Extra solar panel option June 15, 2020, 11:46:25 am Would the extra panel option benefit charging time enough to justify its cost?I know $850 sounds real high priced for one panel install but I'd consider it if it makes a big difference.I'm not planning for extra battery banks and an inverter.Just the stock configuration.
Re: Extra solar panel option Reply #1 – June 15, 2020, 12:08:22 pm Is this on a new coach?My thinking would be like this. If I was likely to be happy with 1 panel but considering 2, I'd buy 2.I would stick with one if I was likely to substantially upgrade the system beyond 2 in my first few years of ownership.'I have too much solar capacity', said no one, ever......Rich'03 MB in NC 5 Likes
Re: Extra solar panel option Reply #2 – June 15, 2020, 12:34:22 pm We've been through this before, but...Everybody's needs are different. Some might be fine with a single panel. For some, like me, 5 panels are barely enough. I would rather have 6. What you need depends on how you use your equipment, where you camp geographically, when you camp seasonally, and whether you are in campgrounds with hookups or whether you are dry camping. When I ordered my rig, I knew I would need much more than two panels, so I requested no panels, and had AM Solar do the entire setup.If you think your needs will be minimal, after calculating your daily energy consumption needs, or if you think you might need more than two panels some day, go with the single panel for now. If you know you will need more than two, and can get the rig with none, do that, and have your system designed and installed with all matching panels, the right wiring, the right battery bank, the right solar controller, all matched so you get maximum efficiency.If in doubt of your needs, the way to determine your energy consumption is to look at every single piece of electrical power, determine its consumption, figure how many hours a day you use it, then add that all up. Take the maximum power a panel can provide and divide it by 2, because you will rarely get that power, except for midday, summertime, with the sun directly overhead on cloudless days. Using the panel power you just calculated, assume 3 hours of charging in the winter, and 5 hours in the summer, with lower charge rates earlier and later in the day. Then, knowing what you are likely to need, and what a panel can provide, you can estimate how many panels you will need. If someone tells you you will need no more than two panels without going through the numbers, pay no attention. Again, we are all different, and what works for one of us is not necessarily adequate for someone else.Ken F in WY 6 Likes
Re: Extra solar panel option Reply #3 – June 15, 2020, 12:34:57 pm Quote from: rich - June 15, 2020, 12:08:22 pmIs this on a new coach?My thinking would be like this. If I was likely to be happy with 1 panel but considering 2, I'd buy 2.I would stick with one if I was likely to substantially upgrade the system beyond 2 in my first few years of ownership.'I have too much solar capacity', said no one, ever......Rich'03 MB in NCThanks.Yes, new.
Re: Extra solar panel option Reply #4 – June 15, 2020, 12:36:46 pm Quote from: rich - June 15, 2020, 12:08:22 pm'I have too much solar capacity', said no one, ever......Get the second panel, unless you plan on upgrading to even more solar capacity n the future.Our electrical needs seem to increase over time, and not decease.In the wintertime, a single panel may have difficulties keeping the battery charged, even with light usage.Larry
Re: Extra solar panel option Reply #5 – June 15, 2020, 12:45:10 pm Quote from: Kenneth Fears - June 15, 2020, 12:34:22 pmWe've been through this before, but...Everybody's needs are different. Some might be fine with a single panel. For some, like me, 5 panels are barely enough. I would rather have 6. What you need depends on how you use your equipment, where you camp geographically, when you camp seasonally, and whether you are in campgrounds with hookups or whether you are dry camping. When I ordered my rig, I knew I would need much more than two panels, so I requested no panels, and had AM Solar do the entire setup.If you think your needs will be minimal, after calculating your daily energy consumption needs, or if you think you might need more than two panels some day, go with the single panel for now. If you know you will need more than two, and can get the rig with none, do that, and have your system designed and installed with all matching panels, the right wiring, the right battery bank, the right solar controller, all matched so you get maximum efficiency.If in doubt of your needs, the way to determine your energy consumption is to look at every single piece of electrical power, determine its consumption, figure how many hours a day you use it, then add that all up. Take the maximum power a panel can provide and divide it by 2, because you will rarely get that power, except for midday, summertime, with the sun directly overhead on cloudless days. Using the panel power you just calculated, assume 3 hours of charging in the winter, and 5 hours in the summer, with lower charge rates earlier and later in the day. Then, knowing what you are likely to need, and what a panel can provide, you can estimate how many panels you will need. If someone tells you you will need no more than two panels without going through the numbers, pay no attention. Again, we are all different, and what works for one of us is not necessarily adequate for someone else.Ken F in WYWe've been happy with our 1995TK with 2 Trojan 105's. I changed out the converter to a Progressive Dynamics and that really helped. We have no solar and have gotten by okay. I'd love to not need a generator to charge though.
