OT, solar power.

[dsergison]

I have outrageous utility bills. like $400-$600 a month on my house.

I have several loads tha really only need to run when it's hot and sunny. a 1 hp pool pump. a 1/4 hp pond pump. and a pair of central AC.

I have a flat roof of at least 3,000 sf. (on a house of 1,800sf) it has 4' overhang eaves and a large carport area.

so I went looking for PV solar stuff. I had visions of sellling power back (illinois has net meetering)

holy sticker shock!!!!! $30,000 for a 5kw grid tie system (you install)

they are all around $6 a watt. seems like a looooong ROI. but they say they last forever.

I had hoped that the energy savings would make the payments for 3-5 year loan. I see that's not even close. (well I havent actually calculated it, but it looks way off)


anyone tried this? what's your experience.

[Jackmo]

Check with your state to see if they offer any rebates or tax breaks. The Feds might also offer help.

In MA. they have programs to help both communities & individuals.

Jackmo

[hesstool]

IIRC, Kustomizer converted his shop to PV and it was seriously expensive. Maybe he'll chime in tell his story again.

[surplusjohn]

have you considered using your pool as a heat sink for your AC? how about solar control film for your windows or awnings or shade cloth. I am adding exterior shade cloth covers that can be rolled down over a few windows that really bake the house in summer. I experimented with this last summer with cotton simply tacked up over the windows and it made a hugh difference. Lowes sells the shade fabric that reduces tansmission by 75%, trick is keeping outside the house vs a shade inside the window.

[sch]

Windpower might be a bit cheaper and Illinois may not be
a bad place for it, depending on the average windspeed
in your area. Not well correlated with sunlight however.
Still talking $5-20k depending on size. Urbanites probably
would take exception to an 800rpm turbine 60' in the air
in the back yard of the neighbor however.
http://www.homepower.com/article/?fi..._pg34_Sagrillo

[dsergison]

about the pool . i though i might heat it. my entire yard is full of great big trees, so it gets very little sun. about 2 hours. but the flat roof gets almost totally full sun.

so I thought I would Y off the pump return with a 1" or so plastic waterline over to the house and up on the roof, and maybe just throw a big coil of black plastic tubing up there.
I had not figured on anything hight tech there. just back plastic pipe.

I lost my chance at free goethermal install. when I moved in 8 years ago I had the septic bed replaced. I coulda-woulda-shoulda thrown a bunch of plastic line in the pit before the gravel and tile went down.

[mark thomas]

I've researched this a bit both for home and work. What I found is that five year ROI is just not a realistic expectation for any generation system (solar, wind, higher efficiency retrofits, whatever.) Ten to twenty years is typical, and the shorter end of the spectrum normally achieved only with Fed and/or State and/or utility credits of various sorts. However, typically these ROI calcs assume reasonably constant energy costs, which has historically been the case, but a pessimistic (optimistic?) projection of future energy cost increases can shorten the ROI, and increase the post-ROI savings.

The idea that solar systems will last forever is pretty dubious however.

[surplusjohn]

D. 35 years ago I built pools and did a few modifications doing just what you suggested, works great. all you need is 50 foot or more of pe tubing and a bypass valve set up, only run it in the day otherwise it will cool your pool. no need to cover the tube with plastic, it will get plenty hot.

[rayman]

One way to save money is not to run you pool pump 24/7. I used run mine (24' dia. above gground) two hours a day - noon and midnight. The thing is that you have to stay on top of the chlorine. I had a floater with the small tabs tethered near the inlet to the pool. It was one of the easiest things ever I had to take care of.

[SteveF]

Originally Posted by dsergison

I lost my chance at free goethermal install. when I moved in 8 years ago I had the septic bed replaced. I coulda-woulda-shoulda thrown a bunch of plastic line in the pit before the gravel and tile went down.

Don't kick yourself too much. The septic trench wasn't deep enough and plastic pipe buried in gravel in a bad idea.

Steve.

[surplusjohn]

good point Ray. There is no reason to run your pump all the time. A 1 hp pump running 24/7 would cost me about 80 bucks a month alone. 3 or 4 hours a day if you have the right chemicals.

[dsergison]

it was a whole septic field . 4' deep. and 20' x 30' or so.

but thanks. I know the heat transfer to gravel sucks. but at least it would have been wet poopy gravel. actually I woud have put a little earth over it before covering with gravel.


it all just happened too fast. the diggers came......I saw the hole after work, and though hey..... what can I do to take advantage of this? the next day it was filled back in.



