| Author | Message | ||
| Gary Carter Rating: |
The information on solar seems to mixed in with electric fan testing. So breaking it out. I also have 500 watts laying flat on the roof and the greatest output that I have seen is 18 amps in June in MN when the sun us directly over head. Our system is 12vdc. 500 watts should be about 40 amps at 12vdc. It just doesn't happen. Replaced the controler with a FlexCharge controller. Will see what kind of rate we get this summer. I also agree that solar is a waste of money. Or at least in our case it is. Now if I had a sun tracker we might get close to our rated output. We have friends that boondock all winter in AZ and Mexico. They are set up for this and still average an hour a day of generator time. | ||
| CoryDaneRTS Rating: N/A |
The messages were developed for James Maxwell, as he feels he has a problem with his system. I attempted to help out but for what he expects out of the array, I must have not looked at the right numbers because my figures indicated that he did not have enough panel to produce the power that he beleived he should have. I have been wrong in the past so I am waiting to see how his tests come out. Solar is not a total waste. If a system is producing 15 amps for 4 hours a day, thats a lot of power that is NOT being expended by the battery or is charging for the night cycle. If you didn't have it, you would most likely feel it. For booners, it is great because you will noticably see less time running a genset or the RV motor for recharging batts. Most are spoiled with the amount of power enjoyed at home and treat the camper the same way and some are hard pressed to downSize the way they use power in a coach. I read an posting one time where a gentleman had a coach with solar panels supplying all the power he needed. They didn't even plug in at campgrounds. That would certainly be the goal for us all. Another coach was ALL ELECTRIC and some how he claimed that he RARELY plugged in and only occasionally ran the genset. Its all in the set up and ability to conserve the power, though these fellows told me that they didn't particularly pay attention to their electric useage. (to this I feel that they have gotton into a routine and using little power was now a habit to them). Yeah, Yeah, I know what you are saying, and I had my doubts too. It would be much better if we had this all documented but not many folks have done this with their solar installations. One of them had been documented (somewhat) in BusConv Mag a couple years back. He did mention his good luck with solar in that article. If I remember right, the bus didn't have particularly large batteries for the coach either. They had to fill the space where the spare tire used to be. We had traded emails a few times about the system until they changed addresses but I was assured the system worked well. Can I ask what the benefit of a FLexcharge controller is? The unit I have presently is a pulse charger. I may upgrade in the near future. cd | ||
| niles steckbauer (Niles500)
Rating: N/A |
CD - brings up the point that difference in peoples results may have to do with both the equipment they used and maybe more importantly their habits - some people have a habit of leaving every light in the house on and some turn each one on and off as they enter or leave a room - some leave the water running as they brush their teeth and others don't - almost every one on my street leaves 2 or 3 garbage cans at the street twice a week and I leave 1 - once a week (I just don't bring so much garbage and packaging home with me) - I guess solar is good and useful for the latter and a waste of money for the former - (BTW - not talking about James here - sounds like he has one of the mystery bugs that plague every one from time to time) - It seems that they are ideal systems for people who have to store their bus off site where there is no PP to maintain the batts - maybe extends their life by keeping them floated - Niles | ||
| Jim (Jim_in_california)
Rating: N/A |
Besides "habits", ask this question: how much money did they spend on low-voltage appliances, and what's their appliance use like? On low-voltage appliances, a good example are the refridgerators based on Danfoss 12v/24v compressors. That's a good $1k gone right there, but it makes a BIG difference over a 120v fridge. On habits: I have this huge advantage. I don't like coffee. Can't *stand* the stuff. So no electric coffee pot...at most I'll do tea off the stove. The *propane* stove. When you make toast, do you fry bread in some butter with a frying pan, or do you fire up a toaster? Is your lighting DC powered (and low wattage) or AC powered (in which case even if it's low wattage, you have to pay the 6% to 12% typical inverter penalty). ---------------- Here's a thought: what if you simply couldn't get fuel for a while? ANY kind of fuel? Oil has gone and spiked to $300+/barrel, the US is in a depression