Alternatives, Renewables, and a home project : LUSENET : Renewable Energy / Home Power : One Thread

Here's an issue that's been befuddling me for awhile.

There's an obvious distinction between renewable energy sources and alternative energy sources. Renewables would include solar, hydro, and wind. Energy sources such as fuel cells and microturbines fall more into a category of "alternative energy", simply because all require the use of a non-renewable resource (ex: natural gas; propane).

There's two approaches to homepower, I think. One is the purist's view, which is taking advantage of only true renewable energy resources. The other is from a pragmatic perspective, which takes advantage of a combination of renewable and alternative energy resources.

You're going to get to follow me in my pursuit for more energy self-sufficiency over the next 12 months. I'll be expanding upon my Y2k-inspired home energy system in full public view on the website, and I think that the pragmatic approach is the way to go. Let me give you the particulars, and then any suggestions from the community would be most welcomed.

Here's what I have now: 200 amp service grid connection, with a 60 amp GenTran transfer switch/subpanel assembly, and a 6500 watt gas powered generator (a noisy little sucker in a suburban environment, to be sure) as an emergency power system. My house is relatively wired - in the summer, with the central a/c (3 ton unit) and pool filter running, my usage easily exceeds 1200KwHr/month. So, my first quest will be to replace some of my major appliances (particularly the a/c unit and the 6 year old 22cuft refer/freezer combo) with something much more economical. Also, some "bad habits" may have to be relearned - drying clothes on the line, and washing dishes by hand more often than using the dishwasher come immediately to mind.

My initial thoughts are to start with the "emergency power" circuits - the circuits I determined were vital loads in the house, and the ones that are wired to the GenTran subpanel. The GenTran has 6 circuits, and there are watt meters on the ABC leg and the DEF leg. I rarely exceed 1500W on either leg, although both are peak rated at 3000W. The starting point will be a small solar array (two 90W panels), deep cycle batteries, and a small inverter (a Trace 1750W or something similar) tied into the circuits DEF leg, which is normally pulling between 200 and 400w/hr unless the washing machine is running. I can then remove that leg totally from the grid. I realize that two 90W solar panels are probably not going to provide sufficient charging capability to handle all loads on that leg 24X7, so I may have to juggle some loads, and supplement the charging with the genny for the time being. Once I've done that successfully, then I can mirror what I've done onto the ABC leg circuits, or trade up to a system that will acceptably handle both legs.

That doesn't take care of my "monster" loads, though, off of the main panel. For those, I think it's going to be necessary to start playing with some alternative energy sources rather than renewables. By the time I'm ready to go there, I'm hoping that I'll be able to lay my hands on one of the demonstration fuel cells that will be on the market (maybe wishful thinking on my part). Certainly, a high efficiency heat pump system may be in the cards to replace the A/C unit, and I've gotta dump the electric range/oven. Other than that, I have no other 240V loads in the house.

So, there's my initial thoughts. Your constructive criticism would be welcome, as would any derisive comments. ;-) This project commences at the end of April, so I have plenty of time to plan, research, adjust plans, and acquire material.

-- Rick Cowles (, February 16, 2000


Two 90W panels, Rick? You better be thinking in terms of at least 6, IMHO. I'll chase down some sizing numbers for you, and post back later, but 2 ain't gonna cut what you're looking to do. Also, I've got some recommendations on what ones to look at, if you'd like.

When you find a place to get a demo fuel cell let me know, my friend - I want one of them suckers,

-- Dan Webster (, February 16, 2000.


I agree with your thinking that a combination of renewable and alternative energy resources makes sense. At our house, we're considering a propane stove as replacement to our old electric appliance.

Our goal (Wilmington, North Carolina)is to design and build a system that satisfies our needs independent of grid supplied electricity.

As first steps in the learning process, we're going to go through several evaluation plans to get comfortable that we've adequately addressed our needs. Once we have our usage history mapped, we'll figure out how to pare down. We've already started by replacing incandescants with compact flourescents.

Here's the online resources I'm using now:
For a comprehensive guide to system planning, check out Sunelco.

For a Site Evaluation and Load Information Sheet, check out Oasis Montana Inc.

This installation checklist helps evaluate your property. It's at

There's a clear introduction and system sizing worksheet at EV Solar Products.

Finally, a simple step-by-step Solar Evaluation is provided by Solar Electric Inc
I'll let you know what we've learned after we've tried all five offerings.

"Getting the right mix of fire"

-- Critt Jarvis (, February 17, 2000.

Hi, Rick,

I've been checking in every few days; glad to see a new post!

Re alternative vs. renewable, I think it's a valid distinction, althout many of them are really a mixture; for instance, if you use solar panels, and especially the batteries that usually go with them, is it really TOTALLY renewable? After all, it is necessary to replace the equipment when it wears out, and that is done with non renewable resources.

I'd also like to add WOOD to your list of renewable resources. If you cut the wood with hand tools, I would consider it totally renewable, I guess, but if you use a chain saw, it would be kind of like the solar; you would be using gasoline, oil and replacement chainsaw parts, which are non renewable. I'm probably being overly picky here, so I don't need an answer, unless you want to be picky too.

