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In the rush to get the solar energy systems up and running, we are throwing low-efficiency PV cells on prime solar land. This does not make for a good investment. Subsequently, there are three major cost factors that include PV efficiency which make for a good solar PV farm. I will discuss these factors later. But, let us divert for a moment to delve into some other PV areas.
Quality: Approximately 92% of all PV cells produced are the crystalline silicon (c-Si) type. Many manufacturers in the silicon PV industry utilize the gravitational deposition of silicon, be it either as molten silicon, particulate silicon in a solvent, or decomposition of silane on backing plates. In most of these PV cell fabrication processes, recrystallization at high temperature is done. However, there are still quality problems.
There are several technical reports concerning silicon layer uniformity and performance by the industry's current method. Hsu, et.al., have indicated uniformity problems (1). Oxygen precipitates (SiO2) which interrupt the uniformity of silicon layers is discussed by Wang, et. al (2). P-type and n-type doping via ion implantation results in induced lattice damage and non-uniformity (3). Plasma enhanced chemical vapor deposition processes have resulted in chronic non-uniformity of deposited layers (4). Graf, et.al., has shown improved silicon wafer integrity after annealing at 1200 degrees C in argon and hydrogen atmospheres. This shows some reduction of crystal defects with some improvement in uniformity (5). Shimizu, et.al. has used the Bridgman method for phosphorus deposition that resulted in crystal defects (6).
Conversion Efficiency: Solar conversion efficiency of the PV cells is important from several aspects. The efficiency appears several times in the cost factor equation as shown later.
A number of reported attempts have been made in improving silicon's direct conversion efficiency by improving high temperature annealing or sintering. K. Drain has announced a silane laser decomposition method for deposition of silicon on monolithic large glass substrate. Recrystallization was conducted at high temperatures (8). Konarka has shown a 12% efficiency with its thin film hybrid silicon (a-Si) PV cells (9). Although, no aging studies have been done. They are doing further research with IMEC (Belgium) to improve that to >20%. Signet Solar has started manufacturing thin-film silicon modules that achieves 6.2% efficiency (9). NREL tested Global Solar Energy's (GSE) new prototype CIGS cell at 15.45% but GSE's production cells are still 11.7% (10). In addition, CdTe production solar cells as made by First Solar achieves 9% efficiency (8). EMPA, the Swiss Federal Labs have improved the efficiency of flexible CdTe cells to 12.4% (11). Both CdTe and CIGS are susceptible to efficiency degradation by moisture.
A recent contract signed by Evergreen Solar (c-Si) requires PV panels of 19% efficiency (9). The "Q-Cells" Company has achieved 15% efficiency for their crystalline Si cells (10). However, in all cases, the efficiency for field installed solar PV cells should achieve 20% or higher for good return on investment.
Solar Tracking: There are two types of solar tracking equipment for mounting the PV modules. These are 2-axis and single-axis tracking units. The current 2-axis tracking units do not gain sufficient increase in wattage to be economical during the lifetime of the PV modules. For the single-axis tracking units, they would be a marginal investment if their installed price is below $0.50/watt.
Cost Factors: There are three major cost factors that can be developed for the cost of the installed PV modules. The solar PV efficiency is an important factor in two of the three major cost factors. The three major factors are:
Land area cost
PV module cost
and can be shown as:
Total Cost = Land area cost + PV module cost + Installation cost
For a good return on the investment, all three factors should be minimized. The land area required for a given PV solar farm, e.g. 20 MWe, is dependent inversely on the solar cell efficiency:
Land area required: 20 x 103 kW/(1 kW/m2 x solar PV efficiency)
For the given solar farm size of 20 MWe, the PV module cost can be expressed as:
(The factor 1 kW/m2 is the solar insolation factor at noon.)
The third factor, installation cost, is composed of a number of items including module support structure, labor, land preparation, etc.
In summary, for a given "farm" size and when the solar conversion efficiencies approach 22% vs. current 9-14%, then fewer acres are required and, hence, the land cost is lower. In addition, fewer PV panels are required and, therefore, installation costs are less.
Cost Reduction: For the past three years, ICT Corporation, a little known company in upper Michigan, has experimented and developed a unique and innovative method for producing crystalline PV cells. This new development produces the Solar Industry's lowest cost PV cells based on their 40 years experience in high temperature furnaces.
