Karl W4KRL w4krl at dcm-va.com
Sat Feb 6 01:44:28 CST 2010

I was referring to the deceptive precision obtained by dividing 10GW by 3 to 5 yielding an effective capacity of 3.3GW. Just because a calculator has a bunch of digits on it doesn't mean you can derive two decimal precision fromm single decimal data.

But why is an estimate needed? Surely these generators have KWh meters on them and no one is giving the electricity away for free. It should be possible tp know exactly how much wind generated electricity was delivered.

Karl W4KRL

-- Sent from my Verizon Palm Pre
Mike O'Dell wrote:

it has nothing to do with sloppiness

wind and solar have problems with "dispatch reliability"

the wind doesn't blow the best way all the time

and clouds are equally difficult to predict a year in

after a wind farm or solar farm is in operation for a while,

the planning assumptions, developed from detailed monitoring

for an extended period before the farm gets built, are validated

with "real life", and those can be used to estimate the expected

output from the facility. but those are *estimates* based on

past history, and weather is notoriously unreliable.

until we have realistic grid-scale power storage ability, or

until wind and solar have enough geographic diversity to allow

large-scale averaging, and the transmission infrastructure is

sufficiently modernized to support significant transit traffic,

wind and solar cannot be used for "base load" distribution because

they cannot be relied upon to be there when required.

as a result, every megawatt of generation contracted with

wind or solar has to be backed-up with a contract for

dispatch-reliable generation (fossil or nuclear).

just last year, in the Texas Independent Operating Area

(larger than Texas but it is the majority of the area),

they were using a large wind farm in northwest Texas

to carry part of the daytime peak load. to the vast

surprise, a little dry line moved through, dropping the

wind speed to essentially zero in the space of two or

three minutes. suddenly the TIOA had a deficit of several

hundred megawatts and the impact was felt all the

way into Canada. the TIOA has rightly decided they have

to solve this problem before they can carry base load

generation with wind or solar.

progress is being made on grid-scale storage,

and plans are being developed for a new long-haul

transmission core to make it easier to move power

long distances. the current transmission infrastructure

was designed to be regional at most, within one power

company's regional footprint. moving power from

the sunny southwest to the dreary northeast is just

not realistic at the moment. new EHV transmission coupled

with a move to DC-based interties offer the possibility

of both building a new transmission core as well as making

the existing grid more stable by sectionalizing it.

it turns out large AC power grids and large dynamically-routed

data networks have the same fundamental problem: they are

both too large to be synchronous. the speed of light is just

too bloody slow. the solution in both cases is to break

the network into subnets small enough to be quite stable

and then interconnect those regional subnets with technology

which doesn't propagate instability. those are DC interties

in the electric power case and exterior routing protocols

in the packet network case.

the Europeans have been doing DC interties and DC transmission

for quite some time now and the technologies are relatively

mature, but the network planning and engineering required

to exploit them are not as well-developed or well-understood

over here. and utilities are not prone to spend money they

can't relate directly to bottom-line growth, so the incentives

may require a bit of tuning to produce the desired behavior.

but it is gonna happen - just not terribly quickly.

-mo

On 2/4/10 11:12 AM, Karl W4KRL wrote:

> Andre,

>

> There should be exact figures for how much wind-generated electricity was

> produced. Then we would not need to resort to rules of thumb to compare wind

> capacity to non-intermittent capacity. It is sad to see the degree of

> precision increase when applying approximate factors. Shame on the author!

>

> An interesting statistic that was missed is that US wind generation capacity

> was increased 40% in one year.

>

> 73 Karl W4KRL

>

> -----Original Message-----

> From: andre kesteloot [mailto:andre.kesteloot at verizon.net]

> Sent: Wednesday, February 03, 2010 12:39 PM

> To: Tacos

> Subject: IEEE: About Wind Turbines

>

> New turbines amounting to almost 10 gigawatts were installed in the

> United States in 2009

> &lt;http://www.awea.org/newsroom/releases/01-26-10_AWEA_Q4_and_Year-End_Report_

> Release.html>,

> bringing the country's total wind capacity to about 35 GW, according to

> data released by the American Wind Energy Association this week. Next

> week the Global Wind Energy Council, based in Brussels, is expected to

> release figures showing that wind installation worldwide almost equalled

> the booming growth rates seen in recent years, which have been around 28

> percent per annum.

>

> Putting its spin on the rather sensational 2009 news, the American wind

> association asserts

> &lt;http://www.awea.org/newsroom/releases/12-22-09_Wind_Energy_Industry_Highlig

> hts_of_2009.html>

> that additional U.S. wind capacity avoids or saves more than 60 million

> metric tons of annual carbon dioxide emissions, 200,000 tons of sulfur

> dioxide, 80,000 tons of nitrous oxide, and 20 billion tons of water. A

> spokesperson for the association claims, perhaps a little dubiously,

> that their numbers crunchers got these results whether the generation

> that wind is substituting for is taken to be the average national mix or

> the specific mix replaced by specific turbines.

>

> To keep things in perspective, recall that when wind (or solar) capacity

> is compared to baseload fossil or nuclear generation, it is normally

> divided by a factor of three, four or even five, to account for

> intermittancy. (The wind doesn't always blow and the sun doesn't always

> shine.) By that standard, the new wind capacity really is equivalent to

> no more than 3.3 GW of natural gas. But even by that reduced benchmark,

> it's the equal of three nuclear power plants--not a single one of which

> is getting built in the United States at present.

>

>

>

>

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--

"Of course it's hard!

If it was easy, we'd be buying it from somebody else!"

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