Can this be done?

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Hi Everyone,

I'm new to this forum (5 minutes). I have been looking for someone to educate me on the possibility of a solar generator having the capability to carry the entire power load of a 10 floor building especially the elevator (even if it can handle just one of them), close to 200 computers (approx half are desktops and the others laptops), copiers and printers etc, flourescent lighting for the entire 10 floors, pumping machines for water supply to toilets etc.

The airconditioning can be moved to an alternative power source. Most other appliances can also be moved though the load for the solar generator as described above may increase.

I don't know too much about power and electrics so I may seem lost but thats true. I am looking for direction. I could find out approximate wattage etc and provide an approximate load estimate but I am a neophyte and may be far off track (which is why I have detailed equipment making up the load).

Approximation is the idea.

Thanks

Comments

  • mike95490
    mike95490 Solar Expert Posts: 9,583 ✭✭✭✭✭
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    Re: Can this be done?

    Anything can be done, whether it's wise to do, depends.

    It's hard to guess what the load is, you'd need the size of each floor, x10.

    However, it will take a LOT of PV panels. Do you have a large parking lot, you can cover it with panels, and shade the cars below?

    Covering your roof, will power 1 floor, is my guess.

    Hope you have a friendly bean counter that will let todays investment pay off in 8 years, instead of 1 year - investors and CEO's all want quick payoffs, hence the poor state of infrastructure here in USA.
    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: Can this be done?

    Yes, there is a very large parking lot plus the possibility of renting roof space around. Suppose one were to decide to invest in this, is there any posiibility of an estimate (rough, offhand, say, plus or minus 30% accuracy).

    Another question if you don't mind. you suggested 8 years as an idea of recouping investment. Thats based on comparisions with relevant grid (utility) rates. How would you compare against the situation where you run a diesel generator 10 hours daily through the working day?

    An approximate fuel consumption rate follows

    Generator size ---- 200 Kw
    1/4 Load
    4.7 (gal/hr)
    1/2 Load
    7.7 (gal/hr)
    3/4 Load
    11.0 (gal/hr)
    Full Load
    14.4 (gal/hr)

    Thanks :D
  • mike95490
    mike95490 Solar Expert Posts: 9,583 ✭✭✭✭✭
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    Re: Can this be done?

    Well, now that there is a generator, with a load, we can *guess* at the PV needed. What is the normal building load of the Generator?

    I'll guess at 75% of 200KW : 150KW of PV needed. add losses and such, and you need 200KW of PV installed.

    The Generator will be much less $$

    Guessing your PV cost about $6 per watt : $1,200,000
    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 ,

  • BB.
    BB. Super Moderators, Administrators Posts: 33,491 admin
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    Re: Can this be done?

    Are you trying to do this in Beirut, Lebanon?

    Several issues... Generally, it is better to do everything you can first to conserve power. Changing desktop PC's to laptops (or newer energy efficient desktop PC which are probably just now coming to meet the US Energy Star standards) is just one example... If you have A/C, removing all sources of excess heat (old desktop computers, filament lights, etc.) will reduce your A/C loads too.

    Also, you will want to characterize the loads using watt-hour meter(s) to measure the actual power you are using and have an idea of how that changes over time (seasons, weather, etc.). Solar generally have seasonal variations--obviously, you have sunny seasons, windy seasons, storms, etc..

    I guess, that you may also want this system to provide backup power, rather than just a way to get cheaper power--although, you may be running the building on its own generators (fuel=expensive)--which can change the equation a bit.

    And, if you go "solar' you have to be able to store the power for use at night and during bad weather--usually batteries are the answer here. But they will need to be replaced every ~5-15 years (depending on type, costs, and maintenance).

    If, you are trying to reduce costs, Grid Tied Inverters which take the Solar (or wind) DC electricity and convert it into AC voltage which can be pumped back into the Grid--In the US, laws have been passed in many areas that require Electric Utilities to allow approved G-T inverters to be attached to their networks.