for 10 or 20 years. Things really suck. If you'd dropped $4000 on some serious panels and an Outback MX60 back when your money was worth something (before the hyperinflation), wouldn't you be damned glad under those circumstances, esp. when any excess juice you could sell back to a homebrew neighborhood mini-grid would be worth megabucks? Now I'm not saying this is by any means guaranteed to occur. But there's some credible voices saying it could. I am NOT one of the people who was sucked into the Y2K scare, not at all...this on the other hand does scare the hell out of me. In part because many of the world's leaders appear to be acting in a fashion compatible with that scenario, from China's dams to certain adventures in the Middle East to stabilize that area away from totalitarianism and anti-Americanism. Add in one more: the ONLY piece of high-tech gear which is steadily rising in price right now (past normal US moderate inflation rates) is solar panels. Meaning maybe quite a few people are catching a clue... But anyways. Near as I can tell, the equipment to be *totally* off-grid zero-fuel for the next 20 years would run in the area of $7k. That's for serious panels, a HUP $2500ish monster battery from hell (literally 20 years usable life), multiple small inverters of respectable quality, good solar charge controller and spare. | ||
| Jim (Jim_in_california)
Rating: N/A |
Lemme show y'all some links: http://www.jeffvail.net/2005/03/is-it-time-to-cry-peak-oil.html The two powerpoint presentations (in PDF format) he introduces come straight out of the big energy industry. They'll scare the hell out of you. The best research starting point (including links to criticisms of the concept) is on Wikipedia: http://en.wikipedia.org/wiki/Hubbert_peak | ||
| JV Rating: N/A |
In ten years, we may remember April 22, 2005 as Peak Oil Day, not Earth Day: The Saudis today officially ended OPEC production quotas. When this happened in 1971 in Texas, it signalled the peak of domestic production. Furthermore, prices of unrefined oil continue to rise. Simple economics tells us that since refinery capacity (demand) is fixed, this is caused by a drop in supply. See http://www.jeffvail.net/ for an update. | ||
| Jim (Jim_in_california)
Rating: N/A |
And if this really is the situation, then the prices of solar gear is only going to climb. The value of the gear you buy now will be higher, and so will the value of the juice you can put out. And if all this does NOT come to pass and genset-produced electricity continues to be a good value, well hell...guess what, you've STILL got one *killer* "boondocker special" that doesn't make noise and will hence be tolerated where a genset-powered rig might not be. As to the battery costs: the up-front costs on a HUP or high-end Surrette bank (two big six-volts or three fours) are high as hell but the total lifespan and number of discharge/recharge cycles lets them keep up in terms of price-performance. See also: http://www.thesolar.biz/hup_solar_one_batteries.htm http://www.thesolar.biz/Surrette_Batteries.htm http://www.thesolar.biz/Cost_Table_batteries.htm | ||
| James Maxwell (Jmaxwell)
Rating: N/A |
Anybody who followed the fan/solar thread will quickly conclude that I don't think much of solar as a feasible or economic source for power needs. Comparatively, I have gotten the same results that Gary reports. I never expected my 500 watt peak system to fulfill my needs. I fully understand that when I have an electric refrigerator and a tv/monitor that pulls 210 watts that a 500w peak output solar system is not going to satisfy my demands. However, I'm not asking for 2kw of power from my system, but I do reasonably expect at least 400watts/hr from it during optimum performance periods of sun, not the measly 200 that I get. I'm talking wattage here, not amperage at a certain voltage, just pure and simple wattage. I could just as well string my 4 125w panels for 48v, I should still get 80% or better of the total wattage rating: the total wattage off the panels should be there whether I'm running 12v, 24v, or 48v. How much I use during the course of a day is a completely different matter. I make no claim or pretense that I am conservative and like living like a Tibetan Monk. That's why I also invested in a fully capable diesel genset. With CD having given me a couple of ideas for things to check for, hopefully I can track down the shortcoming of my system. Thus far, the guy that sold it to me and a Kyocera field rep have not been able to. Time will tell. Hell Gary, you and I could combine our systems and then we could throw the candles away! | ||
| Jim and Myrna Lawrence (Daffycanuck)
Rating: N/A |
