Slashdot is powered by your submissions, so send in your scoop

 



Forgot your password?
typodupeerror
×
Power Earth The Almighty Buck

Solar Panels Reach $1 a Watt 381

ZosX writes "An article over at Popular Mechanics announces that, for the first time, solar cells have been manufactured for the much sought-after figure of $1/Watt. They also talk about a new study of the cost of the particular raw materials used in different manufacturing processes. The conclusion is that the company that just achieved the $1/W milestone, using cadmium telluride technology, may not prove to be the long-term winner capable of meeting demand when it rises into the terawatt range."
This discussion has been archived. No new comments can be posted.

Solar Panels Reach $1 a Watt

Comments Filter:
  • Re:TCO (Score:5, Informative)

    by stabiesoft ( 733417 ) on Sunday March 01, 2009 @03:59PM (#27032117) Homepage

    It does not take that long to put in the "grid" part. My system was wired (the part requiring an electrician) in a couple of hours. The large cost component besides the panels is the inverter for a DIY. The magical box converts the DC from the panels to a sync'ed grid AC. The DC from the panels is extracted in such a way as to maximize the power, by constantly adjusting the voltage of the panel output. Its a cool little box with all sorts of protection to make sure the power company and your line doesn't crackle.

  • Re:TCO (Score:5, Informative)

    by Anonymous Coward on Sunday March 01, 2009 @04:01PM (#27032127)

    I'm preparing to install solar on my roof. It isn't that hard. I've completed almost all of the paperwork for the CSI grant and local permits. Mounting the panels to the roof is simple as is figuring out which way to point them. The wiring is brain dead simple. I have a local electrician lined up to come out and hook it into the actual panel for me. Total cost for his time is about $300. I'm saving $10k by doing this myself! Total out the door cost is about $23,500 for 4.6 Kw.

  • by wjh31 ( 1372867 ) on Sunday March 01, 2009 @04:05PM (#27032159) Homepage
    20cents per kWh, one kilowatt used for one hour, whereas this is $1 per watt of capacity, i.e $1 will allow you to generate 1watt, which will generate 1kWh in 1000hrs.
  • Re:Some comments... (Score:3, Informative)

    by polar red ( 215081 ) on Sunday March 01, 2009 @04:10PM (#27032207)

    better insulation seriously reduces the need for airco or heating. investments in insulation are said to have a pyback time of 1 to 2 years. (this means 50% to 100% return of investment per year)

  • Re:TCO (Score:5, Informative)

    by ducomputergeek ( 595742 ) on Sunday March 01, 2009 @04:14PM (#27032263)

    That may be true, but for TCO, we're talking set up costs vs. money saved over the expected life span of the panels. We put some up at work, enough to cover about 50 - 70% of our energy needs depending on the time of year. (we ran out of roof space to cover 100% of our energy needs) Now we viewed that as a sunk cost on the part of the business. Last year we all couldn't take anymore money home without getting bumped up into higher tax brackets. So we decided to reinvest the profits to help improve cash flow. Which it has. It freed up enough to hire a jr. developer.

    Total time to ROI is about 7 - 9 years by the absolute numbers in terms of savings on our utility bills. But the extra developer allowed us to put a product on the market this quarter instead of late Q2 or even Q3 of this year. Already it is earning enough to cover 40% of his salary and should be profitable by the end of the year. The product could make enough by this time next year to pay for the solar panels. If not next year, certainly within 24 months. If the solar panels last us 15 years, we're looking at recovering a good long term ROI even figuring in the replacement of certain parts at least once during that period.

    I would like to see more people putting these on their homes where it makes sense. Obviously places like Seattle aren't ideal candidates, but if you could turn every house and flat roof into a power producer instead of consumer. I'm sure the power companies don't want that. And I'm not sure if the current government would like that since it would empower people to take individual action to meet their energy needs instead of relying on the government. Even if every home/business just produced 20% of the power they used, it would reduce the load on the power grid by that much. And it would make life easier for places that are already having brown outs etc.. (California)

  • Re:Chilling effects. (Score:4, Informative)

    by westlake ( 615356 ) on Sunday March 01, 2009 @04:35PM (#27032439)
    What happens when we line the world's deserts with endless fields of solar panels and tip past the breaking point of global cooling?

    What are the desert sands but another form of solar collector?