    If your power is primarily provided by an on-site generator--you could possibly work up a system where the solar panels reduce your generator's load during the day--saving fuel and not changing much else your power system. Doing this is not a trivial task--The general Grid Tied inverter expect the utility to take 100% of the power generated--if, in your case with a large solar array, the panels could generate more power than needed, this would try to back-drive the generator(s)--not a good thing. So, other controls would have to be added.

    In any case, this stuff is not cheap (in the US, it costs roughly $5.00 per watt of solar panel--retail). If your building uses 100kWatts (just a guess)--then you would need USD$500,000 worth of solar panels--and a safe place to put them (made from glass and very easy to break). If you want to panels to provide power 24 hours per day + battery backup/operation--then you may need several times more solar panels in costs (guessing that this would be a multi-million U$D project). Don't know if this is "worth it" for your installation--too many unknowns right now.

    -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: Can this be done?

    Actually, I'm writing from Nigeria. As I said, its a bank but we need to have an idea of pricing and other issues. The Inverter grid is not possible (such don't exist here) and the system is needed mainly for work hours (8am to 6pm) though at pay/report/such time, that extends to 10PM (rarely). Past 6PM, the only need for power would mostly be to hold up the bank servers and a few lights. As always, things do change but I think you get the idea. A/Cs will NOT come on the solar system or maybe for two executive staff.

    We have terrible power issues here so business would happily run on the elevators and the computers (with copiers, printers). Worst case, fans will be used rather than A/Cs.

    Reason why I specified the size of Diesel generator being used was just to give an idea. Reality is that the fuel consumption shows the generator load is slightly above 1/4 load almost always. For this reason, I personally think a 60 to 80Kw would do the job. But to be safe, I brought up the 200Kw. But its definite the generator is under-utilised.

    To keep the cells, the roof is available and I have seen photos of cells mounted on the sides of high rise buildings.

    If you'd like an idea of what its like here, please look at

    http://www.washingtonpost.com/wp-dyn/content/article/2007/03/02/AR2007030200673.html
    http://news.bbc.co.uk/2/hi/africa/6245448.stm
    http://www.worldbank.org/afr/findings/english/find221.pdf
    http://www.economist.com/world/africa/displaystory.cfm?story_id=9234468
    http://www.nairaland.com/nigeria/topic-66182.0.html
    http://www.budgetmonitoringng.org/Spotlights/2007/04/10/News11850/
    http://www.cenbank.org/out/annual/ACZRU/2001/Owe-01-3.pdf
    http://www.forum.org.ng/node/22

    Thanks. Appreciate your thoughts and guidance.
  • System2
    System2 Posts: 6,290 admin
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    Re: Can this be done?

    My thoughts are that the entire load in the building can be split into two: "Essential" and the "Others" and put essentials on the Solar system. Some of the lights, copiers, fax machines and even some staff computers may come under "others" to reduce cost and load. However, for the distance and since it would certainly be an "imported" solution, I doubt the power requirement would go below 40 - 50Kw. Below that would not make fiscal sense and even that may be unreasonable.

    My major challenge is knowing the power consumption of elevators. Just one of these GUARANTEED to be working all day is fine. The others can be on the public utility normally and diesel backup for critical times only.
  • BB.
    BB. Super Moderators, Administrators Posts: 33,491 admin
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    Re: Can this be done?

    A standard 10,000 lb rated hydraulic elevator (~4,500 KG?) is rated about a minimum of 25 horsepower (or 746W/HP * 25 HP = 18.6 KWatt... That will get you a rough starting point (a DC to AC inverter should probably be twice that rating for starting surges--measuring, talking with the Elevator Company, type of lift system, etc. will change all of those numbers).

    For actual power usage, take the number of times the elevator goes up (perhaps up and down if winch system rather than hydraulic--winch/cable system may use less power) and down in a day... Convert that to hours (1 minute trip up, 15 times an hour = 0.25 hour trips per hour, 0.25*8 hours per day = 2 hours of motor use, 2 hours * 18.6 kWatts = 37.2 kWhrs per day). These numbers are probably close to useless--you will need to gather the true values for your system.

    Again, this would be a pretty large system (batteries, solar panels, wind power, etc.)... For example if you need to support a 100kW load, with a 48 VDC battery bank (not practical for your use--too small), that would require current of over 2,000 amperes... You are in the area where a large company specializing in this stuff would be helpful.

