New Member - Need some professional advice

System · April 2008

Hello everyone, I could really use some help with a basic solar setup.

I run a large 30K member online forum and live in a very rural area where we have power outages more than most.

For the past few years I have depended on a generator for backup power but with fuel costs it is no longer an option.

I have been looking into Solar but the Internet is swamped with "Budget Solar Kits" and I do not know enough about them to know if I am getting a good deal or even if it is what I need.

I am hoping someone could help me design a basic system that would run a laptop and a router in case of an outage.

I would like to start with a very basic system but have the option to add a few panels and batteries later as funds become available.

Starting costs of $700 - $800 would be great.

Any help would be greatly appreciated.

westbranch · April 2008

Re: New Member - Need some professional advice

Welcome... there is lots of info here, you just have to start reading...also several strings on just your topic though they may not be labeled that way. Aslo a good read is on (off?) the NAWS home page ( Northern Arizona Wind and Sun)...

I think you may be a bit on the low side for $$$... Basically you will need panels, a charge controller, inverter and interconnect, fuses, wire,etc

If all you want is power for back up you need to isolate the circuits for your servers otherwise you will need a large solar installation and that aint cheap...

you will need to identify your power demands first then look into what can provide that to you. A Kill a Watt meter is essential here...

There are lots more here with much more insight/knowlege than I so once you have some consumption details, bring them on.;)

Cheers

Eric

System2 · April 2008

Re: New Member - Need some professional advice

Thank you for the fast reply.

Let me clarify some things:

I only need to run a laptop and a small Linksys router. My server is located in a large office building and I operate it remotely.

I will buy the batteries separate from the basic items I am asking about here.

I have been looking at 80W - 100W "Starter" kits for around $700 but I want to make sure they have quality components and will enable me to get online for a few hours in case of a power outage.

I also want to make sure I am able to add a panel or two as well as extra batteries to the system later.

I like the 12V systems with an Inverter but here is where my knowledge ends.

I would need an inverter and a charge controller which would allow me to add a few extra batteries and panels later.

Kits like these seem to be a good start for my needs but I do not know if I can add the panels and batteries later or not:

http://www.jatsgreenpower.com/solar-powerpac-2.html

http://www.solarexpert.com/Gp/Cottage-Kits.html

Again, thank you for the quick reply and all advice and or help is appreciated.

westbranch · April 2008

Re: New Member - Need some professional advice

OK, back to the basics: How much power and for how long?

There are calcs that can be done with the above 2 numbers and then a system can be built based on them plus efficiencies/inefficiencies of solar collection, location, inverter and charge controller losses, etc.

Batteries can only be drown down to a max.. ~ 50%, MAX, past that and they can essentially be thought of as DEAD! The selection of the batteries is based on the answer to the 2 questions also

Also where are you situated? Do you have a clear shot at the sun SE to SW? How far from the panels to where you want the power delivered?

HTH

cheers

Eric

BB. · April 2008

Re: New Member - Need some professional advice

Are you by any chance somewhere in the woods of Missouri (vs New York City--IP address)...

In the end, you will get, roughly 3-6 hours of "sun" (winter/summer) per day...

A 100 watt panel would give you, very roughly, ~5-8 kWhr per month or 166 - 266 Watt*Hours per day (winter/summer)...

If you have a 30 watt laptop and a 20 watt router, that would be:

166 watt * hours / (30+20) = 3.3 hours of operation during an "average" winter day...

266 watt * hours / (30+20) = 5.3 during an average summer day...

You can review this post/thread--basically the same question you asked and I answered earlier today...

Question about the generator/power issue... How long are the power outages and how much power do you want to backup...

Frankly, a UPS and a Honda eu1000i or eu2000i would give you power pretty cheaply...

For example a Honda eu2000i running at 400 watts (1/4 load) will use 1.1 gallons of fuel for 15 hours of runtime. And if you want longer runtime, you can buy or build an external fuel tank system that will expand the 0.6-1.1 gallon internal tank to 6 gallon fuel cans (example of over priced "commercial" product).

And, you can either get a large-ish UPS or even get purchase a real inverter/charger combination (true sine wave recommended) and mix between battery backup for "short" failures and use the generator to recharge the batteries for longer failures.

The inverter would plug into your AC mains and keep the batteries charged until the AC failed--chug along on DC backup until you transfer to your little Honda and fire it up--then the inverter switches over back to the generator AC and at the same time, the inverter/charger recharges your battery bank...

There are an endless amount of combinations you can make between inverters, chargers, generators, and even solar panels + solar charge controllers...

Much of it depends on how much you want to spend, how "reliable" the backup power needs to be, and how long/often are your outages.

The Honda eu2000i running at 400 watts (minimum "cost effective" load) will generate your power at about $0.73 per kWhr with $4.00 per gallon gasoline... You can use less power--but the 1.1 gallons of fuel will probably still run out in ~15 hours or so (fuel required just to turn the engine/generator even if zero watts are being used)...

A true off grid capable solar panel system will generate power at >$1.00 per kWhr (including cost of storage batteries and their replacement every 7-10 years or so)... And even then, you will probably need a generator for cloudy weather backup...

In the end, if you want to use solar panels + storage batteries to support your load for multiple days--the system will probably have to be much larger than you have initially estimated (if you want more than 3-5 hours per day of "uptime").

-Bill

mike95490 · April 2008

Re: New Member - Need some professional advice

Do you need automatic switch over ? Autostart ?

How handy are you, do you want a "turnkey" solution, or DIY ? DIY will save you $.

Solar panels cost $$$, no avoiding that. Maybe just a battery bank run from a grid fed battery charger will be your best answer. Backup charger could be a genset. Batteries would run you several hours each.

Is you laptop the forum server, or is this just for your personal laptop ?

Mike
http://www.ae-zone.org/Designs/monolith/monolith.html
Now linked to my facebook page, which is open access to this album:
http://www.facebook.com/album.php?aid=2074858&id=1196643274&l=7e66e96c3c

niel · April 2008

Re: New Member - Need some professional advice

it may also be a good idea for me to point out that sometimes these items can be operated from 12v thus saving the conversion losses and the expense of an inverter.

New Member - Need some professional advice

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