How many times have you heard that there is a form of solar power that can indeed supply what is termed as Base Load Power?
How many times have you heard the story of a solar plant in Spain that can supply power for 24 hours straight?
How many times have you heard that we have now reached the stage with solar power where it can take the place of coal fired power?
How many times have you heard that we can do solar power anywhere, because they are doing it now on a large scale in Spain?
Well then, let’s look at all those things and see if there is any truth in any of those statements.
You may have recently heard that the much talked about Gemasolar solar plant in Spain which can provide 24 hour electrical power actually did do just that for 36 consecutive days in mid Summer. At first reading, this occurrence actually gives the impression that a plant of this nature can deliver power that is on a par with coal fired power.
However, is that statement actually correct, that a plant like this can compare favorably with those large scale coal fired power plants which do provide that 24/7/365 power referred to as Base Load Power?
Spain now has constructed 24 of these type of Concentrating Solar plants and they are spread across the length and breadth of Spain, so we can in fact use this as a guide because there are now a fairly significant number of them in operation, and have been in operation now for a number of years.
The technology is referred to as Solar Thermal Power, but the more correct term is Concentrating Solar Power. (CSP)
The light from the Sun is focused to a central point which then generates a huge amount of heat. This heat can be used in a couple of ways. It can be used to heat water directly to make steam, or it can be used to make a compound (usually a salt) molten. This molten compound is then used to boil the water to steam. In both cases, the steam is used to drive a conventional turbine which then drives the generator that generates the electrical power.
It can be done in a couple of ways as well. The most common form is the parabolic trough, which is a series of concave mirrors in a series of long rows. At the focal point of these mirrors, a pipe carries either water or the salt compound. The second is what is referred to as a Power Tower. All the mirrors are focused onto the top of a large tower. At that point atop the tower, the compound is passed and the huge focused heat makes this compound molten. In both cases, the mirrors are articulated to track the progress of the Sun across the sky during daylight hours. There is also another method, Linear Fresnel Mirrors, which is still only on a small scale, and shown below as the last solar plant on the list.
One aspect of both methods is the ability to divert some of that molten compound to be kept in as close to a molten state as possible for as long as possible. This is referred to as Heat Storage. The disadvantage of this is that it is a huge added extra cost at the construction phase. A second disadvantage is that it limits the total power that can be generated by the plant as not all the heat is used all of the time to generate as much power as possible.
That is best explained with this diagram, which looks complex, but is relatively easy to understand. The main thing to look for here is the actual total power being generated by this plant, and that is shown by the solid red line along the bottom of the chart indicating that this plant can generate 50MW of power (as indicated by the right side vertical axis – Power in MW) With heat diversion this plant might actually generate this 50MW for 19 consecutive hours. Keep in mind that this is a theoretical model and this is for a typical mid summer’s day with no overcast.
Spain now has 24 of these plants, and while we could look at an individual plant, what I have done here is to collate all 24 of these plants and make a chart with all the relevant details of the plant.
The first column is the name of the Plant. The second column is the type of plant. The third column indicates the total area covered by the mirrors for this plant, and some of those areas are indeed quite large. The next column indicates whether this plant has any heat storage capability and the number of hours of that heat storage. The next column indicates the total Nameplate Capacity for the plant. The next column indicates the actual power being generated by the plant that is delivered to the grids for consumption by all consumers of electricity. The next column is the actual Capacity Factor (CF) for the plant. This is the ratio of power delivered versus Nameplate Capacity, and this is the Industry Standard for that rate of power delivery. The last column shows that CF extrapolated down to a daily average. Now while some days power delivery may be spread over a longer period, then there will be days in mid Winter when that same delivery of power would be impossible, so this is that total yearly CF expressed in average hours per day for that Plant.
For the following, I will occasionally refer to the Bayswater Power Station. Now, while this power plant is located in Australia, it is typical for a large scale coal fired power plant anywhere they are in operation around the World. This plant has 4 units, and has a total Nameplate Capacity of 2640MW.
Now, while the total area is interesting, and some may think it is important for the power generated with respect to area, I have only included it here for the sake of interest. The total for all these plants comes in at 13,548 Acres, which equates to 21.2 Square Miles or just under 55 Square Kilometres, which is a lot of land.
