Yet another solar question

[mchero]

Been RV'ing for a long time & have been reading ALL solar posts with interest.

I was reading a recent solar post and one person brought up Solar Blvd. I visited their web site and ran across this deal;
http://www.solarblvd.com/Solar-Panels-&-Systems-Solar-Panels-By-The-Pallet/c1_250/p2815/10-LG-270-Wa...

10 LG 270 Watt 24V Solar Panels And 10 Enphase M250 Inverters for 3,499. A total of 2700 watts in panels. I also understand that the price also includes the M250 inverters.

It looks like this setup enables one to see what each panel is outputting. Also, it appears of one panel is in the shade the others will continue to produce power.

Is this a system for a fixed structure or can one use a system like this on an RV. I'm not sure what other hardware would be needed.

I'm amazed at the prices these days. Might5 be time to pull the trigger on Solar.

Thanks

[69_Avion]

Almot wrote:
BFL... 230W panel is (usually) 40 lbs or less. 250W would be same size and weight. Maybe they were 48 lbs some time ago, but today it's closer to 40. There were reports of much lighter panels, but with the cell efficiency pretty much the same I don't believe in panels too light, they would cut the corners, making a thinner frame or glass. Size is still a problem, pulling it through the door and finding some space to tuck it in for travel.

Just to make it clear - those $ numbers in BFL post refer to controllers cost, not the panels.

My 250 watt, 24 volt Sharp panels are about 40 pounds each. They aren't strong enough by themselves unless I mount them on a flat surface. I'm making an additional aluminum frame for them. I'll post a picture if I ever get time to work on it.

[BFL13]

Almot, I have seen a range of weights per wattage among panels by brand and whether 12v or 24v; don't know if any is the "proper" weight.

My 130w Sharp panel (no longer made) has quite a heavy stiff frame compared with those Sun brand panels I had.

Sharp 130w-- 31 lbs
Sun 120w-- 21 lbs

Sun 230w-- 43 lbs
my Hanwha 230--48 lbs
Hanwha 235--44 lbs

Even at that 48lbs, the panel flexs quite a bit in its frame--the Sharp 130 no flex. Both Sharp and Hanwha have 1.9" deep frames but the much lighter Sun 12s (that flex a lot too) have only 1.5" deep frames.

I have no way to tell if the cells themselves are thicker or heavier or if weight is any measure of quality as such. The Sun panels I had worked just fine.

I make wooden trays to sit my portable panels in so the stress and strain of mounting in a contraption or on the roof is on the tray not the panel. This makes flexing a non-issue for me (but I do like that solidly built Sharp panel)

[Almot]

BFL... 230W panel is (usually) 40 lbs or less. 250W would be same size and weight. Maybe they were 48 lbs some time ago, but today it's closer to 40. There were reports of much lighter panels, but with the cell efficiency pretty much the same I don't believe in panels too light, they would cut the corners, making a thinner frame or glass. Size is still a problem, pulling it through the door and finding some space to tuck it in for travel.

Just to make it clear - those $ numbers in BFL post refer to controllers cost, not the panels.

[BFL13]

I can compare "starting try it out" sets where you can subsequently expand if desired based on some lessons learned :

Two 100w 12v panels and a simple 20a PWM controller ($13) , with
Single 230w 24v panel and a low cost 20a MPPT controller ($102)

(the 230w panel weighs 48lbs, each 100w half that)

The two 100w cost about the same as the single 230 so it is all about the controller costs and practical matters.

The main thing is with the two 100s and the cheap controller, you don't have to buy an expensive MPPT controller up front. You can't choose the low cost MPPT controller either, because it will only run one big panel, so to expand you need another and another. You can have several controllers all at once, but it is easier to run it all with one controller if yiou can get one with that capacity (in max Voc input and enough amps rating)

Instead, you can play with the two light-weight panels and learn how solar works, then if you want to expand, by now you will know by how much and then get the right sized expensive controller ($400 + )

The key to all that is the two 100w 12v panels can be put in series to become like one 200w panel and be run by an MPPT controller. So that would be your first "big panel" in your subsequent solar set up-- so not wasted.

If you ever fry your fancy MPPT controller, then at least you can still do some solar by reverting to just the two 100s back in parallel and the $13 controller (won't run the big panel) till you get back in business with the big set-up

And yes, that 48lb 230w panel is no fun to lug around as a portable, but the little 100w panels are easy doing one at a time.

[Almot]

mchero wrote:

Long term plans are to upgrade to a newer coach, perhaps 10 years newer so I don't want to go nuts on a full solar system.

When boon docking it's just mainly lights, TV, DirecTV box and perhaps the furnace. If we are camping late fall.

230-250W panel "might" be a full solar system for all those devices, plus those that you forgot to mention, like pumps and 12V circuit of LP fridge. Assuming you don't watch sat TV more than 4 hours a day, AND don't play online games on laptop when not watching TV, AND the furnace doesn't cycle more than 25% in the night AND it's warm enough in daytime. A lot of assumptions. For some people this will work, for some won't.

230-250W will cost $300 together with Ecoworthy clone for MPPT, panel weight ~35 lbs, 3x5ft large. Possible to take in and out, a little awkward without help but doable. Easy to lean up against the wall outside.

In reality, I doubt 250W could be a full solar for you. With more than one person, you don't know what they might have in mind. You could be fishing and your partner running sat TV and bunch of lights for hours. And very powerful 120V devices like coffee maker, toaster, and microwave, all at the same time 🙂 ... Each of those will dwarf your sat TV and lights, in terms of energy. I don't consider these kitchen appliances essential for a comfortable living, but many will disagree.

