Just added the 5th solar panel and thanks to Roger's design it was KISS. with 6 circuits on the fuse block and only 4 in use, all I had to do was add the 2 wires. Everything else was already in play. Now have 1450 watts.
Feeling like a lesser man now with only 1180 watts.....
Congratulations!!! No such thing as too much money, solar or too large a black tank..
Tim Fiedler
Gen-Pro.biz
630 240-9139
Thanks for the shout out Chuck. I have to give a lot of credit to Alan at Bay Marine who walked me theough the details to get it right. The fuse block makes it easy to combine, add or isolate panels. Congrats on five panels.
All RVers should install 370W panels, for the most power per square foot:
https://stellarsolar.net/wp-content/uploads/2017/08/sp_X22_370_360_d_ac_datasheet_527025_A.pdf
All RVers. Of course.
The panels look to be about $700 each. Twice the price of LGs. Four times what I paid for 300 watt commercial panels with a 25 yr warranty delivered to MN.
Do what you want to do for what you want to spend.
Over 22% efficient. How does the physical size compare to other panels? They mention valuable roof real estate. I would like the max power and still have some roof access. Some of the newer panels mention less power loss hot?
These panels seem to output 240 volt? That might allow recharging a Tesla power wall ll?
My unistalled magnum pt-100 solar controller seems to handle 240 volts. 6600 watts 100 ADC.
Maybe makes more sense that the magnum is a residential solar controller and the panels put out the bigger voltage and the Tesla matches. Duh.
The Tesla says 120/240V. 5000 watt continuous inverter built in, charge at 240 take out at 120 would match the coach I would think and furnish power to run the 12volt side at float all the time.
What fun
$10k worth of panels and battery but more than 8 d's worth of power at 50% SOC and maybe able to take a slower recharge and not sulphate the batteries as they are li-ion and as roger mentioned the Tesla is temp controlled which fixes the rv temp extreme issues. Especially mounted under the couch?
And the magnum controller connects to my system. Fuzzy on the details as this was a future project but I am liking this outcome as it gives enough power to run the coach completely. Stacked inverters would have enough output to run both roof airs at the same time plus other loads like the aqua hot on ac.
I am barely starting learning but would the 240 volt use smaller wires?
Thanks for the panel post. I have a family member in the solar biz. May have to call him.
As long as a Tesla is able to run partially charged without damage then an immediate recharge is not as needed.
More things to spend money on. Ten year unlimited cycle warranty on the Tesla
Incredible performance claims should always be taken with a grain of salt. Just saying.
I agree but my reading of the UL is dependent on what exact verification you want. Different UL stickers. Actual ratings can be verified, would be stupid to lie. Too easy to verify. The footnotes mention testing multiple panels
They are 44 x62 inches and weigh 46 lb, abput 25% less per watt than my cheap Chinese panels. Think of getting almost 2x the power (or 1/2 the space) over the lifetime of the panels, including:
- Better efficiency, 22.7%
- Better integration, with built-in microinverters
- Better warranty
- Better low-light performance
- More reliable. Our rigs are high-vibration environments. With Sunpower, there is less chance of having to replace a panel.
The cost of solar is mostly about labor and lifecycle costs, not the cost of the panels.
Thanks. Any research on the Tesla Powerwall ll?
UL is a safety standard. Chinese are pretty much immune to litigation so they can and do make incredible claims. Other Asian companies claims also suspect also, especially when it comes to HVAC equipment.
SunPower panels are made in China. Twice the power at 1/2 the space is simply not true.
SunPower is very long on promises but actually finding data on performance and price is very difficult.
SunPower Spiraling Towards Bankruptcy - SunPower Corporation (NASDAQ:SPWR) |... (https://seekingalpha.com/article/4217598-sunpower-spiraling-towards-bankruptcy)
SunPower Spiraling Towards Bankruptcy
Craneman,
You are leaving us in the dust and even have room for another up top. Enough power to look like Las Vegas in your campsite.
