Tuesday, May 11, 2010

Advice for building a solar generator?

We are moving to a remote location without any electricity, and would like to produce our own. We have read that it is pretty easy to set up solar power, and there are ready-made solar generators for sale. If we build our own, how many solar panels would we need to comfortably power a small cabin, and what other materials will we need to set it up? About how much will this all cost?Advice for building a solar generator?
A solar electric system consist of in simplest terms a panel, charge controller, battery, and a load ';lights, radio, etc';. This system can be expanded on.


The first item you need to consider is the loads, what do you want them to be. How much energy do they consume per hour and how many hours a day are they used. The next is the voltage of the items 12volt dc, 24 volts dc, 120 volts ac. In general 120 volt ac itmes are easier to obtain but in general less effeciant but also have longer life spans then the 12 and 24 volt dc versions.


Example we use 1 light bulb that consumes 20 watts at 12 volt for 4 hours a day. This buld would need 20*4=80 watts of energy per day. Next lets say you had 5 of these light bulbs and they were all used the same amount every day, you would need 80*5=400 watts to run these lights. Next lets say you want 2 days of reserve enegy incase it rains or something 400 *2=800 watts.


These 2 figures help give us the panel and battery size. Lets look at the panels first. we determind we needed 400 watts per day. Look around on the interent and you will find a chart with hours a day of sun light for your area. Lets say your area get 2.5 hours of direct sun per day in the worst time of year you would need 400/2.5=160 watts of panels.


The next figure is the 800 watts of battery. You never want to discharge your battery more than 40% this will reduce your battery life. So lets do the math again. (800/40)*100=2000


Now lets assume your battery back is 12 volts 2000/12=167 amp hour back.


So your system would consist now of 160 watts of solar panels 167 amp 12 volt battery bank a charge controller mounting system for the panels, box for the batteries, and an small fuse or breaker panel to protect all the equipment.


This would be a very simple system but if you wanted to add tv's radios computer etc. you need to do the load calcs on them add them all together and do the math. Don't just go out and buy a system someone off the internet sales you it may not be right for what you need.


Something else you will need to see the sun most of the day no shading of the panels. Good luck solar is great.Advice for building a solar generator?
I just read up on that Xpower product. I could not find how much power it used. It takes power to charge up the unit just like it would to charge up batteries so I would think it would use more power not less. It seems to be a surge protector and not much more. They even have a disclaimer in each page pretty much saying the statements are not legal and binding. That tells me to watch out..





Now for an answer to your question.





I agree with the first answer you got. But the price for an off grid system is a little higher. I am willing to bet you will spend more like $50,000 unless you are willing to make some changes.





And if you are not sure of yourself I would make sure you have someone around that knows about wiring. You will only be using at most 48 volts on the dc side and 120 volts on the AC side but if wired wrong you could burn down your home. If you do not size the wires correctly they will over heat.





But yes you can get pre packaged system that can be grid tied and stand-alone in the same unit. I know of no off grid systems that come in a package deal. But a grid tie with battery backup would work just as good. Just add a enough batteries to the system to cover your needs.





Here is a link to some packages that come with everything you need and with installation documents.





http://store.oynot.com/gtb-grid-tie-back鈼?/a>
Depends on how much electricity you use...





Low useage... you can set up a 18 watt solar panel, charge regulator, a couple of Gel-Cell 12 V batteries and LED based light bulbs. Very efficient. About $300.





To power an average house (1200 to 2000 sq ft) ... you'll need $20,000 to $30,000 worth of panels, batteries, regulator, inverter....
Our solar system cost $40,000 (CA) for a 2,200 sqft home. But, we didn't size the unit large enough %26amp; have had bills th last 2 years. We were talking about buying more panels; until we came across the XPower Energy Saver, it's working great %26amp; alot cheaper.


A solar company can get you an estimate to generate for your cabin, but I've not heard of a do-it yourself kit that works. We used Borego solar in CA.





If you already have electric %26amp; want to save money.... get an XPower. Basically, it's a storage %26amp; conditioning device.


It only cost $250.00. The company advertises to cut your electric bill by 25%; but we were closer to 50%.





Good luck!

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