×

Welcome to the Slashdot Beta site -- learn more here. Use the link in the footer or click here to return to the Classic version of Slashdot.

Thank you!

Before you choose to head back to the Classic look of the site, we'd appreciate it if you share your thoughts on the Beta; your feedback is what drives our ongoing development.

Beta is different and we value you taking the time to try it out. Please take a look at the changes we've made in Beta and  learn more about it. Thanks for reading, and for making the site better!

Method for $1/Watt Solar Panels Will Soon See Commercial Use

Zonk posted more than 5 years ago | from the i'll-take-five dept.

Power 502

An anonymous reader writes "A method developed at Colorado State University for crafting solar panels has been developed to the point where they are nearly ready for mass production. Professor W.S. Sampath's technique has resulted in a low-cost, high-efficiency process for creating the panels, which will soon be fabricated by a commercial interest. 'Produced at less than $1 per watt, the panels will dramatically reduce the cost of generating solar electricity and could power homes and businesses around the globe with clean energy for roughly the same cost as traditionally generated electricity. Sampath has developed a continuous, automated manufacturing process for solar panels using glass coating with a cadmium telluride thin film instead of the standard high-cost crystalline silicon. Because the process produces high efficiency devices (ranging from 11% to 13%) at a very high rate and yield, it can be done much more cheaply than with existing technologies.'"

cancel ×
This is a preview of your comment

No Comment Title Entered

Anonymous Coward 1 minute ago

No Comment Entered

502 comments

cost benefit analysis (3, Insightful)

acdc_rules (519822) | more than 5 years ago | (#20721227)

ya, but for how long do they last

Re:cost benefit analysis (3, Insightful)

arivanov (12034) | more than 5 years ago | (#20721251)

I agree. A few obvious questions: what is the actual performance deterioration curve, what is the efficiency after 5-10 years and what are the disposal requirements (it has the dirty "C" word in so do not expect them to be accepted at the tip).

Re:cost benefit analysis (5, Interesting)

Lumpy (12016) | more than 5 years ago | (#20721623)

Exactly! $1 a watt panels are darn expensive if they only last 5 years.

I run on 20 year old Solar panels here. I buy only used and discarded from solar plants out west and they look brown from the years of solar exposure but cost me far FAR less than buying new so I can afford more watts for the money. Decent used one approach $2.00 a watt but that is at higher voltages. and my panels will last another 30 years easily with care.

Back of the envelope (5, Interesting)

goombah99 (560566) | more than 5 years ago | (#20721743)

Lets see. Assume the competing cost is at present 10 to 25 cents per KW-hour. We'll use the upper end because future power prices will rise whereas the Solar panel is a fixed cost.

So let's see the solar panels are 100000 cents per KiloWatt. if the last 4000 then that's breakeven. We'll assume that the power is available 10 hours per day. That's not realistic for individual use but perhaps with batteries, and selling back to the grid this could be done. So 4000 hours is 400 days. Or about 1 year. Not too bad.

Now that ignores the efficiency of either pushing back to the grid or battery storage. Let's assume 50% loss. Then this is 2 years to payback on the cells. But now we also have to payback on the batteries. Let's assume the batteries needed const aout the same as the solar cells. That would double this payback to 4 years.

Finally this is assuming capital is free. Assume one borrows at 8 % interest. Then this another 5 months to payback.

So the whole operation needs to run undegraded for 4 to 4.5 years I estimate for break even.

That figure could be cut in half if one could sell back to the grid rather than batteries. ( Fine--as long as there is a grid and every one does not do that!. )

If the cells were down to 50% effiency after 4 years then this extends out to ~7 years to payback. If one cannot get that watt for the full ten hours then this gets even longer.

It sounds to me, roughly speaking that at 1 dollar per what things are in the ballpark for breakeven.

Re:cost benefit analysis (0)

Anonymous Coward | more than 5 years ago | (#20721271)

At least until nightfall...

13% is considered "high efficiency" now? (1, Insightful)

Anonymous Coward | more than 5 years ago | (#20721233)

You know, $1/watt panels are good and all, but shouldn't someone be more concerned with making them useful? It doesn't matter if the panels are $0.01/watt if I still need the entire neighborhood covered in them to run the coffee maker. You need to get to the point where covering the roof of the house is sufficient to make a major impact on the power needed from the rest of the grid (if not replace it totally, a pipe dream).

Re:13% is considered "high efficiency" now? (5, Informative)

Jarik C-Bol (894741) | more than 5 years ago | (#20721267)

actualy, a 20x20 foot aray with good batterys and inverters will power a home with a family of four quite nicely. (I myself lived in a house that was totaly off the grid for about 5 years, pure sunlight on a 20x20 grid in the summer, minor supliment by propane generator in the winter months)

Re:13% is considered "high efficiency" now? (1)

alan_dershowitz (586542) | more than 5 years ago | (#20721469)

Can you provide more details? Where did you live? How did you deal with refrigeration and other high drain devices?

The trouble is cost. (5, Interesting)

Anonymous Coward | more than 5 years ago | (#20721569)

Unless they have no alternative to home-generated electricity, the cost of alternative generation systems is an uneconomic solution for most people.

I too live off-grid, in a small observatory at the top of a high mountain. Even though the cost of AC mains to the site was well-beyond my means, the only reason I could afford to generate my own electricity was because I work in the electrical industry and got the batteries, heavy cable, components for regulators and inverters, etc, for free.

The only things I had to pay for was the PV array and that was not a trivial expense, at $10 per-watt, excluding taxes and shipping.

My off-grid system works very well, but it requires a lot of on-going TLC, far more than most people I know could be bothered with providing. They want systems they don't have to think about and which "just work". Few have the self-discipline and willpower required to minimise their loads, letalone perform regular maintenance checks.

I've always been a Renewable Energy geek, but if I could have got an affordable AC mains connection to my site, I would have one. As much as I love playing with windgens and solar setups, with a wife and two kids now, I simply don't have as much free time on my hands as I used to.

Re:The trouble is cost. (3, Insightful)

rrhal (88665) | more than 5 years ago | (#20721779)

"The Grid" is highly subsidized. If people had to pay the full capitol costs of bringing the Grid to their property up front they would find many situations where solar arrays on the house was the cheaper option. It's also pretty easy to save most of the electricity we use:

- efficient lighting
- 12v brushless dc motors in appliances
- use gas to heat stove, dryer, water heater

You can buy a nice solar array for the actual cost (not the subsidized cost) of bringing residential electric onto your property to the meter base and on into the breaker panel.

