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Posted

John... Just a word about trying to use solar to any great extent and relying upon it in areas north of 40 degrees latitude...

 

A few years ago, I was asked to participate in a local power company seminar regarding the future of solar energy.  The meeting was scheduled for a full 8 hours but was terminated after only 90 minutes because several engineers and heating/air conditioning company owners spoke up unanimously discounting solar due to the shallow sun angle most of the year north of 40 degrees latitude, the short sunlight time periods available to hit the panels roughly 8 months of the year and snow cover obstructing the panels.  While technology of solar panels may be a bit more efficient these days, the physics of sun availability in the northern climates is still a primary factor in unreliable system operation.  Do your own study on the average number of cloudy days in your area as well as the number of hours of good sun angle that would actually hit the panels properly and yearly snow fall, and you may see that solar is not what it is pronounced to be in the north by 'green' lobyists.

 

Jumping in to this technology in northern areas may be disappointing, so please do your homework before you get financially involved.

 

As an example... several communities in my area have TRIED to use solar to power flashing LED traffic advisory signs through the night time hours. All of them have been replaced by hard wired signs because there is insufficient solar generation up this way to keep the batteries charged for operation through the night.  I can travel around my area for several hours and try to find solar panels without success, and even when a framework is spotted, the panels are covered with snow and are not operational.

 

These systems may work in more southern climates, but from the personal experiencese I have seen myself and heard about from others, it is a waste of money in the north. Best of luck to you in your research.

Posted

thanks Gary.

maybe a wind/solar combo would be better. I'm roughly 41*31'23" but surrounded by 50'+ white pines. the other problem being a non heated shack w/regard to the batteries.

really don't want to do an 800'+ electrical run just for the radio and there are too many rules about doing that here.

Posted

John, I have played with Solar for quite some time and have built quite a few of these solar generators for friends.  If you just want to run a shed/garage on a small scale (radios, small power tools, a few lights) that can be done fairly easy.  It is when you try to run household appliances on a normal basis that solar becomes not very viable. 

 

A 100/200  Watts of panels and two Series 27 125 aHr Marine Deap cycle batteries, 1000 Watt quality inverter and 15 Amp solar charger regulator  you could easily keep you radio running 24/7 on DC and have enough juice to run the inverter for hours at a time with small items (drill, lighting, etc.)  I do it all the time.  Make your lighting LED and you can have it on 24/7 as well.

 

The unit above was my research platform, 1 deep cycle battery 2-20 Watt Solar Panels, 10 Amp charger regulator and a 800/1200 Watt invertor.  I powered my repeater on it for two days without a charge, it was used during Sandy quite extensively as a portable battery charger/generator and lighting station.  It will run a 3/8 drill and circular saw.  I have found that 40 Watts/3.5 Amps is the minimum you want to use to maintain a deep cycle battery, that is why I recommended 100 Watts for two, that extra amp will give you a greater charge efficiency.  If you can go bigger there is nothing wrong with that either, you can always add a panel if you feel your system does not replenish fast enough.  It was my intention to set this up in my shed but have not got around to it.  When I relocate I plan on setting up and entire detached garage via solar to include 24 volt Marine/RV appliances.  On a small scale it is very doable.  Bill

 

 

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Posted

Here in south Florida, we have a retailer USsolar, they sell high quality 255 watt solar panels for about $230 bucks each. They also sell Trojan battery's and charge controllers. I do go to harbor Freight, but I would never consider their plastic mono solar panels. They are basic "Junk" I am aware of solar panels being used effectively as far north as Alaska. with necessary high inclination of panels at such latitude, snow accumulation on panels would be minimized. I love Solar power and here in Florida it's a "no brainer" I remember the last time I was in New Jersey the local utility had placed solar panels on top of each utility pole. not very attractive looking but it works. Our new house is just 3 weeks from Finnish and includes 6800 watt's of solar panels on our southern exposure. 

