# Off grid, going green ideas??



## user_12345a (Nov 23, 2014)

You need to do a heck of a lot of research and consult pros who do this stuff for a living in your area before undertaking a project like this.

If this place is only for recreational use (ie power failures which are more common in remote areas) and you can connect to the grid for under $10 000, you should go that route.

Going green alone isn't a good reason to go off the grid. 

Off the grid is not necessarily better environmentally than on the grid. The solar panels/batteries contain toxic materials and take a lot of energy to produce and the backup diesel generator which is essential is dirty, noisy, and not nearly as efficiency as fossil fuel burning power plants.

The cost is of the hardware to generate electricity on it's own without any grid support is so astronomical that you pretty much have to get your power use down to the bear minimum to do it economically. If you're in an area that has a lot of hydro or even nuclear, I would argue that it would be better to connect to the grid and use electricity for major energy-sucking heating loads - avoid the fossil fuel use all together. *With off the grid you pretty much have to use propane or oil for cooking, heating water, space heating. (unless you put in a wood stove; many off people in rural locations do that)

Off the grid also requires maintenance; can't have the batteries go flat, system has to be monitored.

For a place that's used intermittently, solar is not very economical. The $ per kwh is very very high unless all the power is either used or the surplus is dumped back on to the grid with a net metering scheme. In off the grid once the batteries get fully charged, the power gets wasted with a diversion load; often a super-inefficient large draw like a baseboard heater.

The overall design of the cabin and usage will determine which route to take.

*Questions to ask yourself:*

1. How will you heat this place? Does this place need to be cooled?
2. Do you need to pump water from a well? How much energy will it take (rainwater won't cut it)
3. Do you need to heat water?
4. What will the electricity load be?
5. How much would it cost to connect to the grid?
6. What is the cost of propane, fuel oil, diesel (for the generator), or grid tied electrcity
7. What would an off the grid system for your needs cost?

*


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## user_12345a (Nov 23, 2014)

Also, if you're serious, get yourself a a copy of the renewable energy handbook for homeowners by william kemp. It has tons of info on energy conservation and what's involved in actually going off the grid. It may be out of print - try your library first.


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## SeniorSitizen (Sep 10, 2012)

You could do similar to how I was raised. Wood stoves, kitchen and living room and a windmill with a 1,000 gallon storage tank elevated on a wooden stand for gravity water pressure to the house and stock tank . 

If storage water was to be used for cooking it was boiled. If good fresh well water was desired the Jet Rod was disconnected from the windmill and fresh water was hand pumped from a 150 ft. well. Hand pumped was the norm for both cooking and drinking. Best water I ever drank. Sears ? Silvertone Battery radio to listen to The lone ranger, Amos and Andy and some girlie programs that always made my sisters and brothers fight over the controls. Those were just a smidgen of the Good Ole Days.


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## user_12345a (Nov 23, 2014)

I'll comment on your specific ideas later today or tommorow. doing a tiny 12v system along with a generator for big stuff is totally obsolete these days. there's a better approach.


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## user_12345a (Nov 23, 2014)

Okay, with respect to your ideas:

You pretty much have to use off the grid, professional grade equipmentl; not some simple battery chargers.

With respect to having a 12v dc system for small things, don't do that. Get a good quality 120v sine wave inverter/battery charge controller combo. Have the cabin entirely wired for line voltage, feed it entirely from the inverter.

Put in a large capacity generator not to use directly but to charge the batteries up when they reach a certain discharge point; you would want something that could charge the batteries up in a few hours, then shut off. With the generator charging the batteries, you could maximize generator efficiency (not having a several kw generator running inefficiently most of the time at 10% capacity or so) and minimize noise.

The batteries get sized to for enough a certain number of days of usage 

From there you start adding solar panels to charge the batteries directly and save fuel.

With the solar panels you have to have a diversion load on a special to dump surplus electricity when the batteries are full and nothing is on. It could be a baseboard heater, window air conditioner with manual controls, or something else of that nature.