When you add up the Nameplate Capacity for all those solar plants, that total comes in at 1781MW, a seemingly quite large amount. By comparison, the Bayswater plant has a Nameplate Capacity of 2640MW, a total that is 48% larger than all those 24 solar plants.
Now this next total is by far of greater importance than virtually anything else. That is the amount of actual power being generated by these 24 Plants for delivery to surrounding grids for consumption. That amount of power delivered comes in at 4,483GWH, which at first glance is a seemingly huge amount of power. But, is it really? By comparison, the Bayswater plant actually delivers between 16,000GWH and 17,000GWH of power to the grid for consumption. So this coal fired plant delivers almost four times as much power for consumption than all these 24 solar plants. So, in just 93 days of normal operation, that ONE Bayswater power plant delivers the same power that all these 24 solar plants deliver in a full year.
This next area is probably the most crucial of all, the Capacity Factor. (CF) That is the ratio of power delivered to the theoretical total. Note from the list that one plant have what seems a relatively high CF of 62%. However, when the total power generated is calculated to give that overall CF, then that comes in at only 28.7%. Now, while this percentage factor may seem fairly meaningless, this is the Industry Standard for power plants. This percentage here means that over a full year, all these 24 solar plants deliver only 28.7% of their maximum rated power (Nameplate Capacity), or, exactly the same thing, they are only delivering their maximum rated power for 28.7% of the year. Now, extrapolating that out, then if that is a yearly average, then it can also be expressed as a daily average as well, the same 28.7%, and while there may be days in Mid Summer when some plants can actually deliver their power for much longer periods, then that average tells you immediately that there must also be days when power delivery is of a very short duration. That CF of 28.7% equates to just under 7 hours a day. That is important, because a Base Load requirement is that plants can actually supply their power on a 24/7/365 basis, and that’s 24 hours of every day, and just under 7 hours a day is nowhere even close to doing that.
The next column ties in with what I just mentioned above. The Time Supplied equates to the CF expressed as a daily delivery of power, and while some days there is a lot, the average here for all 24 plants is only just under 7 hours. You can see on the list that some plants have higher totals, but most of them are down as low as only five and a half hours.
So, I mentioned at the top that there was one of these solar plants which actually delivered its full rated power for 36 consecutive days, the much talked about Gemasolar Plant. Now look again at the Nameplate Capacity here ….. 20MW. Here you have a plant covering a huge area, costing a huge amount of money, and yet all it can supply is 20MW. Now, because this plant did actually achieve this 36 consecutive days there will be supporters out there who will now claim that this indeed is now a viable replacement for coal fired power and can indeed supply that Base Load Power.
This is 20MW only.
The Bayswater plant supplies power to the grids of most of Australia. Bayswater is just one of a number of power plants that supply power to most of Australia, and that area in question has a Base Load requirement of a MINIMUM of 18,000MW, that amount of power required 24 hours of every day, 7 days of every week, and 365 days of every year.
18,000MW compared to what this plant can supply for 36 consecutive days in Mid Summer, 20MW.
All right then, let’s actually compare what this solar plant did with Bayswater.
With respect to the total power delivered to grids by this solar plant in those 36 consecutive days, Bayswater delivered that same amount of power in 6.5 hours.
Bayswater delivers the yearly total from this plant in 41 hours.
This Solar plant has a projected lifespan of 25 years, so let’s compare the total power generated by this plant for consumption during this whole life of the plant. At 110GWH per year, than that total is now 2750GWH. That same amount of power is actually generated by the Bayswater plant in 59 days of normal operation.
25 years from the Solar plant and 59 days from the coal fired plant. There just is no comparison.
This Gemasolar costs around $500 Million, so just to replace the Nameplate Capacity of Bayswater, you would need 133 of these plants at a cost of $66.5 BILLION, and still get less power delivered to the grids than what Bayswater delivers.
Concentrating Solar Power has long been thought of as the answer to power needs that actually can do the job now done by coal fired power. This shows that any talk along those lines is not only misplaced, it is totally untrue.
