Guest Post by Willis Eschenbach
The “Annual Energy Outlook” for 2011 is just out from the US Energy Information Administration. The section called “Levelized Cost of New Generation Resources” looks at what are called the “levelized” costs of electric power from a variety of sources. Their study includes “renewable” sources like solar, although I’ve never found out exactly how they plan to renew the sun once it runs out. The EIA data in Figure 1 shows why solar will not be economically viable any time soon.
Figure 1. Levelized costs of the different ways of generating power, from the EIA. Blue bars show the capital costs for the system, while red bars are fuel, operations, and maintenance costs. Estimates are for power plants which would come on line in five years. Operation costs include fuel costs as appropriate. Background: HR diagram of stars in the star cluster M55
“Levelized cost” is a way to compare different electrical generation technologies. It is calculated by converting all of the capita costs and ongoing expenses for the project into current dollars, and dividing that by the amount of energy produced over the lifetime of the plant. For the mathematically inclined there’s a discussion of the various inputs and calculations here. Levelized cost is the all-up cost per kilowatt-hour of generated power. The levelized costs in Fig. 1 include transmission costs but not the costs of backup for intermittent sources.
So why is this chart such bad news for solar electricity? It’s bad news because it shows that solar won’t become cheap enough to be competitive in the open market any time in the near future. Here’s why.
Now, please don’t get me wrong about solar. I lived off the grid for three years on a houseboat with solar power in Fiji, collecting sunshine and drinking rainwater. I am a solar enthusiast and advocate, there are lots of places where it is the best option.
But not on the grid. It’s too expensive.
Yes, it’s true that the sunshine fuel is free. And the operations and maintenance is cheap, 2 cents a kilowatt-hour. And as backers are always claiming, it’s the only technology where the capital cost is falling rather than rising, as the price of solar cells drops.
But here’s the problem. Solar cell prices have already fallen so far that only about thirty percent or so of the cost of an industrial-sized solar power plant is solar cells. The rest is inverters, and wiring, and racks to hold the cells, and the control room and controls, and power conditioners, and clearing huge areas of land, and giant circuit breakers, and roads to access the cells, and the site office, and half a cent for the transmission lines from the remote locations, and labor to transport and install and wire up and connect and test all of the above, and …
That means that out of the twenty cents of capital costs for solar, only about six cents is panel costs. Let us suppose that at some future date solar panels become, as they say, “cheap as chips”. Suppose instead of six cents per kWh of produced power, they drop all the way down to the ridiculous price of one US penny, one cent per kilowatt-hour. Very unlikely in the next few decades, but let’s take best case. That would save five cents per kWh.
The problem is that instead of 22¢ per kWh, the whole solar electric system at that point would have a levelized cost of 17¢ per kWh … and that is still two and a half times the price of the least expensive option, an advanced combination cycle gas turbine.
Finally, this doesn’t include the fact that when you add an intermittent source like solar to an electrical grid, you have to add conventional power for backup as well. This is so you will be sure to still have power during the time when the sun doesn’t shine. Even if you never use it, the backup power will increase the cost of the solar installation by at least the capital cost of the gas plant, which is about two cents per kWh. That brings the levelized cost of solar, IF panels dropped to a levelized cost of only one penny per kWh, and IF the backup generation were never used, to 19¢ per kWh … and that’s way more than anything but offshore wind and solar thermal.
However, it gets worse from there. The cost of fuel for the gas advanced cycle power plant is only about 4 cents per kWh. So even if gas prices triple (which is extremely unlikely given the advent of fracking), the gas plant cost will still only be about 14¢ per kWh, which is still well below even the most wildly optimistic solar costs.
And that means that the dream of economically powering the grid with solar in the near future is just that—an unattainable dream. The idea that we are just helping solar get on its feet is not true. The claim that in the future solar electricity will be economical without subsidies is a chimera.
w.
PS—On a totally separate issue, I suspect that the maintenance costs for wind power are underestimated in the report, that in fact they are higher than the EIA folks assume. For example, both wind and water are free, and the EIA claims that wind and hydro have the same operation and maintenance cost of about one cent per kWh.