Re: Extra solar panel option Reply #6 – June 15, 2020, 02:55:18 pm Quote from: Kenneth Fears - June 15, 2020, 12:34:22 pmWe've been through this before, but...Everybody's needs are different. Some might be fine with a single panel. For some, like me, 5 panels are barely enough. I would rather have 6. What you need depends on how you use your equipment, where you camp geographically, when you camp seasonally, and whether you are in campgrounds with hookups or whether you are dry camping. When I ordered my rig, I knew I would need much more than two panels, so I requested no panels, and had AM Solar do the entire setup.If you think your needs will be minimal, after calculating your daily energy consumption needs, or if you think you might need more than two panels some day, go with the single panel for now. If you know you will need more than two, and can get the rig with none, do that, and have your system designed and installed with all matching panels, the right wiring, the right battery bank, the right solar controller, all matched so you get maximum efficiency.If in doubt of your needs, the way to determine your energy consumption is to look at every single piece of electrical power, determine its consumption, figure how many hours a day you use it, then add that all up. Take the maximum power a panel can provide and divide it by 2, because you will rarely get that power, except for midday, summertime, with the sun directly overhead on cloudless days. Using the panel power you just calculated, assume 3 hours of charging in the winter, and 5 hours in the summer, with lower charge rates earlier and later in the day. Then, knowing what you are likely to need, and what a panel can provide, you can estimate how many panels you will need. If someone tells you you will need no more than two panels without going through the numbers, pay no attention. Again, we are all different, and what works for one of us is not necessarily adequate for someone else.Ken F in WYKen,Do you have any pictures showing how you fit the panels on your rig?I've got an 01 MB that has none at the moment. I've seen some you tube videos that have peaked my interest. I'm looking to plan out solar, lithium batteries, victron multiplus, etc...I seriously doubt it's possible, but I'd love to be able to have enough juice to run the AC off grid. I did see someone that is running a mini-split AC totally off grid, but he had 8 panel's.
Re: Extra solar panel option Reply #7 – June 15, 2020, 03:05:44 pm We have one panel on our 31 foot 07 which we bought new. Gotten by ok boondocking all over U,S, and Canada,[if i had to do it over again, would have purchased 2 panels.Bob] 2 Likes
Re: Extra solar panel option Reply #8 – June 15, 2020, 03:22:34 pm We did exactly as Rich suggested....2 has been fine so far.... 2 Likes
Re: Extra solar panel option Reply #9 – June 15, 2020, 03:23:48 pm Quote from: henness - June 15, 2020, 02:55:18 pmI seriously doubt it's possible, but I'd love to be able to have enough juice to run the AC off grid. I did see someone that is running a mini-split AC totally off grid, but he had 8 panel's.The mini-split in that video is 8000 BTU. Most RV A/C units are 13,500 or 15,000 BTUs, and require even more power.FYI - to let you know what you're up against. Rich'03 MB in NC
Re: Extra solar panel option Reply #10 – June 15, 2020, 03:43:19 pm Henness, no pics but I have one on each side of the front hatch and one on each side of the AC unit. Those 4 are longitudinal. I have a 5th one that is transverse, directly behind the front hatch. I discussed with AM solar putting a 6th one, transverse, behind the AC unit. The concern we both had was lift from air flow, and I decided not to do it. I could have added a 6th if I removed the TV antenna, but I use the TV antenna occasionally. As to running the AC off grid, I believe the AC draw is 20 amps at 120 volts. To run that using your battery bank charged from solar panels, the draw, ignoring losses in cabling and the inverter, would be 200 amps. A 12v 200 amp-hour battery would be drained in 1 hour. My 5 panels max out at between 25 and 30 amps, so I would need 8 hours of 25 amp charging for one hour of run time of the AC unit. Ken F in WY 1 Likes
Re: Extra solar panel option Reply #11 – June 15, 2020, 03:44:51 pm Having worked out all the details for my Solar upgrade at AM Solar next month, I’ve noticed one thing. When it comes to solar upgrades and cost, figure on doubling the cost of any component.Even at AM Solars reasonable hourly rate of $120 a $300 panel will generally cost twice that. Remember also that you’re not just buying the extra panel when upgrading to two panels at the mothership. You are also purchasing the requisite cables needed for the install plus the labor cost.We had the extra panel installed when we purchased our ‘15 RB. It worked well until the AGM’s were ageing out and abused. I’m moving up to 4 more panels on the roof, an added quick connect at ground level for an additional 230 watt portable panel and four 100 amp hour Battle Born Lithium’s. Add to that some serious electronic upgrades to the whole thing and I hope to only fire up the generator for its bi monthly exercise. As close as I can figure, the total cost of the installed parts is half of the overall cost of the completed installation.Pricey? It’ll pay for itself over the next 20 years in ease of operation alone and it’ll be quiet as a lamb and everyone can appreciate that.Kent 3 Likes
