# Solar powered generators



## Piney Woods (Jul 5, 2006)

Has anyone seen or used one? I just heard of one today. If so, any recommendations? This is for Texas (plentiful sun).


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## MattB4 (Jan 3, 2016)

The ones I have seen like the Goal Zero units are highly overpriced for little usable power. They rely on the fact that people are unsophisticated about electrical power. 

Solar panels are nothing new and information about their capacities are wide spread. Always keep in mind that most folks buy utility power at 12 cents per kilowatt-hour or less. A kilowatt- hour is 1000 watts being used for one hours time. 

So a 15-30 watt solar panel coupled to a small 20amp-hour battery with a 300 watt inverter is not much of anything. Compare that to a bug gas generator producing 800 watts using 1/3 of a gallon gas per hour that you can buy at HF for less than $100.


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## Roadking (Oct 8, 2009)

I have purchased panels and controllers from amazon...company renogy...easy to make your own generator. Buy the panel, charge controller and make a battery bank...less expensive and higher output per dollar.
I started small to see if it worked for what we wanted. If you look into it, it is a better way to go, IMO.
Gotta agree with MattB4...prepackaged generators are sort of today's snake oil; check ot the Alternative Energy forum here...lots of insight. I learned a lot from our members.
http://www.homesteadingtoday.com/alternative-energy/

Matt


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## ET1 SS (Oct 22, 2005)

I am on Solar-Power.

We shifted to it last September.


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## cfuhrer (Jun 11, 2013)

Glenn Beck promotes this one.

http://www.endlesspowernow.com/fb.h...medium=FB_EPN_NOV20&utm_campaign=FB_EPN_NOV20


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## ET1 SS (Oct 22, 2005)

cfuhrer said:


> Glenn Beck promotes this one.
> 
> http://www.endlesspowernow.com/fb.h...medium=FB_EPN_NOV20&utm_campaign=FB_EPN_NOV20


Two 100 watt panels, in 5 hours of day-light, can produce roughly 1,000 watt/hours of power.

If you charged a battery-bank with that power, with a 20% loss in the process, you would get roughly 800 watt/hours of charge into the battery.

Enough power to run an electric coffee maker for about 30 minutes, once a day.

Compact Kenmore refrigerator uses around 70 watts to operate. So you could power such a refrigerator for maybe 10hours each day.

At $2,500 that is NOT a good price.


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## TnAndy (Sep 15, 2005)

cfuhrer said:


> Glenn Beck promotes this one.
> 
> http://www.endlesspowernow.com/fb.h...medium=FB_EPN_NOV20&utm_campaign=FB_EPN_NOV20


True snake oil salesmanship.

Everything MattB4 said about them is true....underpowered, overpriced...and depending on people that know little about electric power to buy them.

Either buy a GOOD generator (like a Honda) if you need emergency power, and keep it maintained so it will start when you need it to start

OR

Get serious about solar power, and learn how to make it work for you.

But avoid these 'solar generators'.....if you see that term, you're about to be fleeced.


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## Harry Chickpea (Dec 19, 2008)

Yep. Someone asked about them a year or two back when they first came out. They are overpriced toys for the rich who want to play solar. The use of the word "generator" is a misnomer meant to entice suckers. An electric generator takes power that is rotational energy and generates electricity. A solar system uses photovoltaic cells for the conversion of light energy to electric energy. That energy is then converted or massaged into a form that is more usable by an inverter.

When I read the words "solar generator" I read "uneducated huckster trying to scam the gullible."


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## cfuhrer (Jun 11, 2013)

ET1 SS said:


> Two 100 watt panels, in 5 hours of day-light, can produce roughly 1,000 watt/hours of power.
> 
> If you charged a battery-bank with that power, with a 20% loss in the process, you would get roughly 800 watt/hours of charge into the battery.
> 
> ...


I didn't say anything about their efficacy or efficiency. The OP asked for sources and that is one I had heard of.


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## cfuhrer (Jun 11, 2013)

TnAndy said:


> True snake oil salesmanship.
> 
> Everything MattB4 said about them is true....underpowered, overpriced...and depending on people that know little about electric power to buy them.
> 
> ...


I didn't say anything about their efficacy or efficiency. The OP asked for sources and that is one I had heard of.


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## terri9630 (Mar 12, 2012)

ET1 SS said:


> Two 100 watt panels, in 5 hours of day-light, can produce roughly 1,000 watt/hours of power.
> 
> If you charged a battery-bank with that power, with a 20% loss in the process, you would get roughly 800 watt/hours of charge into the battery.
> 
> ...