    For some smaller systems, there have been good results creating a "hybrid" system--Generator supplies large loads and charges battery bank. At night (and other periods of low loads), generator is shut down and battery provides power (can cut fuel use by 2/3'rds if your load is highly variable).

    I have to go right now--but hope to hear more.

    Sincerely,
    -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: Can this be done?

    What can I say? Wow (solar expert talking elevator power) and thanks. I'll stay with your figures in lieu of better information. Truth is we import practically everything here and there is next to no real technical know-how with such things as elevators which are rare anyway (rarely can you find anyone using them cos of the cost). Motor use would come to approx 2 hours daily. Its switched off after an hour mornings and then on for about an hour evenings. Between then, you WALK. The world bank at http://www.worldbank.org/afr/finding...sh/find221.pdf gives you facts and figures you may find impossible to comprehend if you are ready for the shock. Have a drink close by. ;)http://www.washingtonpost.com/wp-dyn/content/article/2007/03/02/AR2007030200673_2.html will make you laugh.

    Unfortunately, the report is old and out-dated. That was when things were still "good". Diesel is not N21 anymore. Its N90. If you ain't ready to pay 120 -200% that, you're going home with an empty can. Plus you may spend a week getting a 2 day supply. :grr

    Bill, could you please give me just an idea (yeah, yeah, I know ;)) of the cost of 40Kw, 60Kw and 80Kw? You've solved the major problem of providing an idea of elevator power load. I'll spend the coming days having a detailed inventory taken so I can provide myself with a bench-mark load figure. Its obvious its going to be expensive but if you ever imagined a bank "systems headquarters" being without power for 2 days and the servers going down, you might get a feel for the situation. The URL above makes amazing reading.

    You spoke of large companies specializing in this "stuff". Can you recommend any? I imagine no one can imagine the amount of business they can get here if this works.

    Thanks again.
  • westbranch
    westbranch Solar Expert Posts: 5,183 ✭✭✭✭
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    Re: Can this be done?

    Hello Kubae, I don't know what is going on but the WB link you provided takes me to Afganistan??? at the WB

    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
  • BB.
    BB. Super Moderators, Administrators Posts: 33,491 admin
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    Re: Can this be done?

    Let me keep you from thinking I am both a solar expert and an elevator expert--I am neither...

    But, if you are looking for back of the envelope calculations...

    First, we talked a little bit about conservation... Conservation should be your #1 place were you will be "investing your time and money" (yes, I know that without power, conservation is useless).

    For example, working in round numbers... A large desktop PC can push towards 300 watt, 24 hours per day. A little laptop could be well under 30 watts per 24 hour day--and if it is set to "sleep" when not being used, you may be down to just 4 hours per day of power (and 1-2 watts while "sleeping").

    So, 4h/d * 30W + 18h/d * 1W = 138 WH/day (or 0.138 kWhrs per day per computer)

    That is 24h/d * 300 Watts = 7,200W or 7.2 KWhours per day. But since we are being realistic here--let us assume that they are good guys and only run their desktops 8 hours per day--so that becomes ~2.4kWhr per day for each desktop system.

    2.4/0.138 = 17.4 times as much power to run 1 desktop vs 1 laptop computer... So conservation can have a huge impact on keeping costs low...

    So, how much does "solar" cost per kWhr of load... Hmmm... Asumming that the costs in the US are about the cheapest you will find, that residential retail pricing for power electronics and such will, to a degree, scale lower as you pay for larger and larger installations--Guessing:

    Solar panels per 1 watt: $5.00 +/1 $1.00 per watt...
    Inverter per watt: $0.50 / watt (SWAG)
    Lead Acid Battery: $0.20/Whr or $200 per kWhr of storage for a good quality lead acid battery (large)...

    So, how much power do you need? Generator fuel consumption is an OK estimate--however I would like to see a Watt*Hour meter (or average current * average volts) for a better reading--because the lower the load on the generator the more inefficient they become--by 1/4 fuel flow (or 1/4 load or less), you could be powering anywhere from 0-80kW using the same amount of fuel.

