Powering a T.V and computer with 200 watt system?

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Ive been reading about solar for a few weeks and I wanted to get a small system . This is gonna be used to power low wattage appliances in my home for emergencys and for several hours a day.

T.V. - 90 WATTS
Dish network reciever- 50 WATTS
computer monitor/tower { E- machines} - 420 watts

total- 560 watts....which I will round up to 600 watts even to make it simple and allow for inefficency. I already have a Cobra { 12v-120ac} 2500/5000 watt modfied sine wave inverter and I was hoping this would work well enough for me to see if solar is an option I want to pursue .

Id like to see if My calculations are correct . If I use :

one - 200A/h lead acid deep marine 12 volt battery ,this means the battery will be fully charged at 2400watts and the most I would want to use of that storage is 50% { or can more be used regularly without damaging the battery} ?. So there would be 1200 watts available if the battery is fully charged. This would supply me with 2 hours runtime at 600 watts an hour usage { this would actually be the best scenario considering that my modified sine wave inverter would only be able to operate 90% efficiency}.

Is my above calculations correct and if I wanted to double my runtime, I could just add another 200A/h battery ?

Next, I wanted to be able to fully charge the one 200A/h battery in one day of full 6 hour optimum sunlight conditions. If I take 1200 watts out of that battery and want to put it back in within 6 hours of peak sunlight, I would need a total of 200 watts worth of power out of my solar module/s.. rated for a 12volt system. This would mean that I would really need to purchase enough module/s that are rated at 220 watts to allow for possible ineffieciencys/deficits encountered in the rating systems of solar panels.

Does this sound about right. I want to make sure before I spend the $$$ on everything.

Also, do they make a 200-220 watt single solar panel that will work with a 12 volt system, or will I have to purchase two smaller solar panels {like 110 Watt wired parallel} to keep everything in the 12volt realm.

Thanks .

Comments

  • BB.
    BB. Super Moderators, Administrators Posts: 33,476 admin
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    Re: Powering a T.V and computer with 200 watt system?

    SunnyDay,

    Unfortunately, it is a bit more complicated than that... You do have the basics down, but some details...

    1. Batteries as they discharge at higher currents (60 watts vs 600 watts) have more internal losses. You need to look at the battery you want to use, and look at its Amp*Hour rating vs load... If you discharge a battery in 2 hours, it will not supply as much over all useful power compared with discharging it over 20 hours.

    2. Look at the battery for what it was designed for... A "Marine" deep cycle battery is usually a compromise between an automotive starting battery and a true deep cycle storage battery. Generally, you will have a longer life with a true deep cycle battery (but less starting current available).

    3. Grid Tied Solar--this is the most cost effective method to "go solar". It is the most efficient (using the utility as your "storage battery" and since you don't have to buy/maintain/replace batteries--much lower initial and ongoing costs... Just to pull numbers out of the air--in a good sunny area you can get your solar Grid-Tied power down into the $0.25 per kWhour (before rebates). The downsides, your utility has to allow GT, you will probably need it professionally installed, and a building permit.

    4. Off Grid Solar--I.e., with batteries, solar charger, and inverter. If you have unreliable power, or need power in an emergency, or you are not near utility lines; this works well. However, the overall costs are (from my back of the envelope calculations) run easily a $1.00 per kWhr (batteries, inverter, charge controller, replacement batteries every 5-15 years, not including backup generator, etc.).

    5. You need to pretty carefully characterize your loads for solar (especially off-grid solar where you will be generating the electricity for your loads). For 120 VAC AC, a $30 Kill-A-Watt meter it a great tool (even if you never will use solar power). For example, your computer at 420 watts may be the nameplate power rating--but in real life it may use 1/2 that amount of power (monitor on standby, laser printer only "on" 10% of the time, etc.). A refrigerator is another example where nameplate vs actual power usage over time needs to be measured.

    6. As you can see from the kWhr costs, solar electric power is usually not cheap. And, going for conservation is first step is usually money well spent. For example, your "420 watt" computer vs a 20-30 watt laptop--depending on your use--this would cut your solar power requirements for this one appliance by 90%.

    7. Doubling the size of your battery will, generally, over double the amount of energy (Watt*hours, or kWatt*hours) available--but this is a "one time deal"... If this first system is basically to be used as a large UPS for 2 hours of backup power--that is fine. However, if you want to use 4 hours of power every day, then the solar panels will have to be doubled in size too.

