Did PV solar power just become affordable?

[Pengwuino]

haha and 5 are schools... well i suppose if only places liek schools put em in, i guess they can't b very economical.

 

[russ_watters]

haha and 5 are schools... well i suppose if only places liek schools put em in, i guess they can't b very economical.

In some places, schools are eligible for a big grant for pv.

 

[Moonbear]

From Profile 2:

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Short term costs suggest that green energy is less economic than the brown stuff. The reality is that today's brown energy "profits" come at the cost of tomorrow's generations.
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From Profile 15:

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Our main objective in using this system is to reduce our ecological footprint.
[...]
We will never see a financial payback on this investment.
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Those statements seem pretty amusing when you look at the picture you posted below them. Looks like quite an ecological footprint there! How many trees, shrubs, bird and squirrel homes, etc., do you think they had to clear out of there to make room for those panels and avoid shadows on them from surrounding vegetation? I would only go for a system that could be rooftop mounted, in other words, don't clear any more land than you already needed to for your house. That is, unless you want to turn the entire planet into a desert.

...cost $360,000.
http://66.102.7.104/search?q=cache:...e/2004/06/03/solar/+Adelman+salon+solar&hl=en
http://66.102.7.104/search?q=cache:...3/solar/index1.html+Adelman+salon+solar&hl=en
http://66.102.7.104/search?q=cache:...alon+"fight+for+your+right+to+go+solar"&hl=en
http://66.102.7.104/search?q=cache:...alon+"fight+for+your+right+to+go+solar"&hl=en

I estimate that it produces an average of 3,000 kwh per month. That works out to an up front cost of $120 per installed kwh/month. The opportunity cost of that $360,000 over 30 years at a 5% discount rate and daily compounding is $1,253,242.33. Dividing that by 1,080,000 kwh produced over 30 years gives us a cost of $1.16 per kwh just for the interest alone.

You can see the Adelman's homepower system from space with Google Earth. The exact location of the array is 36^o59'56.28" N, 121^o47'05.61" W.

 

[hitssquad]

The Adelman's solar PV footprint

It is actually quite a distance from the house, Moonbear. (The angle of the picture distorts the distances.) The reason it was placed so far was to avoid cutting down any of those oak trees. Check out Part 3 of the Salon article:

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They eventually ended up with a giant black array of panels, located well down the hill from their house. Next to the panels, one live oak casts a bit of shade on the huge array, but Gabrielle won't let Ken cut down that tree to make the system more efficient. In this, as with every other ecological choice, there are always trade-offs. But as their Web site brags: "No oak trees were harmed in the process."
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As can be seen in the photo on the homepage of their website, the array is located at one end of a field used for farming. So, some farmland was lost.

It is also possibly oversized so they can pump as much solar electricity into the grid as possible (they are solar electric activists). There are a couple of caviats here, though. Their house uses insane amounts of electricity, so that system may actually be about the right size for them. The second caviat is that a different kind of house -- such as a super-insulated thin-shell concrete dome; one for the pool and one or more for the living area -- would radically reduce the need for electricity while not impacting the living standard of the home; and therefore the Adelman's example cannot be taken to imply that all houses with that particular living standard would need a solar PV footprint that large.

I would only go for a system that could be rooftop mounted, in other words, don't clear any more land than you already needed to for your house.

Rooftop mounting is a bad idea. Up on a roof it is dangerous to install, clean and service solar panels because of the fall danger (falls constitute a leading cause of accidental injury and death in America), and most roofs are not engineered to have things mounted on them. People's roofs have been destroyed by solar panels catching the wind. Solar panel mounting hardware has caused leaks in roofs. As far as I am aware, insurance companies have refused to cover any of these solar-panel-related losses.

In other words, roofs are engineered to perform certain tasks and accepting the mounting of PV panels is not one of them.

 

[Pengwuino]

I remember a while ago wondering if you could reflect light into a reservoir of water to create steam to run a turbine just like in that setup you mentioned earlier. I thought i was insane and that it wouldn't work :(

 

[hitssquad]

Rankine cycle and Brayton cycle solar power towers

wondering if you could reflect light into a reservoir of water to create steam to run a turbine

The ones in operation use heliostats (fields of sun-tracking mirrors) aimed at the tops of towers:

http://www.tve.org/images/janus/uploaded/ACFC8.jpg

http://www.menzelphoto.com/images/gallery/big/environment/altenergy/gal_env_alt_02.jpg

They can create steam or heat gas. Gas turbines (Brayton thermal engine cycle) are more efficient than steam turbines (Rankine thermal engine cycle).

 

[pattylou]

"No oak trees were harmed in the process."
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My husband MIke freaks out every time I find a sprouted acorn, because it is illegal to remove Oak Trees here in "Thousand Oaks. " He is a little upset that I have a few oaks that are now three or four years old, in pots, because he doesn't want them going into the ground where they can't be cut down by law! Heheheh. I keep them because they are preferred host plants for several species of butterfly and I have a butterfly garden.

Rooftop mounting is a bad idea. Up on a roof it is dangerous to install, clean and service solar panels because of the fall danger (falls constitute a leading cause of accidental injury and death in America), and most roofs are not engineered to have things mounted on them. People's roofs have been destroyed by solar panels catching the wind. Solar panel mounting hardware has caused leaks in roofs. As far as I am aware, insurance companies have refused to cover any of these solar-panel-related losses.

In other words, roofs are engineered to perform certain tasks and accepting the mounting of PV panels is not one of them.

I hadn't heard of these... maybe you have a point. We clean the panels without going on the roof (hose spray/single story home.) The weight on the roof was offeset by removing the heavy tiles beforehand. Roof mounted is SOP around here...

 

[Pengwuino]

Your cleaning an electrical device with a hose?

I suppose there insulated... how else could they handle the rain.

 

[pattylou]

Your cleaning an electrical device with a hose?

I suppose there insulated... how else could they handle the rain.

yep. Rain. The pollen coats them pretty bad, and the installer said to hose 'em dwon - only thing is make sure they're not hot when that cold water hits.

I'm still curious about the effect of hail, like Moonbear asked.

 

[Pengwuino]

I doubt it would have much of an effect. I am sure they considered it when they designed the panels for sale where you live.

 

[hitssquad]

Trace Engineering says those doing solar homepower 'likely will not save any money'

the world's leading homepower evangelism site says that it is impossible to make money with homepower.

Could you provide a specific quote and link to what you just said?

There is more at the website of Trace Engineering (Xantrex), a leading manufacturer of homepower components:
http://www.xantrex.com/support/readfaq.asp?did=261&p=559

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FAQ
[...]
My utility bills are very high, and I want to switch to off-grid solar power to save money, how much money can I save?

You likely will not save any money. A solar and off-grid electrical system designed to be large enough to off-set high utility bills would be prohibitively expensive. Reducing your energy consumption is the single most effective way to lower utility bills. The typical off-grid home uses well under 10 kW/h of power per day. If your consumption can be reduced to that level you are a good candidate for an independent electrical system.
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