Re: Extra solar panel option Reply #12 – June 15, 2020, 04:05:09 pm Ken said "A 12v 200 amp-hour battery would be drained in 1 hour. My 5 panels max out at between 25 and 30 amps, so I would need 8 hours of 25 amp charging for one hour of run time of the AC unit. "Don't forget battery capacity is usually stated at the 20 hour rate. This means that a 200 AH battery can deliver 10 amps for 20 hours before reaching safe minimum. If you draw more than 10 amps, that capacity is reduced. If you draw 200 amps, you would be lucky to get 30 minutes from that 200 AH battery.Rich - ex 2000 MB - Birch Bay, WA 2 Likes
Re: Extra solar panel option Reply #13 – June 15, 2020, 08:49:14 pm Quote from: tedeboy - June 15, 2020, 11:46:25 amI know $850 sounds real high priced for one panel install but I'd consider it if it makes a big difference.My $.02 worth: I found the single panel was not enough for boondocking when I started doing so in 2018. I can convince myself absent any empirical data that a second one would be sufficient. Last year I added 460 W for about $6K. I can also convince myself that that is a $5K penalty for short shortsightedness.That said, I'm glad I have 560 W.YMMVJoel 1 Likes
Re: Extra solar panel option Reply #14 – June 15, 2020, 11:33:10 pm Here's a photo of my former midbath's roof with six 100 W panels. Note that there's no "batwing" TV antenna and no satellite-TV dish. Since I don't have a TV, I removed them both. If I hadn't, I would not have been able to fit six panels. And as you can see, there's barely room to walk on the roof.(The black and orange box just aft of the air conditioner is a Ridgid tool case that contains the tilt bars for the panels.)"I did see someone that is running a mini-split AC totally off grid, but he had 8 panel's."Be aware that a solar panel can generate anywhere from 80 watts to several hundred. So seeing that a rig has a certain number of panels doesn't tell you anything. What counts is how many watts it has.Keep in mind that battery capacity must be matched to panel wattage. It won't do you much good to have a thousand watts of panels if you only have a couple hundred amp-hours of batteries. The most common rule of thumb is one amp-hour of battery per watt of solar panel.And finally, when under a very heavy load such as running an air conditioner, lead-acid batteries perform well below their rated capacities. (Look up 'Peukert's law' for a technical explanation.) So even if you had a thousand watts of solar panels and a thousand rated amp-hours of batteries, you wouldn't get anywhere near a thousand amp-hours of service when running an air conditioner.LiFePO4 batteries do much better with heavy loads, but now you're talking five times the cost. 5 Likes
Re: Extra solar panel option Reply #15 – June 17, 2020, 12:56:26 am For reference, here's our 24' Twin King at AM Solar with 640 watts in place. Losing the bat wing, which we have yet to use, we could easily have a fifth panel for a total of 800w. However our current setup allows for months of boondocking, running the microwave every day plus computers and everything else without any real effort to converve energy. Only the air conditioning would require shore power or generator.When we're at our home base, we have no problems running the 2800cfm swamp cooler off the inverter/battery when Edison is having issue, like right now as I type!Steve 4 Likes
Re: Extra solar panel option Reply #16 – June 17, 2020, 01:54:11 am Very impressive, Steve! I would not have thought you could get that much wattage on a T/K.
Re: Extra solar panel option Reply #17 – June 17, 2020, 08:46:06 am Nice, Steve. It looks to my eye that you might fit another between the front vent and the AC. Did you measure for that? It also looks like the panels vary in size. Is that just the angle of the pic?Ken F in WY
Re: Extra solar panel option Reply #18 – June 17, 2020, 09:40:03 pm Quote from: Andy Baird - June 15, 2020, 11:33:10 pmHere's a photo of my former midbath's roof with six 100 W panels. Note that there's no "batwing" TV antenna and no satellite-TV dish. Since I don't have a TV, I removed them both. If I hadn't, I would not have been able to fit six panels. And as you can see, there's barely room to walk on the roof.(The black and orange box just aft of the air conditioner is a Ridgid tool case that contains the tilt bars for the panels.)"I did see someone that is running a mini-split AC totally off grid, but he had 8 panel's."Be aware that a solar panel can generate anywhere from 80 watts to several hundred. So seeing that a rig has a certain number of panels doesn't tell you anything. What counts is how many watts it has.Keep in mind that battery capacity must be matched to panel wattage. It won't do you much good to have a thousand watts of panels if you only have a couple hundred amp-hours of batteries. The most common rule of thumb is one amp-hour of battery per watt of solar panel.And finally, when under a very heavy load such as running an air conditioner, lead-acid batteries perform well below their rated capacities. (Look up 'Peukert's law' for a technical explanation.) So even if you had a thousand watts of solar panels and a thousand rated amp-hours of batteries, you wouldn't get anywhere near a thousand amp-hours of service when running an air conditioner.LiFePO4 batteries do much better with heavy loads, but now you're talking five times the cost.The plan would be to ditch the lead-acid and go w/ Lithium for batteries. I like your layout for the panels. We have no dish, and don't have a TV so no need for the batwing, so I could lose that easy enough. The rig I saw running the mini-split had an interesting set up where they had the panels double stacked. Looking at your picture, that might be possible for the three at the passenger side. Lots to think about. Will end up being super expensive as well.
