit harder, but I'm sure they are out there somewhere. If you are feeling adventurous, you could even modify a monitor for DC..."
For the laptop, they sell 12vDC->DC converters in most retail stores. buy.com and bestbuy both sell them. They come with interchangeable plugs where you can fit any model laptop onto it. Be sure to check compatability of the power adapter with yoru laptop before purchase.
As for LCD monitors, most also have external AC Adapters. All you need to do is find out what pin does what in the power connector. Then buy an approprieately speced DC->DC converter (just like the one for the laptop) and you might have to cut and splice the connector yourself.
unless the LCD monitor has an integrated AC Adapter (like the viewsonic VP171B) then this trick will work provided you are technically inclined to sort out which pins provide which voltages and how many amps each one requires minimum.
Please don't underestimate the power savings from going DC only. As long as you keep your main power lines high quality and short (from the solar pannel to your batteries, and from batteries to devices) then DC power can cut your solar pannel requirements down by 30-50%.
LCD + Desktop is doable (Score:2)
So you can spend your $1500 just a laptop which gets you down to 60-80
Tested this in college (Score:3, Informative)
How big is your solar array? (Score:3, Informative)
If this is a cabin, you're probably only going to be there on the occasional weekend. In which case get yourself a laptop and a gasoline generator. You can probably get by with one of the dinky little Honda EU1000's. Whisper quiet, stingy on gas and should run your laptop, charge your cell phone battery, a couple lights, maybe a portable TV and small frig (maybe not all at the same time). It won't run a full size frig or electric heater, but it's easy to carry. Around 800 dollars. If you need more power, a Generac 4,000 watt is quiet, produces clean power and should run most of the weekend on 5-8 gallons of gas (depending on usage). Lot cheaper than Honda's for the same amount of power and that will run a full size refrigerator, heater, TV, satellite receiver, whatever you want. Home Despot, around $750.00. It weighs about 150 lbs (on wheels), so you'll need a pickup or small trailer to haul it back and forth.
With any generator you have to look at the sustained wattage and surge wattage. Honda tends to advertise their surge wattage, which a generator can't maintain very long.
If you ever decide to live up there permanently, you'll want to look at either a big solar or combo solar/wind system. Figure on 15 to 20 thousand depending on the wattage you need. If you have a stream or spring, you're golden. Hydro electric is the cheapest and best, until the creek runs dry.
APPLE LAPTOP (Score:3, Insightful)
Anyway, I'd suggest doing anything but use a computer.
Man, enjoy nature! (wildness, mountains, girls,
Laptop (Score:3, Interesting)
1.) I move about once a year. I'm sick of lugging my desktop around. When it goes extinct, that's it for desktops to me.
2.) I wanted an LCD that'd do 1600 by 1200, and the cheapest I've found those is $1,000. My laptop was only $700 on top of that. (Yay for Dell.)
3.) When it's time to replace my laptop, this one will still be useful. I have 4 towers at home that'll never see the light of day again, but the laptop I bought back in 99 is still finding use as a web terminal. (plus, selling them is easy.)
4.) I'm no longer sold on the upgradability factor. By the time mid-range processors are 4x what I currently have, I've saved up enough for a new laptop. I'm not the type to drop $500 in a vid card for a few extra FPS. (Lately I've been gaming on my Game Cube anyway.)
5.) Extra desk space. Need I say more?
My current desktop has been promoted to 'server', and I send it rendering jobs to do once in a while. Eventually I'm just going to hide it in a dark corner somewhere.
Laptop Warning! (Score:5, Funny)
According to the naturalists I know, grizzly bears are extremely smart, and damn near unstoppable when they want something.
When the grizzlies look in through that window and see that shiny new glowy-apple Powerbook, you *know* they're gonna want it.
Just be careful out there, is all...
_how_ to power a PC (Score:5, Insightful)
Both a notebook and a desktop system suffer from the same thing: They both run on 110AC. Inverting your DC solar power to that will cost you 30-40% of your power. Converting back to DC (for your notebook/desktop) will cost you a second round of 30-40%. This is bad.
Find a method that can keep you at DC power, ideally as close to the voltages you need. Many of the mini-itx boards will have an option for 'dc power'. These will run on 12-15 volts, and will cost you more like 10-15% TOTAL. Plus, many of the mini-itx boards will consume far less power - - some of them as little as 15-20watts. You won't quite have the speed mentioned (1.7ghz), but close to it (900-1200mhz).
You could use a notebook & build a native DC supply for it - - but many of todays notebooks, regardless of size, draw MASSIVE amounts of power. My dell notebook draws 3.5amps@20 volts [70watts]. That's at 1.2ghz/512megs of ram/15" screen.
As others have pointed out, you'll need power storage. This can be calculated based on your consumption & number of panels used. You can lookup the typical number of solar hours per day for your region.
Solar panels cost around $1USD per watt. The charge controller & storage will also be somewhat costly - - do some reasearch, and purchase a few books on the subject before spending to much...
Depends... (Score:5, Informative)
I'm in the process of building (year #5, woo-hoo!) a totally off-grid home in (almost) the middle of nowhere. I've gone through this already.
