Log In | Register
Skip to main content
Topic: Some thoughts on tilting solar panels (Read 34 times) previous topic - next topic
0 Members and 2 Guests are viewing this topic.
Some thoughts on tilting solar panels
Yahoo Message Number: 151050
In recent months I've made a couple of informal tests that I thought might be interesting to those who dry-camp in the winter. The question was how much benefit one could get from tilting solar panels.

Let me first say that these results are better than most RVers will see. The time of year (winter), times of day (midmorning and midafternoon), geographic location (southern Arizona), and orientation of the panels (tilted south) were all such as to yield maximum improvement from tilting the panels. So the gains shown here are probably the best you can expect.

Setup: I have 500 watts of AM Solar AM100 (23 V) panels feeding a MorningStar TriStar MPPT-45 solar charging controller. The panels can be tilted to about 45° using AM Solar tilt bars.

Mid-December, 3:30 p.m.

Panels flat: 111 watts; panels tilted: 200 watts

Mid-February, 10:30 a.m.
Panels flat: 123 watts; panels tilted: 240 watts

Again, these are more or less optimum results. In the summer, or at noon, or with the panels facing in a different compass direction, you'd see much less difference between the tilted and un-tilted states. And of course you have to go up on the roof to tilt the panels. It takes me about twenty minutes to get my five panels up or down. (And they must be lowered before traveling!)

Conclusion: for most RVers, most of the time, tilting solar panels is probably not worthwhile. I rarely do it myself. But under the right conditions--say, at Quartzsite or Death Valley in wintertime, and assuming you're going to be staying in one place for a while--titling can make a major difference in the amount of solar power you harvest.

Andy Baird

Travels with Andy
Andy Baird
2021 Ford Ranger towing 2019 Airstream 19CB
Previously: 1985 LD Twin/King "Gertie"; 2003 LD Midbath "Skylark"
Re: Some thoughts on tilting solar panels
Reply #1 –
Yahoo Message Number: 151053
Setup: I have 500 watts of AM Solar AM100 (23  V) panels feeding a MorningStar TriStar MPPT-45 solar charging controller. The  panels can be tilted to about 45° using AM Solar tilt bars.

Mid-December,  3:30 p.m.

Panels flat: 111 watts; panels tilted: 200  watts

Mid-February, 10:30  a.m.
Panels flat: 123 watts; panels tilted: 240  watts

Andy

*******

Very interesting numbers Andy. When the panels are flat you get 25 of rated watts and when tilted you get about 50%.

A question did you check what the out put was at the prime time of about noon when the sun would be at right angles to the panels. Did it go up much then. Also what is the high numbers that you have seen in relation to the 500 watts rated.

George

Retired Plumber
Re: Some thoughts on tilting solar panels
Reply #2 –
Yahoo Message Number: 151084
Andy,
 So, this was with the panels tilted as far as you could tilt them, i.e. 45 degrees toward the south, correct?  Were you able to tilt to 50-55 degrees, might you have obtained even better voltage?  You got no shade from one panel on another?

Thanx much,

Dorrin, a SOB long-time lurker, OH
Re: Some thoughts on tilting solar panels
Reply #3 –
Yahoo Message Number: 151085
"this was with the panels tilted as far as you could tilt them, i.e. 45 degrees toward the south, correct?"

Right. The AM Solar tilt bars (at least the 2006-vintage ones I have) only allow a 45° angle.

"[If] able to tilt to 50-55 degrees, might you have obtained even better voltage?"

I can't say, since I don't have the option. In theory, the best output will always be obtained with the panel at right angles to a line pointing at the Sun. Some commercial solar power farms have "heliostats" that move their panels to continuously track the Sun, to ensure that optimum angle.

But a heliostat is a rather expensive and cumbersome piece of machinery to put on an RV's roof--and remember, tilting only helps significantly in the winter--so few if any RVers do it. Instead, we make do with a fixed vertical angle and horizontal orientation, which at this time of year does quite a bit of good.

"You got no shade from one panel on another?"

Actually, I forgot to mention that in the most recent test, one panel was slightly shaded by the air conditioner, while another had a sliver of shade from the open escape hatch. I meant to close the hatch to see whether that made a difference, but forgot.