    8. To give you some very rough estimates for sizing of your system.

    a. Solar Irradiation (hours of sun per day): Look Here
    Little Rock averages about 5 hours of sun over the year (3.5 to 5.9 hours; winter/summer). Hours of sun also vary based on weather/pollution and such. Sizing will include the minimum amount of power you will need, and if critical power, a generator is usually required.
    b. Efficiencies (or losses). Every "piece" of the solar puzzle has some losses...
    PTC rating on solar panels is about 85% of the STC rating (15% less) due to real world (warm) conditions

    Solar Chargers... To basic types. For small systems there is the PWM which is quite inefficient but for ~<400 watt systems, is more efficient than the MPPT (maximum power point tracking) types which are used on ~>400 watt systems and are in the 93%+/- efficiency range.

    Batteries: Normal flooded cell batteries work out to be roughly 80% efficient. AGM are ~90% efficient (but are easier to damage if overcharged). Flooded cell batteries tend to be easier to damage on over discharge, under charged, or water levels not kept up.

    Inverters: efficiencies vary around 80% to 90% depending on design and load. Highly recommend "true sine" vs Modified Sine/Square wave inverters (true sine are much more expensive, Mod Sq. can cause electronics and motors to overheat and fail).
    The equation for calculating the size of your solar panels (just using "default" efficiency numbers in order listed above:

    SPV = (load (watt*hours) * 1/0.85 * 1/0.93 * 1/0.80 * 1/0.85) / Hours of sun per day

    If you want run your 600 watts for 2 hours (=1,200 Watt*Hours--the *Hours is very important here--kind of like the difference between miles per hour and miles driven. Watts are a rate, Watt*Hours is the overall energy used/supplied).

    SPV = 1,200 WH * 1.86 (eff. factor) / 5.9 hours of sun (full summer day) = 378 watts of solar panels (assuming MPPT type solar controller).

    Notice that you can only run your loads on a bright summer day--at best. During the winter, you will have almost 1/2 the amount of average sun.

    If you are trying just for 2 hours of backup power (local utility failures), then the solar panels don't have to be near this large--they only have to be large enough to trickle charge the battery (~5-15 watts--depending). However, with this small number of panels, you would need an external battery charger/device to refill the batteries after a power failure.

    In my humble experience, you need to define the application more clearly (at least for me). For example, I would have liked a Grid Tie / Off Grid system as this is the best of both worlds--but frankly, it was much cheaper and easier for me to go Grid Tie with a little Honda eu2000i generator for backup (plus, I did a whole bunch of conservation measures on my home first).

    I will stop here at the moment... Please feel free to ask more questions or direct us where you would like to head from here...

    -Bill
    Near San Francisco California: 3.5kWatt Grid Tied Solar power system+small backup genset
  • icarus
    icarus Solar Expert Posts: 5,436 ✭✭✭✭
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    Re: Powering a T.V and computer with 200 watt system?

    As usual, Bill has it just about right. I would second the opinion about conservation. Conservation is your cheapest dollar, and the savings in load relate big time to a reduction in cost of any pv system. In addition to the lap top, look at low wattage lcd tv's for emergencies. I know the naysayers out there would say, "I don't want to replace all the stuff I have now". But a amll lap top, and a 12 vdc tv etc can be had for way less than the cost of more panel/battery capacity.

    Icarus
  • System2
    System2 Posts: 6,290 admin
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    Re: Powering a T.V and computer with 200 watt system?

    I would like to stay off grid for a few reasons...One is that we have some bad thunderstorms in my neck of the woods and power gets knocked out and also going on grid would be more labor intensive/expensive and its something I doubt I could do alone.


    Our computer system is about a 8 year old Emachines system with Windows XP preinstalled { 1.0 Ghz intel processor, 128 MB ram, 20Gb hardrive}. It works great but draws 420 watts total. If I wanted to totally do away with this pc system and replace it with a low wattage laptop system, what is currently available as far as a inexpensive laptop and its total wattage draw and would this laptop be able to do everything { or more} then our current 8 year old Emachines PC. ? Also, can any of these laptops currently on the market, reliably by powered by a modfied sine wave inverter ? The Cobra 2500 watt/ 5000 peak MSW I currently have does a good job of powering things like TVS or fans, lights ,etc...but I havent tryed it on a computer yet because I wasnt sure if it would blow it up :} ...
  • crewzer
    crewzer Registered Users, Solar Expert Posts: 1,832 ✭✭✭✭
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    Re: Powering a T.V and computer with 200 watt system?

