Green Peace Leader Rags on Solar Power

[Besoeker]

Originally Posted by LMagic007

In the mean time, think about these words, then go ask NREL if you are still unclear about their intended meaning.

No uncertainty on my part.
The 70% is not for the entire plant.

[Wobs]

Why we need to be cautious:

You link from NREL states:
http://www.nrel.gov/csp/troughnet/pdfs/32160.pdf

Just like for wind, California was the birthplace of solar power. In the late 1980s and early
1990s, a remarkable U.S.-Israeli consortium built 354 MW of thermal parabolic trough solar
power in the Mojave Desert (see “The 354-MW SEGS Power Plants”). Over the last decade these
units have delivered reliable power to Southern California Edison and have demonstrated the
commercial practicality of solar power generation. Two power tower demonstration projects,
Solar One and Solar Two, were also built during that time period and during their demonstration
period verified the power tower concept and the effectiveness of molten-salt heat storage.
During the same time period, dish Stirling solar power systems have quietly accumulated thousands of operating hours at various experimental sites in the Southwest."

However,Meanwhile:
Renewable Energy - Why Renewable Energy Is Not Cheap and Not Green

Thermal Solar
Thermal solar systems receive sunlight, concentrated in a parabolic dish trough or in a tower, which is then converted to electricity by a heat engine and electric generator. A 1978 study found that the materials required for thermal solar projects were 1,000 times greater than for a similarly sized fossil fuel facility, creating substantial incremental energy consumption and industrial pollution.168 An updated study into the total fuel-cycle environmental costs of solar has been investigated but not rigorously pursued. The mentality, according to one participant who wished to remain anonymous, is "keep the closet closed so you don't know what is in there."169 However, an energy specialist at the California Energy Commission calculated that the production of concrete per thousand megawatts of nameplate solar capacity (a proportionally high input) results in carbon emissions equivalent to 10 billion cubic feet of combusted natural gas -- approximately a year's worth of fuel for a similarly sized gas-fired plant.170
Thermal solar installations have had a disappointing past. Solar One, a 10-megawatt solar thermal project operated by Southern California Edison for high demand periods, closed in 1988 after six years of operation. The facility, 80 percent of which was funded by the U. S. Department of Energy, was so experimental and expensive that no cost per kwh was publicly revealed.171 In addition to heavy land requirements, bird deaths ("the birds died primarily from collisions with the picture-like surface of the heliostats") are as much as 10 times the kill at Altamont Pass per megawatt, although endangered species and other high profile birds have not been at risk.172
Solar Two, a $48 million, 10-megawatt demonstration project cofunded by an industry consortium led by Southern California Edison, the Department of Energy and the California Energy Commission, entered production in 1996. In place of a parabolic dish, this project uses a receiver tower where the concentrated heat from the field mirrors (called heliostats) is converted to electricity. Its $4,000 per kilowatt installed cost -- which would have been as much as $14,000 more per kilowatt if Solar One's equipment had not been utilized173 -- is still between five and 10 times greater than a gas-fired plant under current technology. The plan to generate power at between 7 and 8 cents per kwh will be virtually impossible at this capital-cost level.174 An annual operating cost of $3 million virtually ensures a shutdown in 1999, the year federal subsidies are scheduled to terminate.
The 1,900 mirrored panels, each measuring over 100 square yards, come out to 17 acres per megawatt of capacity.175 That is 50 times greater than a similarly sized gas-fired facility on a nameplate basis but 150 times greater on a generation basis. And unlike wind power, the land concentration of solar farms is very dense.
These concerns led a Worldwatch Institute study to conclude:
Solar Two looks good on paper, and it is expected to provide steady baseload electricity as well as late afternoon peaking capacity, but the future of all the central solar generators is in doubt. They are expensive to build, their very scale escalates financial risks -- as with nuclear power -- and their massive height (in excess of 200 meters) may attract opposition.176
The economic plight of central-station thermal solar was revealed with the bankruptcy liquidation of LUZ International in December 1991. LUZ, which was responsible for virtually all solar capacity in California, blamed lower fossil fuel prices for its plight.177 A restart company utilizing LUZ technology, heavily subsidized by private and public Israeli interests, hopes to lower thermal solar costs to 7 to 7.5 cents per kwh after the turn of the century.178 However, gas-fired technology, the Department of Energy predicts, will be around one-half as much,179 and this estimate has already been exceeded.

I'm not saying that this means that all solar thermal technology is not worth pursueing, or the current crop is no good, but it shows that different sources give different views, and that if we had looked at Solar2 back then it would have looked fab, but history says otherwise.

This is an example of why we need caution. New technology is nearly always touted as the best thing since sliced bread, but a shake down often reveals its cracks. Its often hard to find the real issues with the latest kit on the block, and so we must try to learn from some history.

[LMagic007]

Originally Posted by Besoeker

No uncertainty on my part.

Originally Posted by Besoeker

The 70% is not for the entire plant.

Again your opinion, but NREL's language is very clear. When one talks about a power generation plant in comparison with other power generation plants, they are usually referring to the entire plant, unless specified otherwise.

