Are you off the Grid?

[hayden]

Clint, I've got a second home that's off the grid. It's solar powered with a backup generator, and I plan to add a small hyro plant in the next few years.

Regarding the economics, your comparison is unfortunately apples to oranges. As I go through this, keep in mind that I'm a fan of solar/hydro and locally generated power.

A solar setup that can produce the same power that you use today (and pay $100+ per month) will cost way more than $30k. A $30k solar setup would have to be coupled with significant power consumption reductions in your home. Of course if you make those same reductions, your $100 power bill will drop too. It unfortunately turns out that the per KWH cost of commercial power is still below that of solar (figuring the solar cost of a 30 year period).

Turns out there's another fly in the ointment. Batteries. They have a limited life, and are expensive. Just the cost of the batteries assuming a 10 year life gets you close to many grid power rates.

Where I've found independent power to make clear economic sense is where a house is a distance from commercial power and the up front cost of running power lines is the same or greater than the cost of installing solar or some other independent power generation. This was my case and the economics are unquestionable.

I can see all this changing over time. Grid power is costing more and more, and solar is dropping in cost. They keep getting closer and closer, and as the solar control technology continues to improve, it makes solar as seamless to use as grid power.

I've found that just going through the exercise of figuring out where all your power is going will make you a more efficient consumer. You can save energy and money starting today, and start the process of readying your home for solar.

Enjoy it, it's lots of fun.

 

[hayden]

There's another way to do this as well. It's called a ram pump or something like that. I don't know all the details, but essentially you take a portion of the energy from flowing water, and use it to pump a fraction of the water. The pumped water can be used as presurized domestic water, or can be converted to electricity. The waterwheel principal is the same, but with a different mechanism.

This approach basically let's you convert water flow into water pressure. Water has energy based on it's mass (how much water), and the distance it's dropping. Lot's of water with a small drop still contains lots of energy, but low water pressure. Domestic water use requires 15+ psi of pressure. Harnessing some of the low pressure water energy can be used to pump some of the water up to a higher pressure. There are a number of mechanisms to accomplish this conversion. You described a water wheel powering a pump. There's also this funky thing called a water ram pump.

 

[rationalizer]

One more thing to think about is "cost of money". Several notes have compared "one time up front investments" in solar equipment to the "monthly bill" being paid each month for 30 years etc. This isn't a fair comparison - and makes solar look more attractive than it really is.

If you put the $30K (or whatever) in the bank you should earn "some interest" (I know - these days that is wishfull thinking /forums/images/graemlins/frown.gif - but "typical" rates should apply over a 30 year timeframe) So - if you actually had the $30k today and put it in the bank you might be able to pay for your energy costs out of the interest - and still have the $30k or more left at the end of the 30 years...
Mass produced energy is very cheap....

Bill

 

[TWINKLE_TOES]

<font color="blue"> I plan to add a small hyro plant </font>
Nigel Smith wrote a book "Motors as Generators fo Micro Hydro Power". (on Amazon) He has done a great deal of work in developing Hydro power in third world countries where the economics and maintenance are big factors. He explains how to use three phase motors as generators driving Pelton wheels.

 

[StoneHeartFarm]

</font><font color="blue" class="small">( I met this guy who was going to pump water with his well to run a hydro generator. I asked him where the electrity was going to come from to run the well pump?----this dude clearly failed grade school science. J )</font>

Sounds like the same guy I talked to. He wanted to put an electric motor on a windmill. When the wind was blowing, the windmill would make electricity. When the wind wasn't blowing, the motor would turn the windmill, thereby making electricity.

He also wanted to dig a hole into the bank down by the river. He figured he could live there for the summer and not have to pay any rent. Neeedless to say, he was not impressed when I suggested that instead of diggin a hole, he should get a precast septic tank to live in.
/forums/images/graemlins/smile.gif

Steve

 

[hayden]

I'll check it out - thanks

 

[TWINKLE_TOES]

What kind of flow and head do you think you may be able to achieve?

 

[hayden]

I can get 100 feet of head (elevation), maybe more depending on how long I'm willing to make the pipeline. It will be a minimum of around 1200ft and that's a lot of digging.

I also did a very rough measurement of water flow a few winters ago before the droughts and figured I could draw off 30 gal/ min without seriously altering the flow in the stream. According to my books, that should yield a continuous 300 to 350W depending on the type of alternator used. That's gobs and gobs of power for my needs.

My thinking is to run the hydro hard in the winter when there's plenty of water and not much sun, then actually shut it down in the summer since at least the past two years the stream has run so low it wouldn't produce any power. But of course the sun is plentify in the summer so I think the two systems will compliment each other nicely across all seasons.

By the way, I ordered that book yesterday - thanks again for the tip.

 

[TWINKLE_TOES]

Fun project Hayden I'm envious. I have plenty of water head but no depenable flow. Varies from 100's of gallons per minute to zip. This link, which you probably already have, has lots of design information. Micro Hydro
I looked up your configuration and your right on @ 300-350 watts. For 100 feet of head, (no head loss figured) your are at 43 PSI. For 30 GPM you need a 3/8 nozzle which will give you a turbine speed of 2070 RPM. Good luck, post your progress.

 

[Cacinok]

I appreciate all of the posts. I have been doing some more research and here is what I have found.

Hayden, my $30k number that I used in my last example was based upon what previous posters had said they priced out systems at. I did some research and this is a valid number. I found two kits, one solar about 280 square feet worth and one wind (batteries included). When pricing I leaned toward the higher powered set ups and my price came in at $25k.