Andy Baird

Travels with Andy
Andy Baird
2021 Ford Ranger towing 2019 Airstream 19CB
Previously: 1985 LD Twin/King "Gertie"; 2003 LD Midbath "Skylark"
Waste hookup
Reply #5 –
Yahoo Message Number: 151091
Hi

I would like to install a waste line by my driveway so a RV can be parked in it and the toilet be used.  My driveway slopes towards the back of the house and my house is raised.  So my waste line is higher than the driveway.  So I would have to install a 3" ABS pipe that would flow to the back of my garage to a pit where a pump would have to pump it around the garage and up and into the waste line that is under the house.  About a 30 foot run and 4 foot rise.

My question is what is the normal length of waste line people carry in their RV?  I need this length to layout the pipe connection.

Or put it another way, does everyone carry a hose that will reach at least to the end of their RV (plus ??)  How about extensions?  If the RV is backed in against my garage and if enough room is left to lift the door (old fashion type), I think 10' would be long enough to reach my future drain, from the driver's rear corner of the RV.

The pump I would like to get has a bronze propeller and costs about a grand.

I would like to get it set up to invite retired moderators to my home in North Park, San Diego.  Southern Arizona is not that far away.
My driveway is large enough for a 73' Bekins van, so any size RV can fit in it.

Thanks

right
.

Re: Waste hookup
Reply #6 –
Yahoo Message Number: 151093
I don't know what the "normal" length of Sewer hose is most people carry. I use a 15 ft. hose which is a good compromise of length and storage area it takes up. BTW it doesn't fit in the factory tube storage area, mainly due to heavy duty large end fittings. This is one place I don't want a failure to occur, ever. I replace the hose about every 2 yr.s as a preventative measure.

Bob
Re: Waste hookup
Reply #7 –
Yahoo Message Number: 151098
Just a suggestion: check into any local regulations against installing a sewer cleanout in your driveway; I tried to do this but found no plumbing company or independent contractor who would tap into the sewer line to put in an "aftermarket" cleanout. Every one cited the "could lose my license" mantra. (True or not, none would do the installation.)

Every locality's rules, if any, are different, of course; I hope it works for you, as a "home dump station" would be very convenient! ;-)

Joan
2003 TK has a new home
Re: Waste hookup
Reply #8 –
Yahoo Message Number: 151101
Another suggestion . . . check out Flojet RV wastepump. I installed a fused heavy wire from battery to a jack near RV waste valve. This allows the unit to pump waste through a garden hose. For the plug and jack, check out Powerlet plugs.

bumper
bumper
"Yonder" '05 MB
"WLDBLU" glider trailer
Re: Waste hookup
Reply #9 –
Yahoo Message Number: 151105
Roger

Our home's sewer is not accessable,  with the closest access being the washing machine's drain, in the garage.
To dump at home, we use a 12-volt potable macerator with  50' of  ' 3/4" hose.                                          We have used the macerator many times when visiing friends and family and a dump station is not locally availble and carry 65' of dedicated hose Instead of replumbing your garage and adding a lift(pump) station, you may be able to use a 12-volt macerator and run a hose to  he nearest sewer cleanout or add a fitting.
 No matter if you have a dump righ next to your LD or use a pump, you should not leave the black valve open all he time,  instead dumping when the tank is a least 1/2  or more full.

Larry
Larry
2003 23.5' Front Lounge, since new.  Previously 1983 22' Front Lounge.
Tow vehicles  2020 Jeep Wrangler Rubicon, 2001 Jeep Cherokee
Photo Collection: Lazy Daze
Re: Waste hookup
Reply #10 –
Yahoo Message Number: 151107
"you should not leave the black valve open all the time, instead dumping when the tank is a least 1/2 or more full."

---- For those new to RVing, the reason for not leaving the black tank valve open when hooked up to a sewer dump is that the "liquids" in the black tank flow off, leaving "solids" that can mass at the bottom of the tank. This material will soon form itself into a "black pyramid" which defies any attempts to dislodge/liquefy the buildup so the tank can be dumped; resolving this issue is can be a tedious, unpleasant chore. Keeping the black tank valve closed and allowing the black tank to fill (as far as practical) before dumping allows the contents to achieve a dumpable state of "slurry"; any residue can be easily flushed out.

