PV solar is still basically for backup and/or far-from-grid applications.

And, even then, it is for restricted power levels.

The system that would allow you to act as if the power came from the grid, power-draw-wise, would be extremely expensive, and essentially cannot pay back when gaged against even some significant future increases of rates.

However, the equipment lasts.

I had to replace solar cells a couple years ago, NOT from fall-off of power, but due to fall-on of tree.... Those panels had been installed almost 15 years, and were NOT new then, they came from the Carrizo experimental power plant. I still have the old ones, but 3 of 4 are physically cracked. I can probably salvage a lot of the cells, if I can dissolve the glue, but the tempered glass is toast.

I need to replace batteries this year...... they are 16+ years old, and have had some abuse. Trojan T-105s. They don't get a good gravity anymore, and are basically at end-of life now.

I consider that the system lasted very well.

Not only that, but in my experience if gravel made a heavy indentation on the pipe, even if it was not sharp enough to wear into the pipe, it would eventually crack at that indentation. It seems as though my pipe would crack wherever it was seriously deformed.

I finally dug up all my plastic pipe and replaced it. By the time I got around to doing it, the old stuff had repairs every three or four feet. Now, I have a lifetime supply of salvaged hose clamps.

Orrin

A nephew of mine lives in California and works for Pacific Gas and Electric. Not only is he a tech whiz, his job gives him the inside track to all the subsidies and deals available for installing a solar system.

His home is solar and built with conservation in mind. He hasn't paid a power bill in ages. Granted, he is a bachelor so he doesn't have the energy needs of the average family; but, his experience shows that solar pays dividends. IIRC, he usually gets a check from PG&E for his excess energy, even though he lives in Northern California where sunshine can be scarce in the winter.

Orrin

We have a 30kw system running our plave, with rebates and tax deductions we expecy it to pay for itself in about 6 to 8 years from the install date( about 3 years ago), most of the incentives in California seem to be for business not residential, here it would take fourty forevers to pay for a system on your home, and this may or may not be the same where you live.

The first step weather you wish to go solar or not is to spend some time and in many cases some money on conservation. We spent at least a year looking for ways to cut back our power usage with adversly affecting our everyday lives, for instance we bought a device called a "Kill a watt", you plug it in to the wall and another tool, refer, freezer or whatever into it and it will tell you the power usage of that item. I installed wind up timers and or motion sensors on things we would forget to turn off, we lowered our air pressure from 175psi to 90ish and added tanks for volume so the motor would sart less times, and the same with our well system for the same reason, a motor can run a long time on the power it takes to start it.

Of course I don't have the knowlege or experiance to cure someone elses
troubles as I still have a long list of my own, But solar heat for your pool could be as easy as a large coil of that black tubing they run down wells and run some of your water thru it, a pool is a large consumer of time and money for most folks that have them but you can cover it when not in use and keep some of the tree stuff out of it so you could pump a bit less perhaps.

Conservation without too much inconvience is the key , we all have to start there and you will be amazed at how much it helps, then you can look at alternative sources.

Do you realize that we are spending $341 million per day in Iraq??

Imagine if we gave a modicum of priority to researching improvements in PV technology. Too expensive is what everybody says. Look what this insane war for oil is costing us.

Imagine if there were really aggressive tax incentives and a Manhattan Project level of national commitment to developing solar energy technologies.

I have felt for many years that getting off of petroleum should be our number one priority- it trumps everything else. Energy is the root of many of our problems.

Silicon PV panels are really an inefficient and expensive technology, but they do work. Imagine what it could be like if we had cheap PV and cheap energy storage.

Aw'hell, if we are going to go there, if we spent 10% on alternative energy of what we spend on things like Viagra, pv would be so far advanced we couldn't use all the power, the trouble is that the money goes where the money wants it to go, we are just noisey spectators in this world. I could retire quite well on 10% of the freight charge to send a mini backhoe to mars.

If a frog had wings he wouldn't bump his but when he hopped.

If a ducks butt wasn't water tight the little bastard would sink.

on and on

My day job is as a senior product designer for one of the largest solar energy companies in the US. Our business model is to sign power purchase agreements with large national big-box chains, who then purchase their electricity from us. We get the roof, upon which we install large, grid tied, state of the art PV arrays. The smallest we'll do is about 100kW. Our largest to date is close to 10mW of tracking ground mounts. The rebates and renewable energy credits are ours for the 20 year term of the power purchase agreement. Business was huge in California, but the rebate system, which is determined by a performance-based index, has dropped to a tier where present PV module prices (which are driven by Germany and Spain's insatiable thirst for modules) are high enough to make it exceptionally difficult to be profitable. Subsequently, we're doing the bulk of our US projects in NJ, CT, MD, OR, TX, NC, and other states where programs are coming on line. Having an established base of ready roofs allows us to lock in lots of projects as soon as a state opens. About 1/2 our business was international this year, and it will be even more next year. The company grew from 50 or so employees a little over a year ago when I joined the company, to over 500 now.