Technology has advanced almost to the stage now where they might be able to generate enough steam to drive a turbine that could drive a 125MW generator, and the current average maximum is 50MW, but now you have single units at coal fired power plants that have 1300MW generators.
These plants are using the absolute best and most recent technology, and still they cannot deliver power on the scale required to even be considered as coming close to replacing coal fired power.
In actual fact, these figures shown here for ALL 24 solar plants in Spain are currently only on par with Wind Power which currently has a Capacity Factor approaching 30%.
All this shows is that this form of power generation will only ever be of boutique and very small supply, all at an enormous cost.
What it effectively shows is that Concentrating Solar Power is indeed a failure, an expensive failure at that.
Reference for all Electrical power data for Spanish Solar Plants: List Of Solar Thermal Power Plants
Alain Van Laethem
Mon 03/19/2018
You compare the efficiency of the total installed Solar plants of Spain to 1 coal plant of Australia which is not fair. CSP are still under innovation and Gemasol is with 60% efficiency the latest reference. This could be achieved with other CSP as well. For Australia which requires 30.000MW of power generation , a total surface of 750km2 of CSP like Gemasol would be needed. Even if this seems a fairly huge amount of space , it represents only 0.01% of the total area of Australia. CSP’s are still under development and that explains the high costs , in general wind and solar energy is cheaper. Above all it is clean and requires less resources expect the human one.
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TonyfromOz
Mon 03/19/2018
Alain,
thank you for dropping by and leaving a comment here.
However, I’m afraid you are wrong on so many counts here. I know that you have only just seen this Post, and perhaps if you checked the date, you’ll see that it was written in 2013, five years ago.
At the time, what I had listed there were all the CSP plants in Spain, and that came in at a Nameplate Capacity of just under 1800MW. Since that time, there have been even more of these CSP plants constructed, and now, there is around 2600MW in Nameplate Capacity just of CSP plants. The Gemasol Plant with its CF of 60% is in fact the only one with a CF that high. The average CF for all those CF plants is still barely 29%. As I explained, the trade off in gaining a high CF is is the actual size of the generator itself. The more you have in heat diversion, the less there is to actually drive the generator itself, hence the size is barely 20MW. No matter how much innovation they have, actual engineering technology is what dictates all of this. Also keep in mind, that this CSP technology has now been around for a very long time, and still they have barely advanced at all, so innovation is not advancing here at all.
Now, you may note that the current (2018) Nameplate Capacity is around 2600MW. So, at that CF of 29%, that effectively means that the total generated power across a full year is 6600GWH. and the coal fired power plant I compared it with is also 2640MW, so in effect the same Nameplate. However, that coal fired power plant generates 17500MW a year, and that is greater than all of those CSP plants, (every single one of them all added together) by a factor of 2.7. So, as to the cost becoming cheaper, add the cost of every single one of those CSP plants together, then multiply that cost by 2.7, and trust me on this, that is horrendously more expensive than ANY single coal fired plant. The price of those plants would need to be the tiniest fraction of what it was even in 2013, and even then, EVERY single one of them added together and multiplied by 2.7 would still be way way more expensive than any coal fired plant.
Even so, the coal fired plant can supply its power for 24 hours of every day, and there are no current CSP plants which can do this on a year round basis, and no amount of innovation will ever be able to achieve this, because of the physical nature of these type of plants. I have been researching this and writing about it for ten years now, and while the technology of CSP has been around for a lot longer than I have been writing about it, they have hardly advanced at all.
They will never be able to do what coal fired power does on the scale required.
As to the patent dream that they can supply Australia with its power, that also is totally false. Australia requires 18,000MW of power on an ABSOLUTE basis, as that is the minimum power that is consumed at the lowest point in time of the day, around 4AM, while nearly everyone is sound asleep. That’s 18000MW, and it is required for 24 hours of every day, seven days a week, and 365 days a year. Trust me also on this, Solar Power will NEVER be able to supply that.
What I wrote in that Post dated in 2013 is still 100% valid today, five years later. Supporters of solar power will never understand these facts.
Again, thanks for leaving this comment.
Tony.
