Adding more panels to RV?

[easye]

That is the problem they have in Hawaii. The grid can't handle more localized PV installations so the POCO's were not approving them. The home owner now has the option to install a battery (at their cost) to help stabilize the grid.

And hence the reality of their situation is starting to come to realization. Kauai recently installed a 13 megawatt solar install with TESLA power packs. Word from the POCO is it's cheaper than their current generation. This is no doubt and extreme situation (island with no natural resources to burn) but it's an example of how things are changing. All this "it won't work" "just get a generator" "just buy it from the POCO and don't waste your time" talk will end soon. 5-10 years and this "SOLAR" stuff will be a no-brainer. within 2 years conventional batteries will be a thing of the past. they probably already are and you just don't know it.

[Wrybread]

SunKing, you have no reading comprehension or you're just a troll. I explained a bunch of times the reasoning behind wiring in parallel (that my controller can't handle my 3 panels in series, so going parallel for now, might upgrade it in the future). I'm well aware of the drawbacks. And as far as "multipliers", I was just quoting another thread as I said. And you yourself quoted a 15% reduction in efficiency for flat mounted panels, and guess what: that's a multiplier. Honestly, you *can't* be this stupid, so I'm going to guess you're simply a troll. Or someone who just likes to rant. Maybe a little less coffee would help?

Anyway, I'm done even reading your childish rants and overly argumentative posts.

[Sunking]

That is so profoundly against my 20 years of having solar in RVs (and a few years living full-time off-grid in a house) it's not even funny. I'd expect it elsewhere, but on a forum dedicated to solar it's flat out amazing.

It is amazing. You claim 20 years experience and still do not know anything like you should NOT using parallel connected panels on a MPPT controller, and inputting 900 watts into a controller only made to handle 500 watts. The noise is you my friend, you do not know simple basic fundamentals or simple formulas. Your thread proves you do not know what you are doing and what everyone has been trying to tell you. You should not be answering any questions. All the equipment in your so called thread is incompatible.

Multipliers, now that is some funny ignorant stuff, I don't care who you are.

[Wrybread]

And by the way Zoar I really really like the installation you did on your food truck, very very nice job. If you do find a DIY solar forum with a higher signal to noise ratio (basically one not dominated by a few anti-solar alarmist blow-hards), please PM me or email me at wrybread at gmail dot you know what.

You can see my thread fighting to get a little signal among the noise (and planning an expansion of my array) here:

https://www.solarpaneltalk.com/forum...ps-on-my-setup

[Wrybread]

I see this is a pro- FOSSIL fuel forum so I am going to bow out now. After about a month here it is clear it is pro Fossil Fuel FIRST and the constant digs against solar are not what I can tolerate anymore. Bye everyone. I'm gone. Enjoy the fumes.

@zoar: I'm getting the same vibe. If it weren't for a couple of voices of sanity here I'd give up on this forum too. I'm probably not far behind you, but because of the occasional signal among the noise I'm still hopeful. And ha look at the post above me as I type this. From someone with almost 20,000 posts!

Solar is just for show and tell or for extending long stays. You still need a generator or Isolator to get charged up dry camping for extended periods.

That is so profoundly against my 20 years of having solar in RVs (and a few years living full-time off-grid in a house) it's not even funny. I'd expect it elsewhere, but on a forum dedicated to solar it's flat out amazing.

[Sunking]

I understand what you are saying here, but a lot of those issues, depth of discharge, charge and discharge rate, Peukert effect, go out the window when you start looking at the various Lithium chemistries like LiFePO4 I understand also the typical view of the economics of this

I already addressed that. You are preaching to the choir. LFP brings up a whole lot of other issues to deal with.

I am also weighing this as a health issue for my wife. Getting overheated and ending up in the hospital is not cheap either.

I understand that and empathetic. But Solar is limited, and you can work around it. Like I said leave here in the store while you get the RV and pick her up. She can ride in front with you in the cab with the AC blasting away. Your RV cab AC is at least 2-Tons of cooling aka 24,000 BTU's There are several things you can do. I wish you luck and good health.

[Isaac-1]

I understand what you are saying here, but a lot of those issues, depth of discharge, charge and discharge rate, Peukert effect, go out the window when you start looking at the various Lithium chemistries like LiFePO4 I understand also the typical view of the economics of this, and your view of roughing it, but I am also weighing this as a health issue for my wife. Getting overheated and ending up in the hospital is not cheap either.

[Sunking]

I don't get where you are coming from with this statement, but I will start off with stating that my motorhome does have a battery isolator (diode type) . As to the rest solar does a lot. It allows one to store an RV in a storage lot that does not have electrical service while still running low draw items like exhaust fans for humidity control. It allows for extended off grid camping in locations where loud RV generators are not allowed such as National Forest Campgrounds (most have a 60 Db sound limit, which excludes all but the small inverter generators) And for cases like the point at hand it may allow one to extend the battery run time for an air conditioner.