5 hrs of sun? Here in the desert the winter suns up from 6am to about 5pm. Even longer in summer. Who only gets 5 hrs a day? That would really suck....


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## DaveNay (Nov 25, 2012)

terri9630 said:


> 5 hrs of sun? Here in the desert the winter suns up from 6am to about 5pm. Even longer in summer. Who only gets 5 hrs a day? That would really suck....


Solar efficiency is highly dependent on the rays of the sun being perpendicular to the solar panel. As the angle changes, efficiency drops dramatically. The two hours after sunrise and before sunset, the panel might only be generating 20% of it's rated capacity. Peak capacity is only reached for a couple hours right around solar noon.

Here in the "not desert" solar panels are not very efficient in the winter. (the angle of the sun in the winter months makes a big difference too)


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## terri9630 (Mar 12, 2012)

DaveNay said:


> Solar efficiency is highly dependent on the rays of the sun being perpendicular to the solar panel. As the angle changes, efficiency drops dramatically. The two hours after sunrise and before sunset, the panel might only be generating 20% of it's rated capacity. Peak capacity is only reached for a couple hours right around solar noon.
> 
> Here in the "not desert" solar panels are not very efficient in the winter. (the angle of the sun in the winter months makes a big difference too)


That makes sense. Couldn't the angle of the panels be.adjusted to match the angle of the sun? That's what I do with my solar oven to keep it in the 3-350 range in the winter.


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## ET1 SS (Oct 22, 2005)

terri9630 said:


> 5 hrs of sun? Here in the desert the winter suns up from 6am to about 5pm. Even longer in summer. Who only gets 5 hrs a day? That would really suck....


Websites say that in my location we are supposed to get 5 hours of usable sunlight per day at Winter Solstice.

We find In-Real-Life that we are charging batteries at around 8am and we are still charging around 3pm.

Usually by 10am our Battery-Bank is at or near 100%. So from 10am on the electricity is wasted.


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## ET1 SS (Oct 22, 2005)

DaveNay said:


> Solar efficiency is highly dependent on the rays of the sun being perpendicular to the solar panel. As the angle changes, efficiency drops dramatically. The two hours after sunrise and before sunset, the panel might only be generating 20% of it's rated capacity. Peak capacity is only reached for a couple hours right around solar noon.
> 
> Here in the "not desert" solar panels are not very efficient in the winter. (the angle of the sun in the winter months makes a big difference too)


My panels are mounted in a method that allows the angle to be adjusted.

We have: a Summer Solstice angle, a Spring and Autumn angle, and a Winter Solstice angle.


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## wy_white_wolf (Oct 14, 2004)

terri9630 said:


> 5 hrs of sun? Here in the desert the winter suns up from 6am to about 5pm. Even longer in summer. Who only gets 5 hrs a day? That would really suck....


 Solar insolation and daylight are different things. Insolation has to do with the amount of energy available for PV. Morning and evening there is less energy available in sunlight as it has to travel further through the atmosphere. Solar panels work towards the violet end of the spectrum. That end is affected more than the red end. Your solar oven works closer to the red end as it is a thermal collector. Yes, trackers do help but only increase the output of solar panels by about 25%. 

The figure is also a daily average for the month. Cloudy days really have a drastic affect on the number.

WWW


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## GREENCOUNTYPETE (Jul 25, 2006)

terri9630 said:


> 5 hrs of sun? Here in the desert the winter suns up from 6am to about 5pm. Even longer in summer. Who only gets 5 hrs a day? That would really suck....



sun , haven't seen it since it was in my eyes tuesday morning , of course I drove home from work in the dark you can have one or the other these days not both till march

some time in march till some time in October so about 7 months we get to drive to work in the light and home in the light 

I think what they are saying is even when we get like 8 hours of sun on Dec 21 it is only usable over head for 5 hours it has to get above so many degrees off the horizon to be usable 

I think 5 hours is more of a hours of useful charging light average


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## ET1 SS (Oct 22, 2005)

wy_white_wolf said:


> Solar insolation and daylight are different things. Insolation has to do with the amount of energy available for PV. Morning and evening there is less energy available in sunlight as it has to travel further through the atmosphere. Solar panels work towards the violet end of the spectrum. That end is affected more than the red end. Your solar oven works closer to the red end as it is a thermal collector. Yes, trackers do help but only increase the output of solar panels by about 25%.
> 
> The figure is also a daily average for the month. Cloudy days really have a drastic affect on the number.
> 
> WWW


MPPT technology focuses on fixing that.