The little joys of RVing are without number! ;-)

Joan
2003 TK has a new home
Re: Waste hookup
Reply #11 –
Yahoo Message Number: 151121
I have the flushers installed in gray and black water tanks. After dumping a full tank I close valve, turn on flusher and watch tank fill up with Sea Level gauge. When up to 75-80% full I open valve and dump again. followed by flushing with valve open for a couple minutes. Some have complained of flushers clogging but my cheap Camco ones have never given me a problem. I use them religiously.

I have seen what happens when people leave valve open in a full hook up environment. Then they have to call one of the RV guys that  have high pressure washers and other equipment to clear the clog. A most unpleasant, messy task. I helped a lady out when camping in the Sierras one year with a clog. It was the hardest Beer I ever earned.

Bob
Re: Waste hookup
Reply #12 –
Yahoo Message Number: 151136
I will be doing this myself.

Just wondering about hose lengths

thanks

Just a suggestion: check into any local regulations against installing a sewer cleanout in your driveway;



Re: Waste hookup
Reply #13 –
Yahoo Message Number: 151140
"Just wondering about hose lengths"

As others have said, ten feet is typical.

Andy Baird

Travels with Andy
Andy Baird
2021 Ford Ranger towing 2019 Airstream 19CB
Previously: 1985 LD Twin/King "Gertie"; 2003 LD Midbath "Skylark"
Re: Waste hookup
Reply #14 –
Yahoo Message Number: 151141
This might be a better solution for me

Is it common for RVs to carry a 12v macerator with them or is this some thing I should provide? 25' of 3/4 hose will make it to my main sewer line via a 2" ABS line.

Looking at Amazon there seems to be 2 types,  One connects to the RV waste line directly and the other looks like it needs to be plumbed in.  So can I assume you use the kind that twists onto the RV?

What would power the pump?  Jumper cables from the engine batteries?

thanks

.

Re: Waste hookup
Reply #15 –
Yahoo Message Number: 151144
Roger, it occurred to me that there might be a simpler, less expensive solution for you.  My understanding is that your wish is to have a way to empty your waste tanks while your RV is in your driveway.  You have been thinking about using a holding tank, a pump, and a drain line leading to the holding tank.
 Have you considered getting a macerator pump?  It would attach to your dump valves with a bayonet connection just like the drain hose does.  When you open the valve, the pump will pump the waste contents (black water first) through a 3/4" garden type hose to a sewer clean-out on your property somewhere.  (Once, with no other options, I pumped directly into a toilet when no clean-out was available.)  It takes a little while, and the tank does not flush as thoroughly as with the 3" line running open because there is less fluid current in the tank contents to carry out solids, but it will empty the tank.  My pump has an attachment that allows a flush hose to be connected to it.  When the tank was empty, I would turn on the flush hose and run fresh water through the pump and waste hose to clean them.
 If you decide to go this route, you need some way of monitoring the flow.  The pump sound does change when the tank runs empty, but my tired ears can have a hard time hearing the difference.  I used the pump before I had a clear Camco connection to the tank, so I used a 2' length of clear 3/4" hose with garden hose fittings on the end on the outlet.  With it, I could see when I was pumping air rather than waste water.  Now, with that clear connector, I would be able to use it and a connected hose to jet water into the waste tank at the valve, obtaining a partial tank flush while flushing out the pump and waste hose and eliminating the need for the 2' clear hose.
 A straight dump with the 3" hose is faster and easier, and I have not needed to use my macerater pump in 5 years, but it is there if I ever need it again.
 I don't know if that would work for you.  There are limits to the length and lift of the waste hose, else you risk burning out the macerater pump, but if it would work, you would save a PILE of $$$.

Ken F in NM
'08 MB
Re: Waste hookup
Reply #16 –
Yahoo Message Number: 151146
thanks Ken

a 12v macerator pump is the answer for me

"so I used a 2' length of clear 3/4" hose with garden hose fittings on the end on the outlet"

I really like the idea of a short clear hose

Roger

.