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Aditya Makkar
Tue 06/02/2015
I have read some of your previous articles stating that CSP plants can’t create high temperature and pressure steam needed to rotate TONS of machinery used in a full scale Thermal Plant using coal. Please give a comparison of the amount of water used in a typical 50MWe CSP plant to that in a Thermal Plant using coal.
Thanks and Regard.
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Kahatah Anthony
Fri 01/10/2014
Tony im a day in day out enthusiast reader of your articles due to the fact that our country Kenya is about to fall prey to this renewable energy campaigners conmen,N.G.O’s and Jihadist Especially on suitability of solar power farms. first our earmarked areas are in semi arid as per the geographical statuesque.
but they experience temperature recorded throughout the year beyond 35 degrees Celsius and ground temperatures rise a bove 40 degrees Celsius making it difficult especially when it comes to maintaining batteries, a fact evident even on the car batteries
What i know is batteries cant store charge if exposed to excessive temperatures and the best ambient temperatures are 25 degrees Celsius, and below.
what i would want to know from you is what are the cost implication and out lay for maintaining batteries for one those plants that have batteries as there backups.
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TonyfromOz
Sat 01/11/2014
Kahatah Anthony
Thanks for your comment.
That’s what I love about this format where I can Post blogs. Every time I get a comment like this, it prompts me to go to the data for that Country and find out more about it.
So, then, for the sake of comparison, let’s then compare Kenya with somewhere approximately the same size where there actually is a good constant regulated supply of electricity that can service all of that area and all of the people contained in that area.
Now, Kenya is quite a large Country, so it has to be somewhere BIG.
Texas is slightly larger in area than Kenya, so here we have two areas approximately the same size.
However, when it comes to population, we have an entirely different comparison.
The Population of Texas is 26.5 Million people.
In Kenya, the population is 44 Million, considerably larger than it is for Texas.
However, when it comes to actual access to electrical power, the situation is entirely different.
Over the course of a year. Kenya generates for actual consumption a total of 7.4 TeraWattHours (TWH) of electrical power from a Nameplate Capacity of 1,700MW, and yes that is the total Nameplate Capacity for electrical power in Kenya, just slightly less than, and wait for this ….. ONE large scale coal fired power plant of 2000MW.
The actual power being generated in Texas, comes in at 364TWH, and has that sunk in yet, 364TWH.
That’s FIFTY TWO times the power consumption for the whole of Kenya.
So to service slightly more than half the people Texas consumes 52 times as much power as is generated in the whole of Kenya.
What that immediately tells me is that they are not frugal when it comes to power consumption in Kenya. What it does tell me is that very few people living in Kenya have access to a reliable and constant source of electrical power, something we take so much for granted.
And now here they are, going ahead and putting in a piddlingly small new solar power plant, pandering to the renewable lobby, that power adding very little to the overall power generation in a Country sorely in need of even the tiniest fraction of power which we in the already developed World have such regular access to.
So, Anthony, thank you so much for leaving a comment. Besides knowing I have a following, what comments like this achieve is it makes me go and look, and find out facts, which I can then put down here, telling everyone else who wishes to read just how lucky we really are in the Countries we live in, and just how badly they are doing in other Countries not so fortunate as we are.
In answer to your question regarding solar power, I have found an article on the plant in question, and I will add a further reply a little later, but just off the cuff, this is a Solar PV plant, which uses the solar cells to generate electricity during daylight hours only, and does not use batteries, so the question of battery life does not enter into it.
The proposed plant is 50MW only, and will supply a further, wait for it, ONE Percent to the total power being generated.
Tony.
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Zheng Jie Ng
Thu 02/06/2014
may i know the environmental and social disadvantages of CSP plants??
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Guido Bronner
Thu 01/09/2014
Hi Michael,
you should be more equitable in your comparison.
for coal power plant you did not include
– the area required for the mining of coal (increasing every year), since major part the solar plant are the reflectors
– the costs of the coal (mining, transportation) and not only the initial investment: otherwise you should not consider the costs and the area of the reflector part of the solar plant and compare directly with the coal plant
Guido
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Jacques Lemiere
Sun 11/10/2013
really interesting…
well you should add more about money cost and so on..