As soon as sun-light kits our array, we are charging the battery-bank.


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## terri9630 (Mar 12, 2012)

Thanks y'all. The only thing I know about solar is that it will cook my dinner. The rest is written Klingon or some other language I don't understand.


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## TnAndy (Sep 15, 2005)

cfuhrer said:


> I didn't say anything about their efficacy or efficiency. The OP asked for sources and that is one I had heard of.


I understand you were simply offering an example.

My comments were directed to the equipment and Glenn Beck's endorsement of junk, not you.


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## texican (Oct 4, 2003)

I'd pass on any kind of solar 'generator'.... you're paying for something that really doesn't exist. The concept of 'generator' makes one think of on demand power, whereas solar power is anything BUT on demand.

Panels are dirt cheap. Get a few, a controller, a battery pack (bigger the better) and a 12vdc outlets, and an inverter. You can get several times as much energy out of the equation for the same amount of money....

You're NOT going to move around a 'generator' with a big enough battery pack to actually be useful. When I was offgrid, the smallest battery I had (6v deep cycle... needed two to make 12v) weighed ~70lbs or so.... 140 or so for 12v...


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## terri9630 (Mar 12, 2012)

texican said:


> I'd pass on any kind of solar 'generator'.... you're paying for something that really doesn't exist. The concept of 'generator' makes one think of on demand power, whereas solar power is anything BUT on demand.
> 
> Panels are dirt cheap. Get a few, a controller, a battery pack (bigger the better) and a 12vdc outlets, and an inverter. You can get several times as much energy out of the equation for the same amount of money....
> 
> You're NOT going to move around a 'generator' with a big enough battery pack to actually be useful. When I was offgrid, the smallest battery I had (6v deep cycle... needed two to make 12v) weighed ~70lbs or so.... 140 or so for 12v...


You could build a cart for it.


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## texican (Oct 4, 2003)

terri9630 said:


> You could build a cart for it.


A cart would work... even better so you could revolve it every few hours to maximize solar gain... one of the weaknesses of fixed mounts.


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## Tomcat58 (Mar 21, 2016)

My grid power goes off now and then but not enough to get into a expensive solar system. But not knowing what the future will bring I have a small Honda 2000i generator and I built a mobile solar generator. But solar is to expensive to just let it sit and wait for a power outage so I built a solar canoe and use it to fish and enjoy water ways and when i not on the water I use it to charge my RV, and for power at remote work sites. Every ones needs vary so your needs will surely vary. https://sites.google.com/site/serenitysolarcanoe/


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## Bellyman (Jul 6, 2013)

texican said:


> A cart would work... even better so you could revolve it every few hours to maximize solar gain... one of the weaknesses of fixed mounts.


I remember of seeing a video where someone modified an old satellite dish mount (the large ones like people used to have maybe 30 years ago) for maybe 8 or 10 decent sized panels. The mount was modified so that it could move in a couple of different ways via jack motors and was capable of following the sun. It did take a bit of electricity to move the dish but I seem to recall it was an interesting setup. It may even have had a small panel and battery right there at the mount who's sole purpose was running the dish, can't quite remember. Every 15 minutes or so, it would run for just a few seconds and then at the end of the day, it would run all the way back to await the sunrise.

It's hard to imagine that a fairly simple, mechanical setup couldn't happen that would allow panels to track the sun, at least partially, even in a ground mount type setup, something that wouldn't have to be ultra expensive or take much electricity to keep the panels pointed towards the sun. (Maybe it already exists and I haven't seen it.?)


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## TnAndy (Sep 15, 2005)

Sure, there are commercial and homemade tracking mounts. You don't hear of them much now, since panel prices have come WAY down in price, the economics of trackers doesn't work any more. Additionally, what you would 'think' would be simple *really isn't. *

Commercial trackers fall in the active type...using motors and some type of sensor/controller to cause them to move...and the passive type, like Zomeworks, that use a well balanced mount with a tube of freon that boils as the sun hits it, causing the freon (and weight of the pivoting tracker) to shift from one side to the other end of the tube. This weight shift pivots the tracker during the day, at night the freon cools, returns to the other end of the tube, causing the tracker to shift back to the east to pickup the morning sun again.

When I first started my system, "way back" in 2007, panel prices were $4/watt......down from 5-6/w just a few years before. I decided to mount my panels on trackers I'd home build.

First, dig out/frame up 2 holes for 4'x4'x4' block of concrete to hold 6" steel pipe that will hold the mounts.











Then get concrete to then somehow....in my case, a pump service.