I dont run it 24-7. maybe 2-4 hours a day. but runing for "free" would be nice. $6000 buys a 1kw system
http://www.affordable-solar.com/kaco...tie-system.htm
I could run it a couple hours in the morning with this.. and run an air conditioner with it the rest of the day ?

I need to figure out the power consumption of my air conditioner. and the sun rating for my location

[gradstdnt_99]

Check these guys out. They take the up front costs out of solar. Intestesting business model. I don't have any first hand experience.

http://renu.citizenre.com/index.php?c=1213805395

[Billy Boy]

$6/watt is pretty high for just panels. I would shop around a bit. Of course, the real trade off is in sq feet/watt. The panels that generate more power from less space are considerably more expencive than the cheap $4/watt system that needs lots of sq feet.

If the grid tie is calced back into your $6/watt the deal is probably decent. Who ever is selling this stuff to you ought to have a pretty good idea of the various discounts that are available in your area from the fed, state, and local govs.

But the truth is that home solar is not really presently an economical source of electricity when compared to the grid. The places where solar makes the most sense are in non-grid tied apps. Generally the solar market rises and falls pretty directly with subsidy structures. When California put their old subsidies in place, installations sky rocketed. The state gov was bleeding money on the program, and so they restructured the subsidies... and demand dried up. I'm not sure if this is still true, but the largest market for solar in the world is (used to be?) Germany... not because they've got much sun (they don't) but because of generous subsidies. Without the German subsidies, solar technology and production would still be totally fringe. The Germans have really done a great deed in helping the industry get off the ground, and German politics seems capable of carrying the burden.

Wind is cheaper (per watt) up front, and depending on your net metering arrangement, the time of day might not matter a bit. But the windmills have moving parts and don't carry the 25 year warranty that solar panels often do, so the economics in the end are usually comparable.

Still, there is just no electricity that is cheaper than coal power provisioned over the grid (given that the large costs to society are not counted in the equation). If there were something out there, lord knows folks would be soaking it up as fast as they could! Folks who install solar/wind etc. are generally not doing it for purely economical reasons. Perhaps some are betting on sharp rises in electrical costs. Most are just trying to do good.

If economics are your only driver, your best bet by far is investment in energy efficiency.

Good luck.

B

[dsergison]

thanks. that pretty well sums up what I have found.

6$/watt was whole system, inverter, wires, etc... 4$/watt is the pannels.

I have to think that the solar manufacturers simply price their components at just as high as they can. which is pretty much just barely economically feasible WITH all the rebates/incentives you can get.

how can you buy a fast new computer system for less than a single solar pannel?
are they really that materials or labor intensive?

[John Madarasz]

You could heat your pool and home with a used unit. Capstone is the world leader in Microturbines, although for residential home they recommend wind turbines I expect a lot of shops, and manufacturing facilities, will begin to use these more and more as the price of oil maintains a new floor around $100 bbl in the years to come.

http://www.globalmicroturbine.com/Si...roturbine.html

http://www.globalmicroturbine.com/Si...d_Turbine.html

[MBensema]

This article was run in the local paper a couple weeks ago, price of the system is similar to what you are seeing, but he got significant reductions in the cost from the rebates. Might give you some ideas on how to make it more affordable.

http://www.newstimes.com/ci_9527293?....newstimes.com

I looked into windpower to help offset some costs, but even with great wind where we live, it would take about 10 years or more to pay off any of the turbines. I ended up putting a timer on our electric water heater and noticed an immediate savings of about $15-20 per month and paid off the timer in two months. We also save A/C costs by opening the windows at night to cool the house and closing all of them first thing in the morning as well as keeping the shades closed. Except for a few days a year when it is really humid, we don't need to run the A/C and longer.

[Billy Boy]

The cost of solar is primarily to do with the cost of materials... silicon wafers. The other major cost is capital cost.

Think about the amount of silicon that is in a solar panel, and then think about the amount of silicon in a computer chip. As a gauge note, that solar panels are generally quoted in sq feet or sq meters. Computer chips are working with silicon wafers that are generally measured in mils or millimeters.

B

[Lenord]

http://www.abcsolar.com/residential_solar.html


FWIW
Lenord

[SteveF]

Originally Posted by dsergison

but thanks. I know the heat transfer to gravel sucks. but at least it would have been wet poopy gravel. actually I woud have put a little earth over it before covering with gravel.

It's not the heat transfer that's the problem. It's the plastic pipe vibrating from water flowing through against sharp gravel which wears through and makes it leak.

For the amount of electricity you are using you should call the power company and see if they have a power meter you could borrow to see exactly where your power is being used. Borrowed one once and checked things around my house. Pretty educational.

Steve.