But with hydro (or almost any other conventional technology) you only need to maintain one really big generator on the ground.
With wind, on the other hand, to get the same amount of power you need to maintain dozens and dozens of still plenty big separate generators, which are stuck way up at the top of really tall separate towers … and also have huge, hundred-foot (30 m) propeller blades whipping around in the sky. You can imagine the trek you’ll have when you forget to bring the size #2 Torx head screwdriver …
Do you really think those two systems, both feeding the same amount of power into the grid, would cost the same to maintain? Check out the windfarms and count how many of the fans are not turning at any given time …
Willis writes “I objected that you had left out the other incremental cost of wires and the upsizing of the alternator and the additional rack to mount the panel and the labor to do all of that …”
Thats fair enough there are certainly initial installation costs involved but not all panels will always require an increase in the inverter capacity if the existing inverter still has capacity and at any rate they’re paid for over much less than the life of the panel.
There are concrete examples today actually. I have several friends who have solar PV installations and so far their projected payback period is about 8 years. Probably less if the cost of energy increases as is likely. The solar rebates are decreasing in Australia solar instllations are still affordable and popular.
I disagree with your general suggestion that the cost is about as low as its going to get. PV solar is still far from a consumer product in the same way a computer is now. Computers have dropped to a tiny fraction of what they were once worth and the same will happen to any technology that gets mass adoption. Much lower than you think is possible I would suggest.
Willis writes “Although I understand the words, I fear that I don’t believe what they say. Why will the running costs (presumably of solar) reduce? ”
Because there are virtually no running costs for PV solar. Once installed they pretty much take care of themselves and over time their reliability will improve too.
Compare this fundamental feature of the enrergy production to that of oil where there are ongoing costs to produce that oil. Exploration, development, extraction, processing, distribution. All those costs are always with us and always increasing.
Now you might argue that you can make more money by “investing” rather than spending on PV solar with a return over many years. And you may well be right but thats irrelevent This isn’t about how you can make the most money, its about how we can best cater to our future energy needs and “investing” sure doesn’t do that.
You can “invest” in fossil fuels and sure you’d make more money. Great if thats the goal to make money but its not the path I prefer.
Willis writes “It means lots of small switchgear, which is more expensive than single large switchgear. Same is true for inverters.”
Its that kind of reasoning that leads to statements like ““I think there is a world market for maybe five computers – Thomas J. Watson .””. Reality has an electric drill in every household and on average its used only a few times ever. People dont mind buying and owning stuff even when they could simply borrow someone else’s drill or hire one. Thats a fact of life.
Willis writes “Redundancy also means a whole lot more generating units that need to be reliably disconnected from the grid when there is a power outage, to keep from frying the repair personnel.”
You’re dissing redundancy? Distribution companies spend a fortune on redundant feeders and switchgear to manage them. Live line maintenance is common and in the worst case, one only needs to disconnect a bit upstream and downstream of the fault to isolate it.
@juanslayton: You have pointed out the inherent weakness of all future casting. We make assumptions, based on the available evidence, and then run the numbers and see how it pans out. My analysis MUST include a life-cycle-cost analysis or it’s worthless. To make that analysis, we decide in advance what we expect future cost increases (or decreases) to look like. EIA projects such numbers, and I use them despite my misgivings (there was another thread, here or somewhere, about how EIA consistently over-estimates future cost of fossil fuels, and under-estimates future costs of “renewables” as defined by legislation). Here’s the thing, though, when we do an engineering analysis we are comparing alternatives. i.e., do I keep what I have, do I buy more of what I have, do I install more of option A (maybe that’s solar PV) do I install more of option B (call that solar thermal) or option C (maybe that’s wind). From that analysis you derive Levelized Costs (gee, where have I heard that term before? Oh, yeah, refer to the title.)