  • Re:thats nice (Score:5, Informative)

    by OeLeWaPpErKe ( 412765 ) on Sunday March 01, 2009 @04:39PM (#27032483) Homepage

    Well as long as they're using rare earth metals, they will never become available. Their supply is much too limited.

    Cadmium may not be that expensive, and not that super-rare (though calling the supply abundant would be a stretch), there is barely any tellurium supply.

    From the wikipedia page :

    Tellurium is extremely rare, one of the nine rarest metallic elements on Earth. It is in the same chemical family as oxygen, sulfur, selenium, and polonium (the chalcogens).

    And the reality is ... of all the atoms in the universe (and "more or less" on earth) you have the following relation, for every ton of gold in existence (on earth), there's about 100 grams of Tellurium available.

    It's not expensive, because no-one's using it. But if you start mass-producing anything with tellurium in it that cheapness will disappear sooner than you can say "exhausted supply".

    It would probably be a very good investment to buy (right now) a ton or so of tellurium and put in your basement. Perhaps a bit unorthodox an investment, but before 20 years pass it will be many times more valuable than gold or platinum. Right now it costs between $70 and $100 per pound. You can reasonably expect that to become at least several thousand within the next ten years.

  • Re:Chilling effects. (Score:2, Informative)

    by UCSCTek ( 806902 ) on Sunday March 01, 2009 @04:48PM (#27032543)

    For those who might take the parent seriously:

    Global cooling would only follow if we just stored all of the energy collected by the panels. Assuming we used it, or otherwise released it, which we would probably have to, this would create an amount of thermal energy equal to the initial loss. In the end, only the local energy density on Earth has changed.

    Generally, global warming/cooling effects will need to involve changing the rate at which energy enters or exits the Earth. For example, carbon dioxide emissions increase the energy retention, while increased cloud cover can decrease energy entry.

  • Re:TCO (Score:4, Informative)

    by shermo ( 1284310 ) on Sunday March 01, 2009 @04:53PM (#27032579)

    http://en.wikipedia.org/wiki/HVDC#Advantages_of_HVDC_over_AC_transmission [wikipedia.org]

    Advantages and disadvantages of DC vs AC current.

    That's because DC doesn't travel very well along long wires.

    For transporting large amounts of electricity point to point over large distances ("along long wires") DC is the better option.

  • Re:Wow (Score:5, Informative)

    by bcrowell ( 177657 ) on Sunday March 01, 2009 @04:57PM (#27032629) Homepage

    I'm not sure what my peak load is at home, but at $1/Watt I imagine I could generate all my own electricity for less than $10,000.

    It doesn't matter what your peak load is. If you're in an area that's on the grid, then you want a grid-tied system, and therefore any power you can't generate on your own will come from the grid. At other times, when you have extra (e.g., a hot sunny day when you're out hiking), the power company buys it from you. There is typically a very strong economic incentive to buy a system that matches your yearly consumption, not your peak load. If it's providing less than your yearly consumption, then you aren't getting the best deal, because you still had to pay for a day's labor by the crew with the crane, etc., and you still had to pay for an inverter. The converse is also true: you probably don't want an oversized system. I have photovoltaics on my roof, and in my area, if I produce more than I use over a 12-month period, the electric company won't pay me for the excess. They'll just say, "Gosh, thanks for all that surplus power."

    It's typically very, very difficult to make a realistic calculation of how long it will take a residential PV system to pay for itself. People always ask me how long mine will take to pay for itself, and I always tell them honestly that I have absolutely no idea. The problem is that energy prices are extremely volatile -- that's why they exclude them from the CPI. Remember just recently when gas was $4 a gallon? Historically, the price of electric power has always tended to go up, but we don't know how much it will go up over the 25-year design lifetime of our system.

    What you can do is to consider all your local factors: latitude, amount of sunny weather, whether you have a south-facing roof, whether there is any shade on your roof, and current local prices for electricity. Every time this topic comes up on slashdot, people will make blanked statements about whether PV is economically viable. That's just nonsense. It depends on all those factors. If it was an utter economic no-go, the industry wouldn't exist. If it was 100% clear that it was economically favorable for everyone in, say, LA, then you'd see PV systems on the roof of every house in LA whose owners had sufficient capital to pay for the system. The fact that the industry exists, but is still fairly small, tells you that there's a lot of uncertainty about it. You're welcome to invest your money in the stock market instead, but it won't help with global warming.

