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Wednesday, September 4, 2013

Good Light and Shadow at Bullion King Lake, and The High Cost of "Free Energy" from the Sun

Mike and Nancy, Marathon Man Leonard's brother and sis-in-law, came calling on him up in the Big Box, Californicated, Desert City of Mo-Town...said they'd like to do a light hike someplace Purdy (they're from Austin and that's how they tawlk). So ole Leon contacted the professionals at Mark and Bobbie's Guide Services of Lovely Ouray for ideas about a place to go that would knock socks off...but not put them in a casket—a place where he could maybe take an ice water plunge, preferably in a lake he hasn't seen yet, and not too far of a drive, and less than two level miles from the parking lot. Spreadsheet says....

Actually we ignored most of the parameters given and just drug them to a place we like—12,000 feet, 4 miles total, uphill both ways—but there was a lake to jump in :).

Before we get to the slide show and movie, I'd like to express appreciation for your input on solarizing Goldie. I have been working at synthesizing all the suggestions and have come to a few conclusions, the first of which is that I should pay a pro to do the installation. 

So I looked into some roaming installers who could meet us somewhere in Utah in October. Bingo; found one with more credentials tagging along after his name than a rocket scientist. We emailed back and forth about the nature and scope of the project...the somewhat limited space on Goldie's roof and that I wanted at least 300 watts but couldn't afford top-of-the-line equipment. As usual, I put the cart before the horse. I could have saved him and me a lot of effort and time by asking how much he charged to do an install like mine FIRST! And now I can't find my socks, as his estimate came in at 12 to 16 hours @ $100 bucks an hour. 

Don't misunderstand; I'm sure he knows electrons from photons, watts from amps, sun from shade, and would do a professional job and dot all i's and cross all t's. But...how do I say this without sounding like I'm a cheapskate?...we didn't pay much more than that for Goldie, which has nothing to do with anything except that's the way I think, you know, relative value and shit. It would be like investing $2000 dollars worth of Michelin tires on a $500 dollar car...again, flawed logic, but that's how I "do math."

So the handwriting is on my tombstone: this will be a DIY "Monkey Wench" job that'll turn Ed Abbey over in his grave. 

Thanks to your advice and links, here's the way it's going to shake down:
I'm going with AM solar out of Oregon
I'm going with 3 smaller 100 watt panels instead of two 150's
I will oversize the wiring for one or two more eventual panels
I will use mounting that tilts two directions instead of one
I will splurge and use the more costly but more efficient controller
I will work again next summer to pay for so-called "free energy"  
I will do it myself
I will save up to $1600 bucks by doing so
And finally, I will pray to God Almighty that I don't regret it.... 



  1. Hi Mark, You may want to have a look at the following two websites concerning RV Solar before you make a costly mistake. Bob and Jack are two RV solar authorities. http://www.Handybobsolar.bolgspot.com and http://www.jackdanmayer.com/rv_electrical_and_solar.htm


  2. My solar equipment will never pay for itself in savings of electrical costs. It paid for itself very quickly in campground fees not paid when boondocking.

  3. Your plan seemed like a pretty sensible one to me. Don't over-think and over-worry. Don't over-study blog sites that give advice on solar energy; they are mostly interested in linkbait and google ad income. They make everything more complicated than it is.

  4. That Leonard will use any excuse to take his clothes off!

  5. Read, and re-read HandBob's blog. You should be able to do most of it yourself. Remember, any time a shadow falls on your solar panel, it will shut down. This is one of the biggest mistakes made, and by "professionals' who should know better.

    Larry M

  6. Larry
    if what you say is true then when I'm camped in a site where the sun is dappled by a branch and a few leaves it means I will get nothing?...like zero? No charge whatsoever?

  7. Ok....learning my way around your backyard. Did you go up Yankee Boy to Blue Lake? Gorgeous photos!

  8. The shadow killing all output thing is only true with old panels or the super cheapies intended for fixed locations where you can ensure no shade.

