California schools $120M solar project

[Ahem A Rivet's Shot]

The PV array link you pointed at is the cheapest I have seen on offer -
has anyone here obtained one? Or are they vapourware?

The string ribbon process mentioned appears to belong to Evergreen
Solar, it looks to be a very clever process for producing silicon PV cells.

 

[Paul Keinanen]

If Klipstein mounts one of the modules I referenced above in full sun
in Philly on a cool day and measures the output, he'll conclude that
it costs out at ~$2 per Watt, not the $30-$40 he managed to arrive at.

Unfortunately the Earth does not constantly turn the same face against
the sun.

In places close to th equator with only rare clouds (such as Sahara)
with dual axis tracker, in principle the nominal power would be
avaible 50 % of the time, thus the average cost would be $4/W.
However, the air mass losses close to the horizon will limit the full
power time to 8-10 hours a day, thus at least $5/W in ideal cases.

For fixed installations in ideal cases 1/4 of the peak power would be
available on average (hence $8/W) .

For higher latitudes, the winter atmospheric losses will reduce the
available power significantly, even with ideal orientation.

In many places, there are those pesky things called clouds ....

This will further reduce the annual energy output and hence increase
the cost/W.

To avoid starting with worst case PV costs he could google "best price
PV". And he could skip even more GIGO by using HOMER or some such.
http://homerenergy.com/ Which would prevent erroneous assumptions such
as his 5% of production for tracking.

While 5 % may be a lot, but on the other hand, can you buy a system
with a solar panel mounted on a dual tracker capable of surviving
snow/ice/sand storm/hurricanes for $2/W (peak) ?

 

[vaughn]

Right... the store pays the shipping and passes the cost right on to
the customer.

Naturally, the retailer must pass *everything* on to the customer if they wish
to stay in business. That said, the store pays for wholesale shipping of large
lots, which is far cheaper than retail shipping of small lots to residential
addresses. PV panels are large, heavy, and must often be custom repackaged for
shipping if sold in small lots. All that costs money.

Vaughn

 

[vaughn]

I bought a rechargeable drill from them awhile back, and the NiCd
battery charger doesn't even have a sensor telling when charging is
done. You have to guess when it's done charging.

I have one; that is exactly true and is clearly mentioned in the manual! Forget
and leave the battery in the charger for a couple days and you can kiss that
battery goodbye. I bought 2 of those drill kits so I could have 2 batteries
plus spare parts. Already, one of the chargers has died. Also the chuck tends
to come unscrewed when you run the drill backwards, making it 50% usless as a
screwdriver. Further, the batteries self-discharge after sitting about two
weeks, so it will always be dead if you only use it occasionally. Other than
all that stuff, it honestly is a strong, useful drill.

Dad wanted to buy same drill (on sale for $15); I talked him out of it.

Same here. I bought him a new lithium Ryobi kit just yesterday. He will get if
for his 92nd birthday next month!


Vaughn

 

[[email protected]]

That is their price per peak output per watt installed and seems
unusually low.

I picked a module that I know several of my neighbors have purchased.
Occasionally the same site I mentioned has modules for even less.
The downward trend for PV is likely to continue, same as the upward
trend for grid energy. Which makes long-term estimates silly if they
don't include some allowances.

$4/W is still about the going rate

A better argument is that PV generally requires other hardware that
increases the basic cost.

and some are closer to
$8/W where you paying a premium for higher efficiency.

Some might be selling for $100 per W. If you were buying, which would
you seek out? Here's the thing - the people who are buying find the
low prices, and the people who seek to discourage others from buying
find higher prices.

But unless you can arrange continuous sunlight the average output over
the year allowing for clouds and including diffuse light is something
like 1/8 to 1/10 of peak installed capacity. So his $30-40/W delivered
for use is basically in the right ballpark in the long term.

Nonsense. I've lived off-grid for ~15 years. My costs for the solar
portion (including batteries, inverters, trackers, etc, but not
counting sweat equity), were ~ $13 per watt. PV was ~$5 back then.
Inverters were similar to current prices, but batteries were less.

Operating at peak efficiency with a clear sky and normal incidence
sunlight then the array can achieve peak performance, but the rest of
the time it does not by a long way. And obviously at night it is idle.

Again, no kidding?

I think you just have to be clear about what measure you are using.

Sure. Most people use Wh and specify location, application, and
everything that's required to make it all work. Dollar per W is a
strange measure.

The PV array link you pointed at is the cheapest I have seen on offer -
has anyone here obtained one? Or are they vapourware?

Yes, several posters here (AEH), including me, have used that outfit,
and many have purchased at ~$2 per watt. Choices at the low end of the
price scale are sometimes limited though. A friend had to pay a little
over $3 a few months ago to get modules with a voltage that fit his
application. And some of the best deals are on stuff that isn't UL
rated, which can be an issue.