Now if we make the wrong assumption about, say, the future costs of electricity, in many cases it won’t matter if we’re comparing something that just uses different amounts of electricity, the same “wrong” costs are in all of the life cycle equations, so it still gives a fairly accurate picture of the best choice. But when we’re comparing different technologies, we have to be a bit more certain of our future-casts. But, you start off assuming no consideration was given to a wrongly forecast future price, and in fact, it was carefully considered. As I originally stated, we assumed 35 years ago that our assumptions (double assumption? I’m leaving it in there) were likely wrong in one direction (future costs of capital would decline while future costs of fossil fuels would rise at some rate) and it turned out we were wrong in the other direction (future costs of fossil fuels in inflation-adjusted $ actually declined for a long time, while the future cost of capital equipment, at least the equipment we were selecting, did not decline, or at least not as much as we had hoped, and might have even risen). So at this point, it’s not just a coin flip to determine who’s most likely right, the figures published by EIA have some analysis behind them, while your hypothesis is just that, a figment of your wishful thinking. Guess who I’d put my money on?
Next point, you talk about operating costs of already-installed solar being near zero, and that’s just false. I worked at a place that had made 3 different installations of solar-thermal, and all 3 were deactivated well before the projected end of their expected useful life (the life used in the LIFE-cycle cost analysis) and 1 had been demolished and removed entirely. Why were they inoperative? One thing, well, maybe 2… They got no maintenance, not even drain-down in advance of freezing weather, so much of the tubing burst, and secondly, they were not metering the production of the solar-thermal, so when the question came up, “is it worth it to repair these?” nobody could argue that it was. One of the earlier commenters posted a link to solar installations that had received no maintenance, both solar-PV and solar-thermal, so scroll up. You need to re-evaluate that assumption.
I’ve fitted a vacuum tube solar panel to my roof. Did not seek subsidies nor paid the rip-off rates for buying/fitting here in gloomy UK.
£500, paid for itself in 18 months two years ago and it looks good for the next 25 years of free hot water for 8 months of the year.
Absolute no-brainer. No energy supplier can better that.
TimTheToolMan says:
December 6, 2011 at 1:09 am
None of that makes any difference in the real world, Tim. Sure, once in a while you’ll have spare capacity in the inverter, but in general it was originally sized to match the panels so you can’t just add panels.
Also, whether the inverters are ” for over much less than the life of the panel” is immaterial. You still have to pay for them, right?
How is that a “concrete example” of increasing panels? All that proves is that the Australian taxpayer is subsidizing your friends’ green fantasies.
Perhaps that is because I never made that suggestion. I said that solar could go lower, and I estimated how low it was likely to go. I showed that even if panel pricess dropped through the floor PV would still be uneconomical … where were you when that discussion was going on?
You should refrain from suggesting if that’s the best you can do. I estimated above the likely lowest cost you’ll find a complete system if panels get really, really cheap. It’s at about 18¢ per kWh. It will not drop to a “tiny fraction” of that cost, any more than cars will drop to a “tiny fraction” of their current cost. In fact, you will be lucky to get down to that cost, because the panels are only about 30% of the total cost at present. That means that if panels were free, the system would still be twice as expensive as fossil fuel.
w.
TimTheToolMan says:
December 6, 2011 at 1:18 am
Running costs for solar are currently about 2¢ per kWh. You said they would reduce. I asked how they could reduce much when they are so small. Your answer is that they will reduce because they are so small … say what? They will go up if other costs go up, including fuel costs.
I see the reason for your confusion. You are comparing the running costs of a solar electric system with the extraction, refining, and distribution costs for oil. You seem to be under the impression that oil prices have always gone up. Nothing could be further from the truth. We pay about the same (in constant dollars) now for fuel as we did in 1950.
But in any case, none of this reduces solar costs as you have claimed. It’s the other way around—as I showed above, if fuel prices rise, the cost of solar installations rises as well … and for a doubling of fuel prices, the increase in costs is about the same for both systems.
I would never argue that. I would argue that you can lose more money on solar than on any electricity generation scheme except offshore wind and solar thermal. That’s a very different claim.