I have 390 watts on the top of my MH. They are wired in series and parallel for 24 volts. I get a Consistent 12 - 13 amps (24 - 26 at 12 volt). Now to get that output, I must tilt my panels up to face the sun at roughly 90 degrees. If I leave them flat, I will get just a bit better than half that output. I also have a few other 'objects' on my roof...TV dish, Internet dish, wind generator....all of which could place a shadow on the panels when they are down. That shadow, even a small one covering one cell, will cause a reduction in the output. Yes I'm happy with our panels. I have enough room for 2 more 120 watt units, which I will purchase. We are boondockers and power hogs. I do still have to start the genny for about 1 hour every second day. We have 220 amp hour battery storage. I feel, the secret to getting maximum output from your panels is to get them tilted up and facing into the sun. | ||
| FAST FRED Rating: N/A |
Different folks have different uses for solar. Suprise! Our use is to keep the batt set up all summer when the coach sits in a neighbors space. Electric is only avil with a 200ft extension cord that would be eaten by the lawn guys. So when we go sailing a for couple of months , the coach sits with almost 100% batts ALL the time. Saves loads on replacement batts . 80W Shell and a Trace C12 works for me,WE dont live on it , the COACH does! FAST FRED | ||
| Jerry W Campbell Rating: N/A |
We do live on it at least 4 months a year. And I still don't know enough about it. Its a very foggy affair. The output depends a lot on the state of the batteries. I would like to see what that 500 watts of panels would do when connected directly to a VERY low battery. If you have a smart charger and the batteries are anywhere near full it cuts the amps down to almost nothing and takes forever for that last 10%. In dark weather you have to run your generator the first thing in the morning when the batteries are at their lowest. The rest of the day is spent getting that last 10%. I've worked on a few systems over the years while on the road and the weakest link is the regulator/charger. Then second weakest link is too long or too small wire or bad connections. Only twice in the last 20 years was the problem with the panels. One was corroded from a life on a tropical beach. The other was dropped and cracked. To any one who can, get high voltage panels and a MPPT Charge Controller. You WILL get more from your panels. My system won't put out much unless the batteries are down a few hundred amps. In fact I don't know what the max output is because they will put out more than my charger can handle. So I need another charger. 68 amps of panels and the 70 amp charger controller is putting out 75 amps. And that's very hot, very dirty and laying flat. We haven't finished our bus so we don't have all the appliances in place yet. I just ran 100 ft of 6-3 with ground to my house to power two 15 amp circuits. Now I am only running the 15cuft refer and the microwave. As soon as I get another charge controller I'll add more things until I reach the limit. I can't wait to see my electric bill. We live a simple life but have lots of electrical stuff like Computers, ham radio gear, electric frige, washing machine and other toys. This should be enough power to live a reasonably normal electrical life. One thing for sure, on a solar system if it's always nice and sunny, life is good and there's nothing to do. If it's not, then you must pay attention and adjust you usage and your generator acordingly. It's a pain in the butt, but a necessary part of having a solar system. It is not plug and play. 10 158 watt, 6.82 amps at 23.5 volts solar panels for 12 volt system. Total 1580 watts MX60 Charge Controller 8 Trojan L16HC 395 amp 6 volt 120 lbs Total 1580 amps 12 volts 3000 Prosine pure sine Inverter Monitors,shunts,switches,breakers and various other very expensive stuff. About 10,000 dollars and I shopped hard for 6 months. http://www.peak.org/~jerryc/bus.htm As Red Green says " I'm pullin' for ya, remember we're all in this together" Jerry | ||
| Jim (Jim_in_california)
Rating: N/A |
Jerry, thanks for posting. I'm looking to get almost that much power going...8 116watt Unisolars maybe, I like how tough they are and that they power more the hotter they get. (Their downside is "size efficiency" or lack thereof...) And we agree completely re: the MX60, that sucker *rocks*. But I want to ask you about battery bank choices. Let's say I used three Surrette 4v batteries rated at 1104amp/hrs each - they're under $600 a pop, they weigh 267lbs each(!). My total amp/hrs would be just over 2/3rds of yours, my costs would be only slightly higher than for your 8 Trojans and instead of 700 80% discharge cycles I get 2100 and basically 15-20 years life out of 'em. Your Trojans weigh 1024lbs total, whereas the three Surrette 4v 1104A/H units are 801lbs. Source: http://www.thesolar.biz/Trojan_batteries.htm http://www.thesolar.biz/Surrette_Batteries.htm http://www.thesolar.biz/Cost_Table_batteries.htm The HUP Solar series looks to be even more expensive except that shipping is free. The number of deep-discharge cycles available and total usable lifespan is similar to a Surrette: http://www.thesolar.biz/hup_solar_one_batteries.htm A HUP with power similar to the 801lb Surrette bank would weigh 859lbs. So...given the lifespan issues, it seems to me that giving up 400 - 500 amp/hrs and gaining over double the lifespan for otherwise similar costs and sizes seems...worth it? Or am I missing something here? | ||