ICT's innovative high temperature process directs the silicon material to the proper surface area without any loss of expensive silicon material. This process overcomes the surface energy of molten silicon using a new unique vacuum/purge high temperature centrifuge process designated as the "FW"process. This method spreads the molten silicon uniformly to any chosen thickness. The extreme thinness of the silicon layer (0.0017") on the backing material enables a very significant lowering of manufacturing energy use and material cost.
This very thin layer is the underlying reason for many advantages of this approach. Primarily, minimizing the loss of expensive silicon, i.e. approximately 1/15th of the amount of the sawn methods. Secondarily, the method only heats about 1/10th the amount of silicon resulting in an obvious energy savings. Finally, the method crystallizes the silicon much faster due to the small volume. A crudely-fabricated first version of the high temperature "FW" unit has been used to make small prototype PV cells. Chemical analysis has indicated no harmful defects and the silicon is crystalline. ICT has received one U.S. Patent with six more U.S. Patent applications made and international patent applications being developed.
Independent external review of prototype PV cell has been completed at MIT, Arthur D. Little and Miami Research Labs with highly positive reports. M.I.T. has stated: "these were made of silicon on graphite cells provided by ICT... of the curves, the one in (a) is the one closest to ideal and is the best of all cells tested, including single crystal cells... control of the degree of penetration of the graphite by the silicon layer is unique to the ICT process -- in no other process known at this time is there a way of controlling substrate contact area.
Independent cost analysis has shown a $0.76/watt production cost for up to 40 MWe. This is 25% lower than First Solar's recently announced "lowest production cost" of $0.98/watt (March 2009). First Solar's FOB factory selling price is $2.50/watt (8) while ICT's price is projected at $1.75 (FOB, Michigan). Their current goal is fabrication of PV cells with 20% efficiency. This will make inexpensive solar energy available to homes and businesses.
The innovative "FW" method is broadly applicable such that it can be applied to the improvement in efficiency and cost for the electrolysis electrodes. By applying ICT's "FW" method to the development of nickel electrodes, this removes the expensive platinum electrodes as well as increasing the electrolysis efficiency and, hence, reduces the size and cost of the electrolysis unit. This can also be done using the nickel electrodes for fuel cells. Hence, this would bring down the cost of fuel cells and make them available for auto makers to produce fuel cell autos. ICT's innovative development has far-reaching applications.
Summary: Rapid strides are being made to improve the quality and efficiency of the crystalline silicon solar cells. Silicon solar cells have the added advantage of having a much higher efficiency and lower cost than either the current CdTe or CIGS PV cells.
(1) Hsu, J-C, Lee, C-C, Kuo, C-C, Chen, S-H, Wu, J-Y, Chen, H-L and Wei, C-Y, Applied Optics 44(20) 4402-07, 2005
(2) Wang, Q., Daggubati, M., Yu, R., and Zhang, X-F., Appl. Phys. Lett. 88, 242112, 2008
(3) Sundaresan, S., Doctoral Diss. George Mason Univ., Oct. 2007
(4) Zhao, A., Bulgar, J.M., Green, L.P., Harris, W.C., Hunt, T.J. Marchesseault, W.R., Shuman, R.F., French, M.C. and Lisy, H.C. Adv. Semiconductor Manufacturing Conf. IEEE/SEMI issue 11-12, 143-148, 2005. See also: Xiang, B. et. al.,Nano lett., 2007, 7(2) 323-328.
(5) D. Graf, U. Lambert, M. Brohl, A. Ehlert, R. Wahlich and P. Wagner, J. Electrochem. Soc. 142 (9) 3189-92, 1995.
(6) A. Shimizu, J-I Nishizawa, Y. Oyawa, K. Suto. J. Of Cryst. Growth, Techn. Conf. #1 Sendai, Japan, 2001 229, p119-123.
(7) K. Drain's NanoGram Corp. development as reported by D. Vogler, Sr. Tech. Ed., PV World 21 May 2009.
(8) Doty, "Solar Photovoltaic (PV)" www.dotyenergy.com/markets. See also: Plenary Lecture: "The Solar-Hydrogen Economy - An Analysis" by W.D. Reynolds, presented August, 2007 at SPIE's International Solar Energy Conference, San Diego, CA.
(9) See www.q-cells.com /en/products
(10) See "Global Solar Energy's CIGS Production Material Achieves 15.45% Efficiency" Photovoltaic Wire News: www.electroiq.com 9/18/09
(11) See Thin Film Today Newsletter, 3 September 2009.
For information on purchasing reprints of this article, contact sales. Copyright 2013 CyberTech, Inc.
