Want to read Slashdot from your mobile device? Point it at m.slashdot.org and keep reading!


Forgot your password?
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This discussion has been archived.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:
  • Wow (Score:5, Interesting)

    by Junior J. Junior III ( 192702 ) on Sunday March 01, 2009 @03:48PM (#27032009) 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. Assuming my roof has sufficient room for it, that's really awesome. My current electric bill is around $65/mo. which means that in 153 months this would be paying for itself, or about 12 years. Of course, figuring in things like maintenance, repairs, and so forth makes this harder to gauge, but that's pretty good. Now the consumer electronics industry just needs to convert everything over to run on DC and I'm all set. How soon can I put in an order?
    • Re: (Score:3, Interesting)

      by frieko ( 855745 )
      Most (but surely not all) modern electronics work just fine on 170 VDC, including computers and CFL lamps. (120VAC = 170Vp-p)
    • If I could get one installed for $10,000, it would be a no brainer. My electric bill averages around $300/month. It's lower in the winter ($275) and peaks around $350 in the summer.
    • 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.

      • [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
    • by evilad ( 87480 )

      Your peak load is irrelevant, unless you're planning to try to do this without a battery system. You really just need to meet your average load, and have enough storage capacity to last the rest of the day.

  • TCO (Score:5, Interesting)

    by phantomfive ( 622387 ) on Sunday March 01, 2009 @03:50PM (#27032025) Journal
    Here's something for you, that I didn't realize: apparently it costs MORE to install and set up a set of solar panels on your home than it does to manufacture them. It made me think, "wow, I'm going to install those myself for half the price!" but attaching stuff like that to the power grid is probably not a DIY project. And it isn't just a day labor job either. It's going to take a trained electrician, at $30-$60 an hour putting that stuff in.

    So, their goal is to get the cost of manufacturing down to about 60-70 cents a watt, and the cost of installation down to $1 a watt. I didn't realize the hidden cost of installation was so high.
    • 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.

    • Re: (Score:3, Insightful)

      by icebike ( 68054 )

      Well it is getting to be a DIY field, with controllers and isolators being available off the shelf as well as hundreds of how-to sites springing up all over the web concerning wind, micro-hydro and solar augmentation.

      But its no surprise that installation costs more than the pieces, that's sort of true about just about anything other than plug-it-in-turn-it-on appliances.

      Still there is no reason to assume that the basic modules coming out of FirstSolar's plant are anywhere near ready for Joe Sixpack, and TFA

    • 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: (Score:2, Interesting)

      by Anonymous Coward

      IAAE (I am an electrician) and I can tell you that the major cost consideration of a on-grid PV system (after the panels themselves) is the grid tie inverter. They are SERIOUSLY expensive. The off grid equivalent would be a battery bank which is just as expensive and a potential environmental disaster in the making.

      If you want to save money, energy and the environment then I would suggest a vacuum solar hot water system any day of the week. Much cheaper, much more efficient and still does some dam useful wo

    • Those panels aren't going to last forever, and unlike silicon panels which may involve some toxics during manufacturing but aren't bad once they're finished, cadmium's a nasty toxic material, so cadmium-telluride panels aren't going to be something you can send to the dump for free; I don't think anybody knows what the disposal costs will be.

    • by S-100 ( 1295224 )
      The other figure often neglected is the amount of power (in kWH) generated based on your locale. Obviously, solar panels generate nothing at night, but depending upon your longitude and other factors, the average power generated is substantially less than 1/2 the rated output. For me, the figure is 2.5 full sun hours, which means that the daily average output is the rated output of the panel for 2.5 hours. So, a 10 kW array, which would generate 10 kW under full sun conditions will only generate 25 kWH o
  • Tellurium (Score:4, Interesting)

    by wiredlogic ( 135348 ) on Sunday March 01, 2009 @03:54PM (#27032055)

    Volume production will outstrip the world Tellurium supply in the near future so this isn't going to be a cost effective technology for long.

    • Re:Tellurium (Score:5, Insightful)

      by wjh31 ( 1372867 ) on Sunday March 01, 2009 @04:01PM (#27032129) Homepage
      This is something we are told about just about any mineral resource, and usually once it gets short, we manage to find a new resource, obviously this cant happen forever, but running out mightnt be an issue for a while. Also it means this technology isnt going to be cost effective for long using the current materials.
      • Re:Tellurium (Score:5, Insightful)

        by QuasiEvil ( 74356 ) on Sunday March 01, 2009 @04:25PM (#27032343)

        Mod parent up - the mining industry typically just isn't wandering around prospecting for new ore veins unless they a) don't have enough reserves to meet projected demand or b) the price is high enough to justify opening new mines. When the price gets high enough or the reserves get low enough, they go looking and they usually find something. Most of these alarmist "we're out of element X" projections are based on proved reserve numbers, which are just what the mining companies know about *right now* and can extract.

        It won't last forever, but there's a lot of ground out there to be dug up yet. I can't promise it'll be as economical to extract as current reserves and prices may fluctuate accordingly, but there *IS MORE OUT THERE*.

      • Lets not forget the obvious, once we figure out how to do it with one material successfully we starting looking at cheaper and more common materials that could do the same thing. Especially true when a market has become successful rather than a pure research project.

    • You apparently understimate the rising costs of energy [what-is-what.com] of _all_ types. It is a feedback market, as one type of energy chages price, the others change along with it to keep within a natural price ratio. That ratio changes in the short term, but in the long term non-renewables become more expensive and renewables become cheaper. Are you arguing that solar energy is a non-renewable energy resource because of the tellurium supply? You do realize that there are tellurium supplies that are not currently being min

    • Cadmium's a really nasty material - even if it's available in significant enough quantities to transform the electric industry, it's not the kind of stuff you want to have getting into the water system.

