What kind of generator would we need to run two window air-conditioning units in the DEEP SOUTH, as well as running the computer and TV/VCR a few evenings a week? Also, what kind of generator for power tools, including a table saw? You know those books in the stores: "Accounting for Dummies", "Medicine for Dummies"? well, although we consider ourselves to be fairly sharp, we know nothing at all about generators....we will have about $20,000 to spend..Neil wants to get a kind/type that I can run if the Lord decides to scoop him up before me,so treadmill power is out!Anyone actually off the grid here??????

-- lesley (martchas@bellsouth.net), February 21, 2002

Answers

Go to www.homepower.com and read and read and read. Buy their CD of back issues and read and read and read. If you mean $20K to spend on alternative energy, that is enough to buy a modest system of solar panels, deep cycle batteries, cables, enclosures, mounts, bases, and a large sine wave inverter. But solar doesn't work all that well in the southeast because of cloudy weather so much of the time.

To answer your questions: a 2500 watt generator can run TV, computer, some light, ordinary shop tools, etc. You need more like 5000 watts for safely using big power tools, large home appliance, etc.

Air conditioners? Get real. With alternative power forget air conditioning, electric water heaters, electric heat, and electric stoves. Two air conditioners would push a $20K solar set up to its limit.

I may be wrong about some of these figures but I doubt it. Also if you plan to use the generator day in day out not just for emergencies, it should be a diesel one; the cheap gasoline powereed ones are ok for construction and occasional use but not everyday home power use.

-- Rags (nobody@nowhere.org), February 21, 2002.

Thanks Rags, I will check out that site and hope it is not full of terminology I do not understand yet. If a hospital can run full electrical services including central air on a generator system, why can't a generator run a few window units for a few hours each evening if that's all it is used for at night?

-- lesley (martchas@bellsouth.net), February 21, 2002.

Sure a genereator can run two window units for a few hours in the evening. Lesley, if you have 20k to spend you can get a decent set up with the generator running to batteries (for tv, fans, lights and the like) and a solar system to help the generator out.

I have a book called "Modern Homestead Manual" or something very close to that and it has a nice section on generators. You used to be able to get it through Backwoods Home. You would want to get a diesel and have it run at 1800 rpm instead of the more common 3600 rpm. That prolongs the life of the generator and it also isn't too noisy.

I have a small solar set up to help in case it all goes south, but couldn't swing the generator. I am doing more research as I am hoping to go totally off grid in MO.

My folks have an Onan they bought at auction and did some mechanical work on and they have used it a time or two during ice storms. They put in a key ignition so my Mom can turn it on, and then there is a switching panel inside the house that transfers the applicable circuits to the generator.

If I remember correctly Jim-mi knows some about alternative energy...in a much more applicable sense than I do. Hopefully he will have some suggestions! I would definitely go hybrid if that is even possible.

-- Doreen (bisquit@here.com), February 21, 2002.

What's a"hybrid" mean in terms of generators please? We already have a propane hot water heater, propane heat from a free-standing wall hanging "thing", woodstove for cooking, woodstove to supplement the propane for real cold nights, propane clothes dryer, kerosene lamps, etc.....we can easily hook up the wood stove to a watertank in the winter as well...we do not even use electric clocks..all wind-up oldies and two from the 1800s...the only things we need to use electricity for are the Tv/VCR for a few movies now and again, the computer, and Neils various power tools. We have central air but I refuse to pay the electric company anymore $$$..just too expensive. I am familiar with battery operated floor fans from my Amish buddies, and I must be able to run a small window unit in the hot summer at night or I may kill someone. My personality truly disintegrates into something hideous when the outdoor temp reaches over 80 at midnight.

-- lesley (martchas@bellsouth.net), February 21, 2002.

"Hybrid" means you have an alternative source like solar,wind, hydro but not enough to carry your whole electrical load, and to make up the difference you use a generator. The other part of a hybrid system is a large battery bank: this lets the system run like mad when you want to run some insanely large load like two air conditioner compressors, then recharges at a reasonable rate over a long run time on the generator. In a hybrid system, the object is to use a lower cost, smaller generator than it would take to run the whole system and also use fewer expensive panels (or whatever) than it would take to run your whole load.