My primary focus is finding novel solutions for mounting structures and construction methods to lower the balance-of-system cost (everything except modules, inverters, and wiring). The industry paradigm has been aluminum extrusions, stainless hardware, and little regard paid to parts count and ease of assembly. That makes my job relatively easy, as there's a near absence, it seems, of fundamental "farmer sense" design happening. As for residential solar, MD, where I live has instituted reasonable renewable energy credits, and the likelyhood of being able to source maybe 4-5kW of modules from a decommissioned R&D project is pretty good. I've got a nice South facing roof with about the right tilt, so it's a no-brainer. Still, solar hot water has a really fast payback, and even though I'd need to pay real money for it, I suspect that's where my first effort will be.

And before anyone accuses me of being a damn tree-hugger, renewable energy is the best sector for a generalist designer/fabricator self taught engineering type to grow fast and make a tidy living. Hell, I torched a half a tank of premium and a quarter of set of tires and brake pads in an hour and twenty minutes on Sunday at a race track. How green is that?

My day job is as a senior product designer for one of the largest solar energy companies in the US. Our business model is to sign power purchase agreements with large national big-box chains, who then purchase their electricity from us. We get the roof, upon which we install large, grid tied, state of the art PV arrays. The smallest we'll do is about 100kW. Our largest to date is close to 10mW of tracking ground mounts. The rebates and renewable energy credits are ours for the 20 year term of the power purchase agreement. Business was huge in California, but the rebate system, which is determined by a performance-based index, has dropped to a tier where present PV module prices (which are driven by Germany and Spain's insatiable thirst for modules) are high enough to make it exceptionally difficult to be profitable.

My primary focus is finding novel solutions for mounting structures and construction methods to lower the balance-of-system cost (everything except modules, inverters, and wiring). The industry paradigm has been aluminum extrusions, stainless hardware, and little regard paid to parts count and ease of assembly. That makes my job relatively easy, as there's a near absence, it seems, of fundamental "farmer sense" design happening. As for residential solar, MD, where I live has instituted reasonable renewable energy credits, and the likelyhood of being able to source maybe 4-5kW of modules from a decommissioned R&D project is pretty good. I've got a nice South facing roof with about the right tilt, so it's a no-brainer. Still, solar hot water has a really fast payback, and even though I'd need to pay real money for it, I suspect that's where my first effort will be.

And before anyone accuses me of being a damn tree-hugger, renewable energy is the best sector for a generalist designer/fabricator self taught engineering type to grow fast and make a tidy living. Hell, I torched a half a tank of premium and a quarter of set of tires and brake pads in an hour and twenty minutes on Sunday at a race track. How green is that?

I am a damn tree hugger. Have been all my life. I run a 20 acre farm, I have a shop full of woodworking and metalworking tools, and a complete electronics lab. I write software for a living, and I play pedal steel guitar. One of the main reasons I've been building up my metal shop is to try some alternative energy experiments. I consider myself to be a self-taught engineer, as I am good in a number of disciplines and technologies. And I am very passionate about developing energy solutions.

I'd be very interested in any advice you have on renewable energy businesses for a small timer with farmer sense and a bunch of tools.

I would hold off on buying a system until the new thin film solar panels get on the market
http://www.nanosolar.com/
http://www.engadget.com/2007/12/18/n...t-solar-panel/
http://www.rewarestore.com/tech_thinfilm.html

I believe the cost will drop in the next two years to about 2 dollars a watt or less.
plus the panels will weight about 1/4 what the panels do now.

The supply of panel grade silicon has been low for years and that has keep the price high for panels
Plus the demand has been growing rapidly.

The new thin film panels use little silicon if any and are faster to make.

I think the best way to make money on solar power is to keep lots of them on your showroom, and advertise on the web. At $0.09/kwh and 1.3kwh max output per square yard from the sun it would take a lot of square yards of panels here in Seattle to slow the meter. I'd make a lot more money selling them than buying them.

CSP (concentrating solar power) looks good, and could well be the "next big thing".