Re: Extra solar panel option Reply #19 – June 18, 2020, 11:13:23 am Steve,I understand that the AM Solar installation package allows for tilting each panel. Have you found a need to do so and if so have you noticed an increase in solar gain?I’m so excited. Kent
Re: Extra solar panel option Reply #20 – June 18, 2020, 01:03:54 pm Quote from: Kent Heckethorn - June 18, 2020, 11:13:23 amI understand that the AM Solar installation package allows for tilting each panel. Have you found a need to do so and if so have you noticed an increase in solar gain?Tilting panels will produce more power if...the rig is parked perfectly in an east-west orientation. Get it off 10-15 degrees and all gains are lost. Unless you are boondocking in a flat area, this requirement can be difficult or impossible to achieve.Tilting panels require going up on the roof and manually tilting them. With a roof full of panels, maneuvering between them can be tricky and a slip can send you off the edge. I always suggested to owners who wanted tilting panels to invest in more panels and eliminate having to mess with tilting, especially for short term visits.If you are a long-term boondocker and can orient the rig correctly, tilting does work well for winter use.Larry 3 Likes
Re: Extra solar panel option Reply #21 – June 18, 2020, 03:33:25 pm Thanks Larry,The Zamp 90 watt panels I’ve selected have stats that claim low angel efficiency gain of up to 3-5%. Zamp ZS90L 90W Solar PanelI’ll know better next month if there will be a higher yield panel that fits the RB that can increase overall wattage. There is a lot up there now so the 90’s feel like a good match to the footprint of the panels installed at LD.Clambering up to tilt the panels isn’t something I would like to do on a regular basis. Kent
Re: Extra solar panel option Reply #22 – June 18, 2020, 05:19:15 pm $343 for 90 watts is rather costly--$3.81 per watt. By contrast, standard Renogy 100 W panels cost $1.08 per watt, and even Renogy's high-efficiency (= physically smaller) Eclipse 100 W panels are $1.79 per watt--about half the cost of those skinny 90 W Zamp panels.I do understand that there's sometimes a need to buy an overpriced panel to fit a given space. Case in point: I paid an insane $350 for a single low-profile 45 W Zamp panel, because it was the only one that would fit on top of my Yakima car-top carrier box. That's $7.78 per watt! It hurt like hell to pay that much, but it was literally the only possible choice. (It powers my car fridge.)But in your case, Kent, I'd seriously consider removing the factory-installed panels, which are rarely placed optimally, and starting over from a clean slate with more cost-effective panels. Just a thought. :-) 1 Likes
Re: Extra solar panel option Reply #23 – June 18, 2020, 06:45:49 pm Andy,Garrett mentioned that they carry most items in stock and my final chooses can be discussed upon arriving at the shop. I do agree that 90 watts is rather underpowered but fitting the available real estate is a prime consideration. As of now nothing is etched in stone. If a larger more powerful panel will fit, I’d rather go for the Zamp 190 watt dual mode panels. At $365 each, the price seems more in line with your dollar to watt concerns.I’m not sure what will become of the original panels. Ditching them is no big deal. I’d like to be closer to 1000 watts top side. Perhaps shifting the original panels to another location can be an option. As the panels will be run in parallel, shading should not present too much of an issue from what I understand. At this point, the scheduled install date is set. Once I get there, Garrett will most likely do his best to obtain the best overall panel configuration for the rig. I hope my interjections on this thread have not appeared as a hijack. Seemed pretty appropriate to me.Stay safe.Kent
Re: Extra solar panel option Reply #24 – June 18, 2020, 10:24:06 pm Quote from: Andy Baird - June 18, 2020, 05:19:15 pm$343 for 90 watts is rather costly--$3.81 per watt. By contrast, standard Renogy 100 W panels cost $1.08 per watt, and even Renogy's high-efficiency (= physically smaller) Eclipse 100 W panels are $1.79 per watt-DIY is getting even cheaper, if it fits. 80 cents a watt.https://www.homedepot.com/p/Grape-Solar-100-Watt-Polycrystalline-Solar-Panel-for-RV-s-Boats-and-12-Volt-Systems-GS-Star-100W/204211365Larry 1 Likes