Solar pavement

[samclem]

Quote:

Originally Posted by Schutzie Now lets think about this for a moment. APS gets it's 20 MW generation "plant" cheaper than a solar farm.

It's very hard to believe it would be cheaper or better. Has the state of Arizona run out of cheap desert? These tiny installations on homes are going to be much more expensive to erect and hook up than large banks of panels on some chunk of wasteland desert. And they'll definitely be more expensive to maintain (roofs need to be replaced 1-2 times in that 20 year period, lots of chances to damage the expensive arrays doing that). Houses still catch on fire, kids still have pellet guns, etc. And when the arrays need maintenance, it ain't easy getting up on a residential roof. And then there's the orientation of the roof--it will seldom be optimum. How are you going to stop the neighbor to the south from planting a tree?

And, on top of this, they have to pay each homeowner $30 per month (in kind) for approx 1500 sq ft (tops) of useable rooftop real estate (i.e. not on a north-facing roof slope, blocked by other structure, etc, etc). That means they'll be paying about $10,500 per acre per year for this hard-to-access place to put their panels. 5% interest and a 20 year amortization for that payment equals a purchase price of over $125,000 per acre. I'm very confident AZ has land available for a lot less than $125K per acre. And, if APS just bought the land this way, in 20 years they would own that land forever, already hooked into their grid and ready to install Gen 5 solar panels when the ones installed today wear out.

Or, at least put the panels atop large flat warehouses or other commercial real estate offering economies of scale in installation and maintenance. Not as good as a flat piece of land, but far better than penny-ante installations on houses. This residential scheme makes no sense on its own--I sense the distortion caused by some sort of well-intentioned-but-stupid targeted subsidies, etc. Somebody is getting taken, probably the taxpayer.

[zinger1457]

Quote:

Originally Posted by Schutzie As it turns out, Arizona Public Service was tasked with building a 20 MW power plant, without fueling it with fossil fuels or nuclear. They considered one of those mega solar farms. It would be expensive, and you know, it kills animals.

Although APS didn't build it my understanding is they own all the power generated by the Solana Generating Station in Arizona. It's suppose to be the largest solar plant of it's kind in the world, with a capacity of 280 megawatts. Can't miss it if driving down the I8 freeway near Gila Bend AZ (in the middle of nowhere), plenty of cheap land in this area. Would think it would be tough recruiting workers for this site because of its remoteness, at least 50 miles from any type of civilization.

[ERD50]

Quote:

Originally Posted by Schutzie ok Fine. you don't like Solar roads. I have another idea I found ...

+1 to everything samclem just said.

See the similarity to this and solar roads? There is some magical hand-wave that 'this will be cheaper', bla, bla, bla. But not a shred of evidence to cling to against common sense. Just like roads made out of glass tiles will be cheaper than recycled asphalt - their only 'justification' is that roads are expensive, so this must be cheaper! Makes zero sense.

Quote:

You just can't please everyone, ever.

Why should anyone be pleased by an idea that has no merit, and will just end up wasting time, money, and the environment (since the resources could be better invested)?

Show me an idea with merit, and I'll be behind it 100%. Show me smoke and mirrors, and I'll pull the curtain back on the man with the smoke generator.

BTW, most of the ideas with merit that I've seen lack 'sex appeal', and/or require a bit of technical analysis to understand why they are good ideas. That makes them harder to 'sell'. Hint - conserving a kWh is a kWh that does not need to be generated, does not need to be transported, does not need to be stored, does not need the fuel mined, does not take up any space, doesn't kill any critters, etc, etc, etc

-ERD50

[Chuckanut]

Quote:

Originally Posted by ERD50 Hint - conserving a kWh is a kWh that does not need to be generated, does not need to be transported, does not need to be stored, does not need the fuel mined, does not take up any space, doesn't kill any critters, etc, etc, etc

Absolutely. In a former life I used to work for one of the rich and powerful oil companies. Our 'experts' were quite clear on the matter of of the cost of a barrel of oil - The cheapest barrel was the barrel not pumped out of the ground due to conservation.

Conservation will not single handily save us, but conservation was and still is a huge step towards a better energy future.