So, I doubt that one big panel will cover all your needs. But it could slow down the battery drain and extend you stay enough to not to have to run a gen set before you drive home or some other place with shore power.

Like people said, this is a better alternative than paying thousands to listen to "quiet" generator.

[time2roll]

If you go with 24v panels(high voltage) you will need a more expensive MPPT controller.

24v panels are about 200 to 250 watts each.

1 panel, Morninstar sunsaver 15a MPPT
2 panels, Rogue 30a
3 panels, Morningstar Tristar MPPT 45a
4 panels, Morningstar Tristar MPPT 60a

Trouble is they get expensive so the best value is to max it out. Then there is no room for expansion. Probably the single panel is plenty for most usage. Especially if you have an on-board generator when needed.

A few are looking at the Eco-Worthy 20a MPPT controller as a lower cost option from China.

Otherwise the Rogue might be the best option to go one more panel in the future.

[mchero]

Good point smkettner, starting out with a portable type setup would be the way to go. If we decide to keep the coach I can then mount on the roof. If we decide to U/G then I can take the panel(s) with me.

Thanks for the post.

I guess I'd need to start out with ONE high voltage panel. I just need to figure out the best controller. Something that could handle more panels down the road. Suggestions?

[time2roll]

No reason to go crazy but a small (<250w) system will give great experience on what you want on the next RV.
Very easy to remove from the roof if you prefer to transfer.

[mchero]

When first purchased the Pace I did not have a clue how my electrical system worked. I had to drive from Concord NH. to Rockchester NY. in a Plymouth Grand Voyager to pick up the coach. I purchased from a broker.

After filling out the paperwork the keys where tossed at me & then it hit me.....I have to drive this beast home! LOL

Drove across town & picked up an Auto Transport. Loaded the VAN & headed back to NH.

That night I stopped at a rest stop & got some much needed shuteye. Next morning I woke up to a cold dark motorhome. BOTH chassis & house batteries where flat dead. I was able to back the van off the trailer & jump start the rig.

After arriving home I found that the solenoid that connects both battery banks while driving (to charge the house batteries) ad some bad contacts. I ended up replacing the solenoid, the converter with a P.D. 60Amp w/charge wizard and 4 6-volt batteries from Sam's Club.

Note all the above work was done back in 2005. NEVER had a problem with the electrical since. The batteries each have a white tag marked 2005. I believe swapping out the converter was a real good idea.

Have plenty f space on the roof but I'm thinking about a panel that I can lean up against the rig.

Long term plans are to upgrade to a newer coach, perhaps 10 years newer so I don't want to go nuts on a full solar system.

When boon docking it's just mainly lights, TV, DirecTV box and perhaps the furnace. If we are camping late fall.

I did put a shunt on the house batteries and I have a device to give me all the details on the house batteries. NEVER ran them down since new.

So, that's the story & I'm sticking with it!

Thanks for all the posts!

RM

[JiminDenver]

I tend to be pretty good at finding a deal and actually found two panels for $50 each., then searched for a year to find a affordable controller.

Solarblvd.com has their folding kits again. 160w for $249, 120w for $195 and 100w for $169. I can't build them new for those prices.

[Gulfcoast]

Wish I could find a 230 watt system for $200 including shipping. I did find 100 watts for $200.

[mena661]

JiminDenver wrote:
Then again seeing that people will pay thousands to only have to listen to a quiet generator, not hearing one at all is priceless. 🙂

X2 The only reason I have a generator is because it came with the rig. When we had the 5er, we had NO generator.

[JiminDenver]

Even considering my 230w system was only $200, it will take a long time to save that in gas for the generator. I only saved about $15 this year.

Then again seeing that people will pay thousands to only have to listen to a quiet generator, not hearing one at all is priceless. 🙂

[Almot]

Sweet dreams, Mex...

A year ago - I doubt things have changed drastically since then - there was an article on the solar share in different countries. Germany came on top, with 40% of the summer peak demand generated by sun. Ca was generating 2% of the peak demand. They must be getting plenty of sun, those Germans 🙂 ...

China? I don't know how many of those millions of solar panels will be used for their own needs, but until the (very recent) ban they have been building on the average 1 coal burning station every month. I would not place any more trust in whatever their govt says, than I would in the US. Maybe even less. Right now China is #1 CO2 polluter in the world.

[MEXICOWANDERER]

I was referring to the need (sales) of a battery bank to go along with that energy charging potential. The cost of the panels isn't squat compared to what the batteries and infrastructure needed to handle it is going to cost.

California now has hundreds of acres of privately owned co-generation and electrical kWh growth is flat lining. Hundreds and hundreds of acres MORE worth of rooftop panels are in the planning works stage and now utility companies are suggesting they will have to RAISE rates to remain viable energy entities.

Electrical power down "here" costs about .05 kWh for the first 150 kWh from there it tiers to near fifty cents per kWh on DAC rates. 500 kWh every TWO months is considered to be splurging.

I've seen RV's that consume more kWh per day than a 5 bedroom 4 bath house. Try living on SEVENTY FIVE kWh PER MONTH. I dare you.

The Chinese are now said to be producing seven and a quarter MILLION solar panels a MONTH. It used to be laughable their claim to shoot for producing A BILLION total panels by the end of 2015. Manchuria is going to be a vast toxic wasteland by then, raw materials are coming from Australia, and you are going to be reading headlines in the USA. MAJOR UTILITY COMPANIES FACING CHAPTER 13. FEDERAL FUND BAILOUTS URGENTLY NEEDED.