    Now the consumer electronics industry just needs to convert everything over to run on DC and I'm all set.

    Ain't gonna happen. Network effects are one reason. Another reason is that different devices naturally want to work from different voltages, but you can't step voltage up or down if it's DC.

  • Re:Wow (Score:5, Informative)

    by Zackbass ( 457384 ) on Sunday March 01, 2009 @05:08PM (#27032753)

    First Solar has a 25 year warranty on the power output of their panels. As far as I've seen this is pretty common for panels intended for large installations.

    Here's a couple random links to back that up:
    https://energy.wesrch.com/User_images/Pdf/L02_1221963706.pdf [wesrch.com]
    http://www.evergreensolar.com/upload/pdf/us/Warranty_Cedar_Spruce_v1.5-060329_US.pdf [evergreensolar.com]

  • Re:Wow (Score:1, Informative)

    by drinkypoo ( 153816 ) <drink@hyperlogos.org> on Sunday March 01, 2009 @05:16PM (#27032833) Homepage Journal

    Another reason is that different devices naturally want to work from different voltages, but you can't step voltage up or down if it's DC.

    Stepping voltage down is cheap and easy, you use a switching power supply. You can build one trivially for low voltage applications using one three-legged IC and two capacitors. For 5V, for example, use a 7805. The size of the caps is based on your current requirements. Without a heat sink you can usually do 150mW, with one, 1W. Need more watts? Add more 7805s (or whatever.) You're right about stepping voltage up, but these days you can get a cellphone charger which will give a considerable amount of 5V power to your phone from a common 1.5V lithium or alkaline AA battery... for about four bucks. Obviously stepping up DC voltages for low power devices is totally feasible at a low cost.

  • Re:Wow (Score:4, Informative)

    by frieko ( 855745 ) on Sunday March 01, 2009 @05:33PM (#27032999)
    [1] http://en.wikipedia.org/wiki/Switched-mode_power_supply [wikipedia.org]
    [2] I'm an EE
    [3] I've tried it.

    Of course, the first thing you have to do is take it apart and make sure it's a SMPS and not a traditional 60Hz transformer.
  • Solar Thermal (Score:3, Informative)

    by olddotter ( 638430 ) on Sunday March 01, 2009 @06:03PM (#27033295) Homepage

    There is an interesting link on Solar Thermal power at the bottom of the article. I think it is worth reading in relation to photovoltaic power options.

    Solar Thermal [popularmechanics.com]

    Blog Post [blogspot.com] on the articles.

  • Re:thats nice (Score:5, Informative)

    by An Onerous Coward ( 222037 ) on Sunday March 01, 2009 @06:03PM (#27033297) Homepage

    It's not too much of a worry. Concentrating solar power costs have been falling quickly as well, and they require nothing more exotic than reflective surfaces and mineral oil.

    Also from the Wikipedia page: "Recently, researchers have added an unusual twist - astrophysicists identify tellurium as the most abundant element in the universe with an atomic number over 40." Which disagrees with the thrust of your objections, but hey, it's Wikipedia. Who knows if it's thinking straight today. The tellurium page also says that cosmic abundance is far higher than terrestrial.

    Another thing to keep in mind: one of the reasons so little tellurium is mined is because nobody has had much use for it before. Also, if tellurium becomes a limiting factor, we should be able to get more energy out of each ton by using concentrating reflectors.

    As for the "put a ton in your basement" strategy, it may be sound. But Wikipedia advises that it is mildly toxic and should be handled with care.

  • Re:Wow (Score:2, Informative)

    by dwywit ( 1109409 ) on Sunday March 01, 2009 @06:22PM (#27033477)
    My PV panels are warranted for 20 years - if their output falls below 80% of rated power in that time, they're fixed or replaced.
  • by Kumiorava ( 95318 ) on Sunday March 01, 2009 @06:38PM (#27033651)

    You are confusing something here. To produce 1 kW of power you need to produce 1000 Watts. 1kWh is measure of this 1 kW of power production running for one hour. Therefore 1 W will have to run 1000 hours to produce 1 kWh.