NREL uses the term

parabolic trough plants

so unless they indicate it to mean anything else, then it's reasonable to believe that's what they mean, whether you agree with it or not.

It's evident though that you have uncertainties about what NREL's intended meaning is, even though they have made it clear and spelt it out. Again though instead of wasting your time arguing about it, go find out what they mean for your own piece of mind and when you do know what they mean, tell us and the world about your new found discovery and when you do that, I will then say "now that wasn't that difficult was it ?"

[LMagic007]

Originally Posted by Wobs

Why we need to be cautious:

You link from NREL states:
http://www.nrel.gov/csp/troughnet/pdfs/32160.pdf


However,Meanwhile:
Renewable Energy - Why Renewable Energy Is Not Cheap and Not Green

I'm not saying that this means that all solar thermal technology is not worth pursueing, or the current crop is no good, but it shows that different sources give different views, and that if we had looked at Solar2 back then it would have looked fab, but history says otherwise.

This is an example of why we need caution. New technology is nearly always touted as the best thing since sliced bread, but a shake down often reveals its cracks. Its often hard to find the real issues with the latest kit on the block, and so we must try to learn from some history.

Caution should always be applied in any assessment of any technology. Solar Two is ancient technology ( 13 years old ) and was primarily for testing / development and evaluation purposes. It's a bit like saying, there was a time when nuclear energy was just a dream and it was. Then there was a breakthrough and the technology evolved more rapidly. The same applies to most technologies. One would hope different sources give different views and then at the end of the day as I have always maintained, people can make up their own mind.

[Besoeker]

Originally Posted by LMagic007

Again your opinion, but NREL's language is very clear. When one talks about a power generation plant in comparison with other power generation plants, they are usually referring to the entire plant, unless specified otherwise.

OK.
In your opinion, is there anywhere in the world where the sun shines 17 hours a day on average?

[LMagic007]

Originally Posted by Besoeker

OK.
In your opinion, is there anywhere in the world where the sun shines 17 hours a day on average?

The point is, that they are using thermal storage and their assessment is based on a given configuration of plant. ( collector array size, concentrator size, the absorber size, thermal storage capacity and turbine size ) all bound by various efficiency factors. Thus it's evident you appear to be arriving at conclusions based on interpretations or assumptions about factors that NREL may not be conveying. i.e. it might appear you could be filling in the gaps about information you might not be aware of or might not have factored into the NREL assessment. There is no point in throwing up numbers. If you want to present a hypothesis that would bring into question NREL's 70% capacity factor claims for the potential of future Solar Thermal CSPs , I suggest you might speak to NREL first, then come back with something a bit more meaningful.

[Besoeker]

Originally Posted by LMagic007

The point is, that they are using thermal storage and their assessment is based on a given configuration of plant. ( collector array size, concentrator size, the absorber size, thermal storage capacity and turbine size ) all bound by various efficiency factors.

That's your assumption. Perhaps not an unreasonable one.

Originally Posted by LMagic007

Thus it's evident you appear to be arriving at conclusions based on interpretations or assumptions about factors that NREL may not be conveying. i.e. it might appear you could be filling in the gaps about information you might not be aware of .

No assumptions used or required.
Solar collectors cannot operate at 70% capacity on average.

[LMagic007]

Originally Posted by Besoeker

That's your assumption. Perhaps not an unreasonable one.


No assumptions used or required.
Solar collectors cannot operate at 70% capacity on average.

I don't know where that's come from. It seems you might be loosing your concentration. I was talking about plants. As was NREL. As said before NREL's statement is very clear and if you cant accept that, then ask them directly, rather than continue to speculate and throw up questions about statements, that have not been represented. That type of remark you made just looks silly, when you know very well that NREL has been talking about plants. Get one word into your mind. PLANTS. NREL speak about power PLANTS in the context of potential 70% capacity factors. Stay on point, as talking about separate components in that context, detracts from the point NREL has made, which is about Power PLANTS, when comparing solar to coal power plants.

parabolic trough plants

As the cost of thermal storage is reduced, future parabolic trough plants could yield capacity factors greater than 70%, competing directly with future baseload combined cycle plants or coal plants.

http://www.nrel.gov/csp/troughnet/market_economic_assess.html

[Besoeker]

Originally Posted by LMagic007

I don't know where that's come from.

It's very simple. Solar collectors of any type can only collect when there is solar power to collect.
When there isn't (at night) they are using 0% of therir capacity.

[LMagic007]

Originally Posted by Besoeker

It's very simple. Solar collectors of any type can only collect when there is solar power to collect.
When there isn't (at night) they are using 0% of therir capacity.

You are the only one talking about solar collectors, so you are talking to yourself on that score. Forget about that. NREL is talking about power plants, as am I. You appear to be getting your wires crossed. Read the quote from NREL below. I'm on the same page as NREL on this subject, but clearly you are on your own page. I suggest you turn pages, so you know what NREL and I am referring to. "Power Plants". Otherwise you are not making any sense in this discussion.

As the cost of thermal storage is reduced, future parabolic trough plants could yield capacity factors greater than 70%, competing directly with future baseload combined cycle plants or coal plants.

NREL: TroughNet - Parabolic Trough Power Plant Market, Economic Assessment and Deployment