Re:13% is considered "high efficiency" now? (4, Insightful)

btempleton (149110) | more than 5 years ago | (#20721677)

Note that it's very hard to be green with an off-grid system. Off-grid systems tend to use batteries, and for proper operation you don't want to discharge the batteries too deep, and so quite often you overprovision your cells and you end up throwing away the energy from the cells into mostly full batteries a lot of the time. You can try to live greener (more efficient appliances etc.) and that's almost a must off-grid, but the off grid electricity itself is very expensive.

On grid, every watt generated by the panels goes somewhere and does something, because you feed it back to the grid, where it reduces the demand for fuel-burning electricity.

So living off the grid can be rewarding for those who want to be very non-urban, but it should not be confused with being green, energy wise.

Re:13% is considered "high efficiency" now? (4, Insightful)

xs650 (741277) | more than 5 years ago | (#20721419)

There are several houses on my area in Northern California that have photovoltaic installations that produce more electricity than the homes consume. The excess goes to the power company for a credit against future use. These are homes with air conditioning and people that don't live austere lives. Their installations cover less than the entire south facing slope of a conventional roof. The problem is that they wouldn't come close to paying off without big fat gumnt subsidies. At $2.00/Watt they would be economically feasible without subsidies.

Assume the panels are 1/2 the cost of the system so the total system costs $4/Watt, or $8,000 for a 2 kW system. Assuming 6 hours a day generation, that's 4380 kW-hrs a year, or at $0.10 kW/hr that's $438 worth of electricity. 438/8000 = 5.4% tax free return on investment. If you live in the US with a decent income, you would have to earn over $700 to have $438 for your power bill after taxes.

If you don't like my numbers feel free to substitute your own.

Re:13% is considered "high efficiency" now? (1)

TheRaven64 (641858) | more than 5 years ago | (#20721561)

If you don't like my numbers feel free to substitute your own.
Seriously? In that case, I'll take panels costing 1/kW, and then I only need to spend 2 (or one opinion, without inflation adjustment) for the 2kW system.

Re:13% is considered "high efficiency" now? (1, Interesting)

Anonymous Coward | more than 5 years ago | (#20721641)

And it would take approximately 18 years to pay off that $8000 investment. In comparison, the Dow Jones Industrial Average has gone from $2693 to $13820 between Sep 1989 and Sep 2007. That gives us a 513% return over those 18 years versus simply breaking even and that's just playing it conservatively by buying indexes.

Re:13% is considered "high efficiency" now? (1)

Bloater (12932) | more than 5 years ago | (#20721681)

What proportion of the total cost of the system are existing setups?

Re:13% is considered "high efficiency" now? (5, Informative)

m.dillon (147925) | more than 5 years ago | (#20721683)

Be careful here. In California, which is where I live too, it doesn't get dreadfully hot like it does in the midwest, or at least not for more then a few days a year usually. A solar array of the size normally needed to reach net-zero with the power company doesn't even come close to being able to generate the power needed to run even small whole-home air conditioning systems. As long as the AC is only used a few days out of the year (which is typical in California), then you can still reach net-zero over the whole year. But in somewhere like Texas you wouldn't have a chance. AC is usually not in the cards if you are trying to achieve energy independence.

-Matt

Re:13% is considered "high efficiency" now? (1)

xs650 (741277) | more than 5 years ago | (#20721761)

I would mod you up for that if I could. I try to not think about places that require AC at night :-)

FWIW, this area has around 30 days over 100 per year. Nights are usually comfortable and the daytime humidity is low.

OTOH, there is a whole spectrum of useful levels of solar power that don't require independence. If you're on the grid it makes more sense to use the grid to off load excess power instead of going to the expense of a battery system.

Re:13% is considered "high efficiency" now? (1)

josephdrivein (924831) | more than 5 years ago | (#20721607)

Making low cost cells is very important:

A old linear power supply has a efficiency ~40%, and is considered low efficiency and unacceptable.

Solar cells may be used - and in fact are already in use in some areas - even if they have n ~ 10-20%.
A key factor is that here we are converting a different form of energy in electrical energy, while a converter has the same type of energy at input and output. It is usually supposed that light is widely available and space is relatively cheap, although there are places where this isn't the case.

The idea is: if we absorb a kW and we get only 100W out because the efficiency is very low, we increment the solar cell's area by a factor 10 and get a kW out. This works only if the cells are cheap, of course.

Re:13% is considered "high efficiency" now? (3, Funny)

number11 (129686) | more than 5 years ago | (#20721627)

It doesn't matter if the panels are $0.01/watt if I still need the entire neighborhood covered in them to run the coffee maker

Perhaps making heat is not the best way to use electricity? I have a gas-powered coffee maker, myself.

cadmium telluride thin film on glass... (2, Interesting)

cyfer2000 (548592) | more than 5 years ago | (#20721239)

I have always been worrying the environmental impact of the cadmium. Could some one show me that the cadmium used in the photovoltaic has little or no environmental impact please?

Re:cadmium telluride thin film on glass... (4, Interesting)

Dunbal (464142) | more than 5 years ago | (#20721343)

Could some one show me that the cadmium used in the photovoltaic has little or no environmental impact please?

      You don't need to worry about the environmental impact of cadmium, but rather the environmental impact of cadmium versus the environmental impact of current energy production from fossil fuels, etc.

Re:cadmium telluride thin film on glass... (1)

Reality Master 101 (179095) | more than 5 years ago | (#20721781)

You don't need to worry about the environmental impact of cadmium, but rather the environmental impact of cadmium versus the environmental impact of current energy production from fossil fuels, etc.

The environmental impact of fossil fuels is not calculable in any sort of useful way, whereas with a specific environmental poison, you can more directly trace them to their health effects.

Fuck this liberal environmentalist whining... (3, Funny)

Anonymous Coward | more than 5 years ago | (#20721421)

Let's be like China and make electricity the man's way - with coal! And let's go back to burning leaded gasoline so we don't have to fuck with this unleaded crap that limits engine compression. Also, catalytic converters suck. I always take mine off after inspection or go to shops that don't care. Also, we need to get rid of welfare and we need George W. Bush for another eight years! And fuck solar cells. Solar cells can't even power calculators properly.

