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| New Panel!! |
This is it! The last article in a 6 Part series on my renovation of my Solar Charging System. We've covered why the old solar panels failed, why the new ones are lighter, stronger, faster (OK, not faster, but more efficient and generate additional power) and how you can get the system for your very own.
What's left?
Well, I have been receiving lots of mail from folks that are asking the same few questions. I'm going to try and answer them now.
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| OLD FAILED PANEL FROM CHINA |
1. Are these new style semi-flexible panels the same as the old, out of business, UNISOLAR rollable type?
NO! Those were amorphous laminated silicon at 6.3% efficiency, the power generating modules inside the panels I am using are exactly like the ones inside regular, glass sandwiched, aluminum framed types. The modules we are using are 17.85% efficent, much better than the 14.6% I was getting from the old China sourced ones. The Unisolar panels were very low efficiency per square foot and you need a panel 216" (~18 FEET!) in length to make 144 watts!
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| My Installed Energy Monitor |
2. How do I figure out if your system would work for me?
The first thing anyone should do before deciding on any solar charging system is try to estimate (as close as you are able) the amount of energy you will consume in an average day. There are a few calculators online and spreadsheets that will help, but it's pretty simple. After that, take a look at
Energy Monitors. It's nice to be able to know, at a glance, where you are Power-wise.
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| Old Incandescent LEFT, New L.E.D. RIGHT |
3. How do I figure out how much power I will use?
Easy (mostly.) Take a look at everything you use. I started with
my lights. When I first began, I had lots of incandescent lighting in my rig. These are just standard bulbs, where the filament is heated to produce light. VERY power hungry. Each one used 2+ AMPS of power every hour. Yikes! Now I use LED bulbs, each one uses about 1/10th of an AMP every hour. Essentially dropping my consumption by a factor of ten. Since I had about 20 bulbs around my RV, that was a whopping 40 Amps every hour. Since I only have 100 amps to play with, it got eaten up very quickly. Next, look at your
TV and entertainment use. Most folks these days are using 120V AC TV's and DVD, Satellite,
Media players, etc.
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| My Solar Charge Controller (Left) And Inverter (Right) |
***If you want to run these from your DC power system, you'll need an
Inverter. This just takes your 12V DC battery power and "inverts" it into 120V AC power so you can use your AC devices. The conversion costs extra power, figure you should add about 15% extra amps for AC devices (T.A.N.S.T.A.A.F.L.*). If you use 3 Amps at 120V you will use around 30 amps at 12V
PLUS an extra 15% overhead from the conversion. Also remember that inverters can draw VERY high amounts of current (Amps) from the battery in a short time.***
After entertainment draws, take a look at your parasitic use. Parasitic use is things you can't really turn off. Like your CO/LP detector(s), your Fridge 12V control panel and anything else that stay on no matter what switch you flip!
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| Typical RV Style Propane Heater |
Next is figuring out how much you'll need for varying temperature. For example, if it's cold at night and you want to run your heater that's a pretty large draw from your 12V batteries. I use around 7.5 Amps every hour it runs. Depending on how you set your thermostat, it may run almost all the time, or on and off each hour. You need to know how often it runs each hour and do the math accordingly. For example, at a setting of 68 degrees Fahrenheit, my furnace fan runs about 15 minutes every hour, so for each full hour of run time I use around 7.5 amps. In this case 4 hours of actual time equals 1 hour of furnace run time. Figure 8 hours for an overnight and you get 2x7.5 amps = 15Amp/hours out of your batteries.
***Remember, as soon as sunlight begins to stream onto the panels, you will be generating SOME power, more as it gets lighter. So, that will reduce the amount of power you are drawing from the batteries in the AM or even as it is getting into twilight in the evening.***
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| My Inverter Control (Top) Solar Charge Controller Remote (Bottom) |
I KNOW this all sounds complicated, but it doesn't have to be. As long as you have an idea of your overall use in a day, you can figure out whether a given amount of power coming from you solar charging system will fully charge your batteries in a given day of sunlight. I use around 80Amp/hours as a maximum in any given cycle. Since my panels are generating around about 25Amps each hour (average) I will be fully charged in a bit more than 3 hours after full sunrise, given my 2 105AMP/Hour batteries. A little less, a little more... doesn't really matter in the practical world. Remember, for lead acid, you can use 50% of their capacity without adversely affecting their lifespan. In my case thats 2 x 105amp/hours = 215A/hrs, then divide by 2 = 105A/hrs. For 4 batteries it would be 4 x [battery capacity] dived by 2] . Once you're batteries are charged. The full amount of amps coming from the solar charging system is available to run your "stuff." Essentially, free power. In a future article we'll take another look at
Lithium Phosphate batteries to increase storage capacity and reduce weight.
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| Topping Off My Batteries With DISTILLED Water |
Behavioral Changes: Since I'm not much of a morning person, shifting my power draws away from early morning to later in the morning isn't much of a chore. By moving my energy use to later in the day, I give the batteries a chance to get charged before I start using power. Be
kind to your batteries and they will last a long time! If you use a lot of power when your batteries are at their lowest (after an overnight with heat, for example.) you'll be "kicking then when they're down" and could shorten their life. Especially if it's a high amp draw, like a coffee maker on an inverter (could be as high as 120Amps+ at 12V!!)
All in all, the system I have now, works perfectly for my use. It was designed to be useful and intervention free for most RV folks. Since I KNOW I am raising more questions than I could answer in these short articles, I've set up an email for additional questions and interested parties to contact me about my system. Feel free to email me at:
solar@thewanderman.com. I'll be happy to help anyway I can. This winter in the Northeast (I'm in NY, south of Kingston off the NYS Thruway - US87). I'll be available to take a look at your rigs, make recommendations and if you're interested putting together my system for you.
Be Seeing You...Down The Road,
Rich
"The Wanderman"
www.thewanderman.com
*
There
Ain't
No
Such
Thing
As
A Free
Lunch
*See Part - 1
**See Part -2
***See Part - 3
****See Part - 4
*****See Part - 5
See Original Article