Nice and neat job. Good way to plan for future expansion and it paid off.
You have a residential fridge. What do you think the minimum battery capacity should be? Is this the reason you added a panel?
Pierce
The 3 batteries worked before any solar. About 4 hrs. gen. time per day. With the 4 panels 1 hr. at night. DW watches DTV while I am out fishing. The 5th panel will be new numbers to be determined at Phoenix this coming weekend for NASCAR then to the south rim Grand Canyon after that.
UL has different modalities per their web site. . You CAN have UL verify specs. It's extra. Different sticker.
Bought two appliances from bankrupt sears last month. Figures.
May have to move faster with my research if they are crumbling.
The idea that their panels put out 120/ 240 volt. 60 cycle ac would seem to match the Tesla Powerwall ll.
Would seem to be much easier to assemble a much larger system.
I looked at li-ion six years ago but the temp restrictions and over $10k easily for enough capacity plus the special inverter chargers needed made it not a go.
Tesla building in a 5k inverter and over a thousand amp hours and a -4 to 122 degree useable battery is a gane changer.
Especially if using ithe Powerwall addresses the gorilla in the room problem to me of not charging the batteries at the manufacturers recommended rate of 1/5th C.
In my experience and research the way to help that long term issue is to either use lifeline agm's that can be equalized, flooded cells for the same ability or continue the oem Foretravels use of gels that do not need equalizing.
This use of the Tesla might not need the otherwise larger alternators required to get back to the 1/5th C Foretravel used on every coach made for over 20 years.
I am a long term keeper kind of guy. The lower price system spread over shorter term may be the same annual cost as a more expensive system just over more years.
No non UL stuff for me. No non marine UL cabling.
I would pay more for a resale coach that had verifiably addressed all these possible issues. Wouldn't you?
I know the average buyer would know little of this. If you educate them they normally will pay more.
That worked when I sold some of your current coaches new. Still applies.
If SunPower dies may be some deals on inventory. If their specs are off no big deal as my useage is very low.
I need multiple days not massive power in and out. And to take a slow charge without damaging the batteries.
separating a large barrel bank into smaller groups for the 1/5th C was one way I thought to address that issue.
Remotely switchable would work. Lots of connecting relays and wiring and cost versus just replace the batteries as their capacity drops.
I wonder if I could overlay the Tesla leaving the stock oem setup as-is for the 12 volt side.
Use the .tesla like a shore power input? It puts out 120 volt 60 cycle ac, literally plug it in.
Maybe no need for any mods. iPad monitoring of its charge state. I assume it stops taking a charge when full?
Tesla shows no controller on a house system. It just works it seems.
Plug and play from the 240 volt panels into the Tesla then use the 120 volt out from the Powerwall into the coach like shore power.
10 8g8d's equalivent of power from the combined system eliminates my concerns about powering a residential refer.
Fixed. Run roof airs with 5k watts output. At least for a while?
I would imagine the other overseas makers are dumping panels here.
Man this one is getting way out there.
Foretravel got paid to engineer their coaches correctly. The coach is the power system.
My batteries and inverter were at least two thirds the price of the Tesla. Plus install. And have less than 40% the battery capacity and 2/3's the inverter output it seems.
Tech changes. With ten Powerwalls you could have a electric wheel driven coach like a locomotive. Far future but for sure someday, trucks already exist
I like the way your system is modular craneman. Simply plug and play. I doubt I'll ever change what I now have but ya never know. I'd like to see some major advances in energy storage.
Boy do I miss Dave M.
Am I understanding this correctly?
SunPower® X22-370-D-AC panels are 370 watt at 240 VAC, so wiring from roof is carrying 240 volts AC?
what is the benefit of having 240 VAC from the panels when half of the electrical systems in our Foretravels are 12 volt DC.
My solar system wiring from the roof is carrying 60 volts DC, which can be concerning due to the shock hazard.
I can understand the benefit of 240 VAC in a house which is connected to a power grid but 240 VAC on motorhomes will result in people getting electrocuted.