Anonymous Coward Sig 2.0:
--
Write in George W. Bush in 2008!

Re:Fuck this liberal environmentalist whining... (0, Redundant)

Ziest (143204) | more than 5 years ago | (#20721707)

Let's be like China and make electricity the man's way - with coal! And let's go back to burning leaded gasoline so we don't have to fuck with this unleaded crap that limits engine compression. Also, catalytic converters suck. I always take mine off after inspection or go to shops that don't care. Also, we need to get rid of welfare and we need George W. Bush for another eight years! And fuck solar cells. Solar cells can't even power calculators properly.

Write in George W. Bush in 2008!


Very nice. I would guess that you have never been to Perth Amboy, N.J. or Mexico City or Los Angeles in the early 70's. Why don't to travel to Mexico City when they have one of their inversions and try breathing. Now think what it would like to live there.

Oh by the way, bush can't run for president again. Thank G*D for the Twenty Second Amendment.

Your Heavy Metal Atmosphere (3, Informative)

Yergle143 (848772) | more than 5 years ago | (#20721461)

Management of the environment is constant compromise since nothing is perfect. However. Since burning coal is the major SOURCE of Cd in the environment ...a quick web search reveals a sense of the tonnage: http://www.unu.edu/unupress/unupbooks/80841e/80841E0c.htm [unu.edu] a balanced view considers the following. Which is cleaner? a) a highly controlled manufacturing process b) under-regulated coal bonfires belching Cd in the air and disgorging Cd in the ash. Bonus question: for extra credit what other nasty stuff comes out of a smokestack? ---537

One more question (1)

cyfer2000 (548592) | more than 5 years ago | (#20721737)

If one day a flush of hail breaks the photovotaics on my house, and some of those pieces get all over my house, will the EPA declare my house "extreme poisonous" and "unsafe to inhabit"?

Re:cadmium telluride thin film on glass... (1)

alshithead (981606) | more than 5 years ago | (#20721517)

How about the environmental impact of all the two stroke chainsaws cutting down C02 absorbing trees in order to provide direct sunlight to the roofs where the solar panels will be installed? That is being said kinda "tongue in cheek" but it might be a consideration. An even greater consideration to me personally would be the effect of the loss of shade on my house during the hot summer months. I don't even want to think what my AC would cost without the wonderful shade of 30+ year old trees that surround my house. Perhaps standing the panels off the surface of the roof by a half foot or more might lessen the impact.

Re:cadmium telluride thin film on glass... (1)

gbutler69 (910166) | more than 5 years ago | (#20721713)

Wouldn't the Solar panels being absorbing the sunlight and turning it into electrical energy (or reflecting/reradiating what is not converted) thereby not allowing the sunlight/infrared to become "heat" in your house?

Re:cadmium telluride thin film on glass... (5, Funny)

damn_registrars (1103043) | more than 5 years ago | (#20721539)

A 2003 study on French dietary intake showed an average intake of 3.6 micrograms cadmium per day. Multiply that by the us population of around 300 million, and the US population should be able to safely consume at least 9 grams of cadmium per day. Multiply that by 365 days a year, and we (as a nation) should be able to ingest at least 3.2 kilograms over the course of the year.

Therefore, the solution to the cadium waste is obvious. Put it in the water. After all, dilution is the solution to pollution.

Re:cadmium telluride thin film on glass... (0)

Anonymous Coward | more than 5 years ago | (#20721559)

I did not RTFA, but it is probably polycrystalline CdTe, meaning, there is no elemental Cadmium, only the alloy. This is more or less stable and not that dangerous (when compared with elemental Cd).

Re:cadmium telluride thin film on glass... (1)

cyfer2000 (548592) | more than 5 years ago | (#20721603)

Why? What's the difference between elemental cadmium and alloy cadmium?

Re:cadmium telluride thin film on glass... (1, Informative)

Anonymous Coward | more than 5 years ago | (#20721775)

CdTe is a II-VI semiconductor, the alloy therefore has the magic 8 electrons, which makes its components more likely to stick together and not react chemically with the surrounding stuff. Cd on the other hand is 2 electrons off, so it usually is more reactive.
(This results for example in a much lower boiling temperature for Cd when compared to CdTe.)

Re:cadmium telluride thin film on glass... (1)

krbvroc1 (725200) | more than 5 years ago | (#20721651)

I have always been worrying the environmental impact of the cadmium. Could some one show me that the cadmium used in the photovoltaic has little or no environmental impact please?
To me just the fact that these are installable long-term hardware versus the disposable every two year cell phone consumer items reduces that cadmium issue, whatever it is.

Impresive (2, Insightful)

Jarik C-Bol (894741) | more than 5 years ago | (#20721241)

if it turns out to not be vaporware, it may very well actualy make a dent in our use of coal and other fuels for generating electricity.

Re:Impresive (1)

TheRaven64 (641858) | more than 5 years ago | (#20721337)

Definitely. $1/W is impressive. Assuming electricity costs 10/kWh, you'd need it to run for 1000 hours to break even, which is under a year even if it only works for an hour or so either side of noon. This is a lot better than any I've seen elsewhere.

Re:Impresive (1)

WalksOnDirt (704461) | more than 5 years ago | (#20721433)

One thousand hours at one watt is one kilowatt hour, or ten cents; so you really need 10,000 hours to get back your one dollar per watt for the panels. In a good location this would take about five years, still a good return on the investment.

Re:Impresive (1)

TheRaven64 (641858) | more than 5 years ago | (#20721545)

I realised that as soon as I posted. I was hoping it would get moderated -1 wrong before anyone saw it.

$4 / watt current prices? Where? (1)

ehud42 (314607) | more than 5 years ago | (#20721249)

FTA:


"The cost to the consumer could be as low as $2 per watt"


Sweet! That's awesome, although I'll believe it when I see it.


about half the current cost of solar panels.


What!?! Where does one currently get 100 Watt panels for less then $800? Unless you are buying a few thousand watts worth (at which point I'd call it an industrial purchase and not a consumer purchase), the best price per watt I've seen is $8-9/W.

So, how many watts per sq. meter ? (4, Insightful)

fymidos (512362) | more than 5 years ago | (#20721285)

The article doesn't mention how many watts per square meter this panel will produce. The cost of the panel is important, but so is the cost of the land required and the return of your investment.