It’s about the cost of electricity. You want to make it some kind of noble quest for the holy grail of our “future energy needs” or something. For the rest of us, it’s about cost. We know that our future energy needs will be met by our future citizens in some future way, and it may have nothing at all to do with either solar or fossil fuels.
You seem rather attached to this point, that somehow fossil fuels are not the “path you prefer”. I have no problem with that. What I do have a problem with is paying for your preferred path. If you want to take it, go ahead. But sticking your hand into my pocket to pay for it? Why should I pay for your preferences, Tim?
w.
So, Willis, I’m skeptical of the safety of fracking and I mispelled aquifer and I’d rather see coal burned for electricity than gas. Y’all are tough on skeptics here.
TimTheToolMan says:
December 6, 2011 at 3:14 am
Actually, that statement about computers, as far as anyone can determine, is an urban legend … kinda like your claim that somehow an imaginary statement falsely ascribed to Tom Watson has relevance to your argument.
How are electric drills and Thomas J. Watson relevant to my statement, which is that a fifty kilowatt inverter is going to cost you less than ten five-kilowatt inverters? My statement is clearly true, and you respond with urban legends … kind of symbolic of the whole discussion.
For years they didn’t allow direct connection of your own generation gear (aka rooftop solar) to the grid because it was too dangerous to the repair people. Your claim seems to be that it was never a danger … riiiight …
No, I’m not “dissing redundancy”, Tim. I am a realist who knows that there are problems that come along with every solution, including redundancy. For generator redundancy, one of the problems is disconnection of all of the generators in cases of system failure. Claiming I’m “dissing redundancy” doesn’t make that problem magically vanish.
And having a 30kW rooftop solar system still connected to a down system is a very bad thing. Power goes down … except for one holdout solar system who didn’t get the word. PGE shuts off the mains, but the lines are still live. The lines will remain live, and very dangerously so, until somebody shows up to cut them off. How is that not a problem, especially in an emergency where help may not arrive for a couple days?
And contrary to your claim, you need to do more than “disconnect a bit upstream and downstream”, because that still leaves power on the the rest of the grid, and when the grid is down, that’s dangerous.
Next, in many grids, there is no well-defined “upstream” or “downstream”, particularly if the grid is fed from many, many points as you advocate.
Finally, what about the homeowner who decides to reconnect his system to the grid during a power outage, or does so accidentally?
So your claims about how the generator disconnects don’t matter are an urban legend as well, Tim. 100% reliable disconnection of live generation equipment is a real concern for anyone operating a power grid.
And my more general point is true. There are advantages to redundancy, but there are also problems with redundancy that you are not taking into consideration.
w.
TimTheToolMan says:
December 6, 2011 at 3:14 am
“Willis writes “It means lots of small switchgear, which is more expensive than single large switchgear. Same is true for inverters.”
Its that kind of reasoning that leads to statements like ““I think there is a world market for maybe five computers – Thomas J. Watson .””.”
Here, Tim has a point. We’ve only just started to seriously mass-produce inverters; there’s a lot of room for driving down the production cost. Compared to say, motor electronics, which are produced nearly 100% automated – a typical assembly line produces 5,000 of them or so in an 8 hour shift, and a factory has maybe 10 such lines – inverters are still large boxes with a lot of manually connected cables. This will change when we use one small inverter per module; they become as small and as plentiful as motor electronics boxes, in the millions of pieces range, and the same automation will be used for mass production. Shortly thereafter they might become solid state modules, and later one chip solutions. I’m fantasizing here, but that’s what usually happens when the numbers are scaled up.
” Reality has an electric drill in every household and on average its used only a few times ever. ”
Tim, you shoot yourself in the foot here – that’s exactly not an example for high efficiency ;-).
mike g says:
December 6, 2011 at 11:34 am
You can pretend that was the problem if it helps you to sleep, Mike. I thought I was quite clear, but if not, the problem was that you were waving your hands at the web and telling me to go google for the information to support your argument. Not my argument. Yours.
I don’t do that. I don’t go on your quests for you. If you have a point, you’ll have to make it and support it with citations yourself. We are not “tough on skeptics” here. We’re tough on people who want us to do their work for them.