Re: Waste hookup
Reply #17 –
Yahoo Message Number: 151148
"Is it common for RVs to carry a 12v macerator with them or is this some thing I should provide? 25' of 3/4 hose will make it to my main sewer line via a 2" ABS line." 　
Roger 　 Yes, many use macerators. we had one for about 18 years and use it regularly o dump at home The pre-assembled pumps were not available back then so I bought a Jabco marine macerator and used an old HydroFlush and some plumbing fitings to fabricate one.         It's still in use today                      https://www.flickr.com/photos/lwade/sets/72157602095132874/.
Today, you can buy one in a kit.
http://www.campingworld.com/shopping/item/flojet-rv-waste-pump-kit/26125 　 3/4" hose works best but it will pump quite a distance with 5/8" hose, just at a slower rate. We carry 65' of dedicate drain hose, a big pipe wrench and a 4' cheater, for the wrench. Many time a sewer cleanout is close enough to open and use, when driveway camping.

I recommend installing flushers in at least the black water tank for use with the macerator. Since flushing with a macerator is relatively slow proess, compared to opening a 3" valve, solids are not flushed well.  The added water, from the flusher, keeps things stired up and moving.
The gray tank can be just a nasty as the black and adding flushers to boh tanks is a better idea.
Our flushers are 12 years old and still function fine. Frequent use seems to help keep them from plugging.
We always use the flushers at home and whenever we can while traveling.
https://www.flickr.com/photos/lwade/sets/72157602104741465/show

Larry
Larry
2003 23.5' Front Lounge, since new.  Previously 1983 22' Front Lounge.
Tow vehicles  2020 Jeep Wrangler Rubicon, 2001 Jeep Cherokee
Photo Collection: Lazy Daze
Re: Some thoughts on tilting solar panels
Reply #18 –
Yahoo Message Number: 151152
...Conclusion: for most RVers, most of the time, tilting solar panels is probably not worthwhile. I rarely do it myself. But under the right conditions--say, at Quartzsite or Death Valley in wintertime, and assuming you're going to be staying in one place for a while--titling can make a major difference in the amount of solar power you harvest.

I concur with Andy's conclusion.  We have four AM Solar GS135 panels and a Blue Sky 3024i MPPT charge controller.  We spent one month at Quartzsite this year.  Our panels were elevated to the full 45 degrees permitted by the AM Solar tilt arms.  We noticed a decrease in the time it took to return the batteries to a 100% SOC when they were tilted and oriented to the south.  I would also like to add that tilting adds to the efficiency of the panels on moderately cloudy days.  On moderately cloudy days where you can still discern the sun as a bright(er) spot in the clouds, our panels were still able to return our batteries to a 100% SOC.  There was only one day with sky conditions of very dense clouds that we only returned to a 97% SOC.

I would not go through the effort to tilt the panels if we were only staying a week or less.  But for a longer term stay as we did this year, tilting the panels is worth the effort.

I also noticed that a number of our friends at Quartzsite who could tilt their panels did so.

I would also add that in my opinion, the panels are secure enough in the tilted position to allow the rig to travel short distances at reduced speed to attend to chores such as dumping the waste water tanks and recharging with fresh water.  I did it three times at Quartzsite this year; a three mile round trip with no problems.  The panels were still tight at the end of our stay.

Dan and Lynn 2007 IB 30
2007 IB-30
Re: [LD] Re: Some thoughts on tilting solar panels
Reply #19 –
Yahoo Message Number: 151155
We see people all the time driving around Quartzsite with their solar panels up!  Fortunately, there are no low power lines or underpasses around here to worry about!

Linda Hylton

I would also add that in my opinion, the panels are secure enough in the tilted position to allow the rig to travel short distances at reduced speed to attend to chores such as dumping the waste water tanks and recharging with fresh water.  I did it three times at Quartzsite this year; a three mile round trip with no problems.  The panels were still tight at the end of our stay.

Dan and Lynn
Linda Hylton
Re: Some thoughts on tilting solar panels
Reply #20 –
Yahoo Message Number: 151157
A comment on tilting solar panels in winter - a fixed tilting mechanism will allow increased output assuming siting them south AND measuring during the prime daylight hours, such as indicated by Andy's measurements. However, the output near the beginning and end of the daylight hours will be poorer compared to flat mounting, barring obstructions on the roof. This will slightly mitigate the charge-replacement picture over the span of a day.