Wayne

 

[Jamie]

Good point. For wrenches and such, HF seems good enough for light car
maintenance work. But...

I bought a rechargeable drill from them awhile back, and the NiCd
battery charger doesn't even have a sensor telling when charging is
done. You have to guess when it's done charging.

Dad wanted to buy same drill (on sale for $15); I talked him out of
it.

Michael

Details details..

 

[Jamie]

I have one; that is exactly true and is clearly mentioned in the manual! Forget
and leave the battery in the charger for a couple days and you can kiss that
battery goodbye. I bought 2 of those drill kits so I could have 2 batteries
plus spare parts. Already, one of the chargers has died. Also the chuck tends
to come unscrewed when you run the drill backwards, making it 50% usless as a
screwdriver. Further, the batteries self-discharge after sitting about two
weeks, so it will always be dead if you only use it occasionally. Other than
all that stuff, it honestly is a strong, useful drill.




Same here. I bought him a new lithium Ryobi kit just yesterday. He will get if
for his 92nd birthday next month!


Vaughn

Next time that chuck comes unscrewed, put RED thread lock in there
before screwing it back in.. You'll have no more issues after that..

P.S.
That problem happens to well known brands also along with chargers
going dead.

 

[Jamie]

Yep it's way strong. 18V. Battery is flat every time I want to use
it though. 15 mins of charging gets it juiced up enough for most of
my tasks. I'm sure I've hosed the battery with such short charges
though.

Thanks for the advisory re: drilling backwards.

I was freaked out once when I unplugged the power brick (with the
battery still attached) and the brick got warmer and warmer... that
was strange. Tried to remember never to do that again...






That's a good idea for a Father's Day gift... thanks for the idea!





Michael

Its normal for those kind of batteries to go dead after that much time..
And leaving them off the charger between uses is the best thing you can
do. You'll get a lot more service time from the cells that way..

I have a 7 year old fire storm (cheap) 3/8 B&D drill that I Use at
least every other day for mostly driving machine screws, drilling and
driving a Tap to thread holds up to 1/4 inch, the Reverse/Forward switch
is very sloppy now from the TAP driving and the slip clutch has seen
better das but the batteries still take a good charge and last a
reasonable time period... And these are NiCads

 

[[email protected]]

I picked a module that I know several of my neighbors have purchased.
Occasionally the same site I mentioned has modules for even less.
The downward trend for PV is likely to continue, same as the upward
trend for grid energy. Which makes long-term estimates silly if they
don't include some allowances.

Smart money (government need not apply) waits on the sidelines to see where
the crossing is, if any.

 

[[email protected]]

I see a lot of people buying tools for their business at Harbor
Freight, and at Northern Tools. They don't complain about the quality,
they complain that people steal their tools.

Right. No one would steal a HF tool. <rdh>

BTW, I have an order with them now for a portable dust collector ($70) and a
wide-crown pneumatic stapler ($20). They didn't have them on sale in the
store in Dothan Saturday.

 

[Sylvia Else]

The "economies of scale" aren't just the simple stuff, such as when
you ship 100,000 units a year it becomes worth your while to put most
of the electronics into an ASIC. It covers the sort of developments
where people think that the market is big enough to justify developing
a completely different way of making solar cells.

Inventing a different technology is not an economy of scale, and there's
no guarantee that it will materialise.

This sort of development is highly speculative and costs tens to
hundreds of millions of dollars by the time you've turned it into a
production line - nobody invests that kind of money until they are
pretty confident about the eventual market.

Economists don't understand any of the technical details - they just
know that as the market for a product expands, the unit cost tends to
halve for every ten-fold expansion in production volume.

The first computer I ever worked with hands-on was a PDP-8. It cost
something like ten times what I was being paid per year at the time.
Nowadays there are single chip processors that are moe powerful that
sell for about what I'd earn in a minute if I could persuade someone
to hime me. Solar panels need area in a way that processors don't, but
they are going to get a lot cheaper to make and a lot easier to mount
(perhaps as stick-on films).

So why do car bateries still cost so much?

Sylvia.

 

[Spehro Pefhany]

Yes. You have no details, just a burnt saw. I've seen a lot of
brands burn up over the last 40+ years. Have you ever walked into a
tool repair business? Not one burnt up harbor freight tool, but just
about any other brand you can imagine are waiting for parts.

That's because _nobody_ *repairs* HF tools, you just toss them!

I'm going to have a $9.99 angle grinder repaired? The guy can't take
the screws out for that.


Best regards,
Spehro Pefhany

 

[vaughn]

They charger is two piece, and has an indicator that the
battery is fully charged.

Mine is 2-piece, but only has a charging indicator. The manual clearly states
that the charger is not automatic and is capable of overcharging the battery.

If you can't remeber to unplug the charger, buy a timer.