    I am guessing here (use your numbers here), but lets say 80kW*10 hours per day (remember that 1,000 Watts = 1 k(ilo)Watt, and that watts are like gallons per hour, you need to know the time to know how many gallons you have at the end of the day)...

    So, (80kW*10hperday) = 800kWhrs per day (is that around 80-160 gallons per day of diesel for you?). I am not sure if this was supposed to be 80kWhrs per day or 80kWatts for 10 hours per day, or what... This is about 100x what a normal home in the US uses per day (without A/C, elevators, etc.).

    Assuming that you average about "5 hours per day" of sun (winter/summer will differ, as will cloudy/foggy weather--just use 5 as a good place holder)...

    Assume that the battery bank is sized so that you don't draw down more than 50% of storage (for long life) and that you want "3 days" of storage (usually a good rule of thumb compromise for life, usability).

    Size of solar array (again, using some personal rule of thumb derating factors--solar panels get hot and loose a bit of power, inverters are not 100% efficient, and batteries waste energy too)... So, it would look something like this (hpd=Hours per Day):

    PV Sizing=(800kWhpd/5hpd)*(1/0.75PVeff)*(1/0.8BatEff)*(1/0.85 InvEff)=313.7kW or 314,000 watts of solar panels

    $PV=314,000W*$5/W=USD$1,570,000

    Inverter=80kW, then that would be 80kW*$0.50/kW=$40,000

    Batteries=(80kW*10H)*(3day)*(1/0.5 discharge)= 4,800kWHours of battery

    $Battery cost= 4,800kWhr * $200/kWhr = $960,000 in batteries (with 5-10 year typical life).

    $1,570,000 PV panels
    $40,000 inverters
    $960,000 Batteries
    $2,610,000 for basics.

    Add 33% for labor
    Add 20% for wire, boxes, building, etc.
    Add 100% for shipping to Nigeria

    $2.6M + $2.6M * 153% = $6.578 million dollars.

    Getting back down to small numbers that people can relate to...

    800kWhr per day (with three day backup) = $6.578M

    $6.578M/(800kWhrsperday*365 days per year) = $22.50 per kWhr (per year capital cost)

    Assume 10% cost of money and maintenance, then that becomes about $2.25 per kWhr (ignoring a whole bunch of other accounting stuff)... Or, about 10x what the power costs in a "developed" country... You can see that saving electricity (new laptops, reduce energy efficient lighting, etc.) can really help here too...

    You might want to add another $40,000 for inverters (handle elevator and other surges--but $40,000 is peanuts).

    Price for labor, wiring, breakers, boxes, housing, anchoring solar arrays, and costs of wire, steel, building materials are just a WAG (not even a Scientific Wild Ass Guess)... 100% cost for shipping to Nigeria--might even be low...

    Your comments/questions Kubae?

    -Bill

    PS: I missed your earlier post on generator size and fuel consumption... So, it looks like I did guess right on what your estimated power needs would be for my SWAG estimate here. -BB
    Near San Francisco California: 3.5kWatt Grid Tied Solar power system+small backup genset
  • nigtomdaw
    nigtomdaw Solar Expert Posts: 705 ✭✭
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    Re: Can this be done?

    Kubae, A very interesting project, but please factor in one very important point, With 0.5 to 1.5 million $ of pv panels in a impoverished and corrupt location which the web site links you have provided describe then .......security .....security .....security of panels will be a nightmare!! When the lights go out downtown.. and the criminals come out......................
    Your panels are going to look like money not in the bank !

    Just a thought for your report to the CEO
  • System2
    System2 Posts: 6,290 admin
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    Re: Can this be done?

    Eric:

    Sorry. There's an error on the forum web page. I found I gave you something wrong and tried to correct it. On previewing, it had changed again. Do me a favor and remove the spaces in the following URL http://www.worldbank.org / afr / findings / english / find221.pdf

    Don't know how something happens between the "finding" and "english" that makes it """"afr/finding...sh/find221.pdf """". Take out the blanks on the URL line to see the report. I found Afghanistan too and was scared for a minute. :confused: As you will see, its a Dec 02 report. Tell me what you think.

