Panels on a trailer

heynow999 · November 2008

Hi

I am working on a trailer that is a support trailer for the movie industry. It has batteries now and I will be adding panels in the future. The idea is that the panels will supplement the batteries, then it will be plugged in at night to recharge. The roof is not flat, but is slightly rounded. If the panels are are screwed right on the roof with, one row would be slightly east and the other row slightly west. (assumeing the trailer is parked north/south) Is it a problem if the panels don't recieve the same amount of sunshine at the same time. Will the output be lowered to whatever the output of the lowest panels are?

Here is picture of the trailer. It won't be this exact model, but the roof is the same.

http://www.miskatrailers.com/enclosed/cargo_trailers.asp?utility=7%27_Wide_(_18%27_to_26%27_)_&cc1=6&subs=no

Any ideas on how to mount them best? The trailer will be moved almost everyday, so I am thinking just a flushmount on the roof to reduce the possibility of ot blowing off.

Thanks

Solar Guppy · November 2008

Re: Panels on a trailer

You will have to build an external racking system for the trailer as the roof is mostly the thin aluminum skin with steel supports every few feet.

When you build the rack, just make it flat and then when the panels are mounted they will all be in the same pitch

Cariboocoot · November 2008

Re: Panels on a trailer

If one set is oriented realitively East and the other West the panels shouldn't be connected to the same charge controller.
As Solar Guppy says: build a strong racking system to hold them. Then park the trailer so all panels face south.

heynow999 · November 2008

Re: Panels on a trailer

Thanks for the replies.

Part of the problem is there will be no choice at all about which way to park the trailer. It may be facing any way, under a tree, in the shadow of a building. We just have to set it up to work best in a range of different situations. I like the idea of two separate charge controllers. That way we could mount the panels closer to the edge, they would be on a bigger angle, and you could see them from the street. We want them to be seen, as being "green" is part of the marketing.

Here is a link too the website

http://www.theecotrailer.com/index.htm

Please keep the ideas coming.

Thanks

Peter

mike95490 · November 2008

Re: Panels on a trailer

Deployed PV's on a moving trailer are quite vulnerable. Tree branches, low bridges.... re-label the trailer hight if you do this.

Make a strong rack system, passing an 18 wheeler at freeway speeds generates all sorts of strange +100mph gusts.

Have you considered the power needs of a movie set, and compared it to the roof area PV's ? You may be sadly disappointed, they need 10,000s of watts, and PV can only provide 100's . It starts to look like greenwashing. They film often in my neighborhood, and they have several 80KW trailer generators running all day, filming a 90 sec commercial. That's hard to match in solar for both cost, and power density.

This might be applied to the restroom trailer, but they often have air conditioning, which is beyond roof top solar too. And still have to have the generator for non-sunny weather & night shoots.

niel · November 2008

Re: Panels on a trailer

if the orientation and structure of the trailer is a problem to this degree then i would recommend remoting the pvs on their own little portable mounts and then stored in the trailer at night for some security from theft. i am not quite sure what exactly you do have in mind with the pvs because i don't know if your batteries are going down too far before it is night and time to recharge from a utility source or is it pure show? if it's a need for more charge power because of the excess drawn on the batteries then you will need that much power and more in pvs to keep the batteries from depleting, and this could be in reference to 50% dod rather than dead too. we don't know how much that is in how many batteries as you weren't that specific, but i think you see my general point here in that if you draw for example 100ah extra every day than the batteries can handle before a utility charge is employed then 5a or 10a in pv just won't cover the loss for even with 6hrs of full sun on them it would reap only 30ah to 60ah respectively of what is needed. in the future a larger battery bank charged at night will also work.

heynow999 · November 2008

Re: Panels on a trailer

mike90045 wrote: »

Have you considered the power needs of a movie set, and compared it to the roof area PV's ? You may be sadly disappointed, they need 10,000s of watts, and PV can only provide 100's . It starts to look like greenwashing. They film often in my neighborhood, and they have several 80KW trailer generators running all day, filming a 90 sec commercial. That's hard to match in solar for both cost, and power density.

These trailers are for hair and make-up, or crew support. Thier energy needs are very small. You are right that a movie set requires (or wastes) a lot of electricity that is generated by very polluting diesel generators. I have been working for the last week on thier second trailer and I can assure you it is not "greenwashing". I was skepical at first, but after a few days I could see they were serious. It may not be perfect, but they are trying the best they can. For example, all the lights are LED's. You can get pretty good LED bulbs ($40 each!) but try and find a fixture that suits your needs. There is very little selection. So what they have been doing is buying what ever fixture they think looks good, then taking the fixture apart and fit an LED base in it.