Here's a calculator you can use to determine kwh per day: http://www.affordable-solar.com/residential-solar-home/Off-Grid-Load-Estimator


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## Oso954 (Jun 23, 2012)

> With the solar panels you have to have a diversion load on a special to dump surplus electricity when the batteries are full and nothing is on.


Why do you think a diversion load is necessary ? They are used with wind and hydro, but not solar. The solar charge controller should stop any current from the panels, if the batteries are full.


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## Oso954 (Jun 23, 2012)

> Would one of those chargers charge and keep charged a 12v deep cycle, thinking 29 series, charged while away?


Your 29 series battery is a poor choice for a solar system. It is a hybrid battery that is in between a true deep cycle and a starting battery. You would be much better off using a true deep cycle battery. For a small system, golf cart batteries are fine. With larger systems, there are even bigger batteries available.

I am not sure exactly which harbor freight charger you are referring to. But if it is only a watt or two, you are trying to fill a swimming pool with a teaspoon.


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## Master Brian (Apr 24, 2009)

I don't have much time now and just realized I had replies, which I have only had a chance to glance through, but.....

Let's not over-complicate things as of yet. My reasons for going off grid, aren't primarily to be green, it's because, like I thought I mentioned, I'm trying to do this on a budget and don't plan to finance any of this, so it's as time and money are available to be spent. Right now I'm not ready to invest Ten of thousands of dollars into the property. A few thousand here and there are doable.

I've had a septic analysis done and i'm looking at about $7500 to install the correct septic to build a house. I need another $5000+ to install a well and then until I have both of those AND a foundation for house in ground, I can't get electricity without spending another $5000. As time progresses, I'll have those things, but for now, I'm just trying to get my foot on the ground, pun not necessarily intended! I figure baby steps and get things going. I won't have a diesel generator, it'll be a small ~3000w gasoline portable unit, that I'll either take back/forth or leave in the shed when gone. 

I realize the 29 series batteries are a poor choice, I'll look at golf cart batteries, if that's where I should look....once again, I'm trying to start with simple solutions and build from there as time goes on and as funds permit. My reasons for the 29 series batteries were partly because, I have those in my bass boat and they are a few years old and would be an excuse to update my boat batteries, BEFORE I'm stranded on the lake. 

Heat and cool aren't crucial at this point, hence the 12v fans to help move air, a window ac would be nice, but I know I'm looking at a larger generator and/or larger solar system, which again aren't where I want to spend a bulk of my money now. This is a place I've owned for about a year and I've been there maybe once every two month since then. 

Again, I'll try to get back to this soon, just wanted to clarify a few things, because it sounded as though people were thinking I'd be living here and expecting a complex build. In my past experience with an old box camper we had, dual 27 or 29 series batteries provided what we needed for a weekend....that's all I'm looking for, but I'd like a way to charge them while I'm away and having no grid tie access at the moment.


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## user_12345a (Nov 23, 2014)

12v is totally obsolete with today's inverter technology. Don't do it even if you want to initially run some lights and fans off of solar as an experiment. To start with u could get a small inverter/charger, like 200 watts to run some LED bulbs and a fan off of.

If you spend money on equipment or wiring that can't be re-used when expanding, you're pretty much throwing that money away.

A small gasoline genset, the type you could get at a hardware store is not designed to provide continuous duty power; they're designed for portable power or emergencies. It won't last long for continuous use on weekends and will burn through a lot of gasoline. Just keep that in mind.



> a window ac would be nice


Even the smallest window a/c uses 500 watts when on and the compressor would have a hell of a time initially turning over on most generators. The motor pulls 4-6 times the required current on startup.

For a/c you're looking at the same capacity system you would have on a house, like 2+ kw of pv and 20-40 kwh of batteries.


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## user_12345a (Nov 23, 2014)

forgot to ask - have you looked at some small off the grid starter kits?

Something like this -> http://www.costco.ca/Coleman-300-Wa...ntroller-and-Inverter.product.100159937.html# to run small loads and not run a generator most of the time. With a kit you get stuff that's been proven to work together with instructions and a warranty.