    Good PV panels have bypass diodes so the shaded cells don't kill power generation. BTW, this is one example of what Boonie warned about, so don't pay too much attention to those hyped-up sites and their biased and/or outdated info. Or anonymous comments.

  9. Nice hike! I'm sure that water was freezing. Love the waterfall:)

  10. Purdy pictures. Good luck with your solar. I'm sure you do a fantastic job, and it will be worth every cent.

  11. Mark:
    I read somewhere that parts & installers are available at Quartzsite. It's on our to do list this winter.
    John & Mary

  12. My experience with my solar panels since the first one was installed in Feb 2009 is right in line with what Ted said. No shadow is best for sure.

  13. John,

    Unless technology has changed, and it could have, so far as I know any shadow means no output. I'd read and re-read HandyBob's blog. Maybe send him an email if you don't think it's clear after reading (but only after trying to find the info in his blog; he's a bit cranky at times). Good Luck!

    Larry M

  14. Maybe you'll get good enough at solar installation to sell your services.

    As usual, a gorgeous hike. But I think Leonard is crazy to swim in this obviously cold lake.

  15. Enjoyed your great pictures of a most beautiful hike. Fantastic.

  16. Bullion King Lake, what a great choice for a scenic, high allitude hike. Thanks for the fantastic pictures to remind me of that hike. I think your approarch to solar power solution will work and the enjoyment of learning about solar installs will result in some great camp fire talk. Looking forward to opening NFL game tonight Broncos/Ravens.
    Go Broncos!

  17. Walden Creek rv steveSeptember 5, 2013 at 8:32 AM

    Mark-- 100 dollars an hour????? maybe for serious open heart surgery- no thank you--- although it might be wise to check enclosed instuctions on this project before starting rather than after which I do all the time!

  18. Well my cost came out best for me 1solar panel 225wx225$
    Bracket (non tilting)75$ cable 20ft 20$ tristar45 pwm controller 140$ (the mistake here was not using a MPPT controller )
    Switched to a sunsaver 15w MPPT controller 230$
    2 6v golf cart (new)battery's 100$ each. Cable red/black no,4 10 ft each 18$
    2 switches and fuse 30$
    also I did add a remote meter for in side for 120$
    The panel is the newest kind (even with clouds over days my panel work some )and the controller is a Morningstar the meter is a Morningstar as well
    As I see u can walk on your roof, all that much better
    As to mount your brackets
    That's something I can not do on my roof
    The only thing I did to the 5er was add 13 led type lights
    And that cost me 130$.
    The only power drain is the tv (i have a 200w inverter for that)
    And a microwave. and I have a 1500w for that, (setup to turn on and off as I need it)
    My 2 phone / laptop / iPad (nill)
    Im i Frugal with power yes to some point
    When in use my setup will go to float about 2pm on most any given day
    So as u see the costs are low and u don,t need to give up your last step child or your left n...
    If u can make that basket and bike rack and redo the in side of your MH,, I think u underestimate your ability to do the solar setup yourself
    The only limits are what you put on yourself
    Confidence is starting something
    Pride is knowing YOU did it
    Joy your day

  19. TOM,
    Thank you...been to Bob, and several others. I'll try Jack, then Jill, then their dog, Spot, if I have to to get to the bottom line :))

    That is the true justification...the freedom to get remote. Thanks!!!

    I think you are right...for a change :)

    Ha...you are noticing that trend, are you? I hope it's not contagious!!!

    I changed from the larger 150 watt panels to the 100 watt just to be sure that my AC's shadow doesn't shut down my power plant...just in case you are right :)

    Yeah...trying to separate the wheat from the chaff, truth from fiction, rumor from innuendo is harder that the damn installation... sheesh.

    Thanks for changing the subject :))

    I hope you are correct!

    The big Q scares me....vendors that can pull up stake and disappear leaving me with no recourse. But it could save some install bucks. I'm bound to do this myself tho, cause I'm a masochist at heart :)

    I think I'll steer clear of cranky bloggers :))

    I'll do anything for a hundred bucks an hour!
    and yes...Leon is crazy. That's why I like him.