Isaac I am afraid you have misunderstood and backing up what I have said and do not realize it. Who said anything about storage and who cares. Sure the panels can get the batteries charged up with little or no load.

Yes, it only extends camping time, but as you admit falls short. If you are in National Forest and cannot run the generator,, you can run the engine on the RV if you have the Isolator. One way or the other, solar cannot do what you want. It is not home and called Roughing It for a reason. Going off in a RV is all about unplugging and getting away from TV, phones, and internet. If you want all the comforts, use an RV park with electric hook ups and pull a car.

For the other points I have not seen many tourist stops, dining establishments, or even Wal-Mart stores that have shaded RV parking, if there is shaded parking the branches on the trees are often so low as to not allow an 11+ft tall motorhome to park under them.

What are you talking about? I was referring to camp site. If you need to park in a Walmart for three hours, you are SOL. Leave the wife in the store while you go get the RV and get it cooled down, and picked her up at the front door. Personally if I were a RV'er I would do like I have in the past, pull a small car around to go shopping and site seeing. For Pete's sake you are wanting all the comforts of home to go. Sorry, you cannot have it. Walmart is not going to allow you to set up extra panels by opening the awning and taking up parking spaces so your RV can stay cool while you shop. You are not entitled to six parking spaces. If it is that important, bite the bullet, get a good lock/alarm system and let the engine run.

Lastly do not forget your FLA batteries have a maximum charge current limit. Depending on the type you have C/8 to C/6 is the limit. Try to push more is futile and destructive. That requires using Lithium. With 800 watts of panels I think you said you have generates up to 65 amps at 12 volts. That means you need a minimum 400 to 500 AH battery. If you re not aware if you put a C/4 load of 100 amps on a 400 AH battery means you now have a 275 AH battery and only 50% of that is usable. Mr Peukert is greedy. The physics does not work.

[Isaac-1]

No it does not. Any and every RV system should have an Isolator whether you have solar or not. In fact with the Isolator negates the need for any solar if you drive at least every other day. Solar is just for show and tell or for extending long stays. You still need a generator or Isolator to get charged up dry camping for extended periods. I do not know many people who park RV's where the summer blazing sun is on the RV from Sunrise to Sunset. Even if you did, orientation and tilt angles are not optimum. $60 for the Isolator that does the job, or thousands for panels and controller that cannot do the job alone.

I don't get where you are coming from with this statement, but I will start off with stating that my motorhome does have a battery isolator (diode type) . As to the rest solar does a lot. It allows one to store an RV in a storage lot that does not have electrical service while still running low draw items like exhaust fans for humidity control. It allows for extended off grid camping in locations where loud RV generators are not allowed such as National Forest Campgrounds (most have a 60 Db sound limit, which excludes all but the small inverter generators) And for cases like the point at hand it may allow one to extend the battery run time for an air conditioner.

For the other points I have not seen many tourist stops, dining establishments, or even Wal-Mart stores that have shaded RV parking, if there is shaded parking the branches on the trees are often so low as to not allow an 11+ft tall motorhome to park under them. This is not saying I would not part under them if given the chance. While is true tilt angle is rarely optimal for much of the southern and central US summer noon sun angles tend to be close to directly overhead, this is also the general part of the day when one would likely stop for lunch and need air conditioning. Now back to this magic Isolator of which you speak How does this "Isolator" let you draw 300 amps out of a pair of 200 AH effective capacity batteries over the course of 3 hours? A set of 50 AH output capacity solar panel effectively would (again use of round numbers to keep it simple)

Over the course of 3 hours of a 100amp draw by the air conditioner the batteries could supply 200AH and the solar panels could optimally add another 150AH (50 amps per hour for 3 hours) therefore exceeding the 300 AH needed to run the air conditioner for 3 hours. The alternative here would be to add another 100-150 AH of battery capacity which is not cheap when it comes to Lithium batteries, and weighs a lot with lead acid (much more than a solar panel).

[Sunking]

p.s. as to my original issue, while it is true that the engine alternator can restore battery charge faster than solar panels can, that would require more battery storage

No it does not. Any and every RV system should have an Isolator whether you have solar or not. In fact with the Isolator negates the need for any solar if you drive at least every other day. Solar is just for show and tell or for extending long stays. You still need a generator or Isolator to get charged up dry camping for extended periods. I do not know many people who park RV's where the summer blazing sun is on the RV from Sunrise to Sunset. Even if you did, orientation and tilt angles are not optimum. $60 for the Isolator that does the job, or thousands for panels and controller that cannot do the job alone.