Me, I’m still waiting for what I requested, a statement of your specific claims and the citations to back them up. Until you provide those, you are just whining about how you are being treated … and that don’t impress me much. You want better treatment? Then tell us exactly where fracking did something bad, when it did it, what happened, who was involved, and provide us with the details of the incident.
Because saying “I’m skeptical of the safety of fracking” is meaningless without the details .
w.
Willis Eschenbach says:
December 6, 2011 at 11:46 am
“No, I’m not “dissing redundancy”, Tim. I am a realist who knows that there are problems that come along with every solution, including redundancy. For generator redundancy, one of the problems is disconnection of all of the generators in cases of system failure.”
Willis, all solar inverters used in Germany need to switch themselves off as soon as the grid frequency rises above a certain threshold – because this frequency signalizes overload. Similarly, a lot of emergency conditions are already encoded in the inverters; they have a digital signal processor that does about 15,000 cycles a second and checks these conditions.
Most inverters will only feed in when an outside grid exists; they never build up a grid by themselves! Disconnecting the grid suffices to make them all shutdown by themselves.
On December 3, 2011 at 8:03 pm, Willis Eschenbach says:
“why do you have to be so snarly and ugly and nasty? All it does is make you look like a vicious, vindictive little man.”
Pot, kettle?
Ducky12 says:
December 6, 2011 at 12:02 am
So if I have this straight, you gave up easily on the actual analysis because there were “so many taxes”, you say it’s “pretty much impossible”, and you call the numbers “flat out lies” …
Let’s see. Here’s the order of battle.
On one side we have the Energy Information Agency, who is actually trying to put out real numbers, and generally acknowledged and well respected in the industry for doing so. They have spent hundreds and hundreds of hours, they didn’t complain that there were “so many taxes”, they calculated the numbers as best they knew how.
And other the other side we have a random internet poster named “Ducky12” who says that the math and the work is too tough for him, he can’t figure it out, so it all must be lies …
Ducky, despite the trenchant, biting nature of your keenly incisive analysis of the situation, I fear I’m going to go with the EIA just this once.
Yes, I know there are some difficulties with their numbers, and I have referred to some of those problems above. But overall, they are the best numbers we have, and as long as we keep an open mind that they are best estimates, and that any one of them may be a bit high or low, they are quite useful to us. Throwing them out would be the act of a petulant child. Instead, we work with what we have, and simply include the uncertainties in our analysis.
w.
Louise says:
December 6, 2011 at 12:00 pm
Why pot and kettle, unless you are referring to yourself? Are you revealing your secrets? Louise, have you been fooling us all, have you been sneaking off to where Dave posts, not to discuss the issues, but simply to be a troll and muddy the waters? Do you follow Dave around the web, looking to attack him wherever and whenever he posts, and getting all snarly and ugly and nasty, the same way that Dave does to me?
I know I don’t do that to Dave, which means it can’t be me you are referring to. I simply call Dave a vicious, vindictive little man when he follows me around and acts like one. Other times, when he wants to talk science, I do that instead. You have a problem with that? Sorry, but that’s how people respond to vicious, vindictive little men.
So if there is a pot to his kettle, either that’s you, my dear, or you’ll have to clarify to whom you are referring.
w.
PS—Here’s Dave’s intro, his very first comment to me in this thread, his opening salvo before I had said a word to him. It’s typical vintage Springer:
Like I said, he is a vicious, vindictive little man. You don’t like me calling him that? Sorry, Louise, I call them like I see them. It’s an enduring fault of mine.
PPS- Here is an example upstream of where I answered Dave’s scientific point. I did so to once again check if he is actually interested in a discussion. I simply asked for a citation for his claims. I got nothing in return, which is typical of the way Dave deals with scientific questions. Louise, your defense of the man speaks very well of your heart … but very poorly of your mind.