Re:So, how many watts per sq. meter ? (1)

Alioth (221270) | more than 5 years ago | (#20721347)

The land required is probably taken up by your roof already, so there's no cost to the land (because it's already occupied by something else).

Re:So, how many watts per sq. meter ? (1)

LordVader717 (888547) | more than 5 years ago | (#20721355)

If everyone put them on their roofs, that would probably go a long way.

Re:So, how many watts per sq. meter ? (1)

fymidos (512362) | more than 5 years ago | (#20721519)

Not so much, how many roofs/citizen do you think there are in major population centers? (Most of which are not in very sunny places anyway)

Re:So, how many watts per sq. meter ? (0)

Anonymous Coward | more than 5 years ago | (#20721371)

I use 500W per square meter to estimate the incoming sun light, because on the average, we get about 5~6 kWh per square meter per day, that's somewhere close to 500W per square meter. And given the 0.11~0.13 efficiency, I will say it's about 60W per square meter.

Re:So, how many watts per sq. meter ? (0)

Anonymous Coward | more than 5 years ago | (#20721377)

Wikipedia says that 15% efficiency leads to about 19 to 56 W/m^2 [wikipedia.org] in the contiguous United States. With the slightly lower efficiency (11% to 13%) mentioned in the summary, one would expect slightly fewer W/m^2.

Simple conversion (4, Insightful)

Khyber (864651) | more than 5 years ago | (#20721393)

One square meter of land on a bright sunny day will get appx 1.6kW of light in an hour. Assuming 11-13% efficiency as mentioned in the article, you'd get just a little over 160 watts per square meter per hour.

Re:Simple conversion (4, Informative)

Zebra_X (13249) | more than 5 years ago | (#20721429)

1.6 is very high. A more practical estimate is between 800W and 1.2kW.

Re:Simple conversion (1)

TheRaven64 (641858) | more than 5 years ago | (#20721599)

One interesting thing that occurred to me is that at $1/W it's close to the cost of a battery for my laptop. If they can be folded up, it would be a nice power supply for the summer. Make it into some form of parasol, and let me sit outside in its shade, with my own source of power.

Re:Simple conversion (4, Insightful)

BlueParrot (965239) | more than 5 years ago | (#20721659)

One square meter of land on a bright sunny day will get appx 1.6kW of light in an hour


Eh? Power = Energy / Time
1.6kW is a measure of power, not energy. You probably meant that 1 square metre receives 1.6kW hours of energy in an hour, which would give 160W hours per hour per square meter, or in power terms, 160W/m^2. That is, about the same power as would be necessary to power 3 strong light bulbs.

Somehow I think a 1m^2 window would be simpler, and if you use a triple glazed argon filled one ( as the Germans do for the passive-house standard) then you can neglect heat loss (in fact, you can get a net heat-gain ), making them considerably more efficient than chaining a 11% solar panel to an energy saving light bulb with 7%-8% efficiency (giving an overall efficiency of about 0.8% ).

No, really, in the vast majority of cases your money is better spent on insulating your house.

Re:So, how many watts per sq. meter ? (1)

Gibbs-Duhem (1058152) | more than 5 years ago | (#20721401)

It lists the efficiency. The watts per square meter will depend on the amount of sunlight in your location. 13% is mid-range, people have made up to 60%, but those are state-of-the-art and expensive.

Re:So, how many watts per sq. meter ? (0)

Anonymous Coward | more than 5 years ago | (#20721437)

The article says %10 - %13 efficiency. Given an approximate 1000W / square meter, that's 100W - 130W.

Re:So, how many watts per sq. meter ? (5, Informative)

rcw-home (122017) | more than 5 years ago | (#20721487)

The article doesn't mention how many watts per square meter this panel will produce.

It did mention efficiency, so you can calculate it. Find an insolation map [wikipedia.org], find your location on it, find the average kWh/day you get, and multiply by the 11-13% figure mentioned in the article.

Not precisely (0)

Anonymous Coward | more than 5 years ago | (#20721679)

The solar panel is flat and doesn't move but is tilted toward the sun. That probably doesn't describe the instrument that measures the sunlight. It has probably changed since the last time I looked but we used to use something that looked like a glass hemisphere. You will also pick up a bit of energy if you have reflecting surfaces (like snow in the winter for instance). The bottom line is YMMV. The insolation is a starting point. As in all things, good engineering is conservative engineering.

Re:So, how many watts per sq. meter ? (1)

DieByWire (744043) | more than 5 years ago | (#20721629)

The article doesn't mention how many watts per square meter this panel will produce.

IIRC, solar insolation runs around 1KW per square meter, or roughly 100W per sq foot. They're claiming 11 to 13% efficiency. The rest is an exercise for the reader.

I sure hope their claims are true. Every time I read about the next photovoltaic breakthrough I feel like Charlie Brown getting ready to kick off the season while Lucy tees the pigskin.

Cost/Benefit Analysis (5, Informative)

saterdaies (842986) | more than 5 years ago | (#20721325)

Well, 1 kilowatt for an hour costs me 25 cents (thereabouts). To make a kilowatt, I would need to spend $1,000 on these. That means that they would have to operate for 4,000 hours for me to make my money back (well, 4,000 hours of electric usage).

Basically, it looks like, if they last a couple years, they would pay for themselves (166 days of full utilization, but that's not going to happen in the real world). Not bad. If they're durable (and last 5-10 years), they could really cut down on electric costs.

Oh, plus the whole saving the planet from destruction thing. I guess that might have some value.

Re:Cost/Benefit Analysis (1)

imbaczek (690596) | more than 5 years ago | (#20721369)

Oh, plus the whole saving the planet from destruction thing. I guess that might have some value.
That depends heavily on durability, too, and the process required to make this stuff.

there's also.... (0)

Anonymous Coward | more than 5 years ago | (#20721717)

...when do you make your money back renting electricity from the monopoly grid? You can pay them guys forever and never be "paid off", and you can't get a price contract, so you don't know a year or more from now how much it will be costing.



Solar became affordable years ago, for everyone except highrise apartment renters (no space nor say in their reality) and get rich quick scheme house flippers (have manuel j illegal slap contractor white on it, done, all repairs complete). for everyone else, normal middle class working people, who plan stay put in their house, it's been "there" for around a decade now. Current panels are rated 20-30 years, with maybe around 80% efficiency left then. I don't know on these new cheap panels, didn't see specs on it.

