On the Rise: Solar Thermal Power ?

[Besoeker]

Originally Posted by LMagic007

Yes so it might be best for people to reach mutual appreciation of the terminology to derive meaningful comparisons that can be discussed in a balanced way.

There is no difficulty in defining capacity factor.
What often seems to get missed when the term is used is clarity on exactly what process it is used to define.
A wind turbine system, for example, might have a rating of 3MW. The turbine, the gearbox, the generator, the power converter and transformer would all be rated similarly. Maximum output would thus be 3MW but average output might be 1MW. It is easy to see how a 33% capacity factor can be deduced.

If you add in an energy storage facility you could get a steady 1MW output (assuming the energy storage has no losses). Does that change plant capacity factor? I think not.
Rated turbine system is still 3MW and average output is still 1MW.
Irrespective of storage medium.

But, if you took just the storage and constant output capability, you'd get a much higher capacity factor. In isolation, it wouldn't be wrong. But it doesn't represent the system as a whole.

The same points could be made about solar thermal. A claimed capacity factor of greater than 50% might be valid for some component parts but can't reflect the complete system.

In short, the definition of capacity factor isn't a problem. Selective application is.

[LMagic007]

Originally Posted by Besoeker

There is no difficulty in defining capacity factor.
What often seems to get missed when the term is used is clarity on exactly what process it is used to define. A wind turbine system, for example, might have a rating of 3MW. The turbine, the gearbox, the generator, the power converter and transformer would all be rated similarly. Maximum output would thus be 3MW but average output might be 1MW. It is easy to see how a 33% capacity factor can be deduced. If you add in an energy storage facility you could get a steady 1MW output (assuming the energy storage has no losses). Does that change plant capacity factor? I think not.Rated turbine system is still 3MW and average output is still 1MW. Irrespective of storage medium. But, if you took just the storage and constant output capability, you'd get a much higher capacity factor. In isolation, it wouldn't be wrong. But it doesn't represent the system as a whole.

The same points could be made about solar thermal. A claimed capacity factor of greater than 50% might be valid for some component parts but can't reflect the complete system.

In short, the definition of capacity factor isn't a problem. Selective application is.

Originally Posted by Besoeker

That depends on what is meant by capacity factor. The solar collector array may have a rated capacity of say, 20MW. That capacity can be used when there is solar energy to collect. A 50% capacity for that part of the plant alone would be optimistic. If that's considered as part of overall plant capacity, then overall plant can't do better than 50%.

Hmm, contradiction comes to mind.

Naturally the configuration of the various plant components will influence the overall capacity factor. Thus getting the component mix right will help the plant yield its maximum average annual capacity factor. Simply putting a number an un-sited undefined in principle installation, like 50% and claiming it to be highly optimistic, is highly speculative at best. Some plants will be higher capacity factors some lower depending on all the variables. For example, you would not be building a Solar Thermal plant in Antarctica, but you might build one near or in the Mojave Desert, which is what they are doing. It needs to be appreciated that the numbers you throw around don't necessarily represent all cases.

[LMagic007]

Originally Posted by Wobs

One can never have enough ale.

I'm still waiting for you to address all the points I've raised.
And even to consider more than one in combination. You know, like the real world has to with these kind of issues.

OK fair point to stay on topic, thus getting back on topic. I won't be addressing all the points you have raised because I already have and time is better spent on more entertaining issues. If however you have any key points of such great significance as to be deal breakers for Solar Thermal technology, I welcome you to reiterate them and I will briefly address them once more, given limitations of time available to go over old ground.

[Besoeker]

Originally Posted by LMagic007

Simply putting a number an un-sited undefined in principle installation, like 50% and claiming it to be highly optimistic, is highly speculative at best.

OK.
In posting my totally unjustified and unsupported claim, I was making the outrageously wild speculation that nowhere gets sunshine more than 50% of the time on average.

On reflection, it was an absolutely preposterous idea. Complete and utter nonsense. Probably straight out of The Beano or some equally highbrow publication.
How could I have ever seriously thought such a thing?

[LMagic007]

Originally Posted by Besoeker

OK.
In posting my totally unjustified and unsupported claim, I was making the outrageously wild speculation that nowhere gets sunshine more than 50% of the time on average. On reflection, it was an absolutely preposterous idea. Complete and utter nonsense. Probably straight out of The Beano or some equally highbrow publication. How could I have ever seriously thought such a thing?

Indeed.

[Besoeker]

Originally Posted by LMagic007

Indeed.

OK.
Then I shall retract it in favour of the much more reasonable assertion that the sun shines 25 hours a day in most places.

[LMagic007]

Originally Posted by Besoeker

OK.
Then I shall retract it in favour of the much more reasonable assertion that the sun shines 25 hours a day in most places.

Indeed. Keep talking, it's getting interesting and amusing, but far from convincing.

[prashamk]

Here's some encouraging update from Hawaii...

Sopogy, Incorporated has broken ground on the Big Island of Hawaii on the Keahole Solar Power renewable energy farm. This solar farm will be the first of its kind to use Sopogy’s large-scale MicroCSP solar concentrating system.

The Sopogy MicroCSP solar collector uses optics and reflectors (sans smoke and mirrors) to create heat that turns its turbines to create electricity. Sopogy also has large-scale installations in the Mojave Desert and on the Island of Kona.

What makes the Sopogy system different than other concentrated solar power collectors is that first it is being built to withstand the kinds of storms common in Hawaii that don’t often cross the Mojave Desert. And, second, the operating temperatures (200 – 400 degrees F) are kept such that contractors are easily able to service the solar farm.

According to Sopogy, fixed photovoltaic technology such as that used in residential solar panels, have an efficiency of only around 15-percent. The Sopogy MicroCSP parabolic solar concentrators, which track the sun, however, can sustain efficiencies in the 20 to 40-percent range.

[LMagic007]

Originally Posted by prashamk

Here's some encouraging update from Hawaii...

Cool. It's great to see the concept of solar thermal, shrunk down to distributed market scale. i.e. MicroCSP

But Sopogy's thinking small. Each individual collector produces 500 watts. That's roughly what a house consumes, but strung together in an array on the ground or on a roof, these panels could supply a chunk of a commercial building's needs, for example.

Hawaiian firm shrinks solar thermal power - CNET News.com

Sopogy - MicroCSP Distributed Solar Solutions

The more the better and it's only a matter of time.

[Besoeker]

Originally Posted by LMagic007

Indeed.

Good.
I'm so pleased that you agree with my 25 hours a day assertion.
Thank you for your expert input.
I feel exonerated from my previous asinine posts about the 12 hour average for sunshine.
Our planet will never move the same way again.