No, the panels by themselves only produce the lower numbers on the back. The higher voltage is with the micro inverter designed for house installation. Each panel will have a micro inverter compared to string inverters where there is only one.
Pierce
My thought that I talked to my guru buddy today about was to use the SunPower residential panels which put out a little over one amp per 41 x 61 panel directly to a Tesla Powerwall ll. Like a house. Totally separate from the coaches systems depending on the Powerwalls external hookups.
Run from the Powerwall to the main electric panel? Just like a shore power hookup. Powerwall says 120/240.
Over a thousand fully useable amp hours. 5kw output into the coach. Internal batteries are 48 volt.
Would not seem to need a charge controller as the Powerwall would stop taking in power when full from its BMS.
None is shown on Tesla's hookup drawings. Just a massive source of 60 cycle ac inverted power I think.
Yes I know 7 amps of 240 is worth being careful but I know so little that is that much different from the large panels posted here that must be lower voltage but more amps?
Bob, here is how to read voltage/wattage for solar panels. Lots of good points for almost all aspects of panel output. Takes me back to when I installed ours.
How do I read the solar panel specifications? | Solar Power News & DIY Solar... (https://www.altestore.com/blog/2016/04/how-do-i-read-specifications-of-my-solar-panel/)
For instance, the VOC or voltage open circuit on our panels is about 39 volts. This is the voltage used to figure how to wire the panels to the controller. This voltage is the highest on a cold morning and the sun may not even be above the horizon yet. Our MidNite controller is rated at 150 volts maximum input. You can quickly see that if I had wired in series for all four panels, the input voltage could go as high as 160 volts. Controllers may not be protected against over voltage and many have been damaged this way. Other controllers may not come on until the voltage drops to their maximum voltage input. I chose to wire in a series parallel arrangement so the maximum voltage the controller would see would be about 80 volts. Instead of running two wires down the the controller, I had to run four. No big deal. And, no, I didn't do this on my own. I called MidNite and they recommended this way to be safe. The controller is happy and so am I.
Pierce
The microinverters (enphase) are available in 240 or 120 volts. 97.5% efficient. For an all electric coach or one with a compatible storage component (LG or PowerWall) they would be nice. The advantage is that each panel has its own microinverter. You can run a string of panels (up to about 16 depending on the wattage of the panels) into a combining circuit breaker box and then through a master off switch and then into a transfer switch and into the coach. Adding another panel or two means you will never have an undersized charge controller. And the panels do not have to be the same size or wattage. Just like the land line and the generator it needs to be isolated from other sources. If it feeds directly into a charge controller for a Tesla Power Wall you still need the combiner/circuit breaker box. Output from the Tesla PowerWall needs to go through a transfer switch as well.
Some investigation is needed to determine losses through all of this and the power required to run the PowerWall and its charge controller. The PowerWall has built in heating and cooling. Probably could mount it in a hanging rack from the cieling of a suitable bay. As best I can determine it can not be mounted upside down, that would be nice if it is possible.
You might not need an inverter, just a modest charger an a pair of FullRiver DC400-6 batteries (415 am hrs) for 12 v service.
To clarify how I wired the four panels, each set of two panels was wired in series to bring the voltage up to 2x39+78 volts. The two sets (of two) were wired in series by sending two wires each for a total of four wires down to a mini bus right behind the controller. The 78 volts was then sent to the controller via two wires from the mini bus. I could have brought them together on the roof but wanted all the connections where I could get to them easily behind the controller.
So, yes, the four panels are wired in both series and then in parallel. Series doubles the voltage of each set of two panels, parallel double the amps when the two sets are wired that way.
Sorry if I was confusing as it's harder to explain instead of having a diagram for the wiring.
Here are a couple of photos. The MidNite controller is mounted in the top compartment with the small door. The area behind has be lined with Hardibacker. The red bus brings the two positive wires down from the two sets of roof panels. The black bus does the same. Single wires are then run from the buses to the controller (no room to bring four wires into the controller). You can't see the wires but in controller input and output go through sets of circuit breakers. The controller output goes to the connectors with the huge welding cables against the back wall. From there, it goes down to the big electrical bus next to the wet compartment.