Interesting article. Solar PVs are great for very wealthy tinkerers and idiots, and politicians (but then I repeat myself) who want to look good, but without disclosing costs and limitations. Carter put them on the White House - at taxpayer expense - and Regan took them off. The Obamas will probably put them up again to go along with their 'organic' lifestyle - if they have time, and to h..ll with the deficit!
They are also useful in some ways - small scale - where the grid does not go, and in very small scale applications like calculator power. For large and reliable operation, they are a bust.
Bob Amorosi 10.14.09
I commend the engineers and scientists at ICT Corporation for their efforts in innovative manufacturing. It is these kinds of people who through their creative thinking and practical experimentation that deserve to be called industrial heroes, for they are the types that sometimes achieve breakthroughs in technology that can have a profound impact on industry and the economy down the road. Given the sad industrial demise in the US and Canada over the last few decades, it is becoming very rare to see results like this unfold in a US company anymore.
I hope ICT's name and their people go down in the history books someday after becoming highly successful commercially from their pioneering work.
Bob Amorosi 10.14.09
Note also the above post of J.K. Sutherland, for his dim view of the solar PV technology is typical of many people in industry who denigrate the efforts of new innovation, especially if it threatens in any way the established energy industries. Sure there have been many failures in the past to make solar PV competitive with other large scale generation, but there are never any guarantees in technological research and development - except for one. It's like buying lottery tickets where if you continually buy some you are not guaranteed to win, but if you buy none you are guaranteed to lose.
Jim Beyer 10.14.09
If these lower cost cells are real, that might mean an installed cost of perhaps $1 per Watt. What would that mean? I'm not sure.
As for the politics of Solar energy, I'm not sure what was worse, Carter putting them up, or Reagan taking them down. Given they were already there, I can't see the harm in them. Perhaps they didn't match Nancy Reagan's new China (also bought at taxpayer expense).
Jim Beyer 10.14.09
The Carter Solar Panels cost $28,000 (they were for hot water, not electricity). The Reagan China was $209,000, though it was paid for with private donations. My mistake.
Joseph Rosenthal 10.15.09
I am all for technological innovation so long as it is paid for by the entrepreneur/venture capitalist. I don't want the ratepayers I represent subsidizing anyone's new "socialize the risk/privatize the gain" scheme. Also, generally, anyone who wants to decorate his or her giant home with a solar panel to impress his or her friends should pay for it. Electricity is expensive enough in the Northeast already. I could certainly also live with letting Europe pay for the R&D and the testing for solar and other renewables, then stealing the best technology.
Economies of scale still work in the electricity industry, as evidenced by, well, every place in America that has actually achieved relatively low-cost power.
Jim Beyer 10.16.09
I agree with you. The problem is how much oil is subsidized by our armed forces and gov't involvement in general. Based on your comments, our Middle-East involvements should be paid for by Exxon and Chevron. Others might argue that the Price-Anderson act represents a subsidy to nuclear power by having the government provide reinsurance to our nuclear power plants.
It is disruptive to think about digging this all up, as the status quo has been working pretty well for some time at this point. The problem is that the embedded subsidies have a significant edge over new technologies. I wish there was a more orderly method of updating our technology, but politics and human behavior seem to prevent that from happening.
Bob Amorosi 10.16.09
I sympathize with you big-time on the point of "socialize the risk/privatize the gain", it seems very unfair to taxpayers. The trouble is entrepreneurs and VCs with deep pockets are increasingly hard to find that will fund the R&D of new energy technologies.
The reasons are because firstly energy tech is extremely risky given the industry is so heavily regulated and controlled by government. A political decision can wipe out one's investment in R&D with a stroke of a pen, or similarly make some projects wildly successful. Future political decisions affecting energy are extremely unpredictable.
Secondly, the US and Canada are experiencing a continuous demise in their manufacturing industries, and when combined with the current recession that chokes off money from being spent on R&D and creates massive unemployment, desperation rears its ugly head. In other words, if government doesn't spend public money to help foster new R&D, in hopes of creating new domestic energy industries down the road, few others in the private sector will.
Remember my post comparing R&D to lotteries - continued investment in R&D is never guaranteed to win, but if no one invests America is guaranteed to lose.
And guess what else Joseph, if any new domestic energy industries become viable technologically, governments all over the globe will ensure their commercial success. They will do so by FORCING the public to buy into their technologies. You can see it happening already with the lucrative grid feed-in tariffs being set for renewable source generation, carbon taxes or cap&trade schemes looming on government radar screens, and forced energy efficiency targets being imposed on future manufactured consumer products.