[SunEagle]

I agree about the motivation for people to install rooftop PV systems, but as I see it these home rooftop PV systems are about to reach the market penetration point where they can induce instability in the POCO electrical grid. I see it as inevitable that home solar will increase the demand swings of the grid and sooner or later will result in wide spread brownouts and blackouts even with timeshifting technologies like the Tesla Powerwall. All it takes is enough people moving to rooftop PV and a cold front to come through followed by a few days of cloudy weather.

p.s. as to my original issue, while it is true that the engine alternator can restore battery charge faster than solar panels can, that would require more battery storage capacity, which either means expensive Lithium batteries or heavy lead acid which cut into the cargo carrying capacity. Leaving the engine / generator running while away from the vehicle is also just not an option in a lot of places.

That is the problem they have in Hawaii. The grid can't handle more localized PV installations so the POCO's were not approving them. The home owner now has the option to install a battery (at their cost) to help stabilize the grid.

[J.P.M.]

The only way RE will possibly work 100% of the time would be to install very large energy storage systems.

While that technology may be available it still comes down to "what would you pay for every kWh that you use?" Adding energy storage (even with some expected price drops) will raise the cost of electricity much higher then what 100% of the people in the US pay now. If cost isn't an issue then those people can dream about 100% RE as being a reachable goal.

But based on why most people want to install a pv system is usually due to the existing high cost of power from the POCO now. Why would they spend more for a battery system?

IMO I want to save money not spend more.

At the bottom line, seems to me capitalistic thinking and using less energy are mostly incompatible with one another.

One way to think of R.E., including solar technologies, is to consider them as one class of tools that's part of a set of means to an end, with the end being - as a practical matter - lower energy bills. To make R.E. work most of the time usually means spending more now for less immediate return, or delaying gain. That's the part where emotion and other human failings like lazy thinking get to screw things up.

Seems to me that most folks have been largely B.S.'d to see or think of solar, PV in particular, as almost an end in itself and a way to get even with the evil POCO, or keep up with the Jones', join the lemming crowd, etc., with the larger and actual goal of lower bills, while still there, almost a distant second for a lot of folks who are brainwashed into throwing expensive and cost ineffective solar devices at gnawing but nonetheless self inflicted high electric bills on the often bogus and in most cases poorly understood promises of a solution from con men whose existence is reliant on their mark's solar ignorance.

For off grid stuff, it seems apparent, to me anyway, that most who show up here with off grid/batteries/lifestyle on their mind, like most others, are abysmally ignorant of what they're considering, but have more to get screwed by in terms of cost and unknown additional hassle ./ And, also like others, often and/or usually get rather indignant when their ignorance is pointed out to them by others who try to point out shortcoming in na

[Isaac-1]

I agree about the motivation for people to install rooftop PV systems, but as I see it these home rooftop PV systems are about to reach the market penetration point where they can induce instability in the POCO electrical grid. I see it as inevitable that home solar will increase the demand swings of the grid and sooner or later will result in wide spread brownouts and blackouts even with timeshifting technologies like the Tesla Powerwall. All it takes is enough people moving to rooftop PV and a cold front to come through followed by a few days of cloudy weather.

p.s. as to my original issue, while it is true that the engine alternator can restore battery charge faster than solar panels can, that would require more battery storage capacity, which either means expensive Lithium batteries or heavy lead acid which cut into the cargo carrying capacity. Leaving the engine / generator running while away from the vehicle is also just not an option in a lot of places.

[SunEagle]

As an observation and opinion only, after being around R.E. and R.E. types for ~ 40 years, I think I see a generally positive correlation between how much someone REALLY knows about R.E. and how much they're aware of it's limitations as well as its potential. Such folks sometimes have a bit more ability to work around some of those limitations occasionally and usually within the constraints of common sense. They can dream, but not make dreams their master.

The only way RE will possibly work 100% of the time would be to install very large energy storage systems.

While that technology may be available it still comes down to "what would you pay for every kWh that you use?" Adding energy storage (even with some expected price drops) will raise the cost of electricity much higher then what 100% of the people in the US pay now. If cost isn't an issue then those people can dream about 100% RE as being a reachable goal.

But based on why most people want to install a pv system is usually due to the existing high cost of power from the POCO now. Why would they spend more for a battery system?

IMO I want to save money not spend more.

[J.P.M.]

To get a bit even more off topic on this thread I started, I agree solar and RE in general should be about practicality to a degree, and not a religion. Solar may sound nice, and may even work the vast majority of the time in some locations, but that does not mean it can or will work for everyone as a sole source of power.

As an observation and opinion only, after being around R.E. and R.E. types for ~ 40 years, I think I see a generally positive correlation between how much someone REALLY knows about R.E. and how much they're aware of it's limitations as well as its potential. Such folks sometimes have a bit more ability to work around some of those limitations occasionally and usually within the constraints of common sense. They can dream, but not make dreams their master.