A large fusible link is at the electrical bus to protect the coach in case of an accident or short. So, everything is protected, the panels, the controller and the large cables feeding the electrical bus.
The solar CBs are turned on after the controller is turned on. Shutting down, the panels go off first, then the controller CBs. It has arc protection but this sequence is just extra to make sure.
Thanks Roger and Chuck. I changed parallel to series in the first post. Give me a gun and I would blow my toes off. Why didn't my proof reader catch the mistake? :D :D :D Could not figure out why my ears were burning.
Thanks again,
Pierce
i have a magnum pt-100 charge controller that I bought early this year just to not repeat the undersized controller posts here when adding panels, the pt100 is capable of the 240 volts and 100ADC. Scaleable times 4.
I note the now demonstrated expertise about Powerwalls that I had not seen before today here.
Using non inverted rv panels would need a charge controller then to the rest of the conventional system,
Inverted Residential 240 volt panels seem to go direct to the Powerwall and it seems its internal systems control the charging automatically, plug and play hopefully.
My guru buddy liked the idea right away as almost every coach he works on is somewhat underpowered.
Seems a lot easier to run from the Powerwall to the main breakers to use its output.
Then into the already correct system.
Would have 1400 amp hours total useable. And no voltage drop until the last 375 amp hours,
6 61 x 41 panels should fit our roof just fine. Close to 2k watts output.
When my guru buddy and were the bluebird salesman in 1989 the birds had enough battery and enough inverters that the entire breaker panel was connected.
Roof airs would both operate off of batteries. Not for long obviously but they did work.
Quite likely the Tesla is not designed to be in a moving vehicle. That being said I saw a picture of an early version one mounted on the rear vertical wall of a coach,
On the other side if I put in our house there is a large rebate from the PUC
Hmmmm. Remount the unit? Naw that's cheating. Sort of.
Unit requires fairly specific leveling.
We will see. No hurry for me. I have a good system now.
Just some notes:
1. Sunpower makes their panels in China, Mexico and the Phillipines and has gotten a tarrif exemption.
2. I predict that Sunpower will survive and do not believe the article about shorting the stock. The stock is low because people don't relize that Sunpower is the "Betamax" of solar panels: superior technology but it's higher price puts it at a disadvantage. Laypersons do not know that these panels are far superior in terms of lower temperature coefficient, lower lifecycle degradation and much better warranty. See the following comparison table of Sunpower to a typical cheap Chinese Winaico panel:
Sunpower is far superior in all four key parameters:
COMPARISON, WINAICO VS SUNPOWER
KEY PARAMETER WINAICO SUNPOWER DELTA (% Better)
Efficiency, % 18.6 22.7 18%
Product Warranty, Years 12 25 100%
Power Temperature Coefficient %/oC –.43 -.29 73%
Degradation per year after 5th year, % power .7 .4 63%
3. Not much engineering would have to be done to integrate into a Foretravel. I am running my rig from a true 230 VAC source from my home. That's two 115VAC legs with a neutral. A transfer switch could be designed to engage the solar charger, which would convert the 220VAC from the panels to the correct charge voltage.
4. They are safe. The newer solar panels, including the Sunpower X22-370 panels require no ground because they are all internally grounded and isolated, and UL approved.
5. I believe that microinverters are the future because each panel is isolated, so shading and panel failures will mitigate typical solar panel confounding issues. If one panel fails or is shaded, it will not affect the others.
I'd be happy to engineer a system for an intrepid Foretraveler and share my experience.
Perfect. Thanks Tim. I am far from rich. At the same time I am not a "price buyer." If someone says "it's less money" I Normally I ask why? I personally buy the "best." Long term satisfaction is better in my experience.
You help offer is appreciated. Will my magnum pt-100 work and/or is it needed?