    Adding on to Bill’s great post: I think you’re off to a good start. But we need to understand your energy need a bit better, and, as Bill indicated, we’ll need to get into some performance and technology issues.

    So, let’s say a 600 W load for 4 hours per day. That’ll be 2.4 kWh/day net. Assuming the energy will be supplied via an inverter with an efficiency of 90%, the energy requirement from the battery bank will be 2.4 kWh/day / 90% = 2.67 kWh/day.

    One rule of thumb is to size the battery bank at six times the daily energy need, or 2.67 kWh/day x 6 days = 16 kWh. This allows for three days of autonomy (no Sun) without discharging the battery bank below 50% state-of-charge. A 12 V battery bank that can store 16 kWh will be nominally rated at 1,330 Ah. That’s roughly equivalent to five size 8D batteries, or seven size 4D, wired in parallel.

    Flooded-cell batteries are ~80% energy efficient (Wh out / Wh in). So, to supply 2.67 kWh/day, the average recharge to the batteries must be ~2.67 kWh/day / 80% = 3.34 kWh/day. Assuming a charge controller efficiency of 95% and wiring efficiency of 97%, the average energy output from the PV array will have to be 3.62 kWh/day.

    Assuming the PV array is appropriately aligned and your location receives the equivalent of 4 hours/day of “full” Sun, the array will have to supply 905 W.

    But… PV modules rarely operate at name plate specs. The primary issue is that the specs are based on a 25 C (77 F) cell temperature, which translates to an ambient temperature of ~-10 C (~14 F). Working with an average mid-day temperature of 20 C (68 F), module output is typically reduced by ~15% to 20%.

    So, a PV array rated at ~905 W / (100-20)% = ~1130 W STC would be required to supply ~905 W from the array at mid-day and meet the 2.4 kWh/day net energy need, based on the calculations above.

    Is this what you had in mind?

    HTH,
    Jim / crewzer
  • mike95490
    mike95490 Solar Expert Posts: 9,583 ✭✭✭✭✭
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    Re: Powering a T.V and computer with 200 watt system?

    Laptops cut your power down to about 100W.
    Powerfab top of pole PV mount | Listeroid 6/1 w/st5 gen head | XW6048 inverter/chgr | Iota 48V/15A charger | Morningstar 60A MPPT | 48V, 800A NiFe Battery (in series)| 15, Evergreen 205w "12V" PV array on pole | Midnight ePanel | Grundfos 10 SO5-9 with 3 wire Franklin Electric motor (1/2hp 240V 1ph ) on a timer for 3 hr noontime run - Runs off PV ||
    || Midnight Classic 200 | 10, Evergreen 200w in a 160VOC array ||
    || VEC1093 12V Charger | Maha C401 aa/aaa Charger | SureSine | Sunsaver MPPT 15A

    solar: http://tinyurl.com/LMR-Solar
    gen: http://tinyurl.com/LMR-Lister ,

  • System2
    System2 Posts: 6,290 admin
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    Re: Powering a T.V and computer with 200 watt system?

    Thanks for the replies. Its looking as though the total costs to run my current desires { T.V, COMPUTER, DISH NETWORK RECIEVER } are gonna be far greater then I envisioned and require me to have numerous batteries and solar panels in my backyard. My T.V I wish to run by solar only draws 90 watts and the dish network reciever draws 50 watts- 140 watts total{ I do have a Kill a watt meter on its way to measure everything and get exact numbers} . This brings me to 140 watts. It looks like I may want to purchase a laptop computer to replace my current P.C that is drawing 420 watts.

    With my T.V and receiver drawing 140 watts and purchasing a laptop that draws 100 watts, I would bring down my total watt usage from 560 watts to 240 watts.


    So, can someone tell me of a good laptop that isnt to expensive , draws around 100 watts or less of power, and can do all the things my old Emachines P.C computer can do ? By cutting down my wattage needs to 240 watts, I would assume I could go with a less expensive solar setup that doesnt require numerous solar panels and numerous batteries? Also, can todays laptops be safely operated using MSW inverters ?