And if they made the coal and nuke and oil guys pay full price to produce power, where they would have to actually pass the cost directly along to the consumer, instead of the subsidies and incentives and credits they have gotten for years (cheap access to public land for mining, no environmental cleanup costs until recently, land seized for monopoly grid right of way and no money to the landowners, incredibly cheap per barrel cost back to the government/public till with NO auditing for oil and natgas, etc, indirect military cost to stay forking around in the middle east forever, and nukes, heavily subsidized risk insurance and government protection,not a single nuke plant has full "free market capitalist" risk coverage, the government has said they will cover some eventualities, that means the tax payer, armed guards forever, etc, solar became affordable two decades ago, and windpower further back then that. Turn about is fair play, the anti solar crowd are the first to cry "subsidy-it's not cost effective!!1!" and they always forget about their pet other conventional fuels, including nukes, being massively developed and deployed partially off the tax payers back.

Anyway, this cheaper stuff is quite good news I say. The quicker we can bump coal nukes and oil off the head of the list for power the better. Check the headlines, the three biggest threats the planet faces, shit that causes wars and stuff, is "who is allowed to develop nuclear technology" and "global climate change from greenhouse gases" and "we are running out of clean fresh water from being contaminated mostly from the petroleum and spinoff industries".



  No one is going to war over a bunch of roofs covered in solar panels. Solar PV is so seriously carbon neutral and clean it ain't funny, it barely registers. There's a little from manufacturing, but negligible compared to coal or petroleum, and the toxic waste is of much less import than radioactive waste, uranium tailings, coal slag and exhaust, etc. People right now are being murdered over access to petroleum in the middle east and africa, and pretty soon now another bogus war over who gets to use nuclear tech, and that war could actually go nuclear weapons. This is insane when we have alternatives!! And coal is so damn dirty and obvious, even the industry admits it now, it's just all around bad news, it needs to stay stuck in the ground forever.

Solar, wind, hydro, geothermal, biofuels, and eventually some combo of the above to get to hydrogen, that is our energy future if we want to avoid more big wars and poisoning ourselves out of a planet. Artificial fusion is ridiculous when you have a huge fusion reactor right outside half the day. If we keep using oil coal and nukes-no hope, none, wars and a completely ruined environment. Simple as that. Yes, those three are energy dense, they are also the worst for being "major OMG levels risk dense" and as such, should eventually be banned from use.

Batteries (1)

Xenogyst (1052270) | more than 5 years ago | (#20721341)

I am glad that we are making some headway in solar power, but without better and environmentally safe batteries I don't see the technology really being too useful yet.

Re:Batteries (2, Informative)

Gibbs-Duhem (1058152) | more than 5 years ago | (#20721435)

Right now, the grid acts as a nearly perfect battery by distributing power around as needed. During the daytime, electricity use is far higher than during the night, so solar panels are really very nice in terms of when the provide power. The solar panels installed in houses would decrease daytime load on power plants, resulting in better efficiency throughout the system. Think of it as the solar panels working towards supplementing the grid with enough extra power to handle air conditioning and other day-time power use without running power plants at 100% of their rated output.

Re:Batteries (1)

TheRaven64 (641858) | more than 5 years ago | (#20721637)

A while ago, there was an article here claiming that you could decommission one coal power plant if everyone in the USA switched one light bulb from incandescent to compact fluorescent. That's only a saving of 40W during the evening or morning hours when lights are turned on. There is nothing saying you have to switch to a 100% solar system. Deploying $40 of these would reduce your load by a similar amount to switching one lightbulb, and there goes another coal power plant.

Re:Batteries (1)

ScrewMaster (602015) | more than 5 years ago | (#20721467)

That's true, if your goal is to be independent of the electric grid. But for everyone else, any power you don't use can be fed back into the grid with a synchronized inverter. If you're using less than the incoming solar output, your meter will run backwards. So yes, a few million homes and businesses with panels on their roofs could really help out on those hot summer days, without a storage battery in sight. One problem is that the power companies don't really want this, for a variety of reasons.

Re:Batteries (1)

xs650 (741277) | more than 5 years ago | (#20721605)

The power companies 2 real objections are easily overcome.

1. A meter that measures and records power going both directions so the power company can pay less for the power it gets from the home owner than the home owner pays the power company.

2. Circuitry that disconnects the solar system from the power grid in the event of a power company power failure so the linemen working on the power lines don't get electrocuted.

Re:Batteries (1)

Desert Raven (52125) | more than 5 years ago | (#20721511)

I tend to agree, but in applications that already have large battery banks, it's a definite winner.

Such applications include:

Homes off the power grid
Signal towers, etc off the power grid
RV's

My own interest in for RVs. Typical setup for large RVs is to pull 120v power from a heavy duty inverter and a big battery bank. The batteries get charged while moving from the vehicle's alternator, and while stationary from a generator. Having inexpensive, efficient solar panels means a lot less time on the generator.

Re:Batteries (1)

Dr_Barnowl (709838) | more than 5 years ago | (#20721745)

If EEStor [wikipedia.org] pans out, that could be just the ticket. A 52 kWh device could hold 4 days worth of domestic use for those cloudy spots. And since that's a device that weighs 400 pounds and is designed to fit in a car, there's no reason a house couldn't have more than one.

If it works, the auto industry will prime the pump of mass-production on these things, and the domestic applications can't be far behind.

Re:Batteries (1)

trolltalk.com (1108067) | more than 5 years ago | (#20721787)

> "but without better and environmentally safe batteries "

Why betteries? Why not inertial storage (flywheel in a partial vacuum, for example), or pumped storage (ever see those water towers on stilts?).

The good thing about inertial storage is you could get exceedingly high rates of discharge - enough to power up a car in minutes instead of overnight. SciAm had an article on it in the mid-'70s, comparing flywheels using marging steel vs flywheels made from composites.

There is always a catch (2, Interesting)

BlueParrot (965239) | more than 5 years ago | (#20721349)

a)How long do they last
b)How fragile are they
c)What temperature ranges can they survive
d)How strong light do they need
e)What environmental impact will the cadmium have

Sure, if it works all will be happy and dandy, but I somehow suspect there are some catches not mentioned here.

Found some. (2, Insightful)

BlueParrot (965239) | more than 5 years ago | (#20721507)

From TFA:
The cost to the consumer _could_ be as low as _$2_ per watt.