    Thank you!!!

    John Q,
    Yes, Go Broncos... I'm pulling for INDY this year too...until they meet the broncos :)

    I Know!!!

    THanks for listing your experience in detail...it sure helps me out!!!

  20. Mark,

    You can always take your solar panel out into the sun and measure its output with a Multimeter. Then cast a small shadow over part of it and see what the change is.

    Let us know what you find! :-)

    Larry M

  21. It looks like AM solar is selling 100W high-efficiency panels from Grape Solar (40.8"x20.7") for $278. Home Depot is selling the same for $250 with free shipping.

    If one does not need the highest grade panel, then a Grape Solar panel a bit less efficient (47"x21") is sold by Home Depot for $149. Costco is also selling Grape Solar panels.

    Brand-name controllers like Morningstar can be purchased on eBay or Amazon, but it must match the panels. Ditto for miscellaneous hardware.

    Regarding bypass diodes for shaded cells, practical considerations do not allow bypassing every cell. So, a panel may be bypassed with 3 diodes, or 1/3 of the panel at a time. That's a huge loss, if a bypass diode gets used at all! In fact for a typical 18V panel, losing 1/3 of it, and you do not have enough voltage to charge a 12V battery, which needs 14V.

  22. Oh boy, the wife and I were thinking of graciously asking for the employ of your guide services with those exact parameters (sans lake to jump in) but aren't so sure now, haha.

  23. Thank you NWBound for adding specifics to my contention that shadows falling on solar panels are to be strictly AVOIDED. PERIOD. Regardless of what ANY Ted yahoo says.

    Larry M

  24. It ain't all that complicated with solar installations. Just know where's plus and where's minus and keep'm apart. And if you gotta drill holes in your rig, make sure it ain't gonna rain through it.

  25. I have thoroughly enjoyed the web site by handybob. He is not a scientist, or not even an EE, but he knows a lot about RV solar installation pitfalls. Basically, there are 2 main things to look out for.

    The 1st is to avoid shadows cast by the TV antenna, roof and fridge vents, and AC shroud. That is very dumb, and handybob has several examples on his site showing how a little shadow can really cut down on the power put out by the panels.

    Basically, a typical RV panel has 36 cells (the 4" squares laid out as tiles). They are all wired in series. Each lit cell produces 0.5V, which is fairly constant with light intensity. However, the current (amperage) is proportional to the amount of sunlight.

    If a cell receives less light than the rest, it cannot keep up with the current (amperage) produced by the rest of the panel, and drags the whole string down. Imagine the following situation with a flashlight using 4 alkaline batteries. If you put in one dead battery among the 4, do you still have 3/4 of power remaining, or a whole lot less? It's the weakest link in the chain that matters!

    Note that it is better to have 3 cells shaded by 25% than 1 cell shaded by 75%. In the first case, you lose 25% of the amp, but in the 2nd case you lose 75%. Also note that indirect but even lighting of the panel is a different situation.

    A bit off topic here, but the bypass diodes are more useful for residential installations where panels are wired up in strings to produce up to 600V. Here, if a bypass diode knocks out 6V or 12V off the total (depending on the panel construction), it's not a big deal.

    The 2nd pitfall that handybob rants about is the wiring from the controller to the batteries. To ensure that the batteries get fully charged, the controller wants to bring them up to around 14.4V. However, the controller can only sense the voltage at its terminal, and not at the batteries. Due to the voltage drop in the wiring between the controller and the batteries, 14V at the controller may mean only 13.5V at the batteries. The result is that the controller tapers off its current too soon, thinking the batteries are full. One needs big wires or a short distance.

    The wiring between the panel and the controller is less critical. Remember that the panel puts out 18V, but we only need 14V for charging. That 4V difference is the headroom to accomodate the drop between panels and the controller. The controller can work with either 18V or 17V at its input (hey, its job is to regulate), but its setpoint output voltage of 14.4V must be as close to the battery voltage as possible.