Posted

good info gentlemen, thanks.

plan is to make a 4X8 shack and a 60' tower. undecided on weather to put panels on top of shack or the tower. if I can side arm a small wind turbine on the tower and do a hybrid system I think that would better serve me in the winter.

the repeater will be set to 45W w/no CW ID. on paper it specs .8A in standby .3A w/pwr save, 12A in TX and 1.2A RX. I will have to factor in the RX pre amp also. looking to do 400 AHr b/c once the snow comes I'll have no way to get back to where it will be.

 

thoughts.........

Posted

John, I would use the roof of the shack to my advantage.  Align it for the best exposure time and angle being that you are going to build it from scratch.   It is going to be the best average angle because the suns angle changes by the season but I would optimize it for the winter since there is less sun then.  I also like the idea of the wind turbine.   That would help quite a bit on cloudy and snowy days.  I think 400 amp hours is plenty or storage for the repeater. 

 

Here is some information on the alignment by region and season.  http://solarelectricityhandbook.com/solar-angle-calculator.html

Posted

I just finished up an off grid project on our classroom. My advice would be to always oversize what the calculators say you need. You will lose efficiency over time on both the planels and the batteries. I have three 200 watt panels on the roof with 560 Ah of wet cell batteries. It runs everything I need for 3 days of classes (lights, computer, big screen TV for power points, on demand water pump, etc. but bad weather and winter reduces its capability. I started with 400 watts of panels and that wasn't enough so I added another. I live in Alabama so that's an advantage over higher latitudes.

Posted

good info gentlemen, thanks.

plan is to make a 4X8 shack and a 60' tower. undecided on weather to put panels on top of shack or the tower. if I can side arm a small wind turbine on the tower and do a hybrid system I think that would better serve me in the winter.

the repeater will be set to 45W w/no CW ID. on paper it specs .8A in standby .3A w/pwr save, 12A in TX and 1.2A RX. I will have to factor in the RX pre amp also. looking to do 400 AHr b/c once the snow comes I'll have no way to get back to where it will be.

 

thoughts.........

There is another thread around here about keeping your cool, discussing how to deal with heat.  You are talking about putting a shed up in snow country.  May I suggest you might need to worry about cold.

 

I don’t know how cold it really gets where you are, but you mentioned that once the snow comes you won’t be able to access the site.  You may want to consider if operating a repeater in an inaccessible location is a good idea.  There is an FCC rule stating that the operator must have access to his station.  What if it malfunctions and starts causing harmful interference?  Will you have reliable remote control?  It’s not like you’d have to be Johhny on the spot, but if you have problem on Christmas Eve, the FCC is not going accept that you won’t be able to resolve a problem until Easter J.  You got snowshoes?

 

Since you said the snow makes the site inaccessible, can I assume it gets really cold?  You should consider that you might have to heat the shed.   I can tell you a story about freezing a brand new radio the first night it was installed on one of our mountaintops in the Sierra just a few months ago. 

 

Also keep falling ice in mind.  You might not want your tower right next to your solar panels, or your shed if it doesn’t have a pretty sturdy roof.  If you get icicles on your house, assume they will be on your tower and will fall . . . on your panels.  Ice also adds weight.  I don’t design our tower installations but I have been told that we can’t add anything to a couple of our towers because they don’t meet current ASNI requirements.  The rules we work under now require us to consider ½ inch of radial ice on the tower in addition to wind speed at elevations as low as 2000’ where we are in CA when we want to add any equipment.

 

I have seen frozen batteries burst.  Well, I have never watched them burst, but I have come into rooms with broken cells and electrolyte all over everything.   Most sites don’t use flooded cells anymore so it is not as big a hazard, and there are several very well made AGM batteries that seem to hold up in extreme environments. 

 

There are plenty of examples where radios survive subzero weather in flimsy cabinets is drafty buildings on 9000’ mountains.  I got one of those  -  and it made realize just how tough GE Mastr III base stations are.  J  But I get just as concerned about my gear when it’s below freezing as I do when over 100.

