BCM Community

Bus Discussion => Bus Topics ( click here for quick start! ) => Topic started by: Jeremy on March 27, 2007, 03:43:02 AM

Title: Solar Power - Worth Doing?
Post by: Jeremy on March 27, 2007, 03:43:02 AM
A couple of other posters have mentioned solar power recently; it's something I have often thought about myself, but have been put off by the cost. I did do a rough calculation recently based upon my roof area, and was surprised by how much solar power I could theoretically produce. Given the high up-front cost and low power output, and the only occasional use our coaches get, has anyone calculated whether there is any economic pay-back of fitting solar power, or have those that have installed it so far only done so for convenience reasons (less need of shore-power / generator for battery charging etc)?

Also, does anyone have a view of the current state of photo-voltaic technology? ie. is it a mature technology, or one which is still evolving rapidly? - in other words, do you expect it to get much better / cheaper in the near future, only improve slowly, or even get more expensive as increasing demand outstrips supply?

Interested in your views

Jeremy

Title: Re: Solar Power - Worth Doing?
Post by: Jerry32 on March 27, 2007, 06:31:18 AM
My opinion would be unless you use your bus full time or at least several months a year that it is a luxurery. I had solar on my last coach and did cut my electric bills in winter in the south. I think the popularity of solar makes it more exspensive but also improving the equipment.Jerry
Title: Re: Solar Power - Worth Doing?
Post by: jjrbus on March 27, 2007, 07:25:42 AM
How about putting the solar on the coach, then tying it into the house when the bus is not in use?
Title: Re: Solar Power - Worth Doing?
Post by: H3Jim on March 27, 2007, 08:05:48 AM
I'm probably one of the guilty ones talking about solar lately. 

I use my bus a lot for boondocking, where I am not near a power pole.  If I could always plug in, I'm not sure  solar would be a bonus. I can park for weeks and never need to start the generator at all! 

I did mine for convienience, for the quiet of not having to run the generator, and for being able to always keep my house batts fully charged up. I believe the batteries will last longer before needing to be replaced if I can keep them fully charged.  Running the generator till it goes into float mode adds several hours or more of generator run time, not always possible.

I did not do a cost benefit, and if I did, I might not have put much of any $ into the bus at all.

I would say that the solar panels are one of the best $ I put in, the awnings some of the least bang for the buck - but I still did it as it on occasion it makes the bus a much more pleasant place to be.

Great idea about hooking up to the house and selling $ back to the utils.  I've thought about it as I already have one of the most expensive componenets, the 4024 inverter.

I'm not sure about the technology.   I know a lot of research $ is being spent to improve solar, and they have made improvements.  whether or not there is a major discovery out there that will dramtically improve efficiency and or lower cost, I'm not sure.  Panels are about $4.50 a watt now, and that has not changed much in several years.  I wonder if WalMart decides to go all solar, they could sop up all panel production for several years, dramtically raising the price.  Not likely though.
Title: Re: Solar Power - Worth Doing?
Post by: Nick Badame Refrig/ACC on March 27, 2007, 08:25:18 AM
I'm all for solar as a redundent system!

I wouldn't rely totally on it. I love having multipal systems and options.

Solar is my next project that i'm researching for my bus.

Anybody have a good powerful system in place that I can learn from?

Thanks
Nick-
Title: Re: Solar Power - Worth Doing?
Post by: Jeremy on March 27, 2007, 08:44:49 AM
Quote from: jjrbus on March 27, 2007, 07:25:42 AM
How about putting the solar on the coach, then tying it into the house when the bus is not in use?

You, sir, are a genuis. That's the killer app I've been looking for to justify getting a solar system - I though that if I could at least pretend that there was an economic arguement I could pursuade myself to go that route, but your idea is the perfect answer as it also makes use of the coach's battery bank and inverter system, and is even transportable so I could plug my 'micro generation' plant into other houses in the future. Micro generation is being pushed quite hard here at the moment, with tax breaks etc for 'low carbon' houses and so on. Solar panels on the roof of the bus will be small fry compared to wind-turbines, ground heat etc, and there is no way it would generate enough power to sell back to the grid, but it's the perfect way of starting out

I guess I need to start some serious research into solar systems now!

