Posts tagged ‘MW’

A Typical Clean Energy Boondoggle

Master Resource looks at the California Valley Solar Ranch

In a realistic appraisal of the CVSR we should note the following:

· An investment of $1.6 billion 250 MW breaks down to an extravagant $6,400,000 per megawatt.

· The Solar Ranch covers 1,500 acres.

· The CVSR is projected to produce 482,000 MWh per year, implying an operating capacity factor of around 22%.

· Given a reasonable appraisal of the value of 482,000 MWh per year, it is not possible that the solar panels will be able to provide a return sufficient to pay back the $1.6 billion investment within their functional life (not even close), even when ignoring annual operating and maintenance costs. Hundreds of millions of dollars will be lost (see Updated CSVR Cash Flow).

....

A much more viable alternative to a solar generation facility, although not the only one, is a plant using natural gas. A natural gas combined cycle gas turbine (CCGT) facility capable of 250 MW would have required less than one-fourth the capital investment, would be capable of making four times the electricity per year at 88% capacity factor, and would fit on a single acre.

Also, a CCGT facility could have been located closer to the point(s) of actual use of the electricity, and could provide dispatchable energy which could be increased or decreased as demand fluctuates; something the solar facility is incapable of providing.

So why is this project even happening?  Because most of the project was funded by a taxpayer-gauranteed loan.  And then many of the players got direct subsidies and tax breaks.  And finally the electricity from the project gets bought at an above-market subsidized rate.

 

Another One Bites the Dust

Another solar company which received $2.1 billion in loan guarantees from the Obama Administration has gone bankrupt.  The good news is that it has not spent much of that taxpayer money, and its bankruptcy is probably due more to the bankruptcy of its German parent, which in turn is likely related to the huge cuts Germany has made in its feed-in tariff subsidies.

The big asset possessed by Solar Trust is the Blythe solar project, a planned 1000MW facility that apparently has all of its permitting in place.  The Blythe facility was originally going to be a solar-thermal facility, with adjustable mirrors focusing the sun on a central boiler that would in turn power turbines.   This plan was scrapped last year in favor of a more traditional PV technology, and I know local company First Solar has been hoping to save itself by getting the panel deal (First Solar also has been hammered by the loss of German subsidies).

If we take the cost of this planned 1000MW facility as the stated $2.8 billion (of which 2.1 billion would be guaranteed by US taxpayers), we see the basic problem with solar.   A new 1000MW  natural gas powered electric plant costs no more than about $1 billion.  It produces electricity 24 hours a day.  This solar plant, to be the largest in the world, would produce 1000 MW for only a few hours of the day.  That area of desert gets about 7 peak sun hours per day (the best in the country) so that on a 24 hour basis it only produces 292 MW average.  This gives it a total capital cost per 1000 MW of $9.6 billion, making it approximately 10 times costlier than the natural gas plant to build.  Of course, the solar plant has no fuel costs over time, but solar is never able to close the gap over time, particularly with current very low natural gas prices.

Update:  Apparently the $2.8 billion was just for the initial 484 MW so you can double all the solar costs in the analysis above, making the plant about 20x costlier than a natural gas plant.

More on Wind

I was having a back and forth with a reader about wind power and how much fossil fuel capacity must be kept on standby to support grid reliability with wind.  Here are some excerpts of what I wrote:

Forget all of the studies for a moment.  I used to operate power plants.  Any traditional capacity (fossil fuel, nuclear) except perhaps gas turbines takes on the order of a day or more to start up - if you don't take that long, the thermal stresses alone will blow the whole place up.  During the whole startup and shutdown, and through any "standby" time, the plant is burning fuel.   Since we don't have a good wind energy storage system, some percentage of wind capacity must be backed up with hot standby, because it can disappear in an instant. We are learning now, contrary to earlier assumptions, that wind speeds can be correlated pretty highly over wide geographies, meaning that spreading the wind turbines out does not necessarily do a lot to reduce the standby needs.  And since plant startups take time, even gas turbines take some time to get running, the percentage of wind power that required hot backup is pretty high -- I would love to find this percentage.