[NW-Bound]

Quote:

Originally Posted by zinger1457 Although APS didn't build it my understanding is they own all the power generated by the Solana Generating Station in Arizona. It's suppose to be the largest solar plant of it's kind in the world, with a capacity of 280 megawatts. Can't miss it if driving down the I8 freeway near Gila Bend AZ (in the middle of nowhere), plenty of cheap land in this area. Would think it would be tough recruiting workers for this site because of its remoteness, at least 50 miles from any type of civilization.

The cost of Solana was $2B, or $7/Watt. That at first seems high to me compared to PV generators, but then it has thermal storage capacity to be able to run the turbines for 18 hours/day in the summer, long after the sun has set.

For people not familiar with this plant, it uses parabolic trough mirrors to heat a molten salt, which is then used to generate steam to drive two turbines.



Building the plant required 2,000 workers, but only 85 are needed to operate it.

About finding workers, the location is not really that remote compared to where oil-field workers have to go. I read about oil-field gate guards who man the access gates 24/7. The jobs are usually filled by a married couple taking 12 hours/shift, and they have to be at that gate for a few months solid, living in their RV parked right at the gate. Grocery runs may be 150-mile round trips. It's cold in the winter, and sizzling hot in the summer. And they have to be out in the open, in rattlesnake land, breathing caliche dust.

The job pays $125-150/day total for the couple.

[MooreBonds]

Quote:

Originally Posted by samclem It's very hard to believe it would be cheaper or better. Has the state of Arizona run out of cheap desert? These tiny installations on homes are going to be much more expensive to erect and hook up than large banks of panels on some chunk of wasteland desert. And they'll definitely be more expensive to maintain (roofs need to be replaced 1-2 times in that 20 year period, lots of chances to damage the expensive arrays doing that).

While I agree that it doesn't seem like it would be difficult to get cheap land with 'near perfect' sun exposure, you are forgetting one critical element: infrastructure!

At someone's home, all you need to do is run a wire down to maybe an inverter, then straight to the power pole.

In the desert - you have to trench in (or hang) new power lines back to a substation (?). Connecting the solar array from the cheap land to the grid suddenly takes quite a bit of change that jacks up your total installed $/Watt.

True, there will be maintenance costs on a homeowner's roof - but I presume they would only pick homes that are mostly facing South. Also, in Arizona, I would expect the # of heavy leafy trees that are 80ft-100ft tall would be fairly fewer than in the Midwest or East. Perhaps they are picking any homeowner's regardless of roof orientation....and, perhaps part of their motive is to simply get more and more homeowner's used to seeing solar arrays, so people are more comfortable with them and will be more open to more solar installations (either large scale or residential)?

Quote:

Originally Posted by NW-Bound The job pays $125-150/day total for the couple.

Really? For a 24 hour shift? That's just $6.25/hr for $150/day! Less than federal minimum wage!

[samclem]

Quote:

Originally Posted by MooreBonds In the desert - you have to trench in (or hang) new power lines back to a substation (?). Connecting the solar array from the cheap land to the grid suddenly takes quite a bit of change that jacks up your total installed $/Watt.

I don't think the cost for new lines needs to be very high. APS owns or has ownership interest in three coal-fired power generating stations. These are all located in very remote areas. Our solar panel "lots" could be located anywhere along the existing power distribution lines that feed from these coal plants to their normal grid, this would minimize the need for new wires. In addition, the money they are already willing to pay for the rooftop "land" would buy acreage in outlying industrial areas of towns. "Power plots" could be plunked down in those areas if there is a desire to decentralize the production of the electricity or locate it closer to the users (to reduce transmission losses).

[NW-Bound]

Quote:

Originally Posted by MooreBonds Really? For a 24 hour shift? That's just $6.25/hr for $150/day! Less than federal minimum wage!

That's what I thought, but I guess it is legal because the gate guards are treated as contractors not employees, such that the minimum wage law does not apply.

The work is long-hour and tedious, and exposes the guards to the weather, but it is not hard labor. And many couples want the jobs because in a month or 4 weeks they can make 4 x 7 x $150/day = $4200. If they work 2 minimum wage jobs, they only make 2 x 4 x 5 x 8 x $7.25/hr = $2320.

Another plus is that the contracting gate service company provides them with a diesel generator and fuel to run it 24/7, a water tank that gets refilled every week, and sewage pump-out for their RV. The support is obviously required as they are out in the boondocks, and it does not cost them any money.