    BB:

    Can't thank you enough. You've gone past kindness. I'll try to get a detailed breakdown of minimum requirements which could solve WORK issues. If it has to be just servers and laptops (We'll walk but we NEED to WORK) or we can come to an agreement what HAS to be powered and the guys at the top think its worth it, I look forward to reading more comments from you. I will anyway cos I'll be following this forum.

    Many sincere thanks

    NIGTOMDAW:

    Security in a bank? Believe me, security is implied in this business. Remember vaults and minimum cash balances approaching half a million USD? Plus if it could be done, we're looking 1st at the roof and sides (?) of a 10 floor building for the panels. Yeah, I know Spiderman & (whats the Halle Berry one) exists but luckily both are in the USA ;)

    TELL YOU WHAT: I'M GRATEFUL. AND WHIST THE FIGURES ARE SCARY (ASSUMING THEY STAND), LETS TRY SEE IF ANYTHING CAN BE DONE. AT THE LEAST, I HAVE A REFERENCE POINT NOW.
  • System2
    System2 Posts: 6,290 admin
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    Re: Can this be done?

    ERIC:

    Further to the below, here's the original link I pasted again. When I post it without spaces (as I first did), it becomes what you can see here: http://www.worldbank.org/afr/findings/english/find221.pdf.

    Please RIGHT-click on that and choose OPEN IN NEW WINDOW. Your new window opens and the URL has reverted to what I originally intended and it opens the right file. When you've read/saved, close the window then do the normal left-click. It visits Afghanistan.

    Windows problems, I guess.

    I was worried for a minute there. Afghanistan? Phew! As if I don't have enough issues :D
  • System2
    System2 Posts: 6,290 admin
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    Re: Can this be done?

    BB:

    I haven't studied your calculations below in detail but will do so and get back to you with detailed questions.

    Off-hand, however, I know a 40foot container costs US$6, 500 (give or take some) from the US to Nigeria. I doubt any system will utilize 50 containers (prohibitive size) which is US$325, 000. Far from $2,160,000. The number of containers that would cost 2 million Dollars would probably make the building crumble under its weight.

    I would add your 33% for labor and 20% for "sundries" before adding shipping, not after as you've done. Shipping is CIF. Further, 3 days backup seems a bit high. Why not 36 hours? We are in the tropics with the sun up usually by 7:30am and up till 5:30pm cloudless, scorching terribly hot sun. I would say, 7 hours sunlight worst case 10 months annually. The laptops go home with staff at 6pm so aside regular hours, are off the system. The desktops are shut down. Only servers are permanently up and these number less than 20 (not in IT group so not concise but can find out).

    Any comment(s) on impact of above?
  • BB.
    BB. Super Moderators, Administrators Posts: 33,491 admin
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    Re: Can this be done?

    Kubae,

    The 100% was just based on a guess trying to cover shipping, buying from other than the US, engineering costs, import duties, insurance *cough* bribes, etc... I will not claim that I know how much it costs you to import items into Nigeria, but I wanted to give you a realistic range of costs for the system you described (without harding knowing any details or doing any detailed research).

    I have not looked up the solar irradiance for Nigeria... But, TaDa!, found one just for Nigera with long term averages. Depending on the installation, you will have from between ~4 to 6.5 hours per day (coastal to desert, year round averages)... I don't think I saw your city/region in any posts--but you can look at the map and plug in your numbers (just take the size/costs and use 5/4 if 4 hours, use 5/6 if 6 hours of sun, etc.). But, we are still only "typing" about a +/- 20% change in numbers for the solar panels, and would not affect the battery or inverter sizing--so that gets to about a +/-10% in total system costs. Still not bad for a SWAG.

    Why three days for the batteries... Basically, the "standard" (whatever that really is) Lead Acid storage battery is typically rated on a 20 hour rate--basically how long it takes to discharge... If you discharge faster, the amount of energy you can take out goes down as the battery is not as efficient at higher discharge rates. Also, you don't want the batteries to take too long to charge--the longer they sit discharged (and the less often they get equalized--another issue), the shorter their service life will be... Also, if you charge too fast (much more than 1/10 capacity per hour), you can overheat the battery bank (batteries really want to be around 77 degrees F).