I found at least one source for such a percentage, which posits that for England, the percentage of hot backup needed is as high as 80%:  http://www.ref.org.uk/Files/ref.for.decc.28.10.09.i.pdf

I quote from page 6-7:

On any view, including the square root rule of thumb referred to above, the result, imposed for purposes of maintaining adequate response and reserve requirements, implies that a high degree of conventional (dispatchable) plant capacity is retained in the system to support wind generation. Thus, for 25 GW of installed wind capacity only 5 GW of conventional plant can be replaced leaving 20 GW in the role of standby capacity (also known as "Spare" or "Shadow Capacity").3

So 80% of the expected production from wind has to be backed up with hot spares burning fossil fuels.  They go on to say that the percentage of required spare capacity may be lower if the grid area is substantially larger, but not a lot lower.  I had not considered hydro power, but apparently that can be used to provide some quick response to wind production changes.  The report also talks about diesel generators for standby since they can be started up quickly, but these are seriously inefficient devices.  Despite the report's conclusion that the situation might be a bit better on the continent with a larger and more diverse grid, a report of the largest German utility seems to argue that German experience may actually be worse:

As wind power capacity rises, the lower availability of the wind farms determines the reliability of the system as a whole to an ever increasing extent. Consequently the greater reliability of traditional power stations becomes increasingly eclipsed.

As a result, the relative contribution of wind power to the guaranteed capacity of our supply system up to the year 2020 will fall continuously to around 4% (FIGURE 7). In concrete terms, this means that in 2020, with a forecast wind power capacity of over 48,000MW (Source: dena grid study), 2,000MW of traditional power production can be replaced by these wind farms.

It is hard to tell, because 48,000 MW is the nameplate capacity which is virtually meaningless, but my guess is that they are not doing better than 80%.

In Search of Skepticism

PHP4B5A1EED0E9E1Why can't our newspaper here in Arizona apply any skepticism to alternate energy technologies?  Sure, I think this technology is cool, where large solar dishes concentrate heat on what appears to be Stirling cycle engines  (the article, true to form, does not explain the technology, but a few hints plus the name of the company "Stirling Energy Systems" seems to point to that answer).  Other concentrator technologies focus on boiling water, so this a new approach to me.

However, why can't the article actually address real issues, like "how does this technology stack up, based on cost and efficiency, vs. other solar technologies."  It says it uses less water than other concentrator technologies, but is it more or less efficient?  No answer.

We can figure a few things out.  First, as with many "renewable" energy technologies, the company selling it engages in nameplate capacity abuse.  A 1MW coal plant produces 1MW all day long.  A 1MW wind plant produces 1MW when the wind is blowing hard, and less at other times.  And a solar plant produces 1MW when the sun is at its peak.   We can address this latter because folks have calculated sun equivalent hours, the number equivalent max sun-hours per day a site gets through the year.  For the best desert sites in the US, this number is around 6.  This means that the actual capacity of this plant is not 1.5MW, as stated in the article, but about a fourth of that, or  0.375MW.

This matters for a couple of reasons.  They state their build cost as $2.8 million per MW, which seems competitive to coal plants which cost $1.0-2.0 per MW, but in fact the reference number for this solar based on an apples to apples capacity comparison is actually  $11.2 million per MW.   The solar plant gets some credit for having no fuel costs, so it might be possible still for its power to be competitive, but it appears form the limited information in the article that it is not:

Singleton would not disclose what SRP will pay for the electricity, but said the utility will pay a premium for the environmental benefits of the power, and that the price is competitive with other sustainable-energy sources such as wind and geothermal power.

In other words, it is not competitive, so much so that they will not even reveal the price, and only subsidies and government mandates make it possible for a power company to buy the power.

Let's do a reality check.  At best, they get 8 dishes per acre, and 25Kw per dish at max sun.  So this is 8 x 25 x 6/24 = 50Kw per acre.   Lets say we want to get rid of coal.  The US generating capacity of coal plants is about 336,000 MW, or 336,000,000 KW.  To replace it with this solar technology would require 6,720,000 acres (10,500 sq miles or 10% of the state of Arizona) and cost $3.76 trillion dollars if located in the best possible solar areas.   This is not cheap but is not awful.

