Solar energy????

[kysteve]

Thought I'd start another thread here,

     I am all so interested in the pros and cons of the solar energy.  Can anybody give me any insight here as to the energy savings vs the initial installment cost.  All so how is the maintenance for the solar power (if there is any) and what does it take to maintain it.  Cost of the extra batteries vs the extra cost of fuel???  I am not sure if it is even worth while.    ......thanks........Kysteve....

[ol713]

Hi KYSteve;
        Solar panels will do nothing for fuel or fuel milage.  They will,
        however, maintain your house or starting batterys.  I have
        found them handy when the start batterys are low and the
        solar panels will bring up the batterys enough to start the
        coach. If you want to go off the grid to boondock, then you
        need more of the same panels and batterys. Sizing and quanity
        is up to your needs.

                                        Merle.       

[bobsw]

It depends a lot on how you use your bus. We live in our bus for 4 months out of the year. boondocking in the desert . We put 4 130 W panels on and replaced our house batteries with 4 8D AGM batteries. The total was about $7,000.00. This cut our gen. run time by three hours a day.  A gallon and a half a day times four dollars plus a gal. you do the math. I love my solar no maintenance.

[kysteve]

713,  I am talking solely for boondocking.  I too have not figured out how to harness the sun for my 8v71  .  I didn't give enough info earlier and I lost my thread for a minute.

Bob are you guys running your ac off the batteries there in the desert??   If so Id like more info there on your set up.

Thanks Kysteve

[pvcces]

Kysteve,

If you use your solar panels as shade for your roof, then that will reduce the amount of heat entering your coach when the sun is at work. While you cannot produce enough power to run an air conditioner from panels on your roof, there is no problem prducing enough to run a fantastic fan.

Heating and cooling loads for the most part are going to use more power than you can produce from your roof panels. On the other hand, you will be able to run efficient lighting and some electronics without much rationing of either. We use our microwave quite a bit for hot drinks and meals.

All in all, we run a generator a few hours per week, usually during an evening meal, and the panels keep up the rest of the time. I wouldn't be without our 220 watts of panels. We will be adding another 110 watts when we find the panels that we want.

If you are around the unit or find a good control for the purpose, I would think that you could run your refrigerator part of the day to save some propane, if you are not already using all the output.

For what it's worth.

Tom Caffrey

[ktmossman]

It depends a lot on how you use your bus. We live in our bus for 4 months out of the year. boondocking in the desert . We put 4 130 W panels on and replaced our house batteries with 4 8D AGM batteries. The total was about $7,000.00. This cut our gen. run time by three hours a day.  A gallon and a half a day times four dollars plus a gal. you do the math. I love my solar no maintenance.

Now, I am all in favor of using solar and I plan to do so, but...

Let's estimate high (for the moment) - $5/gal.

1.5 Gal saved per day *$5/gal = $7.50 saved per day

Bus used 4 months per year = 120 days, but being generous and wanting to spend as much time a possible in our busses, let's bump it up to 150 days per year.

$7.50/day * 150 days = $1,125/yr savings

Cost of system was $7.000

$7,000 / $1,125 = 6.25 years to recover the cost of the system


Raises some thoughts...

Do the components of the system (panels, batteries, controllers, etc.) have the lifespan to make that economically viable?  If you have to replace parts of the system within that 6.25 years, the ROI takes even longer. 

How many of us spend that many days per year in our bus?

Hmmm.....

[H3Jim]

I don't think the $ I spent  on solar is ecomnomically viable.  But then the $ I spent on the bus is not ecnomically viable either.  I just really like them both.  I have 600 watts of solar up there.  All electric coach.  Energy effcient refrigerator runs 24 /7.  The controller trickle charges my start batteries too, and thats nice if the bus sits for a month between outings, all the batteirs arer always fully charged.  Makes them last longer.

I cannot run my air conditioning from the batteries, at least not for long, but I can run everything else and rarely need to tu the generator. 

[Sean]

Steve,

You generally can not justify solar on a bus based on economics alone.

I wrote extensively about the economics in this thread:
http://www.busnut.com/bbs/messages/233/16802.html

(Of course, that was a year ago, when diesel was 75% what it is today.  But the math is still mostly correct.)

HTH,

-Sean
http://ourodyssey.blogspot.com

[jjrbus]

If you can hook up the bus system to your home puts a little different light on the math!!!! 

[kysteve]

Thanks for the info here too guys,

     This ideal will be aborted all so as I cant see spending the $ to get so small a return.  I will just park the coach in the yard to get it in the green zone    I may look into a small system later to help keep up my starting batteries. 