If you are moving to Tennessee, the Amish can help you. If you mean to do the system at your house here, I can help some and I have a friend who is an expert. A cheap way to get a lot of battery fast is use a used forklift battery. A friend of mine had a system that used 3 of these and he ran his whole house (no AC of course).

A good company to price alternative energy equipment is Kansas Windpower. You can find them on the web and they advertise in BWH mag.

Either way, read Home Power. It is free to download each month online--one of the best deals on the internet.

-- Rags (nobody@nowhere.org), February 21, 2002.

Oh, Lesley, a couple of things I forgot to tell you. An absolute rule of thumb is insulation and weatherproofing save money on the power bill. But NO alternative source can PRODUCE power more cheaply than the power company. That holds true for all forms of alternative generation and all power companies nationwide with the possible exceptions of California and possibly New England. The power company can always make power cheaper than you can. There are a lot of reasons to get off the grid, but saving money is not one of them.

Conservation is essential for any alternative system.

Also, I'm not sure you understand that to use power from batteries you need an inverter. And to run TV and computer you need a good inverter. Doreen mentioned her folks having a transfer panel.That's something else you must have if you use grid power some of the time and home power some of the time.

Solar panels can't be shadowed, either. They must be out from under trees and branches and have a clear southern exposure.

-- Rags (nobody@nowhere.org), February 21, 2002.

okay guys, I am not even close to an expert on this. BUT, we have a generator that could run a small city and it didn't cost anywhere near $20 K. It was a home made or put together. Basically it is a big generator driven by a diesal (sp?) engine in it's own little house. Recently we had an ice storm and were with out grid power for 8 days. We never missed a beat. We ran the ventilation fans on severel barns (10+), heaters, grain elevator, 3 freezers, refidgerator, washer and dryer, as well as dishwasher, central heating for the house and lights . Really roughing it I know......my kids were really disappointed that we didn't get to use the lanterns.

My hubby says that the generator itself was about $9K plus whatever the big diesal engine cost. No the fuel was not cheap.

-- Tana Mc (mcfarm@totelcsi.net), February 21, 2002.

Lesley: What Rags and the others say is correct. Especially about the insulation. Its ALOT cheaper to save energy than it is to make it.

In anticipation of going off grid someday, when we put this place up in 98 we planned for it. Y2K was right around the bend but we didn't have the $$ to do the whole thing right away. I had a Trace SW4855 (SW=sine wave, 48=48volts, 55=5500 watts) installed, 6 L16 batteries and a 5500 watt, Honda powered, generator. This cost about $7200. By the time the PV panels and a small Bergey wind generator is up it'll be close to $20,000.

If we need back-up power short term, the Trace inverter will automatically run the household 110VAC loads for about 12 hrs. The generator will charge the batteries in about 5 hrs.

-- john (natlivent@pcpros.net), February 21, 2002.

John, sounds like you've got a great setup. If you don't mind me asking, do you have any special low consumption appliances like a Staber washer or Sunfrost refrigerator? And does your state have net metering or any incentives for power generation equip? And what sort of wind genny do you recommend?

-- Rags (nobody@nowhere.org), February 22, 2002.

Rags: Bergey has come out with a "low cost" 1500 watt wind generator. Their Exels (1500 watt) are almost bullet proof but very pricey. But Bergeys in general have a great reputation. If the money is available that's likely what I'll go with.

No, we don't have any of the extremely low consumption appliances as yet but I've got a plan for long term electrical outages which will amount to extreme load management. I'd have to have two traces to get 220vac so the submersible water pump is 110vac.

This year I'm gonna be putting up a 30 panel hot water solar system. In mid winter around here I doubt if its gonna heat the house but spring and fall it should do the job well without supplemental heat from the wood boiler. I'll be storing the heat in a 750 gallon insulated tank thats in the basement and preheating the domestic hot water via a coil in the tank too.

Another thing under consideration is bio-diesel co-generation. Because we do have net metering I'd gross over $900/mo in electrical sales with a twenty KW gen set. Running 24/7 in the winter I'd generate about 49 million btus in waste heat too for use in either heating the house or the greenhouse. I've got this idea that if I could economically run the greenhouse all winter, keeping it above freezing with supplemental lighting, I could do real well with locally grown organic tomatos---about $3.00/lb around here.