BTW, I consider wood to be a stored form of solar. And I like this form of power storage a lot better than any chemical batteries I have yet experienced.

Regarding your high efficiency heat pump, I have, as you know, such a beast. I love it. The ironic thing is that I didn't want to pay for it, but was talked into it by my wife, because of her concerns about the very hot, sunny location where we built the house. My plan was to heat with wood, since we have a fairly large, wooded lot.

During our first winter, though, and before I had purchased a woodheater, I fell hopelessly in love with the heat pump. (it's a ground source, for those of you who have not read my previous posts), Now, I let the heat pump come on automatically at whatever time it feels appropriate to bring the house to 71 degrees by 7:00 a.m., when we wake up, then it doesn't run until the next day. That translates to about 30-40 cents per day to run it in the winter. It's a three ton.

Now, the ironic part. The house I built, having been planned out for a year, being earth sheltered downstairs, being well insulated, and having a WONDERFUL whole house fan, doesn't really need the heat pump for air conditioning. Since I'm a male in my fifties, I usually get up at least once a night, and when I do, usually around five or six in the morning, I turn on the whole house fan. Since we have low humidity, with resulatant cool night time temps in the summer, the fan, plus leaving the windows open all night, results in my generally being able to lower the inside temp into the low sixties. The fan will actully lower the temp by ten or more degrees in less than an hour.

Our total run time for the heat pump for cooling is less than twenty hours in two summers! (That translates to $3.60 total cost for two years of cooling)

I don't know what all your "monster loads" are, but I would think that one of them would be water heating. Would this qualify as a monster load?

Regardless, I'd certainly recommend building a solar water heater for at least the frost free months. That is an area which is hundreds of times as cost efficient as solar electric.

Another item we could all consider is wood powered hot water in the cold months. I built, twenty years or so ago, such a device, which heated both the house and the hot water. It heated so much water that we had to dump a bathtub full once of twice a day, after the kids grew up and left home. I have to admit, though, that this home made water/ space heater was nowhere near as efficient as the new wood heaters on the market, such as my Quadrafire.

If I had it to do over, and I may yet do so, I'd have a Quadrafire, or equally efficient, heater for space heating (obviously, in addition to a good passive solar design) and a separate wood powered water heater. There is a wood powered water heater listed somewhere, I'm pretty sure it's in Real Goods, and would be happy to find the article, should someone be interested. That way, the one applicance capable of high efficiency (the space heater) would not be compromised by having to heat water at the same time. I really think the water jacket I incorporated into my home made water/space heater caused the firebox temperature to be too low to be efficient. (not to mention that I had no idea of how to build an efficient wood heater in the first place)

By the way, I don't want to turn this into a sales forum, but I'm planning to market my solar water heater plans by the end of next summer. They are tried and true, but I am going to do some monitoring and a couple of small desing improvements this summer before marketing them.

Rick, if this last statement is out of line, feel free to delete it; I certainly won't be offended, and don't want to offend anyone else by this pseudo marketing statement.


-- jumpoff joe (, February 18, 2000.

Gosh Rick, I'd be honored if you would have a look at one of our systems. These are an integrated system of batteries, inverter, control electronics in an attractive bookshelf type unit. The Gen-Tran switch is a perfect way to "grow" into energy self sufficiency as you can switch on one circuit at a time as your capacity increases! Please give me your snail mail address, I'll shoot some information to you. Jim (Pierce Independent Power Systems)

-- James S. Baughman (, February 26, 2000.


for your main line stuff, something to consider.
1) replacing the electric stove oven may make sense, but if you convert to gas, you may find yourself caught in a developing propane/nat gas shortage over the next few years. At the least, steeply rising prices. I am thinking of making methane from animal waste (dogs - large, and chickens) supplemented with bio mass.
Also, new light ovens are coming out that are very efficient users of electricity.

2) upgrade the dishwasher. It is a false economy to do dishes by hand. You use more juice as you are not as efficient at hot water usage.
3)you have 120 hotwater heater?

think of two inverters. This way you can segment lights, et cetera from induction loads likely to cause fluctuations or brownouts. Also two inverters imply some level of redundancy for surety. When one breaks down, the other can hold you over.

-- Cliff High (, March 13, 2000.


The nat gas situation is a bit of a concern, but I feel reasonably comfortable that there won't be any supply interruptions. Might pay more, but a gas stove/oven is still much more economical to operate in the short and long run, I think. Methane simply isn't an option in a suburban environment. ;-) I think the neighbors would complain. I compost, but that goes right into the flower beds.

My furnace is a bit of a unique animal - a Columbia gas fired steam boiler. The only electricity is 120vac/12vdc for the controls.

One of the things I definately don't want to do is throw all of my energy eggs in one basket. I want to maintain a decent mix, and will ultimately have some redundancy and flexibility in my systems.

Thanks for the input - the quest begins in earnest shortly...

-- Rick Cowles (, March 14, 2000.

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