# Sustainable Power System a la Bus



## RSpecianjr (Jan 20, 2010)

Hey guys,

Alright, I am working on modifying a Short Bus to travel and live in for quite some time. There are a few electronics that I would like to run and I was hoping someone would help me figure out what can fit, what I need to throw out, and the design of the system (storage, converters etc). ETA May 2012.

The main things in the system that I will want to run are TV, Laptop, Occassionally an Xbox 360 or PS3 or Wii and a thermoelectric cooler (fridge).

Average consumption (from random sources on the web):

Samsung 32" Class / 720p / 60Hz / LCD HDTV - 90W running, .5W Standby (Will likely get a Energy Start 5.1 model when available)

Laptop - ~70W
Xbox 360 - 160W
PS3 - 180W
Wii - 15W (CRAZY!!!!)
TEC (Fridge) - 50W

Speakers?

The only thing that will run 24/7 is the fridge. Roughly 1200W a day. The rest will be on and off, never more than 6 hours.

The idea is to use a battery bank that will be connected to solar panels on the roof and hopefully (if I can get it worked out) a kind of regenative braking system (probably only while stationary). I would also like the ability to plug into an outlet to get some of a charge from the grid.

If I cannot get the regenative braking system worked out, I will have to lose some of the gadgets. Likely the gaming systems and the TV.

I am thinking of using multiple batteries from a prius. A single Battery is 1300W, though I am unsure as to whether that is at the 100% capacity or what they charge it to (~80% I think). Suggestions for different storage?

The engine will run every day at some point during the day so that the batteries can charge. I seriously doubt I have enough room for a solar system that could power it by itself. Who knows... thoughts? 

Being fairly new to this I may not be 100% accurate on calculations. So feel free to correct/critique/comment as much as you'd like. 

Short Bus Modifications

Regards,

Robert D. Specian Jr.


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## octaneman (May 13, 2009)

I don't see why you would have to sacrifice any of your gadgets, why not run a generator off the tank to supplement your solar panels. Tractor trailer operators run generators for everything so why not run a proven system ? 

The rule of thumb is when you set up your power grid always have more than what you actually need. If you don't do it like that your system will be constantly overloaded causing a fire hazard. Solar panels are great when its sunny, but also during the summer heat you need to run an a/c system, a generator is what you will need or else the bus will be an oven. If this was my pet project I'd calculate how much power I need for my basic needs ( water pumps, filtration system, a/c , stove, fridge, etc..) and then If there's room to spare what gadgets I really want. This way I would maximize the space needed to put everything without spending a fortune on things that won't be ergonomically suitable.


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## RSpecianjr (Jan 20, 2010)

Hey octaneman,

That is the general idea. The engine will double as a generator when the vehicle is not moving or running idle (regenative braking, or at least as I understand it). If I do it this way, I figure I can use the airconditioning/heating unit of the bus itself.

This is all mostly speculation at this point and will likely change the more information I get or as things start to come together.

Thanks,

Robert


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## Basementgeek (Feb 7, 2005)

What is your budget for this project?

BG


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## gcavan (Aug 13, 2009)

You will get some charge while moving but don't count on charging your batteries by idling the engine. It will cost you too much in fuel and you will get only a few amps (if any) out of even a high output alternator. Do as octane suggests and incorporate an auxilliary generator to supplement your solar and to carry the heavy loads (AC, water pump).

For solar figure (on average) about 12 watts per square foot of array. This means your largest roof mounted array is going to be about 800 watts (6 feet x 10 feet). You could incorporate a side mounted array which doubles as an awning when parked but the weight is an issue.

In any case you should be planning on a 24 or 48 volt system isolated from the vehicle's electrical system.


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## RSpecianjr (Jan 20, 2010)

Hey guys,

BG -Well, I would like my budget to be as little as possible, but if I had to throw a number out then 15k. This will incorporate everything though, from conversion kit to aesthetics. Obviously the mechanical and electrical are more important.

gcavan - Well, the cost to run it off the engine would be negligible since the engine will run off vegetable oil. Where as running a separate generator would require the use of diesel. Granted there will be a diesel tank attached to the bus for initial startup. For simplicity I might just go with a generator, though it looks like I would be spending about 800 bucks on a generator. Any recommendations there? 

I was guessing about the same output for solar panels if not slightly less.

Hmm, good question I assumed 24v. The idea is to have 3 or 4 battery banks, which would be either 3900W or 5200W. Would you suggest 48v for this and why or why not?

Any comment on the batteries themselves? 

Thanks,

Robert D. Specian Jr.


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## Basementgeek (Feb 7, 2005)

WVO is not free or cheap anymore. It needs processing to be usable for fuel.
I would stay with diesel fuel only. 

Since you have diesel tank, I would look for a diesel powered generator, those are generally big units. I would look at APU for a motor home.
APU for large trucks,. they provide some heating and cooling run but they
run $6,000 - $8,000 USD.

As far as batteries, I would stay with good old lead acid. Easy to charge, easy to convert to 110AC and you can buy them any where.

BG


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## RSpecianjr (Jan 20, 2010)

Hey BG,

Well, the processing isn't that expensive. Not compared to the cost per mile. I will need a way to filter the oil and a conversion kit (looks like $1,500-$2,000) but I don't see many costs outside of the initial setup (and filter replacements). I wouldn't be getting a centrifuge or the such, just simple separation and filtration. Most the grease would be waste picked up from random restaurants around the country, otherwise diesel. Am I missing something else?

Regards,

Robert D. Specian Jr.


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## Basementgeek (Feb 7, 2005)

Hi:

I have not done much research on it, but sounds like you have.
I thought there was more to it that than just filtering it.

Good luck.

BG


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## RSpecianjr (Jan 20, 2010)

Hey BG,

I'd much rather have those questions raised now than find out later haha. 

It just has to be filtered down to 5 microns. Its a slow process unless you use expensive equipment like a centrifuge. Heating the oil prior to filtering it also speeds it up quite a lot. Quite a few people use a two or three tier filtration system, starting with either a pair of jeans or a sock haha. Letting it settle and siphoning off the oil. Then finally going through a micron filter. 

Ciao,

Robert


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