-- john (natlivent@pcpros.net), February 22, 2002.

Rags, I'd like to disagree with you about the following statement you made: "But NO alternative source can PRODUCE power more cheaply than the power company"

There are some power sources where this is not true: Small hydro, if the site has a good high head. Passive solar space heating and design: there are lots of things that can be done for free or very cheaply which will produce power for the life of the home. Solar hot water: I heat all my water during about seven months per year: total cost of my system is less than $200. Photoelectric cells: yes, they are expensive to set up, but once they are in place, they produce power for almost no cost at all if you are on a direct interface to the grid (not using batteries, which are a major part of the expense of non interface system I agree with your statement that there are lots of reason to get off the grid that do not involve saving money, however.

John, and others, you're right on about conservation of energy being cheaper than producing energy, except for a couple of the examples above. Like solar hot water.

John, do you have a sunny winter climate? I thought about doing a solar hot water house heating system, but our insolation here is so close to zero for so much of the time that I decided not to.

BTW, for anyone who's interested, I wrote a fairly long tome about some basic design elements, and cheap design elements for home building. Over on Countryside, I suspect. There is a lot of stuff to do that costs next to nothing, and can result in enormous power savings.

Anyone know how to search the archives?

-- joj (jump@off.c), February 22, 2002.

There is a local school swimming pool heated by the waste heat from a diesel engine. And what does the diesel drive? It generates electricity that is sold to the grid. Apparently this is thought to be more economical than buying electicty to heat the pool.

Maybe the same principle would apply to homesteaders needing winter heat for a green house etc?

-- john hill (john@cnd.co.nz), February 22, 2002.

JOJ: I live in central wisconsin. I'd have to dig up the numbers for this area but just from observation I'd guess the solar system would operate maybe 20% of the time in winter months as the days are often overcast. I'm not real concerned about cost recovery however because the solar panels have cost me nothing so the main expense will be the piping and frame I'll mount it on.

-- john (natlivent@pcpros.net), February 22, 2002.

John Hill: What you're suggesting is called co-generation. By running the gen-set in winter and recovering the heat for space heating makes the whole endeavor ALOT more cost effective, considering roughly 2/3 of the energy that goes into the engine is "wasted" as heat and only 1/3 is used for mechanical power to drive the generator. If you were to do that however I'd get a good idea of your heat requirements and plan accordingly with ample insulated heat storage.

For example, I figure on using a 20KW unit hooked up to a VW Diesel. Lets say I use 1000 KWH/month in electricity. One KWH is equivalent to 3415BTU/hr. Multiply that by twenty and you get 68300 btu/hr in electricity but you also get 136600btu/hr in waste heat.

To meet the electrical demand of 1000KWH/month divide by 20kw and you get 50 hrs. To meet your entire electrical demand you'd have to run the gen set for 50 hrs. While you were doing that you'd also be generating about 6,800,000 btus of waste heat.

You'd be generating waste heat at a much faster rate than you'd be using it so it would be necessary to store it. An inexpensive source of heat storage is a bulk milk tank. They're already insulated and plumbed. I bought a 1500 gallon SS tank for $200. I figure it'll store about 1.5 million BTU.

-- john (natlivent@pcpros.net), February 22, 2002.

Whoops John, sorry I missed one of your earlier contributions where you had already mentioned co-generation.

-- john hill (john@cnd.co.nz), February 22, 2002.

Lesley, If you must have that much power to help keep your sanity, here's another option; A diesel powered generator that automatically starts the genny and transfers the load 5 seconds after the grid goes down. These are totally enclosed and only about 75db [sound]-reasonably. quiet. Daewoo has a 17 KW unit for around $9k and there are other comprable units. So you end up with a UPS----the grid goes down this genny takes over the WHOLE load! I have 2 wind electric generators [ I'm a Bergey dealer} also a KW of PV panels, big battery bank, a 240vac inverter....the whole works and it is a moderate sized system.......BUT...when you start asking for power to run 2 ac's a fridge etc. etc. you would have to have a VERY chunky system to do that!-Chunky means big bucks! So this diesel genny is a way to do it for around $10k--installed by an electrician. There are alot of good thoughts above...but the best one is Conservation! decisions......

-- Jim-mi (hartalteng@voyager.net), February 23, 2002.