    Thanks for all your answers, we are very interested in investing in solar power, but we dont want to over estimate its capabilites while under estimating its costs and size requirements.
  • westbranch
    westbranch Solar Expert Posts: 5,183 ✭✭✭✭
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    Re: Powering a T.V and computer with 200 watt system?

    dont have a brand recommendation , I use a toshiba, but almost anything new on the market will outperform a computer that is over 2 years old, brand independant.
    Our laptop was discontinued within 3 months of purchase, they didnt make anything that SLOW anymore!!! Memory is the key, speed does nothing but go up..
    The O/S is another issue, with the newer O/S's they gobble up RAM, without increasing the response time. Investigate... stay away form Vista, it is esentially in Beta test mode.

    Cheers
    Eric
     
    KID #51B  4s 140W to 24V 900Ah C&D AGM
    CL#29032 FW 2126/ 2073/ 2133 175A E-Panel WBjr, 3 x 4s 140W to 24V 900Ah C&D AGM 
    Cotek ST1500W 24V Inverter,OmniCharge 3024,
    2 x Cisco WRT54GL i/c DD-WRT Rtr & Bridge,
    Eu3/2/1000i Gens, 1680W & E-Panel/WBjr to come, CL #647 asleep
    West Chilcotin, BC, Canada
  • System2
    System2 Posts: 6,290 admin
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    Re: Powering a T.V and computer with 200 watt system?

    quote :

    SPV = 1,200 WH * 1.86 (eff. factor) / 5.9 hours of sun (full summer day) = 378 watts of solar panels (assuming MPPT type solar controller).
    end quote..


    Thanks Bill, So your above calculations would tell me that I need at least 378 watts of solar panels to output 200 watts of power per hour capable of supplying almost a total of 1200 watts over 5.9 hrs on a optimum sunny day ? In other words, your calculation above shows the real inefficiencys of a complete system and to get that 200 watt per hour number, 378 watts of solar panels is the minmum needed ...am I understanding right ?

    So in other words, my assumption that 220 watts worth of solar panels to to produce 200 watts os usable,rechargeable power, is way off ..factoring in inefficiences of the solar panels, inverters, batteries, wire/connecters, cloudy days etc?
  • Solar Guppy
    Solar Guppy Solar Expert Posts: 1,989 ✭✭✭
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    Re: Powering a T.V and computer with 200 watt system?

    laptops are more like 40-50 watts

    check out and watch http://www.techbargains.com/

    They have lots of deals of the day ... ANY laptop would blow away your eMachines. Best price I have seen this year is around 399 and there are lots of great 499 laptops around with free shiping at the above link.

    If your not picky and are content to the eMachines performance level, you can get a 4-5 year old laptop on eBay for about 50 bucks
  • niel
    niel Solar Expert Posts: 10,300 ✭✭✭✭
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    Re: Powering a T.V and computer with 200 watt system?

    sunnyday,
    wait for your killawatt meter to show up and you'll get better ideas of what you require. my pc i thought would be drawing more than it is. it also varies by what you do with it for a dvd drive playing a movie will draw more power than just basic computing. also note that the monitors are also a big factor and you may be able to just use a small flat lcd rather than the old crt type to save on watts used and maybe save on another computer. you will have to be the judge though on what you ultimately want to do as it is an expense no matter what you windup doing.
  • System2
    System2 Posts: 6,290 admin
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    Re: Powering a T.V and computer with 200 watt system?

    Okay, I will wait for my killowatt meter to arrive so I can check the real wattage draws involved. In the meantime, it may be worth getting a laptop to replace my 8 year old emachines that draws over 400 watts of power. If these laptops can be purchased for $400- $600 dollars new and only average drawing 40-100 watts, its definitely an upgrade I need to make prior to purchasing my solar setup. So I can assume any new laptop currently on the market will outperform my 8 yr old emachines ? Will the laptop hook up the exact same way as my P.C does...as far as router connections and would it work with my current, Lexmark color printer copier, or would I have to buy a new one of those also ? And finally, does anyone know if these laptops will safely work using a modified sine wave inverter as a power source ?
  • System2
    System2 Posts: 6,290 admin
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    Re: Powering a T.V and computer with 200 watt system?

