solar panel set up

[Ajax]

anyone know a set up for a decent sized solar panel (3 x 5 etc.) to a trickle charge to a deep cell to the device-camp lights etc. I am clueless to the amperage etc. and how big of a panel I need and how much juice I can get out of it(what load I can run off of it) thanks guys Ajax

[stargeezer]

I would suggest that you give an idea what you want to get out of it, and then answers can be more specific.

How much power do you want to send to lights?

Are these all 12 lights, or are you powering them off an inverter?

If you are going to use an inverter, is there anything else you plan to plug into it?

How long do you want to power these lights and etc.?

If you can give an idea what your consumption will be, the panel can be sized accordingly. The cost of PV is somewhere around $5 per watt, so they are pretty expensive. If you have no other use for the system other than BM, you may want to consider other power options. A very basic system will probably cost $200+ not counting the cost of the batteries.

[Toolmaker]

Like SG said, one would need to know how much juice ya need in order to recommend something. The cheap ones aren't worth squat and for a decent sized setup you can get a cheap genny and battery charger that will work alot faster and without sunlight. With the Chinese burning coal like theres no tomorrow we may not have sunlight too much longer. If you're set on solar the way to go is the full size panels. I don't think something 3x5 card sized will give ya more than a couple watts. They are designed to charge AA batteries over a 8 hour period or to keep a car battery "topped off" during long periods of disuse.

[Ajax]

I was looking more for a 3 foot by 5 foot panel- can that give us some camp lighting or power a single bulb?

[stargeezer]

I was looking more for a 3 foot by 5 foot panel- can that give us some camp lighting or power a single bulb?

Depending on the type of panel, a 3x5 with adequate sunlight during the day would provide more than enough for a single bulb at night, but this is expensive for a little light.

I am going to suggest an option that you probably have not considered. There are several brands of hand crank LED flashlights. Crank them up and they store a charge and the LED drains it very slowly, several minutes anyway. For the cost of a single PV panel, you could purchase several of these and hang them around the camp. If anybody wants more light, they just have to crank it up again. These are very handy devices, and you will find several uses during the year versus the PV panel that would probably get stored for most of the year.

This is a great time of year to pick up a few strings of the LED Christmas lights. If you just use a few of these with a small inverter, you may actually get by with a single car battery for a week. If you build your own strings for 12v, as long as you don't use too many I know a car battery would last the week without needing a charge.

Unless you just have green stuff you want to burn, PV is an expensive approach to solve your problem.

[bigbluedoggy]

This past year I bought one of the Costco solar power setups for about 1400 bucks. I don't have the info in front of me, but I believe the two panels created 320 Watts of 12 volt power at peak efficiency. The system includes the two panels, the charge controller, and a cheap inverter (like one you use from your car lighter to make 110volts). I invested in a pair of deep cycle Trojan 6 volt batteries (about 450 total). I hooked these up in series to do 12 volts. By using two 6 volt batteries instead of a single 12 volt, we had higher capacity of Amp/Hours available.

The setup is incredibly simple. Just hook the panels and the batteries to the charge controller and hook your lighting and stuff to the batteries. We used the system to power most of our Fling of Destiny game. It powered the logic electronics, about 200' of chasing EL wire, UV LED lights (about 400 LEDs total) and all the audio components, including two RAM audio playback units, a small mixer and a car audio amp and speakers. We never once came close to draining the batteries and we ran the game for about 16 - 18 hours a day, from roughly 11am until 3-4am or more. Obviously, the system is more efficient in daytime when the batteries are charging while being used. We probably could have run it 24/7 but we didn't leave it unattended after we all crashed at night. The only thing we didn't run on the solar rig was the StarMaze projector that created the light tunnel effect. Next year I will probably put that on the solar as well and see how it does.

I haven't come up with anything to use this system for off playa yet, but I bought a decent trickle charger for the batteries to keep them well for now. Not sure if this is the sort of info you are looking for. I can't tell you I know all the specs on what we were doing. I was hoping I overspecced it enough to not have any issues and that seemed to work! Our Fling of Destiny is scheduled to make a reprise again this year! Come check it out at the Destiny Lounge!

[stargeezer]

I was looking at panels via the web last night and if you really want to go this route it would appear that panels are selling for at least $5 per watt, with smaller panels being more. As far as size, with a decent panel you should get at least 15 watts per square foot, which means for your 3x5 it should be somewhere around 200 watts and $1000. On the playa that time of year you should expect 8 good hours of collection during clear weather so that means 1.6 KWh. For 12v battery storage, it is a good idea if you don't drain them below 50% charge so that means you would need about 260AH worth of 12v deep cycle batteries. By the time you add a charge controller and inverter, you are probably looking at $1500 or more.

[dragonfly Jafe]

...on the other side of the coin, I found some neat LED Xmas lights about 30' long that draw .2A at 120volts (.2 X 120 = 24 watts). I run them from dusk until dawn, about 12 hours say. That's 288 watt-hours.

But, you cannot power 120v anything directly from a car battery. Usually an Invertor is used to convert 12v dc power into 120v ac power (like you get from your homes wall socket). Most are about 80% efficient. This means you must divide the 288 watt-hours by .8 to get the real power required by the Invertor to give the lights the power they need. In my example that results in 360 watt-hours really needed each night. Note, if you can find 12v lights, this step is not needed.

A 12 volt deep-cycle battery is rated in amp-hours, and like has already been said you don't want to go below 50% on one (don't even think of using a regular car battery for this - if it says CCA or "cold cranking amps" don't use it to power things for more than a few minutes). A good one should be at least 100 amp hours - mine are a bit bigger and are 160 amp hours. If the battery has both CCA and amp-hours, it is a hybrid battery and will work, just not as well.

to convert amp-hours to watt-hours, multiply by the voltage (in this case 12 volts). So 160 amp hours X 12 volts = 1920 watt-hours. De-rate by 50% (to account for what you shouldn't try to pull out of a deep-cycle battery) gets you 960 watt-hours of useable power. Divide 960 by 360 to get the number of nights you can run this without recharging the battery (almost 3). This in fact is about what I get in practice.

I have a small 5 watt solar cell (about 1 foot square) I like to put next to the battery during the day as a sort of joke. It makes people think I am green, but really does very little. 5 watts x 8 hours = 40 watt-hours (maybe 1-1/2 hours worth on my lights). Even assuming 100% charging efficiency it would take 9 full days of sunlight for each night of light. Clearly I get my power from somewhere else, which is I run a battery charger from a generator for 30 minutes or so while I am using it for something else (usually tools).

If I wanted to have a solar panel sized to charge this (small) system each day, it would need to provide at least 360 watt-hours. 360 watt hours divided by 8 hours gives the result of 45 watts, or 1 normal sized panel (costing maybe $300). But then it would run every night until either the battery went bad or the lights burned out or the panels got too dusty.