Anybody spot the weasel word? Then there is the $2 cost to the consumer, rather than the $1 which is the cited production cost. Also, the article makes no mention of what levels of incoming radiation these numbers were calculated for. $1/W means something quite different in Egypt than it would mean in Sweden. Is the $2/W derived from the peak efficiency under ideal weather conditions, or is it the average over a year?

Essentially, if you want a real estimate of the price of a power technology you don't want price per power, you want Energy per Life-cycle costs. So if these cells last for 10 years you want to know how much total energy they could be estimated to produce during that time, compared to the cost of the panel. Other aspects like intermittent production and so on factor in, but in any way, price per [peak ?] power output is not a very useful number from an economical point of view. For solar cells you want at least the estimated cost over a life cycle with the assumed weather conditions specified. Less than that and you can easily massage the data by making strange assumptions.

Re:There is always a catch (0)

Anonymous Coward | more than 5 years ago | (#20721567)

f) How will the existing power-generation companies react? - "Sure, we're here to save the planet too so we welcome individual consumers cutting us out of the profit loop en masse."?

Watching their response should prove interesting ...

This is not a unique claim. (3, Interesting)

ahfoo (223186) | more than 5 years ago | (#20721631)

Here in Taiwan, we just had the annual solar trade show which is becoming a really big deal on the silicon island. Solar has become a huge because it dovetails right in with other semi industry players that get put together in industrial parks.
        So this year there was a big dollar-per-watt announcement from Oerlikon. If you don't know who they are, they're a Swiss provider of turn-key thin film or amorphous silicon solar panel factories. They've got several partners in Taiwan already including, most recently, some of the large-scale optical media manufacturers who already use similar techniques and equipment and have some cash to invest.
        The local Oerlikon rep was saying that producers will be at sixty cents per watt within forty eight months and that this will mean actual product at the dollar a watt level. Hey, I'm just passing along what the sales rep said. Obviously he's got a reason to overstate his case, but that's what he claimed was coming down the piple.
        I think it's also worth noting that a former Slashdot sweetheart that went by the name of Spheral Solar has basically dropped off the map because they realized that amorphous silicon was going to take over.
        Oerlikon bought up Excimer laser of the UK last year. One of the repeated steps in doing thin film solar is laser etching.
        I'm not too sure about the tech being referred to in this piece, but dollar-a-watt PV, which is what the UN and other agencies have said is the tilting point where solar is cheaper than coal or natural gas, is already being spoken of at industry trade shows and shouldn't be seen as a wildly implausible announcement.

This is not high efficiency (1)

andrewzx1 (832134) | more than 5 years ago | (#20721353)

10% - 15% is not high efficiency for photovoltaic panels, 30%+ is high efficiency.

high efficiency devices (ranging from 11% to 13%) (1)

Scrameustache (459504) | more than 5 years ago | (#20721417)

30%+ is high efficiency.
Inigo Montoya would like a word with you people...

Yeah, yeah, I know: Subjective term relative to current efficiency levels... still, they're pushing it.

Re:This is not high efficiency (0)

Anonymous Coward | more than 5 years ago | (#20721445)

This is thin film photovoltaic. 11% is pretty impressive. Also, those 30+% efficiency photovotaic are not really commercially available and feasible.

Approvals (2, Interesting)

Alioth (221270) | more than 5 years ago | (#20721363)

Cadmium... so not RoHS compliant, so not saleable at all in Europe and many other parts of the world. Oh dear.

I wonder if RoHS will be relaxed for solar energy?

Re:Approvals (1)

frieko (855745) | more than 5 years ago | (#20721403)

I would hope not. What's the point of wrecking the environment to... save the environment?

OK in UK (0)

Anonymous Coward | more than 5 years ago | (#20721563)

According to http://www.rohs.gov.uk/ [rohs.gov.uk] on the decision tree link, "Fixed installations are outside the scope of the RoHS Regulations." and below that "Examples of fixed installations are: Domestic electrical supply systems (ring mains, fuse boxes and meters)" so we're good!

watts per what unit of time? (0)

damn_registrars (1103043) | more than 5 years ago | (#20721391)

Electricity is usually billed per kilowatt-hour. Therefore, if these panels are to be compared to buying power from the grid, one would need to know their electric production in watts per unit time. If they generate a watt of power, thats great - but is it a watt per minute (pretty good), a watt per hour (not very good), or a watt per day (almost worthless)?

Re:watts per what unit of time? (1)

sgarringer (751574) | more than 5 years ago | (#20721459)

Huh? Its one watt. If its getting light for 4 hours then it would be 4 watt/hours. You need to go back to 7th grade and brush up on units of measure it would seem.

Re:watts per what unit of time? (0)

Anonymous Coward | more than 5 years ago | (#20721525)

it would be 4 watt/hours

That would actually be watt*hours or watt-hours [wikipedia.org] -- "watts times hours", NOT "watts per hour". I think this is where the OP is getting confused.

Re:watts per what unit of time? (1)

damn_registrars (1103043) | more than 5 years ago | (#20721643)

Indeed. It should be watt*hour, not watt/hour. Not that I would count on the local electricity monopoly to get that correct in writing, either...

And you deserve extra points for not being condescending on that correction, though I have none to assign.

Re:watts per what unit of time? (2, Informative)

Scarblac (122480) | more than 5 years ago | (#20721475)

Watt is a per-time unit. 1 Watt = 1 Joule per second.

A watthour is a 1 watt, sustained for an hour; a kilowatthour 1000 Watt, sustained for one hour.

"Watt per minute" doesn't make sense, except when talking about things like a change in power.

Re:watts per what unit of time? (0)

Anonymous Coward | more than 5 years ago | (#20721477)

Think of Watts as being like a flow rating. Measure flow over time to produce a useful number. "1 watt" means a continuous supply at that rate. If $1 buys 1w of solar cell, $1000 buys 1000 watts, and running it for an hour produces 1 kw/h. Running $500 of cells over two hours produces 1 kw/h. Etc.

Re:watts per what unit of time? (0)

Anonymous Coward | more than 5 years ago | (#20721485)

Watt is a unit of energy per unit time (i.e. can be compared with joules per second)
A kilowatt hour is a unit of energy. (i.e (energy/time)*time=energy, and can be compared with e.g. joules).
In this light, the article is sensible.