    Is a notebook the same as a laptop and what brands should I stay away from as far as them being unreliable? Thanks..and I apologize for going off the solar subject, but it only makes sense for me to go with a newer computer system that draws 50+ % less power and then work on my solar needs.
  • Solar Guppy
    Solar Guppy Solar Expert Posts: 1,989 ✭✭✭
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    Re: Powering a T.V and computer with 200 watt system?

    There all the same ... they are about 20x faster than your emachine, more features. Just by on price and you won't believe what 499 buys compared to what you spent on the eMachine 8 years ago!.
  • BB.
    BB. Super Moderators, Administrators Posts: 33,476 admin
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    Re: Powering a T.V and computer with 200 watt system?

    If you stay with the older operating systems, you don't need the fastest laptop out there... You really need to describe your computing needs and such... If it is simple word processing and web browsing on XP or Mac OS--every PC out there is overpowered for those applications. The big speedup is to make sure you have at least 500 MBytes of main RAM (you need probably 2GB for Vista).

    I am typing on an old Compaq that I never expect to last very long--but low and behold it still runs great (other than the old Windows issues). Uses about 20 watts running, 30-35 watts with the screen on, and about 1 watt on standby.

    In times past (about 4-8 years ago), Dell was somebody to stay away from (bad reliability). I believe that there are only a few companies that build 90% of the name band laptops. Lenovo, for example is the Chinese (I believe) manufacturer of IBM Thinkpads (good laptops)... IBM sold the rights to Lenovo and is now selling under their own name. I was looking for a low power PC before--and one of the older Thinkpads would run down to about 8 watts (slow clock)--I believe.

    Asus (makes good motherboards) is now beginning to sell 7" "laptop" form factor PC. Probably too small for your needs--but getting very interesting for those that need a minimal, but usable, portable computer.

    Laptops become known as Notebook computers because of the issues with batteries catching fire and the companies worried about getting sued by people burning their laps (so the urban legend goes--may be true or not).

    Laptops, with internal batteries, are neat because they also have their own on-board "UPS"... I unplug mine and move it around all the time (Wifi).

    Issues around compatibility--usually printer compatibility has two things to watch out for-- 1. does the OS (or the manufacturer website) have drivers for your version of the OS... and 2. does your laptop have the right connector for the printer... As notebooks get smaller, they loose the old ports (Game ports, RS 232, sometimes Parallel ports, etc.). You will just have to look at your existing hardware and decide what you will need to keep and what you will want to replace.

    Otherwise, if you have the right connection hardware (Ethernet, WIFI, etc.) connection to your router--there should be no "strange connection" problems (other than just the old OS connection setup problems).

    And lastly, as a first approximation, 1,200 Watt*Hours from your battery would supply 1,200 watts for 1 hour, or 200 watts for 6 hours...

    Time=Watt*Hours/Watt=Time
    Time=1,200Watt*Hours / 200 Watts = 6 hours of runtime...

    But, as you draw a higher current, the actual amount of usable power will drop--while the 200 watt load may tick along nicely for 6 hours, the 1,200 watt load may die in 45 minutes.

    A great investment to monitor your battery's condition is the Battery Monitor... Not cheap--but, IMHO, about the best way to do real time monitoring of your battery bank--and many of them have a simple display that anyone can look at and understand if there are problems (100%-0% full)... Checking electrolyte specific gravity, monitoring voltage, watching current are all very prone to errors, misunderstandings, and possibly accidents (acid spills, shorts, fire, explosion) if done wrong.

    -Bill
    Near San Francisco California: 3.5kWatt Grid Tied Solar power system+small backup genset
  • System2
    System2 Posts: 6,290 admin
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    Re: Powering a T.V and computer with 200 watt system?

    Great info..thanks alot.

    I just called 2 companies that sell refurbished laptops with a warranty and both of them suggested the Dell latitude D600 laptop. They said it outperform my old emachines in every aspect and will have the correct USB port to hook up my Lexmark printer/copier. It seems the going price for these refurbished units are between $350-$400 shipped. Does this seem like a good price and is it a reliable laptop or should I just by another model thats brand new and try to get something in the same price range ? The power draw on it is less then 100 watts...so I would be going from my current system of 420 watts down to less then 100 watts. This would mean much less power needed in which I could pattern my solar setup around. So instead of needing a solar setup for :

    600 watts x 16 hrs usage each day..I would only need

    240 watts x 16 hrs each day..