  • by fullon604 ( 895424 ) on Sunday March 01, 2009 @06:46PM (#27033723)
    [A re-post of a comment from a few months ago] Guys -- you all seem to be neglecting the recent developments in solar financing. (Disclaimer -- I do work for SolarCity http://solarcity.com/ [solarcity.com] [solarcity.com] [solarcity.com], a leading installer of residential solar arrays in the SF Bay Area and beyond. We do use First Solar panels, in fact we're the only company using them for residential-scale projects in the US. I won't make a totally shameless plug here, I'm trying to be fair to the other good and clever solar companies out there. A rising tide lifts all boats!) By bringing in a 3rd party commercial owner via an Operating Lease or Power Purchase Agreement (PPA) structure, the customer can save money from solar on Day 1. The 3rd party (an investment fund, or perhaps the solar company themselves) owns the system and claim the full range of available incentives. Commercial owners can take accelerated depreciation on the system, and can utilize the full 30% federal tax credit , and they also get whatever state/local/utility incentives are available as per usual. The customer would have ZERO down-payment, and makes monthly payments over a period of ~15-18 years. There is no lien on the house. The tax investor receives a reasonable return on their investment over time, the installer makes reasonable margins on the installation, and the customers can save money from Day 1. Everybody wins! So to use the parent submitter's house as an example of what we can do -- For a $400/month average bill in Sunnyvale, CA, we might recommend a 7.7 kW DC system. Assuming the customer had decent credit (720 FICO), we would require no down payment, and then charge monthly lease payments of $216/mo, for 15 years. The monthly payments do go up at ~3-4% per year (we could alternatively have 0% escalation, but of course that would require a higher starting payment and so it's harder to show savings right away... there are many possible variations here. Also remember that local PG&E utility rates are increasing at >5% per year on average). With this 7.7kW system, they might expect their average monthly bill to go from $400 to $99 per month. Add the $216/month payment, and their new average monthly electricity cost is (216 + 99) = $315/month, for immediate savings of ~$85/mo!! [As a point of information, virtually all residential solar systems are grid-tied, so that when the panels are active during the daytime, the meter is often "spinning" backwards. This is how the utility-bill-savings part works.] The installers offering these plans usually include full service/maintenance for the life of the lease, including replacement of the DC/AC inverter if necessary. The customer is given the opportunity to purchase the system after years 6/10/15, or if they have to move or sell their house. The panels are warranted by the manufacturers to last 25+ years at 80-90%+ kWh output, so a long-term buy-and-hold strategy is solid. Or, if the customer looks around in 15 years and sees a better/cheaper technology, or just doesn't wish to renew or buy out), they are free to end the lease and we'll remove the panels at our cost. The customer who understands Net Present Value (NPV) calculations can easily demonstrate that this offers far superior savings compared to either a) doing nothing, or b) purchasing the system for cash. So before you all roll your eyes about solar being a poor investment with a many-year paybacks, please consider such alternative financing approaches.
  • Re:thats nice (Score:3, Informative)

    by znerk ( 1162519 ) on Sunday March 01, 2009 @06:59PM (#27033837)

    Dang, I had the same idea... now the price is gonna shoot up overnight as all the slashdotters rush to fill their basements with tellurium!

    Actually, a little googling came up with this tidbit of info:
    http://seekingalpha.com/article/55959-the-tellurium-supernova [seekingalpha.com]

    Looks like the price already did its little "massive production price increase"... partially due to its use in solar panels by First Solar, starting in 2005. (surprise!)

    Interestingly, tellurium is most commonly produced as a by-product of electro-refining gold and copper. From the article I linked, we discover that "Annual global tellurium production is about 170 tons to 200 tons, based on various different estimates." Combine this with the use of approximately 8 grams per panel (also in the article), and we discover that the most massive solar panel production was using... almost 4% of the annual production. The following year, that dropped to 1.6%. Tellurium is also used in recordable optical media and electronics (it appears it is used to dope silicon to make it electrically conductive), to name just a few other uses. It would appear that its primary use is as an alloying agent in iron and steel to improve machinability.

    While tellurium is likely to increase in value slightly over the next decade or so, this is not the makings of a "gold rush". To be quite honest, this isn't even really news, considering that First Solar has been using tellurium in their solar panels for 4 years now.