JOJ, I agree with you. In the statement you quoted I was oversimplying to try to make the point to Lesley. And I meant producing strictly electric power, not all forms of energy like heat or motion.

None of the states Lesley might be considering down here would have utility intertie or net metering either. And most of our grid power is TVA and is relatively cheap. And the problem with most hydro down here is that even the smallest stream can at times get bigger than the Rio Grande and the Colorado put together. We have a similar problem with wind: it either doesn't blow or it blows 100 miles an hour. You should see how we guy wire TV antennaes down here.

But I am not arguing in any way with your points. They are correct and well taken.

-- Rags (nobody@nowhere.org), February 23, 2002.

You folks are ALL so incredibly knowledgeable! I deeply appreciate all of the responses. I should have been more clear though..the major reason I asked the question is that we are looking at a piece of property in TN in the middle of an Old Order Amish community. Since the Amish will not allow the electric company to run wires across their lands, there is zero electrical power available to this homestead, and there probably never will be any. We have many friends among the Amish and already know we would be welcomed there. We sat down and calculated how many electric "things" we use now and how we would like to live without any of them. The list was whittled down to power tools, computer, TV/VCR, and my love of at least the bedroom having AC capability....no AC, no buying this place. If I were in the SE section of TN in August without any AC at all, it would be BAD..LOL....anyway, there would be no grid to disconnect from..Here in AL, if we remain, we would like to explore some back-up power just because we do not admire the electric company and its habit of raising rates in the summer for captive audiences....the extra $ for putting in a generator/solar power system would come from the sale of this place in AL. BTW, the TN property is 28 acres with established fruit and nut trees, a house, workshop, barn, root cellar,chicken coop,woodshed, two year-round springs, new septic and an outhouse for $60K. Thanks again, we are both doing some rapid reading into generators, solar power, etc...

-- lesley (martchas@bellsouth.net), February 23, 2002.

Jim: That daewoo gen-set you mention, is that water cooled? If it was Lesley would be able to use it for heating also. I'm a big fan of co- generation.

Lesley, the place sounds really nice. Since you'd be starting from scratch, electrically speaking, the conservation advice is good advice, especially for the kindsa loads you're talking about. Think insulation and decent windows for the house which should reduce your AC load, maybe considerably, depending on those items in the house now.

In your situation whatever you wind up with you're gonna have to interact with it daily. You'll need to decide if you want a gen-set running all the time when you want electricity. If you don't you need to think of a battery back-up to run the smaller loads while the gen- set isn't running. The gen set Jim described would automatically start up when the batteries went down so how often the gen-set ran would depend on the load and the battery capacity.

-- john (natlivent@pcpros.net), February 23, 2002.

The Daewoo genn I mentioned is a totaly enclosed unit with a shipping weight of 3263 pounds. John I agree on cogeneration posibilitys....but I wouldn't want to void the warranty by changing anything. Lesley thats another ballgame-no grid. There's many smaller [5-6 kw] genn's with remote start capabilitys. Thats called a *Gen/verter* system. The inverter can be programed to start the genn when the battery voltage drops to a set point. then the gen charges the bat bank and powers the load untill the bats are recharged. Advantage here is that IF the load is not too heavy and bats are up---the genn wouldn't be running-read middle of the night---and the bats and inverter would power that light bulb--read middle of the night trip to the pottie! The HUGE fly in the ointment is the airconditioner nasty nasty load!!!! Also to this system you could add a DC input-read PV panels. BTW I bought a used 12vdc fridge from an Amish couple in southern Mich. I was wondering what the clattering noise was so he took me out to one of his outbuildings and there was a China diesel banging away!!........

-- Jim-mi (hartalteng@voyager.net), February 24, 2002.

john (natlivent@pcpros.net), I appreciate your explanation of the electrical and heat energy of your proposed system. I agree with your computations, for the most part.

I do wonder if you aren't leaving out an important piece of the energy "pie", though. Wouldn't there also be a fairly large percentage of energy wasted through inefficiencies in the combustion of the fuel, whether it be diesel or gasoline? Without figuring this, I believe you're coming up with 100% recovery of the potential energy in your fuel. I don't know how large this piece would be, but I assume it exists, and is significant.