| Geoff (Geoff)
Rating: N/A |
The more you guys talk about solar the happier I am that I don't have it! --Geoff '82 RTS CA (with 8kW diesel genset that maybe uses 1/2 gallon of fuel per hour) | ||
| CoryDaneRTS Rating: N/A |
Now Geoff you know you need to move on to keep up with technology. We, who are using the Solar equipment, are actually the second or third stage laboratory for the Solar future. Big business won't even try to improve product unless itis out there, being used with a decent demand in sales. But as Solar panels improve and storage facilities get better or replaced with new technology, Solar will certainly be in the future. I worked my lifes job at the power industry and I can tell you, even though it powers the world now, It ain't gonna power the future. Fossel fuels will run out, are dirty (literally) not to mention the air that is burnt up to burn these fuels. Nuclear is not trusted by the public and the spent fuel has no place to go, having to stay in fuel pools for the milleniium in your back yards? Don't count on it! think of homes with stand alone power systems in super insulated homes. Solar might not be the only runner in this dream quest, but it most likely is the step in the direction to cut away from the power grid. Like power systems on the Motor Home is here in rough form now, being refined every day. The world is our laboratory, the future is our goal. cd | ||
| James Maxwell (Jmaxwell)
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Geoff: Stay happy, buy a few more gallons of dsl. for the genset and stay up past sundown. If I'm interpreting correctly all these guys touting this technology that say my system is ok, then all I can say is the industry as a whole, including all involved, are grossly guilty of misrepresenting their product. When u sell me something that is represented to produce 500 watts and it has never performed over 200, somebody was bs'ing somebody. So along comes the lines of add MPPT @$500, then add an auto-tracker system @ $2k and boy that will do the trick. Now I have $9k invested, and a whole lot of my time, and they still want me to run around checking that I didn't leave some lousy ass 10w halogen bulb on any longer than it took me to get a glimpse of the clock on the wall. The one that gets me most is "aim them at the sun". Oh yeah, like I'm going to spend all day on the roof of my bus aiming these damn panels and then go thru all the hassle of securing them when I want to move tmw. Last time I checked, relative to our position here, the sun is constantly moving. And, find me someplace in the Mojave desert where the sun ain't shining directly down most of the day. Then we have the times where you're someplace that hasn't seen the sun in a week. I'm going to do these tests that have been suggested and after that I am not receptive to any arguments in favor of it if they don't indicate a problem. Let's face it, solar has been around a long time and it has not panned out as a viable, economic, alternative. Most of the big pwr companies that got into it have more or less abandoned it except as a good write-off in the name of R&D. Now, where do I get a good, reliable Hydrogen power cell that won't blow me off the face of Earth in the middle of night when the seporator develops a leak? | ||
| Jim (Jim_in_california)
Rating: N/A |
>>It ain't gonna power the future.<< The problem I see is that it's liable to STOP powering the future rather suddenly. The best available model is much akin to a stock market crash...a sudden spike in costs for fossil fuels. We don't exactly "run out" all of a sudden, it's just that fossil fuel costs rise to a level our economy and infrastructure can't cope with, driven by market panic...or sometimes, market sanity. Example: the House of Saud are *not* nice people. They realize they keep power with US support. So they're running their wells full-tilt-boogie to keep world oil prices at a level the US demands. Problem one: if you pump the wells too fast, you leave unrecoverable oil behind and the net production over the life of the field is lower. Problem two: even if you can get around that, pumping like crazy during the period when world oil costs are still fairly low is actually insane. By the time oil costs are insanely high 75 or so years from now, they'll be dry and nothing but a desert. And the House of Saud as a regime is as unstable as Rosanne Barr's sanity. Any new regime (Fundamentalist or not) will almost realize both of the above. (And yes, Osama Yo Mama realizes all this FULL well. One of the few