Re:watts per what unit of time? (1)

Gibbs-Duhem (1058152) | more than 5 years ago | (#20721513)

talking about a unit of power (energy per unit time) per unit time is meaningless. it's like asking how many watts your computer uses per second, your computer doesn't use watts, it uses energy. the power is the amount of energy per unit time.

what's important is that you can, instead of paying 8 cents or whatnot for electricity per unit energy, you can instead pay an upfront cost of $1/watt and produce your own energy. the important question is the device lifetime

other people have done this calculation, I'll assume they did it correctly, and that their answer of about half a year of full utilization to break even and start producing "free energy" is fine.

Re:watts per what unit of time? (1)

goldentrout25 (954162) | more than 5 years ago | (#20721531)


Electricity is usually billed per kilowatt-hour. Therefore, if these panels are to be compared to buying power from the grid, one would need to know their electric production in watts per unit time. If they generate a watt of power, thats great - but is it a watt per minute (pretty good), a watt per hour (not very good), or a watt per day (almost worthless)?


Do you understand what a watt is? Watt is a unit of power. Power = Energy/time. You are billed in kWh since this represents the total amount of energy you used over the billing period. So take the number of kWh you were billed and the number of hours in the billing cycle to get the total power you used. We shall call this X.

This number, X, then represents the number of Joules/s you used on average. To figure out how much area you need in solar panels, take the W/m^2 factor and multiply by the number of square meters needed to obtain X watts.

Watts/minute = J/(smin).
Watts/hour = J(sh).
Watts/dat = J(sday).

Watt (ha) you really are concerend about is peak power, the maximum in the distibution of you power usage.
Like when you turn the oven on to heat your house.

Re:watts per what unit of time? (1)

aedan (196243) | more than 5 years ago | (#20721533)

I think you are misunderstanding what a Watt is.

A Watt is 1 Joule per second. It already contains a unit of time.

If the panel produces 1 W for an hour then that is 1 W/h If it produces 1 kW for an hour then that is 1 kW/h. If it produces 1 W for 1000 hours then that is 1 kW/h.

Re:watts per what unit of time? (1)

frakir (760204) | more than 5 years ago | (#20721551)

D00de, don't divide. Try multiplying.
Or you'll end up with Libraries of Congress per Soviet Russia times Old Koreans.

Put me down for 5Kw (1)

HangingChad (677530) | more than 5 years ago | (#20721399)

$2/watt retail? I'm there. I'll take 5Kw worth of panels, a couple wind turbines, and backup diesel generator and the power company can kiss my big, white butt. Already have my battery boxes built, best start working on those wiring diagrams!

Interesting (5, Informative)

m.dillon (147925) | more than 5 years ago | (#20721523)

The real question here is how will these panels stack up to current poly panels with regards to their life span? All solar panels degrade over time - that is, produce less power as they get older. Rule of thumb for a poly panel is around 25 years. While there are many types of panels only a few are actually in mass production and have the required life spans. If you are looking to install solar now, polycrystalline panels are what you want to get.

1.5 to 2 KW worth of panels is enough to run a typical house unless you have a machine room. Even if you use more power then your panels can produce, it's actually all to the good because it means the panels are recovering the highest-tier electricity costs for you, dropping you down to a lower tier with your utility company.

You don't want batteries unless you are off-grid, and most people will be on-grid. There are many grid-tie solutions available and costs have come down considerably over the years. Batteries are of course essential if you are off-grid but knowing the many hackers here I'm sure many of you would like to be able to disconnect from the utility completely, survive blackouts, and so forth... but generally speaking, the batteries and equipment required to do that adds a lot to the cost of the system and involve considerably more maintenance and worry.

A straight grid-tie system is completely maintenance free. I literally have not had to touch my system since the day it was installed. I just pop into the garage and stare at the cumulative power display every so often :-)

http://apollo.backplane.com/Solar/ [backplane.com]

-Matt

batteries are still a HUGE problem (4, Informative)

cdn-programmer (468978) | more than 5 years ago | (#20721587)

The solar constant is about 1300 watts per square meter (in space). On earth the best you can hope for is about 1000 watts peak. So on average we will look at about say 50% of 50% and less on a cold winter day when we need both heating and more lighting. In fact on a winer day at about 51 degrees latitude we get about 8 hours of light and even then its less than 250 watts per square meter.

If we take 10% of 250 we get 25 watts. This is about as much as a high efficiency mini florescent uses.

To run a toaster we will need 40 square meters of solar panel and to roast a turkey and cook on top of the stove as well we look at 40 amps @ 240 volts (check your main panel folks) which is about 385 square meters at 25 watts per square meter.

Thing is that we might want to roast the xmas turkey after dusk, so we better plan on batteries.

A deep cycle 12 volt battery (lead acid) can be expected to hold 60 amp-hours.... at least this is what the Hawker batteries I use for my UPS system are rated for.

12*60 = 720 watts hours. To roast the turkey say takes 4 hours at a draw of say 30% of 40 * 240 which is about 11,250 watt hours. So we need 15 batteries for this. Next if we draw them down any more than about 20% the number of cycles goes into the toilet so we'll need about 5x as many so we can draw each to about 20% of their max rating. We'll need 75 batteries.

New these batteries cost more than $250 bux so that is a battery investment of $18,750.

Clearly one will not be running an electric range off that solar system.

I'm not scoffing at the idea. I think its good but one has to find a way to store that energy and perhaps the best use of it will be to create hydrogen.

The thing is that sure it can feed into the grid during the day. All this does is put idle the current generating infrastructure and we still need that infrastructure for night operation. Of course it would save the fuel needed to operate the plant.

But then what would we use the existing generating stations for when they are idle? Generating hydrogen?

Somehow it doesn't make sense to burn fuel to create electricity to make hydrogen when we can simply for instance chemically take the Methane apart and get hydrogen that way.

One really has to think about how this cheap solar technology fits into the full cycle of energy needs.

Nevertheless I think it is good and maybe we should use it to pump water up hill. Then at night we can let the water flow back through the pump and turn it into a motor-generator. Batteries are just one way to store energy. It can be stored as compressed air, water at the top of a hill, chemically such as hydrogen gas... but it will need to be stored and in great quantities if this technology is going to go anywhere.