Joseph Rosenthal 10.16.09
Good points. I guess the other thing I don't understand, though, is why the green industries won't end up leaving when the subsidies stop just like most other industries have. Why would wind turbines, solar turbines, fuel cells, etc. be built here in the long run rather than in China or someplace even poorer than China. We'll pay to get the industries on their feet, and then they'll leave when they can, just like in "Roger and Me." Right?
Bob Amorosi 10.16.09
Very true, the threat of cheaper foreign competition stealing all our manufacturing of new products after we foot the bill to develop them is constantly present. The Ontario government for example has a solution to this threat: the lucrative grid feed-in tariffs are only going to be awarded to those generators built with 40%, and later 50%, local content, meaning a large portion of the facilities’ costs paid to domestic labor or manufactured materials. It has already started attracting existing foreign manufacturers to negotiate setting up new manufacturing plants in Ontario for solar cells and related inverter equipment. Samsung is one of them I am aware of, there are others too.
Governments are also gambling that in many years time when the subsidies come down, their manufacturing costs will have also come substantially down. They are speculating production and maintenance costs will be low enough to keep renewable source generators on line competitively, and the volume manufacturing that created a large penetration of renewables into the grid by that time will have brought their manufacturing costs down low enough to keep building new ones economically.
In my industry, the electronics industry, we have been fighting cheap foreign competition now for three decades if not longer. The only way some survive is to continually innovate, meaning continuously develop next generation products to stay ahead of competitors. Once you mass market a new commercially successful product, it is almost routinely expected that it will have a relatively short life cycle, to be cloned within a year. After that prices begin dropping for it, and so you are already developing the next one where, in smart companies, it is critical that profits from the successful products get re-invested in a continuous R&D stream, tapping into all the government tax break incentives that go with it.
Such rapid and continous innovation has historically been a foreign concept happening much more slowly for energy generation technologies, in part because of the much longer product life cycles, but also because of all the embedded subsidies that conventional power generation and energy sources have received keeping our energy bills relatively extremely low.
Len Gould 10.19.09
This whole discussion goes moot on the day PV generated electricity reaches parity with retail centrally generated electricity. Knowedgeable insider predictions range down to as near as 2012.
Joseph Rosenthal 10.20.09
I can't imagine this discussion moot in the absence of economical energy storage, but perhaps I'm missing something.
Also, 2012 for solar PV power to cost the same as, say, natural gas power (never mind coal)? I hadn't heard that. Massachusetts is paying 90 cents a kwh for solar right now, I believe, so I would think the parity in pricing would be a longer way off, if it ever happens. Is there an assumption of some massive natural gas/oil shortage baked into the 2012 estimate?
David Sweetman 10.20.09
Your points about PV economics are reasonable for utility scale installations, but are not applicable for residential, especially rural. The ROI for PV a residence can make sense now (especially if do not have to deal with urban cost adders), but that is not yet true for utility scale PV. Other renewable energy sources for utility scale generators have better ROI now. Large scale implementation of residential PV eliminates all the immediate concerns for new transmission and distribution lines.
The technical problems you mentioned have long since been resolved in the IC industry. However, without a standard setting organization (such as JEDEC for the IC industry, including free documents for manufacturing, marketing, quality, reliability, shipping, labeling), there is little reason the expect the renewable energy industry will achieve the same continuous cost and performance improvements that propelled the IC industry to dominance.
Since the most productive workers in the world are in the USA (except where there are strong unions), the major impediments to manufacturing in the USA are not labor costs, but the costs of capital, government regulations (all the people to fill out the paperwork), taxation, and poor management (too many MBA's with emphasis on accounting not operations). Address those issues and the differences in ROI between the various energy technologies becomes a moot point.
Jim Hoerner 10.20.09
Solar cells work great in the correct application. For example, for powering the calculators of nuclear engineers.
Mike Vande Voort 10.21.09
PV, like wind energy, in the context of national energy policy, is still a hobby horse approach to this country's energy security and requirements for long term economic competitveness. I applaud all the technology and innovation in the PV industry, but that argument is a nonsequiture to the real issue. The first question to be asked and answered is the following; How do we DELIVER elecricity to the end user, 24x7x365x 99.9999%, for 6 cents a kwh or less ? Address that questiion and let he details take care of themselves. PV has another serious shortcoming. One good volcano eruption and all you're left with is acres of expensive dust collectors.