things he's correct about is that the House of Saud is pissing away Saudi Arabia's future in exchange for short-term survival. Which is why a key Al Queda goal is to bring oil to $200/barrel...and that's why the Iraqi oil fields keep going "boom".) There are serious suggestions afloat to artificially raise fossil fuel prices in the US *now* by a "painful but survivable amount" so that people start switching habits before it's too late. Most of Europe is already doing this with a gallon of gas up near $5/gal equivelent. Odds are the first all-Democrat house/senate/prez combination is likely to follow suit. California's isolated fuel market (via higher-than-Fed emmisions standards) is indirectly having a serious effect along the same lines and probably for a similar reason. So...I dunno, I *really* like the idea of having panels/batteries/chargers that will literally run for 20 years. Call it a form of "short selling" the world energy market... | ||
| James Maxwell (Jmaxwell)
Rating: N/A |
Geoff: Stay happy, buy a few more gallons of dsl. for the genset and stay up past sundown. If I'm interpreting correctly all these guys touting this technology that say my system is ok, then all I can say is the industry as a whole, including all involved, are grossly guilty of misrepresenting their product. When u sell me something that is represented to produce 500 watts and it has never performed over 200, somebody was bs'ing somebody. So along comes the lines of add MPPT @$500, then add an auto-tracker system @ $2k and boy that will do the trick. Now I have $9k invested, and a whole lot of my time, and they still want me to run around checking that I didn't leave some lousy ass 10w halogen bulb on any longer than it took me to get a glimpse of the clock on the wall. The one that gets me most is "aim them at the sun". Oh yeah, like I'm going to spend all day on the roof of my bus aiming these damn panels and then go thru all the hassle of securing them when I want to move tmw. Last time I checked, relative to our position here, the sun is constantly moving. And, find me someplace in the Mojave desert where the sun ain't shining directly down most of the day. Then we have the times where you're someplace that hasn't seen the sun in a week. I'm going to do these tests that have been suggested and after that I am not receptive to any arguments in favor of it if they don't indicate a problem. Let's face it, solar has been around a long time and it has not panned out as a viable, economic, alternative. Most of the big pwr companies that got into it have more or less abandoned it except as a good write-off in the name of R&D. Now, where do I get a good, reliable Hydrogen power cell that won't blow me off the face of Earth in the middle of night when the seporator develops a leak? | ||
| Jim (Jim_in_california)
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James: For god's sake man, head to Quartzite or someplace, find a GOOD solar tech, have him temporarily splice in a controller that doesn't suck wind and check your cables. It would make more sense than invading EVERY thread on solar with "my system blows and I don't know why so this whole concept stinks like a crackhead's underwear!!!" Me? I'm going to use good parts and solder it all up myself with double-thick cables rubber-coated at every junction. | ||
| Jerry W Campbell Rating: N/A |
Hi Jim, I chose the Trojan L16s partly because I can move 120 lbs. Most of the others weigh too much for me to handle. And partly because I got a deal on them. Buy the best you can afford. And James, MPPT Controllers are not something you add later. You plan your system around it. And, You don't NEED to tilt your panels. I can't remember ever reading a label on anything that told the truth. And what about that new car, they say 25 mpg, I don't think so. At what voltage are these panels suppose to produce 500 watts? | ||
| CoryDaneRTS Rating: N/A |
Jerry All the info that JamesM told me about his system is in the "TwoDogs Fan Test" message, two lines above this string. He has a lot of numbers, I think its all from the literature, but I can't make the numbers match his numbers. But unless I have the source in hand, you can't rely on accurate numbers. Take a look, toward mid to bottom of the string. His system sounds sound, so take alook. cd | ||
| DrDave Rating: N/A |
Obviously some people are too busy trying to "imagineer" their solar systems to remember the rules.. Ohms Law Here is an interesting link... http://www.the12volt.com/ohm/ohmslaw.asp | ||
| James Maxwell (Jmaxwell)