      • Well, so is tellurium. Individuals exposed to tellurium even at very low concentrations develop "tellurium breath," a foul garlic-like odor. As an undergrad in chemistry in college, I was informed only half-jokingly by a professor that was an occupational hazard that had restricted our knowledge of the element.

        However, from a production standpoint its scarcity is troubling; Wikipedia states its presence is lower in the crust than that of platinum, making it the rarest stable element by concentration. 500

  • Not only is Tellurium extremely rare, Cadmium Telluride is toxic and I wouldn't want to work in a factory that handles the stuff. (although rendered harmless when build into solar cells). There is nothing to celebrate here. As long as we are not able to create energy (or most other high tech) without using up the rarest of earth's elements at an alarming pace, this is a dead end.
    • by dotancohen ( 1015143 ) on Sunday March 01, 2009 @04:05PM (#27032169) Homepage

      This sounds like the classic solar is not a renewable energy source [what-is-what.com] tale because of the non-renewable materials in solar cells. You do realize that once the cells are built, that they continue to work until damaged or otherwise decommissioned, and that the nonrenewables are not consumed in the process? Also, there are alternative materials to use, and alternative places to mine what there is.

      • and, once they are damaged or destroyed, the materials can be reused ...

        • Re: (Score:2, Funny)

          by Anonymous Coward

          Nonsense. All the edges have been rubbed off the atoms, they'll never work as well again.

        • by vlm ( 69642 )

          and, once they are damaged or destroyed, the materials can be reused ...

          Tellurium is extremely rare... the best "ore" source for it would likely be .... used solar panels. Instead of meth addicts stealing the copper power lines, they'll start stealing panels for tellurium recycling. Weird but true. Wait till all the meth heads figure out automotive catalytic converters contain precious metals, and not just the high functioning ones know.

    • by QuasiEvil ( 74356 ) on Sunday March 01, 2009 @04:35PM (#27032441)

      I hate to break it to you, but nearly everything is toxic at some level. The ugly truth is that we're not going to get to a green utopia without some exotic materials that'll probably kill you if you look at them funny. Coal and oil are very safe, non-toxic materials - as is any reasonable concentration of CO2 - but the reality is that they're not green overall. The "green-ness" of a material is in its overall impact, not in its intrinsic properties. We can engineer around the fact that handling them is toxic - it's just a process and plant design question.

      We aren't going to build a completely renewable energy infrastucture out of rainbows and ponies. It's going to take some very strange stuff, much of it not good for you. We just have to manage it well.

  • How does this compare? My gut reaction is that, government subsidies aside, per kilowatt-hour, I'm sure just about ANYTHING is cheaper than solar at this point.

    When will we finally start building cheap, efficient, and above all clean nuclear plants again instead of wasting our time with this solar and wind crap?

  • One shouldn't forget that the watts in all these price per watt numbers are peak power. From Wikipedia [wikipedia.org]:

    A common rule of thumb is that average power is equal to 20% of peak power, so that each peak kilowatt of solar array output power corresponds to energy production of 4.8 kWh per day (24 hours x 1kWh x 20% = 4.8 kWh)

    In many parts of the world it's even less.

  • by vlm ( 69642 ) on Sunday March 01, 2009 @04:55PM (#27032607)

    The reason why $1 per watt is important, which isn't mentioned in the summary, is not just that it's a nice round number, but the capital cost of electricity for most major industrialized nations averages about a buck a watt. Some more, some less, depends on the cost of land and the economic conditions when the plants were built, technology level, pollution controls, etc, but your local electrical power company happily pays about a buck a watt to build a traditional non-solar plant.

    Solar only works half the day, but probably much lower maintenance, slower depreciation, and no fuel costs at all.

    So, it now costs "about the same" to build a 1 GW coal, a 1 GW natgas, a 1 GW nuke, OR A 1 GW SOLAR ... Which brings solar into the corporate boardroom.

    • by shermo ( 1284310 ) on Sunday March 01, 2009 @05:17PM (#27032851)

      You mentioned that solar only works half the time, but you seemed to dismiss it as irrelevant.

      Total capacity is a very misleading metric to measure power stations by, and is meaningless without information about it's utilization.

      Obviously solar panels only generate when the sun is shining, just like wind plants only generate when the wind is blowing. A very good wind farm will get 40% utilization. A very good solar farm will get maybe 25% utilization.

      And that's not the whole story either. It's also interesting to look at the demand weighted generation. This is a way of accounting for generation being more useful when demand is higher. In general, solar panels have a higher DWG in hot climates (air-con when sun is shining), and a lower DWG in cold climates (heating when sun isn't).

      Current installed prices are about $5/Wp, and I'd be suprised to see %1/Wp before 2015.

  • 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.

      What about this time? [slashdot.org] That was over a year ago.

  • 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.

  • Thermal Solar (Score:5, Insightful)

    by MrKaos ( 858439 ) on Sunday March 01, 2009 @06:05PM (#27033311) Journal
    Thermal Solar is making some great advances and even pushing the boundaries of Stirling engine design. The picture [peswiki.com] is an animated gif of a parabolic dish mounted generator - note the interesting design of the alternator off the power piston.

    There is a lot going on in Thermal Solar right now as it has the greatest potential to meet base load power needs when coupled with molten salt storage. [wikipedia.org]

  • 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".

The optimum committee has no members. -- Norman Augustine