Off Grid Shack
Is anyone out there using a shack completely off the commercial electrical grid? I'm talking the radios, amps, computer and lights. Would like to hear how you are doing it.
- Joe, N5XGG
Totally off the grid? Would that mean no Internet connection also?
Reality is that which, when you stop believing in it, doesn’t go away.
Well, internet can be via DSL phone line (no electrical power needed) or via satelite if really remotely located (the receiver would require electricity). I am primarily thinking of my rural home where I may build shack 75 yards from house (I would have DSL line run to it.)
- Joe, N5XGG
73, Joe - N5XGG
Not for a ham shack, but I do it professionally for some cell tower sites which is the same thing x 100.
It can be done but it gets real expensive real quick. On average it will take $3000/Kwh/day with $1000 of that in batteries that need replaced every 5 years or less. 1 Kwh is not very much power about 10-cents worth. Based on the first 5 year initial investment using 1 Kwh per day you go from paying $0.101/Kwh to $3000/1825 Kwh/day = $1.64/Kwh or 1600% more than buying it.. If you live up north where there is less insolation the cost is even higher because it requires more panel wattage and larger charge controllers
Taking a 100 watt HF Transceiver off the grid is one thing for field operations, taking the whole shack is another thing. 1 Kwh with a Legal limit amp, transceiver, lights, computer, and modem is only going to give you an hour or less operation per day. That is not much and very expensive to do.
Here is an example of what would be required for a 1 Kwh/day in Kansas City MO
Panel wattage required = 700 watts
Charge Controller = 40 amp MPPT
Battery = 24 volt 220 AH
Inverter = 2 Kw True Sine Wave.
Go price that out and see what it comes to, then add all the misc materials and hardware to it. To do it right you would also need a generator for those times you get extended cloud cover of more then 2 days. Either that or just not operate on cloudy days.
Last edited by KF5LJW; 03-20-2012 at 11:22 PM.
I have an array of solar panels measuring 16' x 60' (960 square feet) with a battery bank on a pallet in the garage that occupies 4' x 8' and stacks 5' tall or so, with a regulator and charging system that can power my entire ham shack including rigs, amps and computers; however it's not off-grid, it's grid-tied because it's not enough to power the whole house (including electric cooktops and ovens, air conditioning, pool filter pump, spa pump and heater, etc). We're in a very sunny area (330 days a year of sunshine) with reasonably clear skies and low humidity, so the solar "system" performs better than it would in a cloudy area, but still it cannot power the whole house.
However if I could separate it to power just the shack, it could do that.
Installation cost about $25K or so, but there were rebates and incentives that reduced the actual cost to about $10K.
For "emergency" use, a generator would be a whole lot cheaper. But of course you'd have to provide fuel for that which will eventually run out unless replenished periodically.
I notice the local "completely off grid" radio sites around here (on remote mountaintops where there isn't any grid power available) mostly use LNG or LPG generators with big storage tanks that are filled by trucks delivering the fuel. One such large system is on Frazier Peak (8000') not far from me, and it powers a very large Verizon cell site, multiple TV links and other stuff (about ten towers filled with antennas connected to "stuff" in blockhouses at their bases). I've never been there when they made a delivery, but the local Ranger told me it's only about every three months, so the tanks are pretty big.
For emergency use, I'd just get a gasoline generator and keep some fuel on hand. Likely the cheapest, most effective method.
A government which robs Peter to pay Paul can always depend on the support of Paul.
-- George Bernard Shaw
Not if it is natural gas, fuel supply is unlimited.
Originally Posted by WB2WIK
Well I build those sites for a living, and Verizon Wireless is one of the largest users of solar cell sites. With that said the cost are enormous. A single BTS radio consumes 35 Kwh per day. Depending on the location requires a 6000 to 15,000 watt solar panels and multiple charge controllers. The amount of batteries required are extremely large with a reserve capacity of 175 Kwh. So at 24 volts is 7500 AH weighing in at 10,500 pounds and cost of around $37,000.
Originally Posted by WB2WIK
Throw in a 20 Kw LPG or diesel generator, all the hardware and labor and the bill comes in at $150,000 to $200,000. The real insult to injury is the$37,000 batteries need replaced about every 5 years.
When you run the numbers the Kwh cost for the first 5 years is $3.13/Kwh. That is a hard pill, I mean bill to swallow when commercial power cost are 10 to 12 cents per Kwh.
Anyway the point is: Do not go off-grid battery unless it is the only option available to you. Trust me Verizon or any other business would gladly pay $200,000 for commercial power installation if it were an option.
Last edited by KF5LJW; 03-21-2012 at 03:23 AM.
I would be curious what the specs are. If you do not mind can you share:
Originally Posted by WB2WIK
Charge Controller size in Amps
Battery voltage and AH capacity
My ham bench is always off-grid, with a 135W panel on the roof and AGM battery under the bench. Of course I don't run any amps or other very high power stuff with that. (Don't have them anyway.)
The computers and lights *can* be off-grid. I also have 1kW in panels on the roof (and just bought another 1kW to install) feeding down to a 48V 220AH battery bank (small but sufficient for my purposes) in the garage that feeds a sub panel for my "cricital circuits". During sunny days, and starting this summer during "peak demand" hours, those circuits are switched to the battery bank and inverter. At night I use grid power for them, to keep from unnecessarily depleting the battery bank. If the power goes out everything instantly switches to the battery bank, without even a flicker of the lights.
I also couldn't go completely off-grid, there's no way to run the whole house off solar - especially in summer trying to run the AC!
How about an entire house off the grid? If interested, look up K4ERO here and send him an e-mail.
My cabin is off grid and I operate from there regularly. 100w barefoot, computer thru wi-fi hotspot on my phone. 4@80 watt panels on roof feeding 8@6VDC lead acid 220ah batteries in series/parallel for 24VDC, , inverter/battery charger and charge controler. I have a TV that I use maybe an hour a day, stereo that's on 8+ hours a day, propane cooktop and oven, woodstove for heat, CFLs for lighting, tho LEDs are in my future. I've lived and operated there for 5 days without sun, then used a small generator to top up batteries. I have no electric heating elements of any kind as they just suck power. When I need to use power tools, I run them off the generator as the motors don't like the modified sine way much.
I'm frugal with power so your results may vary.
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