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Jim: I did u one better than the "good" solar tech; I got an engineer from Kyocera to review my system after I got a "good" solar tech. The engineers recommendation: install a Kyocera (formerly SCI) controller (like the one I originally had that shorted out only with a little more capacity and 24 volt rating.) You seem to imply that my Trace c-35 sucks wind. Perhaps it does, but I remind you that a lot of solar outlets highly recommend and tout it and many will sell u nothing but a Trace. It is still one of the most versatile on the market. As I've said, Trace tested the controller and pronounced it sound. CD: The reason that u concluded that my system was sound was I believe based on a math miscalculation in one of your computations. On Apr 16 @ 3:46p posting you wrote: "125w/24=5.2a(roughly)" To achieve 24 volt operation I have wired in series (2) 125w panels for a total of 500w capacity at 24v = 10.4a. I then parallel (2) of these sets into an entire grid of 500w capacity, 24v, 20.8amps. However, the max amperage of a solar panel is based on the wattage capacity at the Peak voltage obtainable, in this case 35.4v. That is the industry standard for computing max. amps available and it is verified in many publications, but I rely on MotherEarth publications here, along w/Siemens, BP, and Kyocera literature. Seems that solar cells are rated by engineered potential, not application. This engineered potential is the primary basis of my opinion that MPPT is a lot of smoke and mirrors, although I do agree that there is usually "room" for improvement in almost anything. In one of the responses along the way, delivered amperage readings were reported that far exceeded the energy potential of the panels--can't happen--end of story. The engineered potential of panels limit the max of wattage, voltage, and amperage of each individual cell and the cellular arrangements of a panel establish the max limits of a panel. Only under certain shorted conditions can they exceed that and then we have a discardable panel. The one factor that I have not been able to nail down as definitive is the relationship of amperage to "controlled" voltage. I have found nothing that emphatically states that Ohms law applies, which could account for higher than rated amperages. It appears that amperage, as it relates to solar cells and panels, is a derived figure rather than an engineered one. If that is the case, it isn't necessarily consistent, or accurate for that matter. I do know that it is not a "benchmark" figure for the industry. With that, I'm off this subject until further testing is accomplished. At that time maybe I'll offer a TD/Stan challenge for suggested "purchase" improvements, only I will go one up on TD: I'll buy the stuff, and you guys place in an escrow account an equal sum that defaults to me when the improvements don't yield improvement. If it does, you get the escrow funds rtn. and I get humble pie and a smiley face. | ||
| Jim and Myrna Lawrence (Daffycanuck)
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Jim, if you're not happy with your system....sell it and go back to a generator.. If the price is right, I would take two of your panels off your hands.....I would take all four if I had the room. | ||
| CoryDaneRTS Rating: N/A |
JamesM I look forward to camping next to your rig and we can sit by the fire, I'll be sipping a Pepsi, you can sip a BEER and we won't even discuss all this Solar mumbo jumbo, LOL I am still interested in your test results so don't forget to let me know how it all turns out. cd | ||
| James Maxwell (Jmaxwell)
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CD: That's a deal, 'cept I seldom drink beer; maybe a six pack a yr. Ice Tea, Pepsi,Coke. Oh, don't worry about power if we have a cloudy day or 3; I have a buddy plug for the genset! J and M: I never left the generator and not for sale. Someday, if it has the potential to work better, I will make it do so. Most likely, it will be a case of just stumbling across a problem that was overlooked or not checked several times before. If it were for sale it would be the best deal you would ever come across on PV panels, so good in fact, that you would add eaves to your roof to accomodate all four. Hell, they are big enough (29x58) that you could use them for window awnings if u fab'ed a set of scissor arms to mount them. | ||
| Jim (Jim_in_california)
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Hey guys, check this out: http://www.equalccw.com/solararrayconcept.gif | ||
| CoryDaneRTS Rating: N/A |
JamesM Hmmm, Iced Tea in the summer sounds great, I'll take two please. I was going tolook at J & M Solar information but their website seems to be down, no access. I am a tinkerer, and I like playing with solar power. I started it as an experiment and as FF says, at the very least, it will keep the batteries charged when the bus is in storage. Helping to defray draining the batt is the plus side. Oh I like toys...... cd | ||
| Jerry W Campbell Rating: N/A |