    Add weather factors for the "average installation" (don't know yours), 3 days seems to work out well as a cost effective average...

    You can do something else and dramatically reduce your battery bank size. One it to use AGM type sealed lead acid batteries... One brand lets you discharge 80% of the power (down to 20% capacity instead of the 50% capacity of standard lead acid storage batteries). Also they charge safely at higher rates. But, they also cost more. AGMs can be very nice (low maintenance--but they are not as rugged and can be killed vary easily with overcharging. Standard wet cell Lead Acid batteries need to be cleaned and watered--but are more rugged (and cheaper).

    Certainly, if you could count on utility power, generators, and only working when the "sun is out"--you could also reduce the size of the battery bank.

    For example, perhaps the elevator is only used when utility/generator power is available--the batteries would only be sized for enough power for a few operations of the elevator when power is not available.

    From reading the article about the Nigerian power company--it is subsidized power (costs them 3x as much to generate as they sell it for--from the dated report) but the utility/government tries to prevent companies bringing in private generators... Sort of the worst of both worlds.

    Sizing of the system has three major components--and to a degree, the .

    The inverters (used to create AC Building power (those are not too expensive--so you can either size for maximum load--emergency or otherwise. And inverters can be added in parallel pretty easily, if planned for. Spares are not too expensive).

    Power storage (usually Batteries)--Size according to your needs. Generally, if you can keep the charge/discharge to 20 hour rates (perhaps even 10 hour rates if you are willing to replace batteries more often and not have emergency power for more than 10 hours). I would not recommend running the wet cell lead acid batteries below 50% capacity--so that "doubles" the size of any installation.

    Power (multiple sources. Use battery to carry through outages--not really a power source. Use other sources to charge batteries and/or provide building power directly):

    Utility Power--connect battery chargers to mains to charge batteries... Might get around utility concerns as the power would still be provided by the utility.

    Generator Power--Can connect battery chargers to carry ~1/10 capacity charge rate (whatever capacity you have decided on)--Battery charging goes in stages--the first stage can take maximum current for a few hours, but the next stage takes longer, but at lower current--You may be able to use a smaller, more fuel efficient generator to top-off the batteries and equalize charge (every few weeks +/-). Obviously, generator(s) will run the building too.

    Solar Power--Cannot power building directly, need to charge batteries, then inverters provide power to building. Depending on weather, season, and local conditions (isn't Nigeria known for dust storms in part of the country)--there is always the trade off between absolute minimum power requirements vs worst case power capabilities of the PV system itself.

    In the end, every power conversion involves losses... Assuming your servers and Desktop PC's have UPS's (Uninterruptible power supplies), those only add to the loses (and heat) in the building. For example, if you have a reliable battery/inverter system (solar/generator/mains charged)--that could be the UPS for the desktop computers. Although, it would probably be better (more power efficient) to replace desktops with laptops (and external monitors--if needed) and use the laptop batteries as the "UPS".

    Critical pieces of equipment will always need their own UPS systems--probably feed by the solar/battery system--but the reliability provided will be worth it...

    I guess I am running out of things to type here (thank heavens!)--I am sorry that I don't have any leads to good Solar/RE companies. I have tried to be pretty conservative in sizing and costing of the system--you will probably be able to reduce system costs by shedding non-critical loads and by better understanding your load profiles and availability of alternate power sources (a couple days without fuel, frequent utility power failures during the day, more or less reliable power at night to charge batterys--batteries/inverters allow load shifting of daytime loads to night time, etc.)

    I would suggest that you contact somebody like the owners of this website and ask for their help--they maybe able to configure a system for you and ship--or they can help you with some leads to others that are better able to meet your needs. I would be just doing the same thing as you otherwise--using google to find companies that can provide the services you need and talking with them.

    Kubae, I am sorry I cannot help more.

    -Bill
    Near San Francisco California: 3.5kWatt Grid Tied Solar power system+small backup genset