    Does anyone know if these laptops will operate correctly on MSW inverters ?
  • BB.
    BB. Super Moderators, Administrators Posts: 33,476 admin
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    Re: Powering a T.V and computer with 200 watt system?

    Unless you find somebody here that is running a MSW inverter with the particular power supply--the usual answer is we don't know... There is probably a 90% that everything will work fine and a 10% chance that it will blow the supply without warning.

    There is another thread on DeWalt drills and rechargers running on MSW... One person had it pop almost immediately, and another had it run just fine (calling the mfg. said it would be just fine on MSW)...

    If you have a local swap meet or used computer supplier (or buy an extra one with your original order)--it might be worth picking an extra one up cheap and see if it works OK or not. If it pops, you have not loss much.

    -Bill
    Near San Francisco California: 3.5kWatt Grid Tied Solar power system+small backup genset
  • System2
    System2 Posts: 6,290 admin
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    Re: Powering a T.V and computer with 200 watt system?

    Yes..that was me on the Dewalt thread. I called Dewalt factory serivce a week ago and asked them about using their charger on a MSW inverter and they told me it would work fine. Evidently some people have tryed it and it damaged the dewalt charger....
  • icarus
    icarus Solar Expert Posts: 5,436 ✭✭✭✭
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    Re: Powering a T.V and computer with 200 watt system?

    The thing with lap tops is, they run on an external power supply (Wall transformer) to charge the battery. The battery acts a a great voltage regulator against errant current. You might damage the transformer with MSW power, but you won't blow the computer. I have charged Dells, and Macs with MSW power with no problem. You can also buy a 12vdc charging cord and use it without the inverter. Look into which way is more effeceint however.

    Also, E-bay is a good source for used laptops. If nothing else, ebay serves as the way to find out what almost anything is worth.

    Icarus
  • BB.
    BB. Super Moderators, Administrators Posts: 33,476 admin
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    Re: Powering a T.V and computer with 200 watt system?

    I would also be careful about charging with a 12 VDC adapter. Problem is that real storage batteries require higher charging voltages than automotive batteries (upwards of 15+ volts during equalization).

    I believe that there was one or two posts here about somebody having a 12 vdc adapter failure for a laptop.

    -Bill
    Near San Francisco California: 3.5kWatt Grid Tied Solar power system+small backup genset
  • icarus
    icarus Solar Expert Posts: 5,436 ✭✭✭✭
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    Re: Powering a T.V and computer with 200 watt system?

    I had a "universal car/plane adapter" It had a 12vdc input, and the output was regulated to the proper voltage for the lap top. Worked great both to run the lap top, but to charge it as well. Wasn't cheap, and indeed wasn't universal as you have to buy a different cord configuration for each type of lap top.

    Icarus
  • System2
    System2 Posts: 6,290 admin
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    Re: Powering a T.V and computer with 200 watt system?

    Regarding your decision to buy a used laptop: The Dell D600 was phased out nearly three years ago, imo $300 is too much for one. Not that I always follow it, a good rule of thumb is to buy electronics new with factory warranty. If there is a problem that is common to the mfg run, it will become apparent and be repaired under warranty. You never know what a used device has been through. My exception to the rule of thumb is to buy used electronics if you get one killer deal or the device is vintage or rare and you just have to have it.

    The 2.5 year old D610 that I'm replying to your post with right now has a 2Ghz Pentium M processor, 1Gb RAM, 80GB disk drive and wireless broadband card that is currently powered up and online. Its 65 watt max power adapter is pulling 23 watts per my Kill a Watt meter. When it's powered off and the power adapter plugged in, it pulls <1 watt. Now I've disconnected the 65 watt power adapter from the D610 and connected it to my two month old D630 with Intel Core2 Duo 2Ghz processor, 2Gb RAM, and 75gb SATA drive. It's pulling 26 watts per the Kill a Watt meter. I would expect similar results from other brands similarly equipped, laptop computers are great power savers. My guess is that your 8 year old desktop PC pulls ~200 watts including a typical 8 year old CRT type monitor.

    As others have warned, many devices do not like MSW. If your plans ever include powering a refrigerator or other motors, you might as well buy a sine wave inverter now. You read it here first, MSW means Mostly Square Wave.