  • Re:Wow (Score:3, Informative)

    by ZOmegaZ ( 687142 ) on Sunday March 01, 2009 @07:08PM (#27033931) Homepage
    A true SMPS will do much better, but unfortunately is more complicated than one three-legged IC and a few caps. Actually, there are several companies that make board-mounted switching regulator modules, allowing you to step DC voltages up or down with >80% efficiency using... just a three-legged IC and a few caps. :) One company even makes one that fits in the same space as a traditional 7805, can't remember the name right now. They're a lot more expensive, but the lack of a heat sink and the additional efficiency is a big plus for certain applications.
  • Re:thats nice (Score:5, Informative)

    by NeverVotedBush ( 1041088 ) on Sunday March 01, 2009 @07:34PM (#27034157)
    "So, not only is there a pound of that stuff in the earth, but it is ALWAYS there. As soon as you take it away - BAM - another pound."

    What you are implying is that promethium is the result of a process subject to equilibrium processes. Radioactive decay is not an equilibrium process.

    I have no idea the natural abundance of promethium, but if you take away a pound of promethium, there is no "BAM - another pound".
  • Beats $3.89:W (Score:3, Informative)

    by Doc Ruby ( 173196 ) on Sunday March 01, 2009 @09:46PM (#27035177) Homepage Journal

    The current lowest price per PV watt [solarbuzz.com] is $3.89. Anything anywhere as cheap as $1:W would revolutionize the current photovoltaic solar industry, which is already just becoming a good priced alternative to getting power from the "city grid".

  • Re:Wow (Score:3, Informative)

    by Kneo24 ( 688412 ) on Sunday March 01, 2009 @10:06PM (#27035335)

    Well, I'll give you a clue. GrahamCox is right.

  • Re:Wow (Score:4, Informative)

    by frieko ( 855745 ) on Sunday March 01, 2009 @11:48PM (#27036103)
    http://bayimg.com/image/ianfdaabn.jpg [bayimg.com] Hey look, exactly what I said! This is approaching my tolerance of trolls so I'm done. But feel free to post some bs critique/excuse for me to ignore.
  • Re:thats nice (Score:1, Informative)

    by Anonymous Coward on Monday March 02, 2009 @12:56AM (#27036683)

    Tellurium is irrelevant. This is not a technical achievement as much as a financial one. In the first body paragraph of the Fine Article, it says:

      "But if we're concerned about the big picture (scaling up solar until it's a cheap and ubiquitous antidote to global warming and foreign oil) a forthcoming study from the University of Californiaâ"Berkeley and Lawrence Berkeley National Laboratory suggests that neither material has what it takes compared to lesser-known alternatives such asâ"we're not kiddingâ"fool's gold."

    And then it links to an abstract of another Fine Article, "Materials Availability Expands the Opportunity for Large-Scale Photovoltaics Deployment," Environmental Science and Technology; and they say:

    "We identify a large material extraction cost (cents/watt) gap between leading thin film materials and a number of unconventional solar cell candidates including FeS2, CuO, and Zn3P2."

    What this means is that IF someone invests in the R&D, the solar panels we end up with could be made of common semi-toxic stuff instead of semi-rare semi-toxic stuff. But having it look likely and profitable to shell-shocked investors is critical. $1/Watt does that neatly.

  • Re:Wow (Score:3, Informative)

    by berend botje ( 1401731 ) on Monday March 02, 2009 @05:46AM (#27038119)
    Or just plug it in and wait a minute. If it still works, it is an SMPS. When it starts to smell rather nasty, it was a traditional transformer.

    Actually, don't do this. It might be dangerous. Fire! Destruction! Loss of well-being! Don't do this, ok?
  • Re:Wow (Score:4, Informative)

    by Biogenesis ( 670772 ) <.overclocker.bre ... ptushome.com.au.> on Monday March 02, 2009 @07:25AM (#27038507) Homepage
    Why do so many people suggest LED lighting for solar instillations or other high efficiency applications?

    CFLs have similar efficiency ratings to LEDs, and a significantly cheaper. The Philips Tornado CFL above me has 75lm/W stamped on it, only the best Cree LEDs exceed this and are rated ~100lm/W when run at below their max power.

    I guess you need a slightly more expensive inverter for a CFL system, but it will probably still work out cheaper with CFLs over LEDs.

Intel CPUs are not defective, they just act that way. -- Henry Spencer

Working...