Then get a buddy to help mount the pivot part. I welded a 5' long pc of 8" wide channel to the top of my pipe, at a 37 degree angle (the optimum angle here for my latitude). On that channel, I mounted a 2" pillow block bearing with a 6' long pc of 2" shaft steel running thru the bearings (the pivot axle), then a frame of 2" square tubing onto the ends of the axle. The actual mounts for the panels ( I used uni-strut electrical stuff to mount mine) go on that pivoting 2" frame.

Then mounted the panels, and a 4' long , 24v linear actuator to drive the array east to west. The motor was controlled by a sensor mounted on the face of the array that triggered an electronic circuit board to 'jog' the motors about every 30seconds or so thru the day, then at dark, reset the array back to the east.

That was a single axis mount....east to west, with the tilt angle (37 degrees) fixed toward south.

Later, I added another, much larger array, which was dual axis.....sensor controlled in the e-w axis, and I could manually operate the actuator in the n-s axis a few times per year (Winter, the ideal angle here is 50 degrees, summer, about 25)

Now those 3 arrays make up 6,000 watts of my 11,000 watt system. Unfortunately, these type of trackers are not only expensive to set up (even though I built mine), but the controllers are a freaking nightmare....I tried 3 different ones over the years, found one that was 'semi-reliable' until the guy that made them basically quit supporting them, then it became useless. SO, my trackers don't 'track' anymore...they are bolted in the fixed noon position permanently.

AND the additional 5,000 watts I added after that are a WAY cheaper, more simple, ground mounted rack that was easy to expand. Light weight pipe/angle, little bit of concrete in some sono-tube forms, and you're good to go.











Bottom line, with panel prices under $1/watt now, it simply doesn't make sense to spend the money on tracking....it is far cheaper, and less frustrating, to simply ADD MORE PANELS....and forget tracking.


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## ET1 SS (Oct 22, 2005)

TnAndy said:


> ... Bottom line, with panel prices under $1/watt now, it simply doesn't make sense to spend the money on tracking....it is far cheaper, and less frustrating, to simply ADD MORE PANELS....and forget tracking.


I agree that tracking is not worth the effort. However mounting systems that allow you to change the angle with the seasons are worth it.


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## Bellyman (Jul 6, 2013)

Thanks for the personal history, TNAndy! I haven't seen a tracker in... probably decades. I think I have a better idea of why. 

Have you rolled around the idea in your brain about individualizing the tracking on a scale such that the pivots are not for the array as a whole but for individual panels? I have this little picture in my head of something closer to a venetian blind of rather large proportion. Maybe a stupid idea, but curious. You may have already been there, done that.


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## TnAndy (Sep 15, 2005)

No, I didn't go there.....because then you deal with multi bearings AND linkage. 

More complex = more points to fail.

Plus you might end up with a shading problem if you mounted the panels too close when you tip them to the end of the axis points....you'd have to separate them far enough to account for that casting of shadow. Not a problem for venetian blinds....big problem for solar panels.


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## TnAndy (Sep 15, 2005)

ET1 SS said:


> I agree that tracking is not worth the effort. However mounting systems that allow you to change the angle with the seasons are worth it.



Don't know. You get the most effect from daily east-west tracking. 

I assume you mean north-south axis, and mount one end of the panels (or entire array) so it pivots, and the other end with a simple mechanical way to lift or lower that end, trying to keep the panels perpendicular to the seasonal tilt. 

You'd still get into somewhat more costly mounting, even assuming you simply raised/lowered the other end by hand (jack screw, or a lever with several locking points). Again, gets back to how cheap panels are, compared to the cost of construction of such a mount (and assume you time is worth nothing to go out and change angles)

Figures I've seen say about 25% increase in production on a single axis (E-W) mount that moves every day, and about 10% on that second axis mount even if moved multiple times automatically during the year. So I'd think something you only moved 4 times/yr by hand would have to be a fair bit less than 10%...

I'd be surprised if the numbers work out over simply adding a panel or two.


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## Bellyman (Jul 6, 2013)

TnAndy said:


> No, I didn't go there.....because then you deal with multi bearings AND linkage.
> 
> More complex = more points to fail.
> 
> Plus you might end up with a shading problem if you mounted the panels too close when you tip them to the end of the axis points....you'd have to separate them far enough to account for that casting of shadow. Not a problem for venetian blinds....big problem for solar panels.


LOL!! Yup, shading would have to be accounted for.

I'll just say I have a bit of an imagination. Who knows, maybe someday, I'll have that flash of intermission for something that's new and will really work! LOL!!


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