Off grid considerations

Carol Reed

In Memoriam
Messages
5,533
Location
Coolidge, AZ
Brent's power out experience got me to thinking more about off grid living. It has always been an interest and now that I have the MH & PP I probably could be closer to actually going there.

Here is a guy on YouTube that proved to be interesting.

http://www.youtube.com/user/LDSPrepper?feature=watch

Which poses a question. Anyone know of an on-line power calculator so one can properly size an off-grid electrical system?
 
:lurk:

This is all really high level but is a nice summary of things to start looking at:
http://energy.gov/energysaver/articles/planning-home-solar-electric-system
http://energy.gov/energysaver/articles/planning-home-renewable-energy-systems
http://energy.gov/energysaver/articles/small-solar-electric-systems

The biggest #1 first up item to planning is to calculate your actual usage/requirements. Unfortunately that is so site/installation/user dependent that I don't think you'll find a single answer to that.

We had installed one of these: http://www.theenergydetective.com/ (there are other competitors as well, we got this one as part of a work deal) for a while, it was pretty interesting and we started turning off our laser printer more aggressively when we weren't using it. For home usage a similar device that tracks the whole house is pretty useful. What I really wish was that there was a reasonably priced (hah) panel (haha) that had per-breaker measurement (preferably built into the breaker itself).

Some sort of clamp on meter you can put on the feed line to your RV where you could track your usage over some period of time would probably be the easiest way to figure it out (http://www.ebay.com/sch/kwhmeters*com/m.html?_nkw=&_armrs=1&_from=&_ipg= is an example - note I am NOT endorsing them as I don't know them from adam - just the result of a search for "energy usage meter rv"). That would also help you figure out what your high usage devices are and start mitigating them if you needed to (i.e. you find out your power usage is waaaay high for some reason you can start looking to find out where the draw is .. or hopefully not but happens.. if there is a short). I'm looking at something like that over a simple ammeter because I think it is useful to be able to get more granular time series data if you are trying to find out what is actually using all the juice - otherwise you're sitting there staring at the dial waiting for the fridge to kick on :rolleyes:

For a house if I was planning partial grid I'd put in a sub panel with all of the critical items on it and have that hooked up with a transfer switch to the main panel/generator (or battery bank or whatever). That can still work with a net-metering setup and a battery backup but requires some more complicated switching gear (especially if you want it automated - and make sure you have charge and draw limiters so that you don't overcharge or over drain your batteries unless you looove spending money).

As an aside, unless you are someplace reaaalllly windy or get a reaaaaalllly good deal on a used system the payback on wind systems is pretty bad. Microhydro with net-metering has probably the best ROI still (on my list of like-to-haves for the eventual property but certainly not holding my breath) but solar keeps getting cheaper so its getting close.
 
Another thing to consider is your sunlight situation, while looking around for other reasons (we're comparing various plausible living locations for winter sun exposure :rolleyes:) we found this: http://maps.nrel.gov/ - the "In My Backyard (IMBY)" tool is pretty cool for calculating probable energy yield in a given location.
 
It is very difficult and / or expensive to go off grid if you wish to continue to consume electrical energy like most power hungry Americans.

Low cost and easy way to work towards going off grid is to learn to start living more like Abe Lincoln than George Jetson.

Not trying to be a wise guy, but to create electrical power anywhere near the $0.10 - $0.75 per KW price ($0.15 being closer to the average) most utilities sell it for is very difficult.

Understand I am very biased - Retired Power Company guy.
 
Carol... zip on over to the escapees site and there are loads of people who've done the solar/generator discussion thing... that I recall (I haven't looked into it that seriously...) Jack Mayer has one of the definitive 'how to ' and 'what works' discussions/sources on his personal site: www.jackdanmayer.com

quick link check and sure enough he has a TON of information all laid out for you.
 
IMBY gave me a 36 year pay back on every option. Have to play with it more to see how variables change the outcome. Interesting site.

I don't think it takes into account a lot of the rebates either. In many areas there are some serious tax credits and other kickbacks that can really drop the price; without them it often doesn't work as well as you'd like.. with them .. it depends.. :D
 
No rebates for MH installations. :( But you gotta know what you need, and then you gotta decide what you want. Two different lists, ya know? :)
 
More random notes.. There are some nice places on the Big Island that are of grid (hey a fellow can dream can't he? :rofl: :rolleyes:).. Looks like the battery cost to run any of my existing tools would be heading towards ruinous though (really need micro-capacitor arrays to be reality!!).

Size (kW) = Array Area (m2) × 1 kW/m2 × Module Efficiency (%)

So if you have a 10'*30' motor home roof and you cover the whole thing in solar panels you have 300 sqare feet or about 27.8709 square meters.
Multiply that by 16%
27.8709 * 0.16 = 4.459344kwh
Now that is a on a good day with full sun at noon with a new panel.
The hand waving numbers I'm seeing are somewhere closer to 1/3 to 1/2 that in delivered power most places (unless you mostly stay in nevada then peak is probably closer to reality :D) and looks like it can drop off significantly morning and noon.

What does all that mean in the real world? Not sure :huh: but I think it means that reduction in use is going to be your first last and best friend. So if you see one of those Barnes #4 treadle lathes.. now may be the best time to splurge (but if I find it first.. I'm taking it with me to hawaii :rofl:)
 
Which all goes to prove you can't have everything you want when you want it! :eek: Solar is not the only consideration however. The first problem to solve is water. Clean safe water in reasonable amounts. MH living brings one into a new awareness of consumption. Boondocking is a temporary thing we soon learn.

You are safe on the lathe. I have never heard of it. So, maybe I ought to investigate..... :D
 
Which all goes to prove you can't have everything you want when you want it! :eek: Solar is not the only consideration however. The first problem to solve is water. Clean safe water in reasonable amounts. MH living brings one into a new awareness of consumption. Boondocking is a temporary thing we soon learn.

You are safe on the lathe. I have never heard of it. So, maybe I ought to investigate..... :D

Yeah water can be rough and its sooo heavy as well. We've been looking at small camp trailers (sort of half interested, but not committed) and water is what just kills the weight on them.

A small two (or three) pass "whole house" (whole rv?) filter would be my first step and would imho be a good idea even if you're hooked up at campgrounds - I have one I use for homebrewing because our tap water is often of questionable quality (goes from really good to dang near pool water chlorine at times; its a smaller water system and they occasionally have "issues"). Doesn't take out all the really small nasties so boiling drinking water unless you know its good is probably not a bad idea, but it will take mediocre water to decent.

The nice little treadle lathes are about as scarce as hens teeth so if either of us finds one in working order I say we're ahead just getting it no matter who does :thumb: :D
 
Top