"The oldest CSP technology, parabolic trough plants, known as SEGS 1 through 9, have been operating reliably in the California and Nevada deserts since the 1970. Parabolic trough plants work by focusing sunlight on pipes by means of parabolic mirrors. These pipes contain a working fluid (several have been used, from water and superheated steam to molten nitrate salts.)"

"Parabolic trough technology allows energy to be stored as heat, which is much less expensive than storing electricity. This allows the energy from these plants to be available at times of peak demand, making the electricity much more valuable."

http://tomkonrad.wordpress.com/2006/...g-solar-power/


I've seen estimates that 100 square miles of mirrors could power the entire United States.

an engineer i worked with told me to build a huge sterling engine and use a rooftop water loop as a source and my pool as a sink.

- big sterling generator certianly appeals to the machinist part of me. i could house it in a plexiglass case in my carport. that would be fun to watch.

I did not realize that the Nano solar was so far along, that is pretty exciting. Moto, I have noticed what you are talking about with all the solar stuff, it looks like they build the whole thing out of McMaster Carr and that a Grad student designed it. Without real world experience you don't understand that things like part count makes a hugh difference. It is easy to design something with 120 washers and nuts and bolts, but is always going to be too expensive for production. BTW, lots of oportunities there for stampings and stacked stampings, ie sandwiches of stampings to make solid parts to replace machined ones.

This will not help with the electric bill, but you might do well to use solar hydronic heating to reduce your domestic hot water and heating costs. I read somwhere (HomePower magazine?) that unless you are a considerable distance (.5 miles or more) from the grid solar electric is still not cost effective.

Good luck,

Rick

I think that PV has a future but it is so ironic that Passive solar has always been practical but is seldom used. And it can be used to a lesser or greater extent and is largly free or so cheap to do, thus the problem it is mainly a design process and there is no product to sell other than design, and I think most home owners are not willing to pay for design, geegaws, yes, real thought , no. I built a passive solar house in 86 that had lots of compromizes, such as 30 degress off south to take advantage of the view, etc and this was before low e glass was generally available and the contractor refused to do a few things, and my heat bills with propane were about 600 per year for a 3000 sq ft house, when natural gas was installed after I sold it, the heat bill went to half of propane. No disadvantges at all, it is a beautiful contemparary but not radical house, [ie nothing weird]. Of course passive solar does not replace much electricity but it does replace natural gas and oil and save money so that is all pretty much the same in the end.

I have what I consider a nice contemporary house.....

when it was built it had a rooftop watering system to naturally cool the house. nice system in the dessert climate I'm told. there were sprinkler heads on the roof. and the roof drains are not at the lowst point.... it had a pitch (tar stuff) roof with gravel -not the typical BUR tar felt crap.

unfortunately Illinois is not the dessert, and so all winter and spring snow and ice and water sit up there. 40+ years and it has degraded. I had a contractor install a "torch down" roof, strips of tar saturated felt. they were supposed to put a very slight angle to all the drains. they did not. 3 years and it is failing, I have to maintain it with mopped tar constantly. it's all soggy underneath.

I'm installing TPO membrane, in 14' wide heat seamed strips over tapered foam pannels about 1/4"per foot, so it drains to the downspouts.

I suppose I'll wait a year or 5 and see if the solar pannel cost comes down.

I'd also like to put a small rooftop greenhouse over the carport section. as my current garden is in the shade too.

BTW, it surprizes me that there are not combination pv and hot water panels, ie a water panel with a pv surface, and glazing, maybe there is a heat issue with the pv, but you would be taking advantage of all the structure all ready there for the pv to make hot water, increasing the ROI.

Good grief, a black tar roof?
My 14,000 squrare fot shop has a shiny galvanized roof, and even after 100 degrees for a few weeks it is still about 70 degrees inside.
Your roof is failing anyway, look into a shiny roof!
Black Absorbs heat in the summer, and there is no better color to radiate heat in the winter, either.
Shiny absorbs less heat, and radiates less heat.
With the 20" of fiberglass insulation in the attic, the unheatd end of the building doesn't even freeeze in the middle of a bitter cold Wisconsin winter. 44-45 degrees is as cold as it gets, and summer temps soaring into the 100's and it get into the 70's.

Insulation, and proper heat reflection on the roof.

ya.. like I said I'm putting down TPO membrane. I'm putting it white side up. I did 1/3 of it 2 years ago I am finishing it this summer as soon as it quits raining. (there are two different levels to my roof, I already did the smaller section)

My intention, and main reason for starting this thread was to put in some anchoring system so that I could easily mount solar pannels when I can afford them. -rather than go back and poke holes in my recently laid roof.

the tapered foam system adds about 4" of styrofoam insulation also.