What seems to be the most important in trying to get off the grid is to reduce your electrical consumption. Many of the "off the grid homes" I read about used between 500 and 900 kWH/ month.

Rationalizer, you could put 30k in the bank an get interest off of it, but by the time you paid taxes the money would not cover my yearly electric bill.

Clint.

 

[Anonymous Poster]

I just wish you were near my place...give me $30K and I will put you on my grid for life. Costs me $4 a day to be on the evil grid, never worry about how or why it works, just write a check. Is it cheaper to own a cow, or buy a gallon of milk every couple days?

 

[ejb]

>>Is it cheaper to own a cow, or buy a gallon of milk every couple days?


In many cases it is cheaper to hire someone with a tractor than to buy one yourself too... /forums/images/graemlins/smile.gif

 

[Egon]

Just curious on what officialdom has to say about useing public water such as streams?

Egon

 

[dmccarty]

HazMat,

The latest issue of Car and Driver had a review of a hydrogen
powered car.

What was interesting was the side bar talking about the use
of hydrogen as a fuel. If one compared H to the gas/diesel
then H really was a good performer. But if on compared the
true cost of H to diesel, H was only about 10% more effiecient
than the Big D. /forums/images/graemlins/grin.gif At least that is the way I read their
poorly written blurb. /forums/images/graemlins/smile.gif Given the problems with using H as
a fuel source 10% just don't get it done...

For people to really use solar cells their price has to drop
dramatically. This can happen pretty easily if the Feds would
require the power companies to buy back power from
individuals on a 1 for 1 basis. In other words, if it cost me $1
to buy X amount of power and I produce power via solar then
the power company should buy back the power from me
at $1 for every X. What one could end up doing is using the
grid to store your power. The Grid is the battery. Course if
the grid goes away you have a problem but using the Grid for
storage would lower the price of solar power.

Some states already have this buying setup in place but most
do not.

If this was in place plus some tax breaks for the individuals
many new power plants might not have to be built since
they would be on millions of roof tops.... NIMBY would go
away to some extent....

Another 2 cents....
Dan

 

[wasabi]

I built a passive solar house in the sixties that actually looked like a normal house....cedar siding, cedar shakes and such. Lots of south facing glazing, thermal curtains, super insulation, thermal mass and a water source heat pump. Got it good and efficient, then promptly sold it and moved south. /forums/images/graemlins/tongue.gif

I too am researching and here is my .02. Dan put his finger on the essentials....unless you are out to make a social or political statement, it boils down to payback timeframe.

Most efficient of all is hydro...a couple hundred GPM with a hundred or so foot of fall can generate all the juice needed. I figure by doing most work myself, using the grid as a virtual battery, I should get in for under 12K with a ten to twelve year payback...after that with exception of maint costs, the power is free. /forums/images/graemlins/grin.gif ...but, as with all of life, easier to talk about than do it....I'll let you know when I flip the switch. /forums/images/graemlins/smirk.gif

IMHO, if we wait about three years, stationary fuel cell systems will be availaible...the lead mfgr as far as I know is a company called Plug Power....in an exclusive marketing agreement with GE. These things are already being sold commercially here in the states and for residential use in Japan. (Maybe their emergence is why the power companies were so anxious to sell the California power grid infrastructure to taxpayers /forums/images/graemlins/shocked.gif /forums/images/graemlins/grin.gif)

 

[Anonymous Poster]

Check this one out, www.capstoneturbine.com
Perfect if you have a gas well on your property.

 

[Cacinok]

Dan, I agree with you 100% on the buy back. I like the way you described the grid as a battery, I had not looked at it from that angle. I believe the Maine house that I referenced in one of my previous posts functions that way. I read that they come out about 500-1000 kwh ahead at the end of the year, Maine has an annualized buy back program.

Egon, re: changing/daming (sp?) streams -- each state can set it's own regulations (in general) -- w/i each state (for the most part) the counties/cities can add on additional restrictions -- so in short there are too many variables to say what you can and can't do.

Where I'm at you can change the stream as long as it doesn't fall under a handful of exceptions.

Wasabi, do you have any details about your future hydro setup? I'd be interest to hear details if you thought it out that far.

Clint.

 

[dmccarty]

Clint,

I have been perusing through the class materials from the
Solar course I took last year. I'm going to throw out some
pieces of info that are in the materials.

Cost of PV over time. Its a chart but in 1975 PVs cost over
$88/watt. In 1990 the cost was $10/watt and in 2000 the
price per watt was $4.5.

Standard PV are now $4.25 per watt with a 25 year warranty.

Thin film PV are $16.5/watt.

PV laminate for metal roofing is $4.5/watt.

PV shingles are $4.5/watt.

A new two story 1,700 square foot house in my area uses
6,000 KWh of power per year.

It would take 517 square feet of roof area on a southern
exposure to produce 2,740 watts with a PV metal roof. The
array would produce 3,000 KWh/year.

This system would cost $25,000. I'm going to check my next
power bill to see how much we are using.

FYI.

Later,
Dan McCarty

 

[hayden]

Wow, another good website. Keep them coming. The book you recommended arrived while I was travelling this past week and I strarted reading it last night.

Don't hold your breath on my project - I expect it's a 2-3 year undertaking.

 

[hayden]

I don't disagree with the prices at all - my system cost in that range - actually a bit less. The thing I want to be sure you know, and I think you do, is that the $25k solar system will not produce anywhere near the power that the same $$ would buy in comercial power. You are correct that the first step to converting to solar is reducing consumption, and that's a good thing to do regardless of whether you convert or not.