Another thing I don't understand; you are probably figuring this right, but I still don't understand it:: if you need 1000 kwh per month, why do you need such a large generator? I assume you must be planning on utilizing a battery bank to store the power the generator produces for the time it's not running? Or are you planning an interface system?

Anyway, why not use a generator which is only large enough to handle your total monthly requirement? If you ran a genny 24/7, you'd be running it about five thousand hours per month. To get your 1000 kwh per month, you'd only need a 200 watt generator, according to my off the cuff calculations. The waste heat would be the same regardless of the size of your genny, but would maybe be more usable coming continously than only during 20 hours per month. Just a thought.

Either way, the cost of the "waste" heat generated, (6.8 million btus) would be about $58, at the arbitrary figure of $1.25 per gallon. The cost of the electricity would be about half that, according to your figures.

All in all, this sounds almost too good to be true. If you are really recovering even close to the full btu's out of the diesel, you'd be getting the electric power for about $29, which makes it cost you only 2.9 cents per kwh; I've yet to see any other source that cheap. Assuming your running costs aren't too high.

Have you checked to make sure that it is actually possible to recover such a high percentage of the 147,000 btus available in each gallon of diesel?

Sorry, this is a bit rambling, but I have enough trouble just writing clearly, much less writing and crunching numbers simultaneously...

-- joj (jump@off.c), February 25, 2002.

One other point, John. I think you may be able to store even more energy than you anticipate. You say it's 1500 gallons, so it would hold about 12,500 pounds of water. Assuming you're using water as the storage medium. So you'd get 12,500 btu storage for each degree you raise the water temp. To get 6.5 million btus of storage, you'd only have to raise the temp of the water 120 degrees; I'd think the heat coming off the diesel motor would raise the water temp even more than this.

What an interesting post, folks!

Rags, I agree with you about almost all electric sources. I'll still stand by my claim about photoelectric, though (if a person wants to cough up the big bucks for an intertie system, it WILL at least have a pay off period.

As far as whether a state has intertie or net metering, about thirty of them do, at present, I believe. However, even without the "official" intertie systems, there is this idea called "guerilla" solar. Check it out at www.homepower.com. Apparently a lot of folks, even in states where interties are allowed, prefer to "just do it", and avoid a lot of boo-ratic hassles. So, if a person is attached to the grid, he can do the intertie bit, with or without "permission" (and it's always easier to apologize than to get permission!) Just be sure to use the right equipment, and learn how to hook it all up safely, so as not to electrocute yourself or your friendly neighborhood lineman. There is a lot of good equipment out there, which is designe especially for this purpose, and has back ups on back ups on back ups. I highly recommend Homepower Magazine. I subscribe, just to support the magazine, but Richard Perez and crew feel so strongly about alternative energy that they put every issue on line for absolutely FREE!

On hydropower, extreme variability in water power, and especially wind power is the rule, rather than the exception. It is a situation which is fairly easily dealt with, actually, in most cases.

In fact, in the last couple or three decades, hydro equipment has become WAY cheaper, since expensive governors are no longer required to regulate the speed of the turbines/generators. Electronic controls have made it the norm for the system to generate power from low flow to medium flows instead of having to figure out what single flow rate to design the system for. What a breakthrough!

-- joj (jump@off.c), February 25, 2002.

Lesley, I see that an intertie system is obviously not an option at your "new" property. And I share your disdain for power companies. However, the one good thing they supply is the equivalent of a limitless battery bank, in the form of their electric grid. If you stay in AL, you can take advantage of this to eliminate the need for the expense, feeding and caring for batteries.

Btw, folks, as far as the overpowering air con load, have you considered a "geothermal" (or "ground source") heat pump for that purpose? I have one of these beasies, and love it. It's total power draw, at all times, is 14 amps at 240 volts, for a three ton unit. (just over 3 kw). Not a small load, but not too bad for a three ton, I don't think.

I actually rarely ever use the cooling function of the heat pump, but run it an hour or two every winter morning to heat the house before getting up and building a fire (getting spoiled in my old age, I guess). The heating funcion of the heat pump is 395% efficient, according to the specs. I don't remember the specs on the cooling end of the curve, but it's gotta be better than a "regular" aircon. (course, my groundwater is 52 degrees, which makes it more efficient than it would probably be in the "deep south"; don't know what the groundwater temp is in Tenn.