I have a burning desire to have a roof deck for the Nascar races we will be at so I am not willing to lose it for the small return.  I will have to investigate about a system you can walk on.

Thanks again for all the help guys........
.......Steve........

[bowmaga]

OK, here's my 2 cents.  solar is the way of the future, I don't care what you think.  If you can get some solar panels now....good luck, but a few years from now they will be affordable.  Why....and how come I know.  My wife works for First Solar, my bus is owned by 4 guys, and also one of those guys works for First Solar.  They are based out of Phoenix Arizona and have manufacturing in Toledo Ohio, and Malaysia....for now.  They are the leading world wide company in thin film solar panels.....it doesn't get any better.  But to try too get one of there panels you better get in line.  You can get a silicon panel that is about half as efficient as a thin film cadmium panel..but it will cost you and they as I said they are half the efficiency.  I have tried for 2 years now to get a First Solar panel and maybe within the next year we can for out bus because of a employee purchase plan...but that's a maybe.  By my calculations....2 First Solar panels...just at 75 watts would produce enough power to run our little bus all day.  Why, these panels suck in more sun light early int he day and at the end of the day when silicon based solar panels quit.  Its the nature of the the technology....I don't know exactly how...but its true.  Ask Germany.....they are at this time the biggest customer to First Solar because they have realized the facts....we can't afford oil any more.  Soon everyone else will realize to.  In my opinion, they are an honest company....doing good.  Type in FSLR in a stock quote and you will see how everyone else has thought in the last year also......and its just going to get better.  When i cam, there will be multiple panels on the side of my bus, roof deck and whatever, but 2 will be plenty.  I hope to get 4 and never have to replace or have more than a few 2 monster $250 batteries again.   I might be a little biased, but just look them up and read about them....here is stat for you.  First solar can make a panel, that produces more power every day than a competitors panel, from start to finish in 2.5 hours.....it takes a silicon based company about 3 days to produce the same size panel that produces less power.  Look them up, is all I can say...if I could get solar panels.....I would only have maybe 1 or 2 batteries for my us.

If you need more info.....I will get my wife...I just get told the good news...she experiences it everyday.

Greg,

[Lin]

I read an article today that said one can get damaged panels for nothing or next to it.  They claimed that many times there are just simple fixes like solder, or replace glass, etc.  If one wanted to experiment with solar, that could be a way to go since there would not be much investment or lose if it fails.

[HighTechRedneck]

OK, here's my 2 cents.  solar is the way of the future, I don't care what you think.  If you can get some solar panels now....good luck, but a few years from now they will be affordable.  Why....and how come I know.  My wife works for First Solar, my bus is owned by 4 guys, and also one of those guys works for First Solar.  They are based out of Phoenix Arizona and have manufacturing in Toledo Ohio, and Malaysia....for now.  They are the leading world wide company in thin film solar panels.....it doesn't get any better.  But to try too get one of there panels you better get in line.  You can get a silicon panel that is about half as efficient as a thin film cadmium panel..but it will cost you and they as I said they are half the efficiency.  I have tried for 2 years now to get a First Solar panel and maybe within the next year we can for out bus because of a employee purchase plan...but that's a maybe.  By my calculations....2 First Solar panels...just at 75 watts would produce enough power to run our little bus all day.  Why, these panels suck in more sun light early int he day and at the end of the day when silicon based solar panels quit.  Its the nature of the the technology....I don't know exactly how...but its true.  Ask Germany.....they are at this time the biggest customer to First Solar because they have realized the facts....we can't afford oil any more.  Soon everyone else will realize to.  In my opinion, they are an honest company....doing good.  Type in FSLR in a stock quote and you will see how everyone else has thought in the last year also......and its just going to get better.  When i cam, there will be multiple panels on the side of my bus, roof deck and whatever, but 2 will be plenty.  I hope to get 4 and never have to replace or have more than a few 2 monster $250 batteries again.   I might be a little biased, but just look them up and read about them....here is stat for you.  First solar can make a panel, that produces more power every day than a competitors panel, from start to finish in 2.5 hours.....it takes a silicon based company about 3 days to produce the same size panel that produces less power.  Look them up, is all I can say...if I could get solar panels.....I would only have maybe 1 or 2 batteries for my us.

If you need more info.....I will get my wife...I just get told the good news...she experiences it everyday.

Greg,

I agree solar panel technology is still in its infancy and will soon be getting more affordable as volumes go up and technology further improves.  I have very little doubt that within 10 years panels will be many times more powerful per square foot than they are now and yet will be much more affordable than the current ones.