jmaxwell Says "In one of the responses along the way, delivered amperage readings were reported that far exceeded the energy potential of the panels--can't happen--end of story." I assume you're referring to me. It seems by the way you talk that your mind is made up. This is for those who have not yet spent their money. When I bought my solar setup I decided to take a chance on this MPPT thing. It's supposed to work better in low light levels. You need high voltage panels so I bought 12 volt panels, Kyocera 158G. 6.82 amps at 23.2 volts. To high a voltage to hook up directly to the batteries. I got an Outback MX60 charge controller. I hooked up 2 panels to the controller to keep my batteries up while I installed the system. Thats a total of 13.64 amps at 23.5 volts to my 12 volt batteries. The charge controller was reading 18 amps into the batteies. My first thought was, that's impossible. So I bought the TriMetric 2020 battery Monitor with a 500 amp shunt. It keeps track of amps coming and going to the batteries. It confirmed that the Outback was indeed putting 18 amps into the batteries. The Outback keeps the voltage of my 24 volt array at about 50 volts although it changes several times a second. I still don't know how tracking the point at which maximum power can be produced works but it has been proven to me that it does. I think what's happening is that because the controller has the ability to keep the voltage of the panels higher than the batteries it can deliver more power. Some body somewhere knows I'm sure. Two Dogs is on one end of the spectrum (trickle charging his bus batteries), I'm on the other end (making ice cubes in the desert). The rest of us are somewhere in the between. If you believe the Manufacturers specks you will be dissapointed. Solar is only 10 to 15% efficient, not to mention everything else in your system so you need as much as you have the space and money for. Then you learn to live with what you've got. Contrary to popular oppinion, This is a very fun thing to do. Jerry | ||
| Jim (Jim_in_california)
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Jerry, responding to: >>I chose the Trojan L16s partly because I can move 120 lbs. Most of the others weigh too much for me to handle. And partly because I got a deal on them.<< HUP actually solved that problem (weight when loading them into the bus). When you buy a "12v battery" fr'instance weighing about 850lb, it's actually split six ways into "cells" that each load on a strap into a metal enclosure that perfectly contains all six (or 12 if you buy a 24v setup). So you first carry the "holder" in (can't weigh more than 10 or 20lbs) and then load each 141lb "cell module" separately. This is only slightly more than a 128lb Trojan. It's Surrette that causes real weight issues while being in the same "longetivity class" as the HUPs. The biggest single voltage available is the 341amp/hr 12v at 272lbs. *Those* would be a real bitchkitty to manhandle in but...hey, they'd be highly theft resistant  . And I'm starting to think a pair of those (equal to about 3 8Ds) would be all I need at a cost of about $1200 and again, there's that "20 year lifespan" thing goin' on that I *really* dig. The various 4v and 6v based Surrettes are little better. But still, given a ramp, dolly and two people this IS doable. | ||
| James Maxwell (Jmaxwell)
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Jerry: Ahhh, the 1st thing said that I can really relate to: "...you will be dissapointed. Solar is only 10 to 15% efficient. ..." How well I know that after nearly $6k. My dollars are already deflated enough to waste them on something that only depletes them further at the rate of 85-90%. | ||
| Jerry W Campbell Rating: N/A |
Jim_in_california I got 1580 amps for about $1300. I would have liked to have gotten sealed batteries. I just could not afford them. For a full life you need to get the right capacity for your load. Battery charging is about 90% efficient up to about 85% battery capacity. Then it goes down to less than 50%. Right now I'm using about 150 amps a day. That is about 10% of my capacity. At 50% charger effeciency that means I have to put 300 amps back in the battery everyday for the 150 amps I use. That means using my system in this way I have twice as many panels as I need. If I had only 450 amps of batteries That would mean I would be taking the batteries down to 66%. And a much better charging effeciency and fewer panels necessary. My appliances will be in this summer and I expect to be down to 60 or 70%. In the meantime I'll have to fully charge and equalize often to fight sulfation. On some things in life you have to start at the bottom and work up. On others you get to start at the top and work down. This is one of those where you start a the top and buy the best you can afford. It will pay off in the long run. Jerry | ||
| Jim (Jim_in_california)