I suspect a person could put in a lot smaller unit than my three ton, to keep the power draw down, too, and maybe not aircondition the entire house, or something? (my house is about 3000 square feet)

-- joj (jump@off.c), February 25, 2002.

Boy, that boy do ramble!

Since no one went and found my bit in the archives, or wherever, I remembered that I'd saved an email I sent to the local paper not long ago. Here it is; some of these ideas are tried and true; others are suggestions:

For temperate climates:

Design your house as much as possible with all the rooms you spend a lot of time in along the south wall, and spaces like stairways, laundry garage, etc. along the north side.

Put nearly all your windows on the south wall

Design the house so that the east west axis is about half again as long as the north south axis. This will maximize solar gain in winter, while minimizing it in winter.

Leave as many trees as possible around east, west and north sides of house. These (especially the east and west) will provide good shading in the summer, but not block the solar gain in the winter, because of where the sun rises and sets in different seasons. They will also provide protection from the wind in the winter.

If there's not adequate shading on east and west, build extra large overhangs on east and west roofs for summer shade. Balconies can also be useful for shading in this way.

Make sure you have enough windows (I also recommend a whole house fan) to cool off the house at night. Close windows and drapes after house cools down to keep house cool in summer. This works especially well in dry summer climates, where there is usually a large diurnal temperature fluctuation.

Consider an attached greenhouse along the south side of house. This will help heat house when it's sunny, and will provide a tempered space along this side of house, helping to keep your heating bills low, even at night and during inclement weather. Waste heat from the house will help keep greenhouse warm, too. (I've only ever had to heat my greenhouse a total of two hours in four and a half years, because of this phenomenon)

Make sure you have plenty of ventilation in your attic, for keeping house cool in summer.

Install a heat exchanger gizmo to recover 50-85% of the energy used to heat the water you use in your shower (and possibly other areas)

Build, or buy, a solar water heater--big energy saver.

Install a wood heater, if you have a source of wood. For emergency power, it can't be beat (make sure it does not require electricity to run, though, as some, e.g. pellet stoves, do.) Firewood is a form of solar energy, by the way.

Design your landscaping and install underground sprinklers before doing finish grading. Install automatic sprinler system-one little accident (like forgetting to turn off the water overnight) can waste as much water as you would otherwise use the rest of the irrigation season. It also allows you to use water at all times in a more efficient way, thus reducing your water bills, and protecting your aquifer.

If you are using a slab floor, consider installing pipes in the slab through which all your irrigation water passes, to cool off the slab in the summer.

Install an air inlet for the wood heater under the floor, which puts fresh air right next to the heater. This will avoid cold drafts coming around doors and windows.

Consider installing a "geothermal" (ground source) heat pump. They are as much as 400% efficient! They are expensive to buy, but the payback can be fairly short, depending on your individual situation.

Evaluate the solar potential of your building site. Avoid building in a frost pocket (I did this on one house, and there was a temperature differential of as much as 28 degrees between my house site and my mailbox, which was 180 feet away)

It’s often significantly colder in valley bottoms than on hillsides during the winter, which means higher heating requirements for the valley bottom house. This is especially true early in the morning.

Consider earth sheltering; while it's nice to cover the walls and the roof, you can cover only the walls, avoiding a lot of expense, and still have a very significant effect on heating and cooling. My house stays so cool, even though it's only earth sheltered downstairs, that we have only used the air con about five hours per summer. And my place is only earth sheltered downstairs.

Evaluate the overhangs on your south wall, for shading in summer and solar gain in winter.

Try to place water heater as close as possible to the points of use. Consider a small, separate water heater for very distant points of use.

Buy, borrow, or check out from the library, THE PASSIVE SOLAR ENERGY BOOK, by Edward Mazria. Read it; it's got lots of other good suggestions, energy charts, solar charts, etc. Published by Rodale Press, interestingly enough.

-- joj (jump@off.c), February 25, 2002.

Great info, Joe, this is getting to be a great thread.

-- Rags (nobody@nowhere.org), February 25, 2002.

This is DEFINITELY getting printed and put in the file. Thank you all so much!!!

-- Doreen (bisquit@here.com), February 25, 2002.