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## user_12345a (Nov 23, 2014)

Oso954 said:


> Why do you think a diversion load is necessary ? They are used with wind and hydro, but not solar. The solar charge controller should stop any current from the panels, if the batteries are full.


didn't know that. 

either way, obviously solar panels that aren't put to use have a much higher cost per kwh. diversion load or not, the capacity would be wasted most of the time.


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## Master Brian (Apr 24, 2009)

Generator wouldn't be for all day use....an hour or two maybe twice a day. Unless on the rare occasion I needed it to run something bigger like a saw or compressor. Again, don't think of this as much as a residence, but more like a glorified camper, which I'm not going to hang out in except to sleep, get dressed, etc. I don't go to the lake to sit in a camper, I go to be outdoors and get away.

I'm a bit curious about the statement saying to forgo using 12v direct, but instead to use an inverter and go with 110v. For certain things isn't that wasting electricity? Let me explain....First, a lot of LED lights have a transformer on them that steps them from 12v to 110v. For instance, I put some LED tape lights around the window(s) in my daughter(s) rooms so they could have some fun lighting. For that, I had to use a transformer to step it up from 12v to 110v. I used the same type of lights around the perimeter of our pontoon to create a cool effect at night off the water, but for those, I just went straight to the battery and ran on 12v direct. Point being, If I did the same thing in the shed/cabin, wouldn't I be wasting energy/electricity to step it from 12v to 110v back down to 12v by using an inverter? It seems a lot of LED task lighting is done this way and being as small of a space as I'm talking, I think I'd be using more task lighting than anything. In fact a couple of automotive style dome lights with LED bulbs would be perfect for the sleeping bunks and if I did a small bath. I have several unused 12v bilge pumps which I've thought about using to transfer water inside, if I have a holding tank of sorts outside and I have 4 or more 12v auto/camping fans. Heck I even have a 12v blender. 

Don't get me wrong, I'm not totally against an inverter, I even installed one in my suburban, so I get that they are useful, and being as I'll occasionally use a generator, I'll have to run some 110v wiring for certain. I'll have to think about this. 

Please don't take it as me argumentative and totally set in my ideas, I'm somewhat brainstorming ideas and trying to learn as well as explain my thought process. 

There are things where I can totally see the inverter being necessary for and thus I'll probably end up with one. 

Yes, I've somewhat looked at the starter solar kits, just wasn't sure they would be a good move. I'll look more at them once I get the initial building up. That coleman one looks nice. Thanks!
lain:


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## Oso954 (Jun 23, 2012)

As long as you are keeping your uses small, and they grouped fairly closely together, 12v systems still work well. Where people get in trouble with them is either running longer wire distances or trying to run medium to larger loads off of them. 

If you remember there is a 10 to 1 ratio between the voltages it helps. In other words, 360 watts is not a huge load at 120v, it's only 3 amps. The same 360 watts is 30 amps at 12 volts. Wire sizing and voltage drop calculations are extremely important in 12vdc systems.

What you need to do is to list everything that you plan to use on your battery system and estimate how many watt hours per day you will be using those items. You can then add a contingency factor to it and use the total watt hours as the design factor for your battery bank. Then calculate how many solar panels you need for makeup. 

The process will tell you if 12v is right for you.

As people put more and more load on their solar systems, they end up increasing the battery bank voltage to 24 or 48 volts. Once you do that, they tend to go all 120vac with no DC loads. But 12vdc systems and mixed 12vdc/120vac systems are still common for smaller off grid systems.

An inverter system is very inefficient at low load levels. Being able to run a few DC lights while the inverter sleeps will save a lot of energy as compared to running the inverter for a couple of AC lights, particularly for long periods of time.


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## beenthere (Oct 11, 2008)

It sounds like your at the point, that you can start small like you want, and build up as you need, or find out you must from a little trial and error.

You'll need a larger panel then you first thought. 

How many amp hours are you 29 series batteries.


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## user_12345a (Nov 23, 2014)

Your point about efficiency is totally valid; the only thing is that 12v appliances/lights for off the grid applications are harder to find, probably far more expensive than conventional line voltage products.