Plants such as trees are another good solar collector. We tend not to use them. They are reasonably efficient and serve as their own battery system because if you need more heat you can chuck another log on the fire. Since most of us tend not to use the solar collectors mother nature already created for us, I suspect that there will be huge issues to overcome in order to deploy even cheap man-made ones.

Now here is another thought. The best efficiency of these collectors is say 10%. If we capture the same energy for space heating our houses we can easily get over 80%. Yet, most of us do not even do this.

A super heated house with R70 in the ceiling and R50 in the walls costs about $1 dollar per square foot of building envelope extra during construction. This will eliminate the vast majority of summer cooling and winter heating loads. Here in Calgary for instance a house like this does not need a furnace and we can have winter days that are 40 below for weeks on end. A house like this can get by with a nice fireplace and wood heat and will burn less than 1 cord of wood per year. That wood costs about $100 dollars.

But, most of us don't even do this.

I think solar is a great idea but a low tech solution makes more sense to me than a high tech solution and I'm left scratching my head wondering if this isn't technology running off looking for a problem to solve. Yet, our wasteful energy consumption is a very very serious problem and as oil climbs over $100 per barrel and we look at more energy shortages due to constraints in Natural Gas supplies and Oil supplies it is really going to hit home. Hopefully people will come to wish they hadn't wasted it. But it will be too late then.

Re:batteries are still a HUGE problem - flywheels (1)

cathector (972646) | more than 5 years ago | (#20721739)

flywheels are an interesting method of energy storage undergoing contemporary research.
in my book they're cool because they're clean and simple.

there was a good article in science news [sciencenews.org] a few months back, but it's subscriber-only.
here's another [itotd.com].

Well (1)

ShooterNeo (555040) | more than 5 years ago | (#20721639)

This could be IT. Or, it could be another technology still in the works, "any day now". Despite the fact that it's been a long, long road dealing with the horrible mess of coal and other CO2 releasing power generation technology, it won't be forever. Cheap as dirt solar should rapidly surpass all other forms of energy generation : no complex, expensive plants like nuclear. No mining coal and having to deal with pollution. No dealing with commodity fuel prices, once the panels are installed they keep making power until they wear out.

Half the problem of fossil fuels could be solved in one stroke. Sure, it would take 20-30 more years before all the existing plants are replaced, but solar can in principle, in conjunction with a good method of energy storage, supply all the energy needed for electric power.

May not be for real. Wait for pilot plant. (4, Interesting)

Animats (122034) | more than 5 years ago | (#20721709)

OK, let's see if this is for real.

First, the "story" is a regurgitated press release. [avasolar.com] For an more critical story by a local reporter, see "AVA Solar enters crowded field", by Tom Hacker [ncbr.com].

The AVA Solar web site has almost no useful information. But they have a patent on the manufacturing process [uspto.gov], which discloses what they're trying to do. Among other things, the patent tells us that "AVA" stands for "Air-Vacuum-Air". The process is mostly conducted in a low grade vacuum, with some preprocessing in air before the vacuum chamber and some final steps after vacuum processing. The big deal is supposed to be that there's only one trip in and out of vacuum, which simplifies the production process. This patent was filed in 2000, so they've been working on this for a while now.

They're trying to make cadmium-telluride solar cells, which aren't new. The new thing is making them with a continuous process, instead of in batches.

AVA Solar has some job ads on Dice. [dice.com] They're looking for a plant manager, and on Dice they say "200+" employees, rather than the "500+" mentioned in the press release. AVA Solar doesn't seem to actually make anything yet, so they have to build and run a new kind of manufacturing plant of their own design without an organization experienced in doing that. That's hard.

They're supposedly building a pilot plant, to be running by the end of 2007. So wait a few months. If that works, it's worth looking at them again.

Irrevelant (1, Insightful)

Anonymous Coward | more than 5 years ago | (#20721771)

It doesn't matter how cheap and efficient solar panels become. The electric companies will do everything in their power to keep this kind of thing off the market to ensure the status quo.

Another baby step along the way (2, Insightful)

Whuffo (1043790) | more than 5 years ago | (#20721789)

Assuming this actually turns into something that you can really buy - and it actually is 15% efficient for $1 per watt then this should be the "push" that starts the large-scale conversion of homes and businesses to solar electric power.

More is needed, though - even with cheap and plentiful solar cells you're still up against some physical limits. You've only got so many square feet of southern exposure you can put panels on - and it's not anywhere near enough to support your current level of electric power consumption. Keep in mind that solar panels are rated at "full sun" and in the middle of winter you'll be lucky to get 10% of that on a bright sunny day.

So a good place to start is to find ways to reduce your power consumption. Not "feel good" little reductions, but serious cutbacks. Think about things like skylights in kitchens / bathrooms (free lighting), better insulation and weather stripping, and even some automatic controls on things like lighting, heating, etc. - these will remember to shut off the lights, turn down the heat, etc. even when you forget.

Pick up a small watt meter; something like the "Kill a Watt" can help you discover where the power is going. You'll find that a lot of it is pure waste and easily eliminated. Use task lighting instead of lighting up the whole room / house, look for more ways to reduce consumption.

You'll have to make some concessions and adjustments to live a low power consumption lifestyle - it's up to you to determine how far you can comfortably go. But if you can cut your consumption by 50% or more (very possible) then you're getting to the point where those solar panels can supply enough power to keep you going.

And you're going to need some kind of backup generation for those dark and dreary winter days. House sized generators are usually NOT cost effective, battery banks are expensive and troublesome. Grid-tied systems are clean and easy - but get the facts from your local utility before going this way. Some are very reasonable, some want to pay you their "generated cost" (less than wholesale) for the power you put into the grid - but charge you peak rate for the power you pull from the grid. This can wipe out your solar savings; be careful. Choose which ever of these best fits your needs and hope you never need to use it.

Load More Comments
Slashdot Account

Need an Account?

Forgot your password?

Don't worry, we never post anything without your permission.

Submission Text Formatting Tips

We support a small subset of HTML, namely these tags:

  • b
  • i
  • p
  • br
  • a
  • ol
  • ul
  • li
  • dl
  • dt
  • dd
  • em
  • strong
  • tt
  • blockquote
  • div
  • quote
  • ecode

"ecode" can be used for code snippets, for example:

<ecode>    while(1) { do_something(); } </ecode>
Sign up for Slashdot Newsletters
Create a Slashdot Account

Loading...