Part of that solution is demand response. I don't know about you, but my retail price for electricity (with delivery) is above 10 cents, and it is much higher on the coasts. Demand response would lower costs for everyone, and would make renewables more viable. (That being said, it should be done bottom up (real-time pricing) not top down.)
Another part of that solution is using a bit less electricity. A 10% efficiency increase is (sort of) the same as reducing the energy cost by 10%.
Joseph Rosenthal 10.21.09
Demand response may help at times, but if we have a massive switch to plug-in cars we are going to need iron-and-steel resources.
Also, if you are basing demand response on baseline usage my guess is that you are frequently buying air, as the baselines can be faked or insufficiently updated.
Finally, there is a known potential overpayment problem for demand response participating in energy markets, as they are selling somehting they haven't "bought."
Demand response has its place. I can't imagine it has a very big place. In the long-run, it might be better to just have smart meters and time-of-use pricing and then people can respond or not to the pricing as they see fit, without having a demand response "program" and middlemen. However, I know I won't win that argument.
Mike Vande Voort 10.21.09
I am all for efficiency, but low cost energy benefits everyone. Why is it that we have to find so many gimmicks to rationalize "renewable" energy ? Wind energy is a fool's errand using endles rationalizations based on junk economics. But heh, build 'em all you want, just don't use tax subsidies to do it. In Nebraska, we get commercial rates under 6 sents (great for data centers !) and I understand that in the front range of Washington state it can be had for a nickel.
Jim Beyer 10.21.09
I'm 95% in agreement with you, but spewing mercury, emitting lots of CO2, leveling mountain tops, and clogging up half of our rail lines could be considered pretty "gimmicky" for coal, if it weren't the status quo.
Bob Amorosi 10.21.09
"the major impediments to manufacturing in the USA are not labor costs, but the costs of capital, government regulations (all the people to fill out the paperwork), taxation, and poor management (too many MBA's with emphasis on accounting not operations)."
I suggest it depends heavily on what industry you are talking about before dismissing labor costs as being insignificant in the US. If a manufactured product is largely produced by machines in large volumes, I would agree labor is a small contribution to costs, but not so for labor intensive manufacturing. A good example is in the clothing industry where Levis, the well-known jeans maker, has absolutley no sewing plants left in North America.
Bob Amorosi 10.21.09
An example of highly automated manufacturing is in the food packaging industry where after the farm has delivered the raw food, its packaging is almost totally done by machine. Hence we have plenty of canning companies, cereal and potato chip packagers, and so on, in the US.
The US has prided itself on having a highly productive workforce mainly BECAUSE of its pioneering history of adopting a high level of factory automation. But as automation has proliferated over the last few decades, invading practically most industries to some degree, eventually the other costs you cite David become relatively important. Indeed many former US companies that were highly automated now find it cheaper to set up their machines in far-east countries to do business.
Bob Amorosi 10.21.09
Low cost energy benefits everyone, sure it does, but the whole world doesn't see many low cost sources down the road anymore. Oil will spike in prices more and more as we pass the production peak, coal is too harmful costing us the environment, and nuclear is too costly up-front to build and fraught with waste disposal and safety issues that the public cannot stomach in spite of its cheap production costs. So what else is left besides pushing efficiency upgrades on everyone, deploying renewable source generation, and pushing demand response programs or conservation on everyone.
Larry Kelley 10.21.09
Dr. Reynolds was very generous to include ICT, Inc. in his article. We are not in production as of yet. We have made 100's of individual cells during out development process. Each of those cells were quite small, measuring only about 0.5" x 0.75". We never assembled any into 'arrays' of any size.
Dr. Reynolds is correct with this statement: " Independent cost analysis has shown a $0.76/watt production cost for up to 40 MWe. This is 25% lower than First Solar's recently announced "lowest production cost" of $0.98/watt (March 2009). First Solar's FOB factory selling price is $2.50/watt (8) while ICT's price is projected at $1.75 (FOB, Michigan). Their current goal is fabrication of PV cells with 20% efficiency. This will make inexpensive solar energy available to homes and businesses."
Obviously, with a 76¢/watt manufacturing cost for a finished array, we could easily sell for $1.75/watt. I would be very wealthy if we could do that! I think a selling price closer to $1/watt would be much more realistic. The only way for solar photovoltaics to compete globally is to make the selling price VERY low. There is NO room in the legitimate solar photovoltaic business for excessive profits.