We full time in our bus, and 150 watts wouldn't even come close to meeting our needs.  Using even the first solar technology, I would probably need to completely cover my bus roof with them to get enough power to run things during the day and fully charge a substantial battery bank to run through the night.  We don't boondock at this time so we are always on the grid when parked.  But someday it will be nice not to require it.

[boogiethecat]

A slightly different but very happy reason for solar...

I hang out in the desert for 2 weeks at a time (Burningman and other events) and for most of my bus-years had a propane fridge onboard.  It couldn't handle the really hot days, driving with the propane on was discomforting, and levelling the bus to keep it working was a giant hassle. 

So after 5 years of this, I went to a cool (no pun) refrigerator website and found a list of the efficiency of all the 110vac fridges out there:
http://www.energystar.gov/index.cfm?fuseaction=refrig.display_products_html
and selected the most efficient fridge I could find, a Summit (no longer made BTW) that was actually bigger inside but smaller outside than my current propane fridge.

I made the change and was quite happy.  I bought a cheap chinese 2KW pure sine inverter from Ebay and wired it permanently to the fridge so that the fridge's thermostat switch hooked into the inverter's off-on switch.  Even though the fridge only draws something like 117 watts when running, starting the compressor requires the full 2KW inverter rating or it just won't work.  (I found this out the hard way by purchasing a 1KW trace inverter that didn't have a chance of starting the compressor!)
Anyway, with the inverter dedicated to the fridge in this way,  the fridge goes on and off as needed but the inverter is never idling and wasting power when the fridge is off... it's off too.

I have four T-125's for my house batteries and this is enough to carry the fridge for about a day and a half, maybe two, then I either have to plug in to shore or run the gene.

Just recently I decided to go solar. The cheap way... There are always solar panels available used, usually thru ebay or craigslist, for around $3 per advertised watt.  Because they are used, they are often less actual capacity than their rating but usable nonetheless, and also considering that mounted flat to a bus roof, they're never going to put out as much power as a set of panels correctly aimed directly at the sun... so I figured getting twice as much wattage as I calculated I'd need would probably do the trick, and this seems to be right on the target.   
  So I bought three 80 watt panels and a cheap Manson 3 stage charge controller, stuck em on the roof and wheeee... no more necessity to plug in or run the gene!!  At least in the desert the three panels produce 130 watts total on average during the day, and this almost perfectly matches the power that gets used considering the fridge, lighting, and occasional bathroom fan, etc.  By morning the batteries are down to 11.75 volts and by end of day they are back charged up on float.  I'm going to stick a 4th panel up soon to make sure I have capacity enough on not-so-ideal days, and also to offset the power my heater fan draws on those occasional nasty cold desert nights.

An aside- when I put these up on the roof I wasn't keen on putting more holes in the roof for wires, so instead I butted them up against my roof air conditioners, ran the cables up under the AC/s, in to them and up "high" under the cowling where there's no chance of rain or water, punched them through into the cool air duct, where inside the bus I could then route them wherever.  It worked out really well.

Anyway, just thought I'd report a successful  solar installation that is extremely practical and definitely better than "useful for an occasional light or fan", and didn't break the bank.  $700 for the three panels, $60 for the controller, (not necessarily part of the solar cost, but $200 for the dedicated inverter and $600 for the fridge), and ten bucks worth of mounting hardware, and I have a fridge that doesn't need levelling, keeps cold even on the hottest days, and runs on energy that doesn't come from some sort of fuel tank.. 

One more thing to note- every watt that the panels see coming from the sun, even if not converted to electricity, is a watt that doesn't hit the roof of the bus.  I noticed immediately the difference inside on a hot sunny day- the bus was quite a bit cooler than it's ever been.  Makes sense... three panels 2 x 4 ft is almost 3 meters of free shade- that's almost 3KW not getting absorbed by the bus roof!!

[H3Jim]

KYsteve,

I have 600 watts of solar p;anel on my roof, 3 roof top airs, 2 fantastic vents, the original 2, 23" escape hatches, TV antenna, front to back awnings mounted on teh roof edge, two Hayen air horns and I still have room for a 7 1/2 by 10 foot roof deck. I may make the deck just square, and put one more 150 watt solar panel up ther, but a roof deck and solar are not mutually exclusive.  

If you want a bigger deck you could mount the panels on the railing for the deck.  When you are not using the deck, the panels will be flat on the roof and capture the sun, when the deck is being used and the railing is up, they won't work as well, but you'll still have them.

My understanding of the thin film solar panels was they are less efficient than the silicon ones, but they are an order of magntude cheaper.  For limited spaces like a bus the silcone ones are still better (for now).