    I created an Excel solar calculator a while back that you can download from within this post at the bottom. It calculates total load, array output, inefficiencies, battery requirements, etc. If you don't have Excel, there are some open source spreadsheet utilities that some here have advised work fine. I don't use those but maybe someone else can assist there.

    Cheers,

    Bad Apple
  • Solar Guppy
    Solar Guppy Solar Expert Posts: 1,989 ✭✭✭
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    Re: Powering a T.V and computer with 200 watt system?

    I wouldn't pay more than 100 bucks for a used laptop .. 350-400 is robbery, goto ebay and search for "Dell Inspiron 8100". I own this laptop and its still a good overall performer with great screen. Right now on ebay they are selling for 50-75 dollars.

    For new, Right after xmas, you should be able to get a NEW one for 399.00, last year, I turn on a friend to a 299.00 NEW deal I say on the tech bargins webite I sent you a link to

    right now:

    NEW Compaq for 449:

    http://www.shopping.hp.com/webapp/shopping/computer_can_series.do?storeName=computer_store&category=notebooks&a1=Usage&v1=Everyday+computing&series_name=C700T_series

    New Dell for 449

    http://www.dell.com/content/products/productdetails.aspx/vostronb_1000?c=us&cs=04&l=en&s=bsd&~tab=bundlestab

    The other issue with used, is ANY repair will be more than the computer is worth!
  • System2
    System2 Posts: 6,290 admin
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    Re: Powering a T.V and computer with 200 watt system?

    I already called about the compaq computer thats advertised for $449...but that isnt its real price...they have to add on $50 shipping charge and then they add on sales tax for the state/town you live in and my location is currently 9%. So instead of getting the laptop for $449...it ends up costing around $550 delivered.


    I will have to call about the dell laptop you posted for $449 and see if they are running the same styled marketing trick...

    Thanks for the advice, I wont purchase the used d600 for $350-400 since the majority on here feels it is way to much to pay for a used system with a 6 month warranty.

    Id really like to go with a new laptop that has a good reliability reputation and is under the $450 mark. If anyone sees any great holiday deals for one, would you please let me know ? I have the money in my account ready to spend. Once Ive gotten a new laptop and my kilawatt meter, I can then have accurate numbers needed for my solar power setup.
  • Solar Guppy
    Solar Guppy Solar Expert Posts: 1,989 ✭✭✭
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    Re: Powering a T.V and computer with 200 watt system?

    Taxes and shipping is added to ANY sale ... I personally think the 449 deals are a good deal and you get it today, not in some unknow months hoping to save 50 bucks. If you want cheap, concider buying a working unit on ebay for 100 bucks
  • System2
    System2 Posts: 6,290 admin
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    Re: Powering a T.V and computer with 200 watt system?
    Taxes and shipping is added to ANY sale ... I personally think the 449 deals are a good deal and you get it today, not in some unknow months hoping to save 50 bucks. If you want cheap, concider buying a working unit on ebay for 100 bucks

    This is not entirely true....some of the websites I checked are offering free shipping for a limited time and if I purchase a new one off ebay, there wont be any taxes applied . I have no problem paying $450 for a reliable, new laptop, but I figure if they are gonna be marked down considerably for Christmas or after Christmas sales, why not wait another 2 weeks to possibly save $100 ? After all, that $100 I saved could go towards a deep cycle battery that I will need for my solar setup.
  • Solar Guppy
    Solar Guppy Solar Expert Posts: 1,989 ✭✭✭
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    Re: Powering a T.V and computer with 200 watt system?

    No warranty with eBay, thats grey market stuff, so thats a false savings

    The one's with free shipping arent selling for 449, anyone claiming free shipping has to jack the cost up to cover

    As for mark downs after xmas, last year there were none ... Bird in hand is worth two in the bush.
  • System2
    System2 Posts: 6,290 admin
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    Re: Powering a T.V and computer with 200 watt system?

    If I offer proof that you are wrong on your assertions, will you coincede ?

    example :

    Starting Price $659

    Instant Savings $210


    Subtotal $449


    FREE Shipping & Handling.
    Limited Time Offer.


    this is directly from Dells website...and there are others...So as you can see, they are offering it for $449 with free shipping :}
  • Solar Guppy
    Solar Guppy Solar Expert Posts: 1,989 ✭✭✭
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    Re: Powering a T.V and computer with 200 watt system?

    Thats a good deal, grab it!