The short answer is if power is all you care about, a notebook is better. My Sony TR1A consumes 13 watts of AC when plugged in at full-tilt according to my power meter, and display-off sucks just 5 watts. However, I care about more than power, like uptime/durability, ability to use off-the-shelf components, and being able to support some modest external hardware, so the actual system that stays on 24/7 is a VIA Epia 533 MHz box. It takes about 11-12 watts but can peak around 24 watts or so, plus a 15-inch LCD monitor which is pretty much never on, but consumes 16 watts when it is; so you're looking at about 30 watts with one of the lowest power desktop configurations possible.
Other odds and ends consume power as well. Inkjet printers are great (Epson C82 sucks 1 watt in standby, about 5 when printing.) Larger ethernet hub-like things are about 5 watts as well. (That'd be hubs, terminal adapters, wireless routers. nearly everything in my 3com officeconnect stack at my real house is 5W per unit.)
As far as power budgets go, it's the time the devices on that really gets you. An 18W average setup running 24 hours a day is 432 watt-hours, almost half a kilowatt hour. While I have a pretty substantial solar array (1 KW at the moment) during the winter I'm going to see maybe 4Kw-hours per day, so I'm burning nearly 10% of my capacity on just one PC.
So.... you can use your kick-ass system if you want, and if you limit it to one hour a day v. 24 hours a day, you'd be ahead.
BTW, my losses on the total system aren't bad at all. Inverters and batteries are pretty efficient these days. I'd gladly accept a 50% loss on storage and conversion, however, if I got 50% efficiency out of the panels instead of the sub-20% that's typical of solar today.
Re:Depends... (Score:3, Informative)
Hot water is handled by solar. I've got two 8' x 10' solar thermal panels feeding an 80 gallon hot water heater. Presently there's no back-up, but I'll probably swap out the he
How to build a low powered Desktop computer... (Score:3, Informative)
Start with an ATX or microATX case. If you choose microATX, make sure that it accepts a normal ATX power supply. You can buy DC-DC ATX power supplies online (but microATX ones are harder to find) As long as your microATX case takes the ATX PSU (i have one i bought for $30 online that does just this, I think enlight's microATX also does it) then purchase an ATX DC-DC power supply online. 180 or 200W should be enough. You may also want to consider a Shuttle Cube barebones with nForce2 motherboard. In this case you could probably still use the DC/DC power supply, but you would have to have it sitting external to the unit (in the back somewhere) Maybe paint it black so it doesn't look ugly, or put it in some sort of asthetically pleasing case of your choice.
- Don't go for the highest power CPU and video card. Select either AthlonXP (barton core only), Duron (latest core), Pentium3, or if you can get your hands on it, Pentium M processor. DO NOT buy a pentium 4 or P4 based Celeron you will seriously regret it. the newer AMD AthlonXP Barton cores have very good power saving features and if you don't overclock it, you will not be in so much hurt. In fact, it is possible with newer motherboards to underclock the chip and under volt it. I would definately consider doing this once you get your system up and running for the long run.
- Select a motherboard for your processor. if you are going with athlonXP or duron, I would recommend the nForce2 Ultra motherboard. Get the one with integrated video. You don't want a seperate video card taking up extra power. The integrated video is decent 3D with quality similar to Geforce MX series. NForce2 Ultra's dual channel memory controller should HELP make up for some slowdowns get for having a lower powered/underclocked CPU.
- With the nforce board (or other comparable board) you won't need addon cards like NIC or Sound. (hopefully your motherboard will be supported under linux with sound and NIC drivers) if you do need addon cards, use only your absolute minimum requirements.
- Buy LARGE 5400RPM hard drives. Don't go for 7200RPM, and don't buy small ones. If you want 160 gigs, don't go out and buy 4x 40GB drives. Just buy one. if a RAID array is required, then still try to stick with 5400RPM drives as large as possible. The larger your drive the fewer you will require in your system. Don't use a buncha extra drives you have laying around. Spend extra on this project and do it right with a single drive solution.
- This next step is a little harder to do with commodity equipment, but is possible. Buy fans that will adjust their speed depending on temperature. Most "temperature sensitive" fans are tuned so that in any real world circumstance, they are either full time full speed, or full time minimum speed. You won't find many fans that are tuned so they slow down when your PC sleeps and speed up when the temp rises due to CPU load. You need seperate logic to do such things. The simplest way to go is with a "fan bus" which has manual knobs on the front of the computer. You turn the fans down as low as they go when you get up and leave your PC idle. AVOID fans smaller than 80mm like the plague. Don't put active cooling on your motherboard chipset, insted opt for a larger heatsink on the northbridge, with quality mounting and quality heatsink grease. Also, opt for expensive but massive and large heatsinks for the CPU. Don't even bother with a 60mm heatsink, as it will cost you in the long run. I personally use 80x80mm alpha heatsinks (with copper inlay) with a 92mm fan that has a 92-> 80mm plastic fan "adapter" cone. This way you can buy LOW SPEED 92mm fan that uses negligable electricity rather than buying high powered high speed 60mm fans. Consider using a single 120MM case fan in the front of the PC running at 5 or 7 volts (you can do this by changing the wires on the MO
Solar is what you want to use... (Score:3, Interesting)
A small system for powering a cabin can be had fairly cheaply - under $5000.00 for a decent system (a very decent system), if you install it yourself. Most of cost will be in the panels and batteries. You won't be able to run a washer/dryer or anything large like that, but if you set up LED lights or compact flourescents, you can have a nice solution for the cabin, to provide lighting, run a small TV or radio, maybe a few small RV/boat appliances (they make appliances specifically for RV's and boats that run off of 12 or 24 volts) - plus a laptop.
