off grid systems status

[StressMan79]

everyone,

I thought about using 24/48 VDC for the power, I don't think I'm going to. I think I'm going to use 12V

This is because so much RV stuff is availiable on 12V, and to reduce it, I'd have to invert, transform and rectify, and I think the losses will be too great. That and I have a 12V charge controller for 12V and I have 3 USBs that use 12V. I was wondering if anyone else had come to a different conclusion or if I am right on. Please tell me what you think.

-Peter

[rreidnauer]

Each have their own pluses and minuses. As I'm sure you know, 12v is great for small systems, especially if you're going to be utilizing mostly 12v appliances. Also, 12v inverters are on the cheaper side too. No doubt, it's the perfect selection for someone trying to keep their costs low. The down side is, the moment you try to make 12v work in a larger system, such as a whole home, you run into serious problems. Not even taking efficiency into account, power distribution alone becomes a huge obstacle. How does one distribute 12v throughout a home? I don't think even 10ga romex would be sufficient for fairly long runs. That's not to say it can't be done. One could theoretically run a heavy buss bar system, and tap off locally as needed.

I originally was going to run DC throughout my home as well, low voltage lighting and all, but as time went on, I realized that efficiency gains at one place always led to losses at another. It's truly a balancing game. In the end, I decided to produce, store, and invert all power outside the home. (essentially building myself a mini power plant)

Your concerns for changing your voltage remind me of something I ran into some time ago, when I needed 9v in a 12v system. I found the following schematic, (still in my old archives!!!!) I built it and it worked. Don't ask me what's needed to convert 24v to 12v. When it comes to solid state, I'm a bit handicapped. I can copy it, but that's about it.
http://img.photobucket.com/albums/v328/titantornado/PowerSupply.jpg
Anyhow, there's one way for you to step your power down without all the steps mentioned earlier.

[Yuhjn]

You're talking about running your entire system as 12v? From what I've read most 12v appliances are built for short-term RV type use and dont hold up under the rigors of constant daily use.

This is actually discuseed in the book more power to you... at least I think that's what the title was.

[StressMan79]

Yuhjn,

That's exactly what I was talking about. I am not worried about lighting, etc, as it takes a whole lot of LED's to take 15A, even at 12V. I don't think I'm going to have a dishwasher or even a washing machine (if I do, I was thinking of running off generator juice). I am quite worried about running a fridge/TEC off of 12V. I suppose this could be done on propane. What other concerns to you have? a big plasma screen TV might get close to 15A @ 12VDC. I was planning on using a fairly large UPS for generating the pure sine AC that is required for that. the laptop would have to be inverted with a cheap mod sine inverter, as it requires 19V and is just rectified again. I spose I'd do this for most AC loads, only using UPS for senitive (non DC) electronics.

I just can't find anything that runs on 24/48V If I could find a fridge, fans, (cheap) inverters, etc. I'd change in a second. it is kindof a trade between the best theory and the best practicality.

Anyone else?

Thanks.