Posted

 my only real concern is the duplexer de-tuning in the cold.its been down to -10 this yr but this was no ordinary yr by far. all of the other equipment is rated from -20 to +140 so no real issue there. as for batteries looking AGM or possibly Lithium ion, still researching that.

  • 1 month later...
Posted

I got my hands on a bunch of 35AHr batteries from a PM job we're doing. most of them have an in service date of 8/13 and they were just back up batteries. have 10 so far but I think 2 are much older so I may toss those. there are suppose to be 6 more coming , keeping my fingers crossed.

w/this in mind I will be able to test how much charging power I will need to keep up the charge while in use. the whole thing can be set up in my garage running on the batts.

Posted

tossed the tower idea in favor of going to one of the trees. going to take pics/vid of the site as is right now and will post later. I need to get a better idea of how tall those trees really are, best guess is ~80'.

browsed posible mouning ideas today at work today but I don't know if drilling a couple of 5/8 holes through it is such a good idea.

http://www.tessco.com/products/displayProductInfo.do?sku=29248&fromSuggestion=true

http://www.tessco.com/products/displayProductInfo.do?sku=15433&eventGroup=4&eventPage=1

thoughts..................

Posted

I also dislike drilling into trees. I wish I had an 80 foot tree. I can think of a lot of ways to mount to a tree w/o drilling into it. I think you would want to shut it down during electrical storms, unless it were grounded? but then again, a ground would attract lightning. lol

Posted

Actually, if you think about it trees ARE grounded - evergreens more so than leafy, deciduous trees.  Evergreens usually have active sap present year round which makes a thick-liquid path to ground. 

 

:D  :D :D  

 

Monitor your SWR when the wind is blowing and the antenna is wavering... the meter can look like a windshield wiper on really windy days...  ;)

Posted

checked voltages today and 2 were 6V or less. going to try to reserct them, the rest were 12.6 or better. put together a bank of 3 and put them on my float charger. will see how long it takes to flip to the float mode.

going to move this to a new thread in the general dicussion forum.

Posted

depending on the size of the battery's and the float charger output. I have a 1.5 amp float charger and two T105 6volt battery's I think 225 AH each, is unable to float these battery's. I think your needs will differ. I am guessing a 1.5 amp float can maintain 70 to 100 AH. at best. but it could be me and or my setup. I have 8 of these T105's They have been sitting left fully charged since I took the panels off of my roof 8 months ago. took 24hrs each at 10amps. to top them off. Would have taken 4 to 5 hrs with the solar panels for all 8.

Posted

moving this here to keep you guys updated on how this is moving along.

here are the batteries I aquired. the bank of 3 on the rigrt are on a being charged w/battery tender jr. the dates were the in service dates. these things are practally new.

http://i1105.photobucket.com/albums/h358/erscom/off%20grid%20site/DSCN0083_zpsde43ad0c.jpg

last I checked voltage was 12.3V, I expect it to turn over by morning. these were the 3 batteries that were in doubt and had no in service dates on them.  as it turns out I had 2 otheres that were rundown to 6V or below. one of those is on my big charger/booster for the car set for 2A charge.. it has a a 2A,20A and a 60A settings as well as 250 boost.

shot some vid at the site but wasn't happy w/it so that will have to wait for now.

Posted

Very nice!  One thing though, I would charge them individually initially to determine the health of the individual battery, if bad you can eliminate that one.  When charged in the bank of three like that you are only as good as the weekest link.  Once you know the health of the individual batteries then you can charge them together to determine what the proper average voltage you are going to have. 

Posted

thanks PG, was looking for a way to do that.

 

the bank of 3 turned over today,going to leave on float till Friday night   at that time I will separate them and let stand overnight then take individual voltages in the morning.

on the bad one it came up but next morning it was at 7V so I think it safe to say that one is a goner.

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