If you have steady wind, a small wind generator or two could be handy as well, as long as you are in a clearing or can get it above the treetop level (just make sure to ground it for lightening strikes).
If you just need some quick and cheap power for lighting, a small solar rig can be easily cobbled together from a small panel or two, one or two small old UPS batteries (like the small desktop UPSs use), a diode (for reverse current protection of the panel), and some wire plus a fuse. I built such a small rig to run a flourescent light in my tent at Burning Man this year - ran great at night, charged it during the day - didn't spend a dime on the batteries, the panel was from a yard sale (think I spent $10.00 on it or something).
Power Sources (Score:3, Informative)
Been there, done that (Score:5, Informative)
A few reflections on what I've learned.
* A PC, as you've learned, will usually consume in excess of 100W of power with the monitor on. Using aggressive settings on your power management software, a VIA EPIA motherboard, and a small LCD monitor you could probably get it around 50 watts. Such a machine is likely to feel slow.
* My Apple Powerbook is very solar-friendly. ~15W during heavy use.
* Try to get everything you need built-in. Things like PC Card devices or external storage really suck down power. The built in devices tend to be engineered for better power management profiles.
* If you find yourself needing to network, wire it. Wired networks suck less juice (at all points) than wireless. And it goes a lot faster.
* If you want to listen to music, budget that into your battery system. A laptop playing a huge MP3 playlist is never going to idle the processor down. Luckily batteries are relatively cheap, so adding just one more battery will add several hours to your runtime.
* If your situation is like mine and you will have a lot of little construction projects on your cabin while you're out there, my power use went WAAAY down when I switched from corded power tools to 18V Ryobi cordless tools. Charging the batteries did not appreciably diminish my reserves, the tools were almost as powerful as those they replaced, and they were much quieter and a joy to work with.
* Don't mess with car batteries. They are no good for this application. At the very least, look at RV/Marine Deep Cycle batteries (12V). Better yet, look at 6V Golf Cart batteries (which you pair up in series for 12V). The Golf Cart batteries will be the ones you want during those overcast weeks.
* Look into lighting, appliances, etc. that run directly off of 12VDC. There are many web sites out there that cater to hunting cabins, homesteaders, RV's, etc. You'll pay more for these appliances up front, but it is much more efficient to run most of your day to day stuff off 12VDC as you lose a lot in the inverter going up to 110VAC. The computer, however, should probably run off 110VAC if for no other reason to ensure that you're getting a steady clean feed from the inverter rather than from your PV panels & batteries, which may surge if the clouds suddenly part or what have you (the inverter will buffer this).
AC/DC and Solar (Score:4, Informative)
One thing you should probably think about, particularly considering your means of generating power (solar), is how you're going to jack this thing into your power system. You'll probably want a transformer to have some AC power in this cabin, but that's an extraordinarily inefficient way of using electricity.
If you go with a desktop computer, the power supply is going to expect AC input. The laptop, on the other hand, is going to have a power brick and a DC jack on the laptop.
For optimum power efficiency, you should get a laptop and then buy a 12V regulator, and a car-lighter type plug. The wattage is important, in terms of power consumption, but the voltage is equally so.
The HP/Compaq laptop we use onboard (its a ze1210, which is a basic consumer model of a year or so vintage -- runs Athlon with PowerNow). Using the DC adapter, the strain on the ship's battery is noticable, but not huge -- much less than the radar, for instance. When we run it off of one of our AC plugs (we only have one, and we almost *never* use it, the transformer usually stays disconnected), its a huge power drain -- more so than our radar array.
So, definately a laptop. Wire your cabin for DC. And consider looking at boating technology guides in general. They probably most closely approximate what you're trying to do.
-Shylock
To hell with lines - microwaves! (Score:2)
Solar? (Score:3, Interesting)
A friend has a place far from anything. Has phone, but no power.
6 solar panels -> a number of truck batteries (and charger) give him loads of power. 19" TV from the 80's works, usually, til midnight.
Gas for stove/fridge.
A couple of the panels are from the 70s. 80% of their orig efficiency.
His best investment of late was a new inverter. THOSE have gotten LOTS better in the last few years.
LCD absolutely.
Laptop has a UPS :)
Laptop can easily be r
Re:Homepower (Score:4, Insightful)
- Input 1.2 Amps.
- Output, 24V, 1.875 Amps.
Of course, a laptop will not likely draw the most power, the SATELLITE dish you need for the net connection... unless your bazillion acre lot has some GPRS coverage (yeah, right)...
Having lived on a 1000 Acre camp, I can tell you the DIRT is what will really drive you nuts, good luck.