DirkH says:
December 6, 2011 at 11:59 am
Thanks, Dirk. And would you be willing to bet your life that the disconnects all work correctly 100% of the time? I wouldn’t, I can easily envision conditions where the breakers wouldn’t pop. I’ve seen too much of “machinery gone wild” to think that safety systems are failure-proof. And repairmen are indeed betting their lives on your claims …
My point was not that the problems of distributed generation could not be solved, at least most of the time. Like any problem (except for finding the value of the “climate sensitivity”), they can generally be solved given enough materials, time, and money. I was responding to Tim, who seemed to think that there were only advantages to distributed generation, and no disadvantages or hidden costs in distributed generation.
In fact, one of the disadvantages is that you need (as you point out above) special switchgear to disconnect each solar rooftop installation.
And that special switchgear is neither free nor 100% reliable … so in fact there are disadvantages and additional costs from distributed generation, not just advantages and no additional costs as Tim was blithely claiming.
w.
DirkH says:
December 6, 2011 at 11:51 am
No, Tim doesn’t have a point. he has a manufactured, false quote that doesn’t support his claim, and that seems to have fooled you as well.
My point was that ten 5 kW inverters will cost more than one 50 kW alternator. You have not brought up anything that shows my point wrong. Yes, prices are falling on electronic gear. Yes, they could come down more.
But that’s not what Tim was claiming. He was claiming that there were lots of benefits to distributed power … and no disadvantages. I pointed out that one disadvantage is that many small things cost more than one big thing, inverters being a prime example
And now, although you obvious don’t understanding what the point of the discussion was, you want to jump in and reveal to me the big secret, the thing you think I don’t understand, that inverter costs are falling?? Ummm … well … thanks, but I’ve known that for years, DirkH, and it makes no difference to the topic under discussion.
Dirk, you seem like a real smart guy, but you are not following the story. Go back and read the interactions between Tim and myself. The discussion is not about whether inverter costs will fall, as you seem to think. It is about whether there are additional costs and disadvantages to a distributed solar generation system, compared to having all of the solar in one place.
w.
Willis Eschenbach says:
December 6, 2011 at 12:40 pm
“Thanks, Dirk. And would you be willing to bet your life that the disconnects all work correctly 100% of the time? I wouldn’t, I can easily envision conditions where the breakers wouldn’t pop. I’ve seen too much of “machinery gone wild” to think that safety systems are failure-proof. And repairmen are indeed betting their lives on your claims …”
I’d much rather trust a system designed under safety-critical considerations than anything else, because that’s the best bet I can make. As an additional precaution, gloves can’t harm 🙂
“In fact, one of the disadvantages is that you need (as you point out above) special switchgear to disconnect each solar rooftop installation.”
That’s exactly one of the beauties of one inverter per module – the inverter semiconductors do the disconnect. When you have a large inverter for a string of modules, you get a DC voltage of about 800 V; that can be nasty. Not so with the microinverters. You have the output DC of one module, that’s 60V or so. (I’m guessing). Even if the the emergency switchoff fails, the voltages are not that dangerous.
At the moment, efficiency lags behind big inverters and total costs are higher. We will see. I’m not trying to advertise anything, at the moment I have no business interests there.
Timthetoolman has a few statements-
1) “Because there are virtually no running costs for PV solar. Once installed they pretty much take care of themselves and over time their reliability will improve too.”
2) “I disagree with your general suggestion that the cost is about as low as its going to get.”
Tim,
In response to statement 1:
My PV system has been in service for 5.5 years. In that time I have had my inverter serviced once (software was incorrect in how it calculated kwh’s- it read low by about 25%)- the upgraded software then read about 10% high per a separate kwh meter I had installed just before my PG&E E-7 net meter. After about 2 years of service my inverter started reporting negative values for one of the attribute it reports (instantaneous wattage). Rather then try to figure out what was wrong with my original inverter the unit was replaced. The new inverter has worked fairly well- it reports my kwh output about 4% high per my secondary kwh meter. The estimated mean time to failure for inverters is around 10 to 15 years, so any cost calculation needs to take this into account. Additionally, the efficiency of the inverter is not going to improve over time.
