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Thinking about next year, also known as my first year with a computerized light show, I have many questions that I need to figure out before I start buying controllers and lights.
My display will be built over a few years (the budget thing) and be over 300 channels when done. I know it sounds like a lot, but it really isn’t because most items will be 4 colors which will quadruple the required channels.
The power requirement questions stem from the “Wacko” idea I have on designing a solar panel system to power it. It also has to make economical sense to build before I start. That’s why I have a few questions.
Does anyone here have any idea how long 6 car batteries could power an average of 8000 to 10,000 LEDs continuously for? Also, any idea what size, in watts, solar panel would be needed to recharge the batteries to maintain the show?
I would rethink using car batteries as your storage system. They are designed for high amperage short burst of power and will fail very quickly when used in a high drain application.
If you Google solar power there is a huge amount of information of panels, systems and storage types and requirements. You may be better off to just push the power back into the grid during the day when the panels are working and then draw off the grid at night. Managing a system in this fashion would circumvent the need for the batteries and the labor that is required to maintain them. In order to calculate the standby capacity you will need to know the amp hour capacity of the batteries you will be using and then divide that by the draw.
grump010 wrote: I would rethink using car batteries as your storage system. They are designed for high amperage short burst of power and will fail very quickly when used in a high drain application.
On the batteries I have a pontoon boat with 2 deep cell batteries and a John boat that has one. I also have friends that are willing to lend batteries during December as ling as I return them in spring fully charged.
The reason for solar powered is I want a Christmas display that will change traffic patterns in my neighborhood. My wife is not as enthused about this as I would like. She would like landscaping lights for the house, trees, walkways, ect. She also is considered about the cost of the electricity for the Christmas display. Unfortunately her eyes glass over when I talk about watts, full wave or half wave, total amperage, and other things like that. When I estimate the cost on the electric bill it isn't based on anything I've done yet. Just an estimate.
When we were Menards she noticed the 50 light C7 solar LED sets and suggested I use those. But I'm not sure how much I would need to modify them to use on a computerized display. Also the idea of having 100 or so of those 3x5 solar collectors all over the yard is not the look I'm going for. So I asked her "what if I built a solar system that could handle the Christmas display as well as everything you want in a landscape display for the other 11 months, how about that?" The idea of purchasing hardware once and nothing for the electricity for both projects sounds great to her.
If there is any way I can design and build the system, many of the lights I would buy would move in the yard depending on what display is currently in use. I could custom build many of the light fixtures to be used on both. But then again... If there is no way to economical build this I will go the easier way by having each one separate.
6 car batteries in series will give you around 72 volts. Are you intending to use DC control boards? If so their max v's is usually 60 volts. Are you handy with electronics as it is possible to use 1 DC channel to switch on up to 10 loads or combo's if you don't want to control brightness of the loads. Are you going to use commerical strings or make your own? If you make your own you can control the current draw to the recommended max of 20ma per series array of leds - 16 3.2v leds across 60 volts with a limiting resistor of 440 ohm will draw 20ma. So if you had 16,000 leds that would be 20 amps. And if your batts were 60 Ahr they SHOULD last 3 hours - perhaps!
____________________ John Muldrock
Hawera - Taranaki''Why would anyone not want to be here'' - Tom Cruise during the TARANAKI filming of the 'last Samurai Movie'
NEW ZEALAND http://www.kamahilights.com
I think you are waaaaay over thinking this project.
8-10,000 LED's will not use much electricity at all. In my opinion, you will be spending much more on the solar panels, regulators, storage batteries, etc (plus replacements) then you would ever be able to recoup in savings on electricity.
In addition, the "standard" animation controllers and off the shelf LED Christmas lights would not work with your idea. You would need to use the DC controlers and custom make all your own light strings. (EDIT: Unless you are then going to convert the DC back to 120 volts AC. More $$$$)
Not saying it can't be done, and in fact it would be kinda cool, but if your onlyreason is to save money on the electric bill, then IMO you would be spending at least 5 times as much as the electric cost for such a small amount (approx 10K LED's ) would ever use.
Not trying to be negative or "shoot your idea down", just don't think you would SAVE any money, if that was your goal.
Last edited on Tuesday January 1st, 2008 01:40 pm by JBullard
JBullard wrote: I think you are waaaaay over thinking this project.
8-10,000 LED's will not use much electricity at all. In my opinion, you will be spending much more on the solar panels, regulators, storage batteries, etc (plus replacements) then you would ever be able to recoup in savings on electricity.
In addition, the "standard" animation controllers and off the shelf LED Christmas lights would not work with your idea. You would need to use the DC controlers and custom make all your own light strings. (EDIT: Unless you are then going to convert the DC back to 120 volts AC. More $$$$)
Not saying it can't be done, and in fact it would be kinda cool, but if your onlyreason is to save money on the electric bill, then IMO you would be spending at least 5 times as much as the electric cost for such a small amount (approx 10K LED's ) would ever use.