With 120v you can use regular LED bulbs bought anywhere, other things brought from home, etc.

If you're only running some some light bulbs, maybe a radio/small fan, you may not need to worry much about using 10% more or something. Even if you get a 200 watts of pv, at even 4 hours of peak sun per day, you'll probably have more than enough power.

To determine required capacity you have to look up peak sun hours in your area.

I think the most important thing is to do it in such a way that the system can be expanded without having to re-wire and change over from 12v to 120v ac. Wiring for 12v is totally different; u need far more current and hence much thicker wires on 12v dc vs 120v ac to deliver the same amount of power, granted, u may not be using much power to begin with.


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## Centex2011 (Dec 14, 2011)

I can't help with the solar and energy, but if you want to use rainwater to drink or anything else besides just irrigation you definitely want to filter it. It could be something complex and expensive that gives you filtered water instantly or it could be something simple that gives you water after it has run through the filter for awhile. I have been researching ways to filter water to use as drinking water and there are several different ways. A simple way is using sand. Just google rainwater sand filter. Anything you do, make sure you get it tested before you drink it to make sure it is safe. I have not done any type of filtering yet of my rainwater as I only use it for watering trees and plants, so I cannot speak for, nor do I endorse, one filtering type over another. Just that from everything I have read you do want to filter rainwater for drinking purposes. If you are not familiar with rainwater collecting, definitely do a little research. There are things you can do to have decent water.


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## Centex2011 (Dec 14, 2011)

As far as the greywater, you can make a soak pit if you have the room on the property. Pretty simple. Just google greywater soak pit. Just make sure you build it big enough. I made the mistake of building mine (for our washing machine) too small and now I am faced with digging in wet, sticky, smelly clay to make mine bigger.


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## Oso954 (Jun 23, 2012)

I would check into the rain water gathering with the building dept and possibly the health dept. the regulations on what you can use it for vary widely.

There is also a difference between various levels of filtering vs water treatment.

I would give a lot of thought to using water collected from a shed roof for washing dishes. In a forested area, what birds or animals may have been on that roof ?

Unless you are boiling the dish water before use or putting a fairly high level of bleach in the final rinse water, I wouldn't want to use it.


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## Centex2011 (Dec 14, 2011)

I am no expert on rainwater collection, but everything I have read says that as long as certain precautions are taken, rainwater collected from just about any type of roof can be used for everyday use like it was from the "tap."

You use pre-filtering screens for large "trash" and use a first flush diverter to collect the first few gallons of rainfall that carries the most junk, dust particulate/air contamination, bird/animal contamination, etc. before it goes into storage tanks. Then from there you do the filtering with either basic filtering like I pointed out or the more expensive filtering routes. I would definitely test any water you plan on using for household use.

If you are interested in just the possibility of collecting rainwater for any reason, do some research. I don't know if there are any restrictions in Missouri. I know here in Texas, they have passed legislation making sure that jurisdictions allow and accept rainwater collection. There are companies that do rainwater collection systems exclusively that have been around numerous years here (I found a videotape back in 1998 or 1999 at a museum/wildflower park) and a lot of landscape and irrigation companies are starting to install rainwater collection systems professionally.


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## Master Brian (Apr 24, 2009)

I wouldn't plan on drinking the water, just using it for other things...quick shower after the lake, maybe dishes, putting out a camp fire, etc... Besides bleach tablets in the holding tank, hadn't thought about much more complex filters. I'll research the sand, because that might be an easy solution for my needs. I don't want to get too complex because I do plan on having a well installed at some point. 

I think for the toilet, I'm setting my eyes on building a very basic composting toilet. I'll probably build a nice box that houses a 5 gallon bucket and use the saw dust method to cover, then build a composting pit. For the grey water, I'll look at the pit recommended, but I can't dig very easily in this soil. I might have to use some sort of holding tank...


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## Arelia (7 mo ago)

are you adding some kind of wind turbine to help charging the batteries?


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