Jeremy
Title: Re: Solar Power - Worth Doing?
Post by: H3Jim on March 27, 2007, 08:53:23 AM
I highly recommend Blue Sky controllers.  They invented and employ a technology that maximizes the amount of power you extract from your panels on cloudy days or in marginal conditions.  They licensed their patents to Heliotrope, but I think Blue sky is the best bar none.

They only sell through distributors, but their website is  http://www.blueskyenergyinc.com/
Title: Re: Solar Power - Worth Doing?
Post by: skipn on March 27, 2007, 09:08:23 AM

  We have two people here at work that are totally off grid and I have been picking there brain for a year now. So what I have learned so far.

    Each has ~$15k into their system with 5 panel systems. 110 watt panels and they would love to upgrade to the 170watt panels.
    As with the bus the batteries are a real variable in cost and size of battery bank needed.
    Inverters are different if you are doing an ingrid system the other option is a grid disconnect if you are running through the bus invertor.
    Both guys have auto tracking on their panels to keep the efficiencies maxed. A lot of designs I have seen for busses are fixed panels
    there are a couple of designs for limited panel tipping but the bus has to be pointed in the right direction.

    Still working on my design I  figure it will take me a couple of years to put a usable system together. I would like to have a tracking system for the bus.
   

     Skip
Title: Re: Solar Power - Worth Doing?
Post by: gr8njt on March 27, 2007, 05:06:34 PM
Like H3Jim, I will have my solar panels for mere convenience sometime next year.
600 watts of solar panels are not cheap but less expensive than a diesel genset.
If I do not have to start my "taboo" DC Kubota genset, why not?
I have an all electric coach  and proheat hydronic system to be installed before the first frost.
Solar power will definitely keep the SW4024 and 800Ah/24V battery bank happy as the proheat pumps away!
Title: Re: Solar Power - Worth Doing?
Post by: jjrbus on March 27, 2007, 05:36:42 PM
                          You, sir, are a genuis.  Thanks for the compliment! I'd like to stay and chat, but I'm off to my MENSA meeting tonight.
Title: Re: Solar Power - Worth Doing?
Post by: niles500 on March 27, 2007, 06:45:52 PM
I've been waiting for one of you to try the new holographic panels which appear to be a great benefit for our use -
Title: Re: Solar Power - Worth Doing?
Post by: H3Jim on March 29, 2007, 04:35:54 PM
skipn,

Those folks tha are living off grid on only 550 watts seems like they must be careful of their electric usage.  I opted to go for more watts than really necessary, and that way I don't have to worry about tilting them.  And then there is the driving off with them up thing I avoid as well.

I have a friend who is very happy with the solar system he has on his bus - he has 2,   150 watt panels, for a total of 300 watts.  He said he is usually fully charged by 10 or 11 am.  I guess it depends on your usage.
Title: Re: Solar Power - Worth Doing?
Post by: pvcces on April 07, 2007, 07:31:59 PM
Jeremy, we have 220 watts of panels laying down flat and use a BZ controller, MPPT250. We use mostly fluorescent lights but gas for heating and refrigerator. With our setup, we usually don't get any use out of the generator unless we use the coach in the winter.

The other important thing for us was that we don't plug the coach in when it is in storage for 2 1/2 months at a time. When we go to use the coach, the batteries are charged.

What is that worth to you? We figure it's worth at least $50 per month while in storage.

For what it's worth.

Tom Caffrey
Title: Re: Solar Power - Worth Doing?
Post by: TomC on April 08, 2007, 06:28:29 AM
Personally, would only use solar if you are going to be boon docking away from land power source for extended periods of time.  Otherwise, just use the generator (make it quiet and it won't bother you).  Solar is a great way to keep the batteries topped off when not using the bus.  I have a standby Diesel gen at the house with a single 31 battery with a small solar panel on the roof.  Battery has never been recharged and is now over 7 years old (bought in 12/99 for the 2000 power scare).  Good Luck, TomC