Also, if you check some of the present photovoltaic manufacturing companies , Evergreen Solar for instance, you may note their financial statements are starting to show the truth about their actual costs.
Larry P Kelley President/Founder ICT, Inc. Shelby, MI 49455 231 861-2165 email@example.com
Len Gould 10.21.09
Mike Vande Voort thinks the first question is "How do we DELIVER elecricity to the end user, 24x7x365x 99.9999%, for 6 cents a kwh or less ?" -- You obviously believe that fairly simple coal generation with free access to commons for waste disposal is a long-term competitive model, but it isn't. It's a selfish short-term "me first, ignore the grandkids" strategy which is not sustainable. (See Scientific American this month).
Sounds like just another stalling article. If we wait for the best technology we never get started, Most solar real estate is essentyally free (rood tops)
Bob Amorosi 10.22.09
"This will make inexpensive solar energy available to homes and businesses." I believe your pioneering heroic company is on the verge of becoming very rich someday, particularly if you partner with distributors and installation companies selling to residential and small business commercial people. I believe these applications rather than large utility-owned solar farms in rural areas have the most potential for large volume commercialization.
The vast numbers of rooftops potentially available on residential homes and small business commercial buildings all over North America are a huge market since these types of sites present the lowest costs to integrate into the grid for a number of reasons. They can be privately owned by the building owner and hence don't suffer from NIMBYs or environmentalist opposition. They don't require long haul transmission lines to connect into the grid since they are by definition already at an end-point on a local grid. And most importantly they can be used to augment the owner's energy use lowering their local utility bills, and can sell excess capacity at times back into the grid.
New home builders and commercial property developers should be partnering with this in a big way for new building construction because these are the low-hanging fruits that are easiest to capitalize on. Just think for a moment what a prospective home buyer would think when shopping for a new house if their local home builder offered a state-of-the-art solar PV power system integrated into the roof of a new house, where its cost was included in the selling price of the house. They could advertise dramatically lower household energy bills, plus the ability to make extra income by periodically selling excess capacity back into the grid, all for a paltry small marginal increment on the mortgage payment to pay for the system.
Mike Vande Voort 10.22.09
I wasn't necessarily talking about coal, and the nuclear waste issue is a problem created by governmnet bureaucrats. With the exception of mecury, and a great deal has been done towards remediation with respect to mecury and coal fired plants, there isn't any valid reason not to use coal for another two or three decades.Clogging rail lines ? I have no doubt that our railroads are more than happy to have their coal business. Unit trains of 120 cars, all filled at the same place and time (from holes in the ground in Wyoming by the way) are probably very efficient and profitable.
What most of you don't seem to get is that PV, whether on vast tracts of land or rooftops, isn't going to result in huge energy savings. By the time you amortize the cost of the PV array and installation, include the extra maintenance to all the components exposed to the weather, the energy storage systems, insurance, etc, your cost per kwh will be higher than store bought electricity. Most of you I fear have no concern ( or maybe idea) for the average guy's cost of living. In my part of the midwest, the everage roof last 10 years, mostly due to hail damage. Then there's is that troublesome issue of snow, are you going to deice these arrays as well ? PV is a non starter.
Lastly, Scientific American has been reduced to little more than a pathetic green rag. Compared to what this publication was 30 years ago, it's the scientific equivalent of the national inquirer.
Bob Amorosi 10.22.09
Frankly I wouldn't care if my rooftop solar PV system got covered in snow a few or half dozen times a year during snowstorms. It's just a few more days (or hours if I shovel it off) of out-of-service in addition to the absent night-time operation every day of the year.
As for cost per kwH, wake up and smell the coffee Mike. Solar fuel is free in case you haven't noticed. Granted fuel is only part of the costs, and costs of PV systems take years of amortization now to recover, but guess what, prices for your "store bought electricity" are on their way up, ... way up, particularly after all the changes looming on our utility industry get factored into the massive rate increases coming down everyone's throats soon. And combined with dropping solar PV hardware costs over time, it won't be long before solar PV will compete with store bought electricity.
Len Gould 10.22.09
Scientific American = National Enquirer? ?? That's like comparing the BBC to Fox News.
S. F. P. Zwart, Professor of Computational Physics.
R. D. Fields, editor in chief of journal Neuron Glia Biology
M. Z. Jacobsen, prof civil and environmental eng., Stanford and M. A. Delucchi researcher at UC Davis.
Kate Wong, editor SA, Bachelor's degree in physical anthropology and zoology from the University of Michigan.