No! If the design of the battery is such that the batery discharges through
the charger when it loses power...what do you think will happen after the timer
turns off the charger?

What I actually do is lay my car keys next to the charger.

Vaughn

 

[GregS]

Mine is 2-piece, but only has a charging indicator. The manual clearly states
that the charger is not automatic and is capable of overcharging the battery.


No! If the design of the battery is such that the batery discharges through
the charger when it loses power...what do you think will happen after the timer

turns off the charger?

What I actually do is lay my car keys next to the charger.

Vaughn

I have had 3 Alltrade kawasaki drills. One trigger went bad. One intermittant.
One still works. I can probably fix again the intermittant, and I
need to order the trigger for about $15.\\What a mess with the Nicds.
First set of 19 volts works OK, and the charger seemed to work OK, but
they recalled it. Got a rebate. Second 19 volt came with a 4 hour manual
charger, that I have really begun to mess up the batteries by
overcharging. The newest 21 volt and charger have been OK except for
the intermmitant. The charger is basically a 1 hour timer which seems OK.

In the interim bought a Sears Lithium, only one battery. Good but
it does not have as low a clutch as the Alltrade which can
be a problem. the direction is also reversed which drives me crazy.

greg

 

[Ahem A Rivet's Shot]

So why do car bateries still cost so much?

Because car batteries are a mature technology that hasn't changed
much in the last half century. Digital electronics is a fast changing
technology with huge demand to drive development. Photovoltaics is a
changing technology with a relatively small but growing demand - many
companies are working on improving the manufacturing technology which is
why we see vacuum sputtered thin film, string ribbon and even roll to roll
printing being developed as manufacturing processes.

 

[vaughn]

Inventing a different technology is not an economy of scale,

Who the hell ever told you that?

New technology is usually where we FIND large economies of scale. Manufacturers
invest in new technologies that promise new efficiencies and lower unit costs,
which gives them a temporary advantage in the marketplace until their
competition catches up by either adopting, improving, or taking the next jump to
yet another new technology. For a wonderful example, look at the memory market
over the last 40 years.

and there's no guarantee that it will materialise.

Boy do you have THAT right! That seems to be especially true in the PV world.
Two or three times a year we hear of some new technology that is going to take
PV prices through the floor. So far, the changes we have seen have been more
evolutionary than revolutionary.

Vaughn

 

[[email protected]]

Not according to some people. Their 'Pittsburgh' brand of hand tools
are stolen fairly often.




Dothan? EWWWWWWWW!!! I had to drive there from Ft Rucker too many
times to pick up parts from a small wholesale electronics place.

We hadn't been in that part of the state yet. Dothan isn't *that* bad. SWMBO
liked the antique stores (I needed some cheap brownie points . Eufaula is
rather nice driving through. The mansions along the main drag are something.
I thought I might like a house on the lake (big lake), but then found out it's
full of 'gators. Maybe not.

If I had taken that civil service job that I was offered in '73, I
would probably still be in the area.

It's about 85mi South of here.

 

[[email protected]]

I have the stapler there, and I've been quite happy with it -- no problems yet
with jamming.

They have two models. One is a combination brad nailer and stapler. This is
just the 1/2" crown stapler. I have a PC 1/4" crown stapler but it was
pulling through the Kraft paper on some insulation. I tried an Arrow cordless
electric stapler - useless. We'll see about this one.

I probably *should* get a dust collector one of these days -- as-is sometimes
a lot of the garage gets covered in sawdust...

I have a 2HP Penn State dust collector for my table saw and planer but it's in
the garage. I'm working on my (eventual) shop in the attic, so needed
something to catch the crap coming out of the (Harbor Freight SCMS. The
shop vac wasn't cutting it. For $70, I thought I'd give the little portable
HF collector a try. If it works I'll mount it to a cart with the Dust Deputy
and use it for little jobs.

 

[[email protected]]

My table saws all have wheels to roll them out of the garage. The
big radial arm saw is under a metal roof behind the garage.

Mine's on wheels too, but it only gets moved to sweep around it. I haven't
fired up the radial arm saw since I moved from NY ('93).

 

[[email protected]]

Good. You don't want to hang around an Army base.

There's also Ft. Bennington, in Columbus. The new Infantry Museum is really
nice. Some of the exhibits are still unfinished but it's a beautiful place.

Even if there was a nice highway to Dothan.

All the highways around here are nice (no frost heaves). US451 is 4-lane,
except for a couple of miles North of Eufaula.

I remember ch 4? from Dothan while I was
building that TV station in Destin. They still started their broadcast
day with a farm report, and their weather forcast used '50s props. That
was in the early '90s.

It's not uncommon for Midwest stations to start their news with the farm
report. Radio stations used to do them from 12:00 to 1:00, when the farmers
were in for lunch.