    As long as some basic principles are understood and the pitfalls avoided, solar installation is really child play. Else, it can still work, but suboptimal and underutilizing the equipment, just like handybob ranted about.

  26. wow, a guy could get edge-u-makated by all this input. I'm sure that readers are learning as much as I am. Much appreciated.
    I ordered my solar equipment, and it should be here early next week. I can't wait.
    Armed with knowledge but still Dangerous Mark

  27. As we all know, there may be conflicting stories from different people, and it is confusing. However, sometimes, if we dig a bit deeper, the differences can often be reconciled. Following is an example.

    I have described how an 18V panel (with 36 cells) typically used for 12V applications, e.g. RVs, can be seriously degraded by shadows.

    Photos shown by handybob and his observations made on real-life examples on his web site corroborate what I said. That is, a partial shade on multiple cells of a panel would still allow the panel to produce some reduced power, but a complete darkness of just one cell shut downs the whole panel.

    Once you have installed your panel, you can test this out easily enough.

    Lay a broom handle across the panel, and observe the reduction of current put out by the controller. Then, take a piece of cardboard and block off one entire cell, and observe again.

    Yet, the above phenomenon is not true with amorphous panels (which few people use due to their low efficiency, meaning fewer watts per sq.ft.). It is also not true with high-voltage panels originally intended for residential applications. Let me explain this latter scenario further.

    On my own RV, I have a 215W panel with 72 cells, which I bought because it was available at a good price locally when I needed one. It is intended for residential applications, and puts out 36V. An MPPT controller (which is a DC/DC converter) is needed to convert the power to a lower voltage while doubling the current.

    This panel has 3 bypass diodes built-in, each of which is connected across a string of 24 cells (3 X 24 = 72 cells total). Each of the 3 strings produces 12V.

    If I completely shade any one cell, I would lose 1/3 of the panel, but still have 24V instead of 36V. The MPPT controller still puts out 2/3 of its previous current.

    Of course, I still made sure that the panel would not be shaded; I used this setup because of the availability to me then, not because of this "shade tolerant" feature.

    Now, one may wonder why panel makers even bother with bypass diodes for residential installations that are preplanned, fixed, and not susceptible to variable shading like an RV installation? Well, there is a serious reason for that, and it does not even have to do with losing power output.

    But, I may just bore everybody to death, as this is a bit more technical.

    1. Hi NWBound... I would like to know a bit more about why residential mfg's use the bypass diodes. If you wouldn't mind shooting me a email or adding a link to the info. Thanks... Tomfraziersemail@gmail.com

  28. Tilting the panels separately means you have to have maybe a foot or more between panels or the forward panel will shade the one behind it in the low angle winter sun.(the only time you need to tilt) They can't be side by side.

    Is why I rebuilt mine into a single tilting group. My original plan had been to "overbuild" the number of panels to eliminate the need to tilt. When the money didn't come in it was on to plan B.

    Three main management goals. 1.Hold discharge to 12.4 volts max as much as possible (that's roughly 20% discharge.It greatly reduces stress/battery damage extending ultimate battery life.
    This requires a battery bank of sufficient size to allow that or using generator more to recharge SOONER and reduce discharge (if you want to maximize batter life)

    2. discharge at least 10%. That also prevents a "damage" from not properly exercising a battery.

    3. Recharge FULLY at least once every 24 hour cycle.

    You can discharge TRUE deep cycle batteries (Marine/RV batteries are hybreds, NOT true deep cycle. Trojan T105 are TRUE deep cycle) 50% and more, BUT, you Greatly reduce battery life doing that.

    Reduce battery life - Raise maintenance/power cost... depends on what your goal is.

    Most will tell you 3-4 years is the life of a battery bank. And it's true... if you do things the way They say.

    Mine will be 7 years old in October, with 3 1/2 years full time heavy cycling use... doubling the battery life expectancy has a HUGE impact on the cost of solar power... Just sayin'


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