Micheal Moyer, staff writer
Dickson Despommier, prof. at Columbia.
(interview on future of autos) L. D. Burns, VP R&D GM. B. Reinert, Nat. Mgr. Adv. tech TOyota USA. M. S. Duvall, Director Elect. Transport EPRI. J. B. Straubel, CTO Tesla.
Above are the credentials of the authors of all main articles in Nov. 2009 Scientific American. ?=Enquirer? Perhaps your prejudices are colouring your judgement, just like your wishing that solar energy will not shortly radically re-structure the energy industry.
Say a local home builder offered as an option a complete solar PV system built into the rooftop, connected with all the necessary hookups to the local utility grid, and with the utility company's official blessing. The option costs say an extra $10,000 on the house price, which is not unthinkable if the technology development continues on its current pathway.
Say the cost added $100 a month maximum (probably less), to my mortgage payments. Augmenting my personal grid power use it saves an average 30% on my monthly electricity bills, the latter which might typically be $100 a month without it, on average. Say the utility company paid me for any excess capacity sold back to the grid during daytime hours, and at a hefty feed-in tariff premium at that.
To top it off, say the manufacturer makes provision for an easy future hookup to store excess capacity output if say economical residential storage is developed down the road that could be retrofitted to my house too.
Sound like I am dreaming? It’s getting closer to reality in places like Ontario for example. For any intelligent house buyer, the math would dictate it is worth strongly considering, especially if you believe also as I do that grid power consumer rates are going to escalate much faster than inflation over the coming years.
John K. Sutherland 10.24.09
Mike, your scathing words on the unscientific Scientific American resonated with me. I have long noticed a significant deterioration of whatever standards they once had. Some of the time however, they do have a good article, but it is hard to forgive the schlock.
Jeff Presley 10.24.09
1) Your house doesn't move, therefore the watts per square meter number for Ontario's lattitude (already bad) gets worse because that is an idealized (and false) average that assumes the earth is a flat plate (not a sphere) and the sun is directly overhead (it isn't).
2) The price is double what you're saying unless/until there are major breakthroughs that haven't materialized. In fact, unless you have a ridiculously small house or are only doing the PV treatment on the south facing side the price will be substantially higher
3) I'm surprised Dr. Reynolds didn't mention the DC-AC conversion losses in his otherwise excellent treatment. Since the PV systems on your home need to be converted to AC to be useful to your appliances, one must account for the conversion losses which can and do approach 50% depending on the conversion method and whether the load is inductive (refrigerators, vacuum cleaners etc.) and where your load is on the inverter efficiency curve. Since you'll be "blending" your household usage with the grid power, you'll have a hard time knowing whether you're giving your inverter enough of a load to make it worth while.
4) Batteries? Then add the losses charging the batteries and add in the inverter losses getting useful AC back out.
Jim Beyer 10.26.09
I admit I didn't read the article, but the Scientific American plan about powering the U.S. with solar sites in the Southwest didn't seem too practical to me. Every grid guy I've talked to moans about how much it costs to move power more than 300 miles. Moving the whole country's power thousands of miles is quite a sea change. Maybe HVDC could do this, but I don't think that technology magically changes the economics that significantly.
On the other hand, I don't think our oil problems go away with "Drill, baby, drill", so there seems to be no shortage of poor thinking on all sides of this problem.
I think you are being a little harsh. If PV got down to $1-$2 per watt installed, that could have a big impact on residential power. Even at 20% capacity, they'd pay for themselves in about 5-10 years. Not too bad, really. I'm not really a huge PV fan, but the one advantage they do have is that they compete with retail electricity rates, which is a big plus. Use any extra to charge your car.
Big problem in high latitudes is energy for heating homes. And it's hard to retrofit existing homes to be super energy efficient, especially old ones.
Bob Amorosi 10.26.09
1) Everyone knows the watts/square meter in Ontario is nowhere near as good as in Arizona or California. But this hasn't stopped several large solar farms from being built in Ontario already, partly because the Ontario government is paying lucrative grid feed-in tariffs, plus we have plenty of huge tracts of rural space in Ontario to build them on.
2) There are indeed breakthroughs on the horizon. Morgan Solar in Toronto is one company about to do so, check their technology out for yourself on their website. And yes, anyone in Ontario who in past implemented rooftop solar has done so on south-facing roof slopes only, this is common sense. For existing homes without a south-facing roof, it is a problem, but not insurmountable.