Not trying to be negative or "shoot your idea down", just don't think you would SAVE any money, if that was your goal.
waaaaay over thinking this project... Is the way I do most projects. By over thinking I can usually bypass some big mistakes. But not always. I already have a inverter on the boat, plenty of batteries at my disposal. miles of several different types of wire, and have plenty of time to find the solar panels at a discount. The panels and some more lights should be my only out of pocket money to start.
Saving money on the electricity will just be a bonus if and when I accomplish it. Being able to build the display of my dreams while overcoming any domestic objections before they arise is my main objective. But... YES, I do plan to have it pay for itself within 3 years and then save me money after that.
Don't worry about shooting down my idea, I have lots of people shooting at my ideas. I'm sure that more than a few members here, while designing their first display heard something like "What? Are you nuts? You can't do that!" from friends, family members, and total strangers.
grump010 wrote: You may be better off to just push the power back into the grid during the day when the panels are working and then draw off the grid at night. Managing a system in this fashion would circumvent the need for the batteries and the labor that is required to maintain them.
Happy New Year
I've been looking around to try to get educated on the topic and I'm finding that I will need a special Grid-Tie Inverter to connect to the grid. The ones I've found have been really expensive. If anyone knows of somewhere to buy them cheap or even build one, I would love to know. To define expensive... The ones I've found are $1400 and up(to the stratosphere). I usually throw nickels around like they are manhole covers. And, Happy New Year right back to you!
kamahilights wrote: 6 car batteries in series will give you around 72 volts. Are you intending to use DC control boards? If so their max v's is usually 60 volts. Are you handy with electronics as it is possible to use 1 DC channel to switch on up to 10 loads or combo's if you don't want to control brightness of the loads. Are you going to use commerical strings or make your own? If you make your own you can control the current draw to the recommended max of 20ma per series array of leds - 16 3.2v leds across 60 volts with a limiting resistor of 440 ohm will draw 20ma. So if you had 16,000 leds that would be 20 amps. And if your batts were 60 Ahr they SHOULD last 3 hours - perhaps!
As I see the basic design in my head, I'm currently planing to use the batteries in parallel using an inverter to go to 110vAC. The run from solar panel to the yard is 60' to 160' depending on where the fixture is and the path of the wire. If my memory is correct making a run that long with 12vDC I will lose most of the power within the wire itself. I think thats why ComEd uses AC. I've been told that low voltage DC doesn't travel well through long wires.
For the mega trees I'm planning on using commercial LED sets using 110vAC. I don't want any problems on anything large. The lights around the windows will be home made strings on DC. Mini trees and smaller things in the yard are still in the air as to AC or DC. I need to test my abilities on custom making short strings first. The boards look like they will be split 50-50 for AC & DC.
The jury is still out on if I will proceed on this or not, but I think I will. I have the better part of a year to do it and I don't have to have the whole thing completed in 2008. I'm still planning on making this a 3 year build-up. I'll let you know next November if I did it.
For that type of draw on batteries you need to go with 6 volt golf cart batteries.
Wire 2-6 volt in series for 12 volts, and then parallel more pairs to add capacity. You get 2-3 times the aH than car batteries or Deep Cycle. As far as the inverter it will take a high quality smooth AC line to power electronics. The LED's will work fine with even a cheap inverter, but the controllers won't be happy. I have 2-6 volt's in my boat with a 2500 watt pure sine and I can run lights, stereo, amp, water pump and fans for about 14-18 hours before I need to recharge. The microwave and TV/DVD will drop that down to about 8. (I did leave the stereo and 250 watt amp on for about 2 weeks once. Thought it was funny that the neighbors were playing the same songs I had on my iPod, until I realized it was in MY backyard.)
The other issue is to be able to recharge by the next show. Usually solar power only gets about 5 hours of sun to recharge depending on the location of the panels. So it will take quite a few panels to produce the aH you need by the next day.
I use 7-6 volt batteries in my cart (42 volts) and at 1/2 charge it takes 6-8 hours at 10-15 amps DC to fully recharge. In my lift I have 4-6 volt (24 volt) and it will charge in about 3 hours.
If you set it up correctly, you could use it year round. 115 AC in the house/garage or power DC lights directly for landscaping and such.
Another way to acquire batteries is to contact the local cellular or wireline telephone companies ( Field Operations or the Build Dept.). They have a prescribed maintenance schedule for their battery plants and when they don't meet specification they are replaced. The out of spec batteries are given away to anyone that will take them, usually battery recyclers will take and rebuild them. I acquired two full 24V, 880 amp hour stack, we rearranged the bus bars and now have 4 12V battery stacks. We use them at our RC Model flying field to power the alarm system, IP camera and recharge power packs for electric airplanes. These stacks are still humming away after 2+ years. This system is recharged with a combination of a wind generator and a couple of solar panels, works reasonably well most of the time.