It would be interesting too to see if this solar power match the need…if not you have some extra costs…backup or forced exportations of electricity at a low price.
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TonyfromOz
Sun 11/10/2013
Jacques,
thank you for your comment.
I would dearly love to use the cost factor for these plants as part of my argument, as they are quite literally horrendously expensive for what amounts to only tiny amounts of electrical power being delivered for consumption. However, there are factors that would tend to make anything I did write slightly misleading.
The Costings for these plants are notoriously difficult to come by with any accuracy. As it is, there are 24 of these solar plants listed here, and after almost exhaustive checking, I can only find details for 9 of those plants, and the capital costings for just those 9 plants come in at 4.4 Billion Euros, which equates to around $6.6 Billion in Australian Dollars.
Now, just having said that, those costings themselves are costings for the time these plants were constructed, some of them, a number of years back now. The (somewhat incorrect) thinking is that the more of these plants which do get constructed, then the price will come down, and that is just not true. One recent example of this is the Abengoa Solana Plant in Arizona, which only recently came into full operation. The cost has been quoted as high as $2.4 Billion, just for this one plant, which started out when first proposed as costing around $750 Million, showing an expansion factor of more than three times.
Again, a further reason that true costings are difficult to come be, especially in this case for Spain, is that Governments have been subsidising these plants with enormous injections of money up front, and those costs are not detailed, so even if you could find accurate costings, these figures of themselves would be misleading.
Suffice to say that the costings that can be found for these Spanish Plants indicate that figure of $AUD6.6 BILLION for barely 600MW of Nameplate Capacity.
As I mentioned, they are horrendously expensive, and only deliver what can be called at best boutique amounts of electrical power on a limited time basis, and only have a lifespan of 25 years at the absolute best case scenario.
Tony.
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addisuwond
Fri 11/08/2013
Reblogged this on Addisuwond.
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michaeljmcfadden
Fri 11/08/2013
Very interesting. Particularly when you view the size of these solar farms in Google Earth. I had no idea efforts of this size were even on the drawing boards, much less actually in full operation.
Tony, you’ve obviously put enough thought into this and have studied it well enough that you might be able to come up with some figures that might actually help your case in people’s minds by looking at a place like Manhattan Island (which I would guess is fairly power hungry), making some adjustments for the higher latitude for power production, and give a ballpark figure for how much of Brooklyn would have to be converted to such solar farming to give Manhattan its power needs.
That something you’d be willing to take a shot at?
😕
MJM
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TonyfromOz
Fri 11/08/2013
Michael,
thanks for leaving a comment.
You pose a very interesting idea really, and one that you might think out of the realms of probability for someone like me, who lives here in Rockhampton in the State of Queensland in Australia, but in fact it is something that can quite easily be worked out.
Manhattan is one of the most electrical power intensive areas on the whole of Planet Earth, if not THE most power intensive.
Because of the huge number of high rise buildings in Manhattan, then nearly all of that power is required for 24 hours of every day, and it would surprise you why. Those towering buildings are all workplaces in the main, and all of them are air conditioned. Now here you think cool in Summer and warm in Winter, but in reality, the temperature is set at the same mark all year round, so it feels warm in Winter and cool in Summer. Each of those buildings have monster conditioning units on the roof. The main reason for these huge units is to supply circulated breathing air into these huge structures, because that is the only way breathable air gets into these buildings. Try opening a window in one of them. You can’t.
So, each of those units draws a huge amount of power, and as the air needs to be in constant circulation, then those units run around the clock.
So there’s your large power consumption right there, ensuring that a constant high power consumption is required around the clock 24 hours of every day.
Now, having got that out of the way, and it is an important piece of this exercise, let’s go back to what I wrote in the main text of the Post about how much time all these solar plants in Spain provide their power. Note I said their Capacity Factor is 28.7%, and that can be equated to supplying their full rated power for 28.7% of a whole year, or even (on average) 28.7% of every day or just a tick under 7 hours a day, some days more, some days less.
So, straight away, it now becomes obvious that these solar plants can NEVER supply the 24 hour power requirement for Manhattan.