If I don’t keep a fig tree trimmed, that is located just south of a couple strings of my panels, my output drops by about 20%. Hence I have some ongoing maintenance for my system to operate at it’s rated POTENTIAL max output. Over the years I have found that without cleaning my panels (especially in the dry, dusty summer months) my overall output will drop between 8 and 10%. My weekly preventative maintenance is rather straightforward- a rinse with water from my garden hose with a fairly strong stream of water- geese fly overhead occasionally and it takes a bit of water pressure to remove their droppings from my panels).
As far as reliability goes each manufacturer of panels is required (in CA anyway) to limit (warranty) the degradation of their potential max output (STS rating) over the expected life of the panels. For my panels an expected degradation in STS max rating was something like a 20% reduction in STS max output over time (time being 20 or 30 years for my panels) of the warranty.
In response to statement 2- “I disagree with your general suggestion that the cost is about as low as its going to get.”
I concur with Willis on this one but with a change in the word cost to price for an installed residential PV system. As the balance of system (copper wire, inverter, aluminum railing system and installation labor, shipping) costs become a larger part of the overall system costs a 5 to 10% improvement in the cost of the panels are going hit the law of diminishing returns from a total price to purchase a self generation option. The price I paid to have my 6.12 Kw system installed in 2006 was $1.10 a Kw. Today the labor and misc materials (some cu wire, shut off switches) costs are between $1.30 and a $1.50 a Kw out here in CA to put a 6.12 Kw system in. The price paid by the wholesaler who I bought my panels from has gone down with the drop in panels costs. Their costs for the Al railing and their cost for the inverter haven’t come down. Their costs for shipping (primarily fuel costs related) have gone through the roof so free shipping is no longer included in the purchase of the hardware components of a PV system. The best price (before rebates, and tax credits) to have a mid sized investment grade residential PV system (4 to 10 kw) installed are likely never going to get below $3.00 to $4.00 (CEC AC rated) watt. Under my version of a best case scenario for residential PVgeneration (lets use the VERY optimistic $3.00 (installed watt cost)* 5.22 CEC Kw rating (the AC rating of my PV system)= $15,660.00 which yields a total yearly output of 9300 kwh- for a 6.12 kw STS rated system). The upfront costs in this best future scenario is $15.6K for a 5.22 kw cec rated residential system and it will yield 9300 kwh a year
DirkH says:
December 6, 2011 at 1:04 pm
So clearly, the answer to my question that you are unwilling to give is that, no, you would not be willing to bet your life that the disconnects would work.
Next time, just answer the question, it makes you look shady and evasive when you answer everything but what was asked …
Oh, they do, do they? And you can point to a system where this is installed and working, I suppose, but you just forgot to do so?
As far as I know, you are talking about a fantasy, a system with an inverter in each panel, which has never been commercially available. But somehow, you didn’t let people know that you were talking about imaginary panels, you acted like you were describing some real system that had been installed and tested. Bad Dirk, no cookies …
As you said, Dirk, you are guessing. You don’t know if anything you are claimed is a fact, because there is no such system yet built, just your fantasies about such a system.
Not only that, but that wasn’t the point of the discussion you jumped in the middle of. We were discussing if ten 5 kW inverters cost more than one 50 kW inverter. Somehow, despite my pointing it out, you haven’t gotten back to that either.
You should start over, talk about real things that actually exist and that you know something about, and follow the discussion. Your guesses about random panel designs that have never been manufactured are meaningless.
w.
Willis, you’re really having a bad day; I’ll leave after this comment. Nobody forced you to answer my comment; so blaming me for saying “Tim has a point there” with “We were discussing whether this kind of inverter is cheaper than that”, well, that’s just silly. No offense; don’t work yourself up. Bye.
http://en.wikipedia.org/wiki/Solar_micro-inverter
“Released in 1993, Mastervolt’s Sunmaster 130S was the first true micro-inverter.”
