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Please school me on solar panels/batteries.
4/4/2012 9:13:45 AM
I want to start using solar power and I figured I would do it by powering a shed I have on the property.
I would like to have enough power to
A) Run a light or two.
B). Possibly run power tools
Can someone help me with size of panel I would need,batteries etc.
I am a complete noob when it comes to solar power please forgive me if this topic has been beaten to death.
Thanks
vm1970
I would like to have enough power to
A) Run a light or two.
B). Possibly run power tools
Can someone help me with size of panel I would need,batteries etc.
I am a complete noob when it comes to solar power please forgive me if this topic has been beaten to death.
Thanks
vm1970
4/4/2012 2:28:32 PM
OK, I'll start the arguments. 
First off, I would give up on running power tools. I have a 3,000 watt inverter on my system and it will NOT start my 10" chop saw. Compressor –– no way! The start-up loads are just too high.
Sizing the system depends on a LOT of variables. Basically, I try to stick to watt-hours out = .75 * watt-hours in. If you want to run 100 watts of lights for four hours a day, then you need about 550 watt-hours of solar power going in. If the sun shines bright for 5 hours a day, then you need at least a 110 watt solar panel. Less sunshine, more panels.
As far as batteries go, golf cart batteries are better than marine deep cycle batteries because they are designed to handle lots of cycles to very deep discharge. There are batteries designed specifically for solar systems, but they can get very pricey. There are hundreds of charge controllers and inverters on the market. Some really good and some not so good. As with the panels, I would pick an inverter and charge controller with at least 25% more capacitiy than you think you need.
Also be aware that most inverters put out what's called modified sine wave power that can cook electronic devices like computers. Pure sine wave inverters are available at a higher cost.
I'll stop here because going further would require a lot more specifics. There are also some forums for solar power out there as well. I joined one and got lots of good info before I built my system.
First off, I would give up on running power tools. I have a 3,000 watt inverter on my system and it will NOT start my 10" chop saw. Compressor –– no way! The start-up loads are just too high.
Sizing the system depends on a LOT of variables. Basically, I try to stick to watt-hours out = .75 * watt-hours in. If you want to run 100 watts of lights for four hours a day, then you need about 550 watt-hours of solar power going in. If the sun shines bright for 5 hours a day, then you need at least a 110 watt solar panel. Less sunshine, more panels.
As far as batteries go, golf cart batteries are better than marine deep cycle batteries because they are designed to handle lots of cycles to very deep discharge. There are batteries designed specifically for solar systems, but they can get very pricey. There are hundreds of charge controllers and inverters on the market. Some really good and some not so good. As with the panels, I would pick an inverter and charge controller with at least 25% more capacitiy than you think you need.
Also be aware that most inverters put out what's called modified sine wave power that can cook electronic devices like computers. Pure sine wave inverters are available at a higher cost.
I'll stop here because going further would require a lot more specifics. There are also some forums for solar power out there as well. I joined one and got lots of good info before I built my system.
4/4/2012 2:55:04 PM
Great place to do some reading, tons of info and folks are great at helping out.
http://www.wind-sun.com/ForumVB/forum.php?s=0f84fa10ec919f13a50297978799c916
http://www.wind-sun.com/ForumVB/forum.php?s=0f84fa10ec919f13a50297978799c916
4/4/2012 4:25:57 PM
Well, for balance, we ran mod sq wave inverters for 9 years in 2 locations and never had a problem "burning computers out". Multiple PC's too, laptops, etc, modern supplies aren't an issue.
PC's use switching supplies and they don't care in our experience and tech knowledge.
In the past year or so we did switch to sinewave inverters because prices have -fallen- so far for them. Xantrex Prowatt Sine series on ebay.
Now they're well worth it.
As far as starting a chop saw, we have a 12" Dewalt radial arm saw, that chokes a Wacker light tower running on 1/2 of it's 6000 windings/watts rating, but the Honda EU2000 and the Xantrex 1800 sine wave inverter runs it OK. But close to the limit.
And I only have 2 ga wire from the batteries and maybe 15 feet of it to the inverter.
The figger 75% rule is good.
Solar panels are at amazingly low prices right now and a couple of us have stocked up at a little over $1.30 a watt.
There is the danger of them being damaged or stolen in a SHTF just like there is your propane tank getting a few holes in it or stolen.
PC's use switching supplies and they don't care in our experience and tech knowledge.
In the past year or so we did switch to sinewave inverters because prices have -fallen- so far for them. Xantrex Prowatt Sine series on ebay.
Now they're well worth it.
As far as starting a chop saw, we have a 12" Dewalt radial arm saw, that chokes a Wacker light tower running on 1/2 of it's 6000 windings/watts rating, but the Honda EU2000 and the Xantrex 1800 sine wave inverter runs it OK. But close to the limit.
And I only have 2 ga wire from the batteries and maybe 15 feet of it to the inverter.
The figger 75% rule is good.
Solar panels are at amazingly low prices right now and a couple of us have stocked up at a little over $1.30 a watt.
There is the danger of them being damaged or stolen in a SHTF just like there is your propane tank getting a few holes in it or stolen.