The eco-friendly idea goes much further than just solar panels and batteries. It is insulated with soy based spray foam insulation to reduce the heating and cooling needs. All the wood used is locally grown maple or plywood. No particle board. The grey water from the sink and shower is used to flush the toilet. The ceiling is bamboo. The finish is no VOC water-based polyurathane. The cotton used in the pillows is organic...Basically, any green product they could use, they did. It's not perfect, like how do you get a "green" RV toilet?

I would say that the biggest green part is that it does not need to be plugged into a diesel generator to operate. So far, the panels on the first trailer has been able to keep up with the demand during the day. If it needs to be plugged in at night, the power will be bought from http://www.bullfrogpower.com/.

As for the power on-board, they have 4 x 330 Ah/hr batteries, with room for 2 more if needed. They have 7 x 3 watt led light (12v DC) plus 3 x 18 watt florescents at the make-up table, a propane heater (I know, fossil fuel, but what else could they use?) that draws 2.8 amps, and two water pumps that draw 7 amps each. They have an inverter for AC power.

They have figured out how many panels and batteries they need. On this second trailer I will probably install the panels so I want to come up with the best set-up. We were trying to think of a way to build a rack so they could be tilted when they park, but I think that would be to complex. I am leaning towards the idea of two strings of three 200 watt panels, with two separate charge controllers. Mount them on a rack but just a few inches above the roof so they can get some airflow around them.

Again, please keep the ideas coming.

Thanks

Peter

Cariboocoot · November 2008

Re: Panels on a trailer

Under the circumstances, you should consider it an RV/Marine application and look for panels/mounts designed for that use. They'll say something like:

"These modules are engineered for extended use in environments with harsh weather conditions and extreme temperatures."

Presumably they'd stand up better to the rigors of traveling down the road. Places sell these things as parts and as kits. One example (not an endorsement):

http://www.wholesalesolar.com/RV.html

niel · November 2008

Re: Panels on a trailer

cariboocoot,
those weather and harsh condition standards apply to most pvs made that we here talk of and granted there are some exceptions. most pvs do have impact resistant glass with strong frameworking as they must endure harsh weather conditions when on our roofs and such so they really don't have to state they are made for harsh weather conditions specifically, but upon looking at the specs it is generally revealed those little clues as to their durability such as hail stone impact ratings. some of the smaller pvs that may be made cheaper in quality are some of the ones to generally watch for and i can't forget about some of those from other countries without us or european approvals.

n3qik · November 2008

Re: Panels on a trailer

Cariboocoot wrote: »

Under the circumstances, you should consider it an RV/Marine application and look for panels/mounts designed for that use.

This is partly true, some manufactures will not honor the warranty if used in a RV application. Food for thought.

RWB · November 2008

Re: Panels on a trailer

Pretty cool trailer alternative for the movie industry. Have you sold any Or do you rent them out?

I'm all for being better for the earth but I'm not digging our goverment is is pushing the global carbon tax in the name of Green. The carbon tax is going to be paid directly to banks, the global elite who have hijacked our goverment and economy and are trying to push thorough a global goverment and one world banking system. But what ever

Be sure to share with us some pics of what you actually work up, I also have been thinking about the best way to do the same thing on the same type of trailer.

I have found various different mounts for panels on this sites store I'm pretty sure, if you don't find what you need I bet you will at least get a good idea from what you see.

heynow999 · November 2008

Re: Panels on a trailer

RWB wrote: »

Pretty cool trailer alternative for the movie industry. Have you sold any Or do you rent them out?

I am not the owner of the trailer, I only helped build the second one. I installed the plumbing and did some of the electrical work. I hope to install the solar panels, so I am looking for good ideas.

There is a really interesting story about the one I was working on. In a nutshell, we worked like mad for a few weeks to prepare the trailer for a certain star who was going to use it. We worked till midnight a few times, and the owner spent thousands to add a shower and hot water. The star came and looked at it, thought it smelled, and asked for another trailer. The finish had been put on the walls the night before and had not dried completely.

Cant say who it was, I want to keep working there

crewzer · December 2008

Re: Panels on a trailer

Parallel discussion: http://www.outbackpower.com/forum/viewtopic.php?f=17&t=3200

Regards,
Jim / crewzer

Panels on a trailer

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