If I am doing the math right, I get something like $70,000 per dish   (1 dish = 25Kw, $2.8 million per MW).  I would think there are a lot of rich folks with some acreage that would pay $70,000 for one of these bad boys.  It would look much cooler than solar panels on the roof.

Window Repair Jobs

Tyler Cowen links to a good article that gets at the fallacy that suddenly obsoleting our energy infrastructure and having to rebuild it will be of net economic benefit.

Optimistically treating European Commission partially funded data, we find that for every renewable energy job that the State manages to finance, Spain's experience cited by President Obama as a model reveals with high confidence, by two different methods, that the U.S. should expect a loss of at least 2.2 jobs on average, or about 9 jobs lost for every 4 created, to which we have to add those jobs that non-subsidized investments with the same resources would have created

Includes 1 million euros in government subsidies per wind job created.

In my mind, the green jobs mantra is a result of the CO2 abatement case becoming fatally weak, with supporters of legislation casting about for other justificaitons.  From the very beginning, many of the most passionate folks are on the AGW bandwagon not because they really understand the science, but because the theory provided justification for a range of government actions (reduced growth, limited technology, reduced energy use, reduction in global trade -- even vegetarianism) that they supported long before AGW made the news.

Update: A quick note on a theme I harp on a lot - nameplate capacity for wind and solar is really, really misleading.  In Spain in the study cited, wind operates at 19% of nameplate over the course of a year and solar operates at 8% (figure 3).  The actual CO2 reduction is even worse, because, particularly for wind, fossil-fuel fired turbines have to be spinning on hot backup for when wind suddenly dies.  Germany, the largest wind user in the word, found only 1,000MW of reduced fossil fuel plant needs from every 24,000 MW of wind capacity.

Rated Capacity

One needs to be a careful consumer of information when reading about the "rated capacity" of certain alternative energy plants. 

Take a 1MW nuclear plant, run it for 24 hours, and you get 24 MW-hours, or something fairly close to that, of electricity.

Leave 1MW worth of solar panels out in the sun for 24 hours, you get much less total electricity, depending on where you put it.  On an average day in New York City, you will get about 4 MW-hours.  In one of the best solar sites in the word, my home of Phoenix, you get about 6.5 MW-hours per day.  The key metric is peak sun-hours per day, and some example figures are here.  So, even in the best solar sites in the world, solar panels run at only about 25-30% of capacity.

It turns out, not surprisingly, that the same relationship holds for wind.

It's not like it's a secret that wind turbines are an unreliable source of electrical power. Bryce points out that, "In
July 2006, for example, wind turbines in California produced power at
only about 10 percent of their capacity; in Texas, one of the most
promising states for wind energy, the windmills produced electricity at
about 17 percent of their rated capacity."

That means
that there has to be nuclear, coal-fired or natural gas power plants
functioning fulltime as a backup to the pathetically unreliable and
inefficient wind farms. Moreover, what electricity they do generate
is lost to some degree in the process of transmitting it over long
distances to distribution facilities.

Now, this should not outright dissuade us from these technologies, but since no one has really licked the night-time / not-windy storage proble, it's certainly an issue.   I have looked at solar for my house a number of times, and the numbers just are not there (even with up to 50% government subsidies!) without a 2-5x decrease in panel costs.  Low yields can potentially be tolerated, but capital costs are going to have to be a lot lower before they make a ton of sense.

Question About Nuclear

I was perusing the US electricity generation data a minute ago, and noticed this trend in nuclear generation in the US (all numbers in millions of MW-hours, from here):

1995..........673
1996..........675
1997..........629
1998..........674
1999..........725
2000..........705
2001..........534
2002..........507
2003..........459
2004..........476
2005..........436
2006..........425

I am wondering at the fall of 300 million megawatts-hours from 1999 to 2006.  My guess is that maybe some of the really old US government-owned plants closed.  But to the extent that this decline is due to aging plants and regulations limiting capacity, it strikes me that if someone in government really wanted to come up with a plan by 2020 to reduce CO2 in utility plant emissions, that regaining a portion of this lost nuclear capacity might be the cheapest and fastest approach.  After all, 300 million MWH is about 20% of total coal-fired generation and about 45 times more capacity than the sum of all US generation from non-hydro renewables (which don't really reduce CO2 anyway).