A vital second point here is the total area covered by all 24 of these solar plants. Note how that comes in at a little over 13,500 acres or 21.2 square miles. The total land area of Manhattan is 23 Square miles, and Central Park is a little under 2 square miles, so the total area covered by these plants is equal to the area of Manhattan Island itself.
Now, a third point, as to power consumption. It’s really a moot point as these 24 plants cannot supply the 24 hour requirement for Manhattan, but let’s do the exercise anyway.
These 24 solar plants supply just under 4,500GWH of power over a full year.
Manhattan actually consumes close to 13,000GWH (and it’s probably more than that) of power over a full year, so these 24 solar plants could only supply around one third of Manhattan’s power requirement, but as I said, it’s moot, because while Manhattan needs its power for 24 hours of every day, these plants can only supply it for around 7 hours a day.
I hope this is as eye opening for you as it was for me.
Tony.
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michaeljmcfadden
Fri 11/08/2013
Thanks for the thoughtful response Tony. I hadn’t realized that about the buildings.
In terms of area, yes, I’d taken the Exifer (?) plant (the largest one) and filled my screen with it from 12,000 feet up. Looking at Central Park, that one plant was almost the same size.
Given the higher latitude, and the 24 hour considerations, you might need the area of Rhode Island (our smallest state… 1200 sq. miles) to guarantee uninterrupted power to Manhattan.
Question: where did you get the power consumption for Manhattan? I had thought that would be difficult.
😕
MJM
PS – (Actually, I’d dropped a decimal in my seat of the plants calculations. You might not need Rhode Island, but you’d probably need at least 120 square miles.)
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TonyfromOz
Fri 11/08/2013
Michael,
I added your further extra Comment into your Comment as the PS you see there.
While it is an interesting exercise, the real point here is that these plants cannot supply power for the full 24 hours, no matter how many of them you have.
You could have Plants enough to supply an equal amount of power in totality, but again, that power is still only available on a limited time basis.
Also, while these plants are in Spain, a Country with a decidedly greater Sunny climate, being closer to the Equator, the further North you go, eg as in Manhattan, and Rhode Island, then you will definitely be getting less hours of Sunlight, and in Winter, probably even snow which would necessitate even greater problems covering the mirrors.
All is this is contingent upon the availability of absolutely enormous amounts of money, with an end result of limited access only (on a time basis) to quite small amounts of power.
As to the total power consumption for Manhattan, some of that information I can gather from the power consumption interactive map for New York, where it mentions that just Manhattan alone consumes considerably more electrical power than, and wait for this, the whole Country of Kenya, just Manhattan alone. Best information I can gather about the power consumption of Kenya is that it is around 11,000GWH per year.
However, as I mentioned, that could be even higher, and that information is relatively current as shown at the EIA site at this link for State by State power consumption. Find New York State on the list and then note the second last column, All Sectors year to date at the end of August 2013. That consumption for NY State comes in at 96,000GWH per year, and here I have equated Manhattan to around one eighth of that total, a relatively conservative estimate.
Again, let me stress that where power availability is a 24 hour requirement, these solar plants cannot fill that requirement, no matter how many of them you have.
Tony.
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michaeljmcfadden
Fri 11/08/2013
Oh ye of little faith Tony! Haven’t you heard the new plan? They’ll use the grids to concentrate STARLIGHT at night!
It is sad that they’re not more efficient. It certainly is a clean way to generate power — although the construction/maintenance aspects could bite into that: I’ve been surprised at (although I don’t really know the credibility of) the claims about the difficulties with the wind machines. People think of the placid, picturesque, naturalistic Dutch windmills (and occasionally Baron von Frankenstein) whenever they think of wind power. It’d be nice if it were true, right?
– MJM
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TonyfromOz
Fri 11/08/2013
Michael,
Wind Power is just as big a failure as any of the forms of solar power.
For some information on Wind Power, then read the following Post. I have literally hundreds detailing the failure that is Wind Power.
These two forms of renewable power will never do what they claim, replace large scale traditional methods of electrical power generation.
Wind Power Fail – 2012 – Same As Always
Tony.
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