3) DC-AC conversion can achieve over 80% if the inverter uses state-of-the-art design techniques, I have designed similar DC-DC switching regulators where with proper design you can get over 95%. For highly inductive loads the grid has the same problems putting extra current demand on generators. In a house this is only a big problem if the TOTAL loading is highly inductive, which is not that common in a residential customer. If it were very common, our local utility companies would start complaining and want to install capacitor banks for power-factor correction in your house, which is almost unheard of.
4) Charging losses in batteries are not that high for high current capacity batteries provided heavy gauge conductors are used to connect to them on the DC side of the inverter. I don't have any data on lead-acid batteries but they are still among the most efficient, which is why you still find them in every automobile today. Charging a large bank of lead-acids has been refined down to an art where the latest charger systems for things like electric fork-lift vehicles use microcontrollers for battery management (I have worked with them in recent years).
Even without battery storage, solar PV as a part-time island generator for private use is becoming more economical every year. And the kicker in my opinion is if electricity bills start becoming higher than average consumer's mortgage payments, as they are threatening to do in some parts of the US, just watch how fast consumers will increasingly start looking for and investing in alternative energy sources.
Mike Vande Voort 10.26.09
Oh goodie, "lucrative grid feed in tariffs"
Let me translate for those of you on the koolaid only diet
Taxpayer takes in the shorts with gubment subsidies to whatever industry (PV, wind, ethanol, biodiesel, etc), gave the most money to their legislators , and the rate payer takes in the shorts by paying the higher rates required for the utility to buy non-competitve energy at the highest possible price.
Bob Amorosi 10.26.09
In the US it is a well known fact that big industry pulls legislators in Washington in whatever direction they want with huge political contributions, which some people will view as legalized bribery. In Canada we have laws severely limiting the size of any corporate or individual political contribution, so the only way to have huge donations to political parties or individual politicians is to offer them real bribes under the table.
I guess what your post above is saying is bribery of legislators is rampant throughout all the renewable energy industries, legally or under the table. Well, well, Mike, I didn’t imagine you having such dim view of our legislators and politicians. I suppose you are going to say that voting in elections is therefore a complete waste of time.
Len Gould 10.27.09
Mike: You think feed in tarifs are koolaid, but valuing oil and gas in the ground at essentially zero, (eg. the cost of discovery and recovery onlly plus perhaps a couple of percent royalty) isn't?
Regarding batteries, here's a possible development of a sodium sulphur battery which runs cool enough to install in the home. Claims 20 kwh storage with unlimited cycling for $2,000 is in near future. Coorstek Low Temp Sodium Sulphur Battery
Regarding Scientific American, I agree that its articles appear to be somewhat less "hard science" than they used to. I attribute all of the change to their apparent need to hire staff writers to do some of their articles, writers who are often not experts in the field of the articles. I assume that is largely a reaction to the loss of monopoly of the english language on all important science, eg. many important scientists no longer have english as their first language, or even an important second. I also assume that their editorial stance on secular religions like climate change and the need for substitute energy sources abrades a lot of the religious deniers of global warming and the finite future of fossil fuels.
Ferdinand E. Banks 10.28.09
Green Rag? Scientific American? I really don't think so. They had an article by Leonardo Maugeri recently that could have orginated in the executive suite at Exxon Mobile. Let's face it, they have to sell their publication, and if in order to do that they have to publish a little nonsense occasionally, then so be it.
Don Giegler 10.31.09
Which was nonsense, Fred, Maugeri's "Squeezing More Oil From The Ground" or Jacobson and Delucchi's "A Path to Sustainable Energy by 2030"? The latter, of course, has my vote. I must agree with some of the others here, though. One does not often find the quality in SciAm that existed ten years ago, e.g., Mandelbrot's "A Multifractal Walk down Wall Street" in February 1999. Or for that matter, "The Amateur Scientist", "Mathematical Recreations", Morrisons' "Wonders", Burke's "Connections", etc. are all amongst the missing. Why for about 120% of the 1999 price, one can enjoy 5 times the editorial tripe and one-fifth of the scientific content.
Len Gould 11.1.09
Don: Perhaps such budget problems are simply a symptom of dropping readership, as with all print publications these days. Hopefully not a symptom of dropping general scientific ability and interest.
Mike Vande Voort 11.4.09
See link below on Germany's PV experience, at a cost of much less than $1 per watt, still a colossal waste by any metric.
Of course, you diehards will simply claim that the Germans are inept in matters of science, engineering technology and economics.