Looks pretty real to me:
http://www.smartsolarsystems.biz/wp-content/uploads/2011/05/micro-inverter-install6.jpg
kakatoa says:
December 6, 2011 at 1:17 pm
Thanks, kadaka. 9300 kWh per year from a 6.12 kW rated system gives a specific yield of 9300/6.12 = about 1,500 kWh annually per kW of installed power. That’s a little better specific yield than here in the San Francisco Bay area, I assume that either you are further south or are using theoretical numbers.
So if we assume a 30 year lifespan for a levelized cost comparison, and two cents per kWh for running costs, your imaginary “best-case” system is costing out at $15,660 divided by (9,300 kWh/yr times 30 years). That gives us about 8¢/kWh for the power.
However, I think your estimates are off for a couple of reasons. At least around here, prices are about $7 / kWh of installed DC power, which in turn is less than the amount of AC power you generate. This estimate of our local cost here (SF Bay) is borne out by the LA times, which comments:
This means that the current cost for your rooftop power system would be about $7.50 * 6.12 / (9300*30)+2¢ for operations, or 19¢ per kWh. I doubt that it will ever be cut by more than half as you suggest, because that would mean that every component, from the panels and racks to the inverters and the labor, would have to see a more than 50% drop … very doubtful on my planet at least. It will come down, but not that far. So you are right that yours is a “VERY optimistic” analysis.
Either your analysis or mine comes to the same conclusion, however, which is that solar will not cost less than fossil fuel any time in the foreseeable future.
w.
The chart shows 16 electrical energy sources. The costs of production do not include externalities, so they constitute a rough guide on real costs of production.
One poster noted that solar hot water, by comparison, in effect delivers energy at a much lower cost, yet this source of energy is omitted.
I also note that a British study has showed that the cost of reducing electricity demand varies from zero (in the case of turning down a thermostat, for example) to less than 1 cent per kw for many simple technologies like lagging of hot water pipes, but almost always much less than the unit cost of supply.
This endless and often bitter dogfight over preferred energy supply technologies is interesting, but it has very limited horizons.
DirkH says:
December 6, 2011 at 1:58 pm
Do they really do that where you grew up? Do they respond to someones reasoned discourse by saying that the person is “just silly”, and then add “No offense, don’t work yourself up.”
No offense? You insult someone, and then you think saying “No offense” somehow makes your comment socially acceptable??? Not where I grew up. We stand behind our words, we don’t say things to offend somebody and then say “No offense”.
In addition, you did come into the middle of a discussion to support one side, by claiming that Tim had a point. Then, instead of defending Tim’s point, you wandered into a whole other topic.
And when I point that out that you claimed to be defending Tim’s point but you didn’t understand or even discuss the point we were talking about … you get into a snit, take your toys, and go home. Gotta love the grown-up type behavior.
You go on to say:
From your reference:
OK, so someone does actually make what they call “micro-inverters”. I thought you were discussing inverters that were a part of and integral to the solar panels, not some add-on type product. My bad.
However, your reference goes on to say:
Since that was my point, since that was the issue that Tim and I were discussing, that more inverters would indeed be more expensive, you have proved it very neatly.
So I will follow your lead, and say “… don’t work yourself up. Bye.”
w.
PS—As I said before, you do seem like a sharp guy. If you want to get all huffy and go home because I had the insufferable gall to actually disagree with you, you are certainly free to do so.
However, do you think that increases or decreases the chances of you being seen as a serious player? Do you think that increases or decreases the chances that your ideas will be believed?
Solar power may be useful as an auxiliary power source, but eventually carbon-power is not going to be an option. (Bio-solar carbon excepted.) I am not prepared to say when that might be, but it does look like we are now consuming more carbon-power than we are discovering, at least in the case of petroleum.
I look at this as a question of whether energy from the sun can replace exhausted carbon-power in all uses. How much of the earth’s surface must be set aside so that each person can collect all the energy needed for heating, transportation, and feeding from the sun. That presumes the manufacture of synthetic transportation fuels. I am guessing that the average recoverable solar energy is less than 100 watts per square yard.
We do know that back in 1880 we had a lifestyle model and total global population that did not depend on carbon-power to the extent we do today.