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Ohhhhkay. Hmmmm. The Surrette 5000 series and the HUPs are rated at 2100 discharges of 80% (in other words only 20% left! Trojans can only do 700 if that website is to be believed). The Surrettes/HUPs can do 4000 or so 50% discharges. 4000 divided by 365 gives you 10 years life. Add another 12v 341amp/hrs Surrette battery and you can drop your daily discharges to only...dunno, let's call it ballpark 75%. Battery lifespan jumps to...God knows, somewhere over 15 years. So yeah. What I'm learning here is that setting up a panel/battery bank good for over 15 years life is NOT EASY, it means not just a big high quality battery but a monster charger/panel setup to drive it while efficiency is DROPPING. Christ. No wonder we're all still so oil-dependent. Question: can the excess panel voltage be tapped in some other direction? Straight to an inverter maybe? Does the Outback MX60 have such a tap? | ||
| CoryDaneRTS Rating: N/A |
(((" Question: can the excess panel voltage be tapped in some other direction? Straight to an inverter maybe? Does the Outback MX60 have such a tap? "))) I'd be real careful here. I did some research on the windgenerator pages sometime ago. They stated that the generators voltages were stabilized to battery voltages by the battery themselves. it was possible to have a system with no regulator, only a high voltage power diverter. What they would do is divert the excess power to a heating element which is stored forever in a container of water to burn off excess power that the battery culd not use. The inverter will not stabilize the voltage, so you could be sending 35v dc into a 24 or 12 volt inverter which will probably pop the transistors inside. It has no capacity to bring the voltage down to a workable level. A regulator would be totally needed and hope it never shorts across sending high voltage to the inverter. In theory, as you increase load demand on the battery, the voltage should go down and the solar regulator will respond by uping its voltage/load source. Your recorder should indicate this unless you don't have enough load to cause this to happen. I was limited by space for the solar installation so I will live with 4 panels. I can say that if I were to do it today, I would go with the peel'n stick panels. I really don't care for the look of the aluminum framed panels on my curved roofline. cd | ||
| Jim (Jim_in_california)
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Ah. In other words...panels pump up the battery bank. Run the inverter and/or 12v loads straight off the battery bank. If the battery charge falls to about 80% - 85% capacity or so, the solar charger (MX60 or whatever) will "kick it up a notch" and come out of "trickle/toppoff mode"...so if you have enough panels to meet your daytime load needs, battery charge never falls below 80% or so? Two points: * Over on the Outback forums they often discuss an ideal panel/battery ratio: one watt of panel for every amp/hr of battery capacity. Which in a ballpark fashion makes sense...sound about right? * I've been wondering if it's possible to do solar-power A/C. Floor-standing "portable" A/C units with an exhaust hose running to a floor vent can be had for about $500 putting out 9000btu and drawing 9000watts (110v AC). Compensating for inverter/charger losses, that means about 1200w of panels (dead minimum) *with* "tilting" of some sort and more like 1500 without. Pretty gnarly panel array  . *Possible* but...the $$$ turns into serious "ca-ching". Sigh. So how well do swamp coolers work? DC-powered swamp coolers ain't that expensive and could live off of 1/3rd or less even such a modest A/C... | ||
| Jerry W Campbell Rating: N/A |
(((" Question: can the excess panel voltage be tapped in some other direction? Straight to an inverter maybe? Does the Outback MX60 have such a tap? "))) You do not want to tap into the line in front of the controller. The MX60 has an auxillary connection of 200ma at 12 volts. It has several uses, one is to trip a relay to divert the excess power for another use. The power comes off the battery or the inverter, It doesent matter because when the voltage drops below a certain level the relay is turned off. I use the auxillary to turn on the exaust fan in my battery box when the batteries reach gassing voltage. If you have excess power it will most likely be in the middle of the day with the most sun. At that time it's time to do laundry or run that portable a/c. "panel/battery ratio: one watt of panel for every amp/hr of battery capacity" I've never heard that before but it makes me feel good because I came up with the same thing. I have 1580 amps of batteries and 1580 watts of solar panels. The idea with the charger is, you want most of your daily load to take the batteries down below 80% because thats where the most efficiency is and it will take less time to charge them. The last 10% you may never get so I would think you must fully charge them at least once a week. On a sunny morning you fire up the generator when they are at their lowest and do your bulk charging with the genset. Then by the end of the day they should be fully charged. Jerry |