Steve
2004 FL
2013 Honda Fit
Re: Waste hookup - Sewer Solution
Reply #21 –
Yahoo Message Number: 151158
In addition to a macerator-type waste system, there is the Sewer Solution Valterra SS01 Boxed SewerSolution System which works using water pressure to liquefy sewage. I bought 30' or 40' of cheap 1" PVC hose at Home Depot and worm clamp it to the SS hose, thus expanding my reach to the clean-out drain.Watts 1-1/8 in. I.D. x 6 ft. PVC Bilge and Pump Hose-HSBBO6 - The Home Depot This  set-up has worked very well for me.

Chris
As an Amazon Associate Lazy Daze Owners' Group earns from qualifying purchases.
Formerly: 2002 30' IB
Re: Some thoughts on tilting solar panels
Reply #22 –
Yahoo Message Number: 151159
"A comment on tilting solar panels in winter - a fixed tilting mechanism will allow increased output assuming siting them south"

When tilting solar panels for increase overall output, the RV must be point directly east to west.  Being off by as little as 10 degree will significantly decrease daily output and negate the tilting effort. This is easy to do when boondocking in the open but much harder to accomplish in campgrounds..
Somewhere in the files is a spread sheet constructed by, I believe, Barry Barnes, showing the effects of the panels east to west orientation. Can't find it now.

Bottom line: if you boondock for longer periods of time and IF you can park facing exactly east to west or west to east. tilting the panels will significantly increase output. You must be willing to go on the roof and make the adjustments. Many owners have never seen their roofs and never will, not feeling safe being off the ground.

For the rest of us who rarely camp in perfect locations or for long enough to make the effort, adding an extra panel  will help make up the difference and will save trips to the roof.
Solar panel are cheap in comparison to just a few years ago, so go crazy and add an extra panel or two, along with upgraded lead-in cable, and not worry about going on the roof.

Occasionally, someone does needs to go up and clean the panels. I have seen panels so dirty that they lose 30% of their output. A little Windex goes a long way.

Larry
Larry
2003 23.5' Front Lounge, since new.  Previously 1983 22' Front Lounge.
Tow vehicles  2020 Jeep Wrangler Rubicon, 2001 Jeep Cherokee
Photo Collection: Lazy Daze
Re: Some thoughts on tilting solar panels
Reply #23 –
Yahoo Message Number: 151170
Larry makes a good point. If you have the space on your roof, adding a panel can be a good alternative to tilting. In my case, I already have five panels, so it would be difficult to add more.

"Solar panels are cheap in comparison to just a few years ago..."
 Case in point: Renogy 100 W monocrystalline panels for $149.99.

"...add an extra panel or two, along with upgraded lead-in cable."

The upgraded cable is very important. I'd be willing to bet that the majority of existing solar panel installations have undersized cable, where by "undersized" I mean "causing 3% or more voltage drop." In my own case, once I added up the voltage drop from panels to combiner box plus the drop from combiner box to solar controller plus the drop from controller to batteries, I was well over 7%--that's energy wasted.

I replaced the #10 panel leads on the roof with #6 cable; the #8 from the combiner box down to the solar controller with #2, and the #6 from the solar controller to the batteries with #2/0. That cut my losses from over 7% to just under 1%. I don't want to throw away any solar power!

"Occasionally, someone does needs to go up and clean the panels. I have seen panels so dirty that they lose 30% of their output. A little Windex goes a long way."

I've found that a long-handled California Duster, if used regularly, keeps the panels clean without the need to wash and wipe.

Larry
As an Amazon Associate Lazy Daze Owners' Group earns from qualifying purchases.
Andy Baird
2021 Ford Ranger towing 2019 Airstream 19CB
Previously: 1985 LD Twin/King "Gertie"; 2003 LD Midbath "Skylark"
Re: Some thoughts on tilting solar panels
Reply #24 –
Yahoo Message Number: 151176
Just add a bit more to the discussion, I had tilting and rotating panels on my LD. In my observations, the biggest difference (between flat and tilted), occurred during less than ideal conditions. Such as cloudy or overcast days. I imagine it would also be at dawn and dusk. Mind you, my panels were movable from inside the rig, so I could move them easily throughout the day.

Victor