|
* I think that the systems marked with an asterisk will
have problems because they do not use an intermediate fluid to receive the
sun's energy to heat the feedwater entering the steam generator. This provides
a very stable well known energy balance. Steam Turbines are made to accept
well known steam inlet conditions. I do not think the systems with direct
hearing from the sun's energy to water- steam can be well known or controlled.
** These system marked with two asterisks suffer the same
problem as above. The 10 MWe Tower Power system at Daggett,
California started with the sun's ray's directed to the water in the tower
to produce steam., and it failed. Later they used a heat
transfer medium, but it also failed because the heat transfer medium froze
in the steam generators. They could have prevent this problem, but failed
to do so.
*** These are the Stirling systems, some 1,750 MWe
produced by 70,000 individual 25 kWe capacity machines. Can they actually
maintain this many machines? They need to learn how to manufacture and keep these
units in top shape. These units have no reserve energy capacity. If or
when the sun goes under cloud cover they would all drop out, requiring the
utility to have an enormous amount of spinning reserve power plants on standby.
The California
Environmental Quality Act requires special emphasis should be placed on
environmental resources. I wonder how this racks up with the need for
copious amounts of water to keep the panels clear?
( c) Knowledge of the
regional setting is critical to the assessment of environmental impacts.
Special emphasis should be placed on environmental resources that are rare
or unique to that region and would be affected by the project. The EIR must
demonstrate that the significant environmental impacts of the proposed
project were adequately investigated and discussed and it must permit the
significant effects of the project to be considered in the full
environmental context
Apparently Solel has bought the
parabolic Mirror system at Kramer's junction and intends to build a giant
new solar plant in the Mojave Desert.
Solel Inc. is developing the 553 MW Mojave Solar
Park 1 (MSP-1), the world's largest solar thermal power plant, in California's
Mojave Desert. In July 2007, Solel Inc. concluded a 25 year Power Purchase
Agreement with Pacific Gas and Electric (PG&E) to provide it with electricity
from MSP-1. Solel will build MSP-1 using Solel 6, Solel's industry leading
solar thermal collector. MSP-1 will encompass nine square miles and will
provide PG&E with 1,388 gigawatts of energy annually at a price competitive with
plants powered by fossil fuels.
Of all of the desert solar
system, I think this one has the best chance of succeeding. The reason for this
is due to the fact that the solar panels heat a heat transfer fluid in
tubes running through the parabolic reflectors. The fluid is then stored in a
large tank and is pumped to a shell and tube stream generator that heats water
to steam for the turbine. This intermediate heat transfer fluid allows the
system to carry out a more controlled heat balance of the power plant system.
In a feasibility study performed by the Electric
Power Research Institute (EPRI) found that the most feasible solar
technology system currently available for a large scale plant is the parabolic
trough.
My comment: I agree with the above
statement. I think the reason for this is due to the use of an intermediate
heat transfer fluid. The parabolic trough heats this fluid which
then goes into a holding tank. The thermal properties of the fluid in the
holding tank are well known. This fluid is then pumped into the shell side of
the steam generator to heat the feedwater coming for the Rankine cycle of
the power plant. This makes it possible to have well known hot fluid thermal
conditions at the inlet to the steam generator. This provides good control
heat balance over the process of generating the steam conditions going to the
turbine. Generating steam is not a simple process. It requires well known
conditions of the heating process and feed water inlet parameters.
The above reasons are why I think the
Tower Power and Fresnel Panel systems will not be as successful as the parabolic
trough systems.
Moreover, the Parabolic Trough system is the
only a proven system in California over the last thirty years. The Tower
Power system at Daggett California was a dismal failure and it was abandoned.
At Kramer Junction,
California, there is a solar installation called SEGS (Solar Electric
Generating System, built by LUZ International), of which there are nine units.
SEGS uses an array of parabolic mirrors (see picture), laid out on north-south
axes to concentrate reflected sunlight onto a black tube through which therminol
flows.
The solar-trough array at Kramer Junction, California.
 The
shiny surfaces
focus sunlight onto the black tubes that run along the
array. The
therminol fluid, thus heated, is pumped to a heat exchanger where it is used to
boil water for a (Rankine) steam cycle system. As the sun
moves from
east to west, the reflectors rotate so as to keep facing the
sun.
To operate
at peak efficiency the mirrors are pressure washed every ten to twenty days. If you
want a full explanation and analysis of the SEGS system go to the NREL.com site.
But be careful they are, in my opinion too optimist about the future of this
concept. Also they are not too free on relating the capacity factors of the
system. Low capacity factors are the bane of renewable energy systems. The
capacity factor of the SEGS plant when operating on solar energy alone is only 25 percent.
It appears that the parabolic trough
system has been adopted as the favorite for concentrating solar plants. Below is
a recent announcement for such a plant being built in Nevada
Assembly of the
parabolic-trough system components is underway for a 64-Megawatt Nevada plant,
which will generate enough electricity to power about 11,000 homes.
Here is what what the Department of Energy Thinks about the trough system.
Trough
systems are commercially available and in use today. However, because of the
very low cost of today's fossil fuels, they cannot yet compete on a
cost-of-electricity basis with fossil-based systems,. A favorable financing
arrangement—one likely to be stimulated by green power markets—could enable
parabolic troughs to begin to play a role in the marketplace, however. And as
global demand for clean energy sources rises, trough systems will become more
financially attractive.
The Linear Fresnel Reflector solar
System
The Carrizo Energy
Company intends to construct a 177 MWe Linear Fresnel Reflector System in
San Luis Obispo County, California. PG&E has contracted to take the energy
from this system.
It
should be noted that PG&E is not putting any money in this venture. They are
only taking the electric energy if any is ever produced. This is necessary due
to the CPUC forcing PG&E to go green.
The Project
design will incorporate Ausra's
proprietary CLFR technology to
concentrate solar energy on tubes in an
elevated receiver. The concentrated
solar energy boils water within a row of specially coated stainless steel tubes in an
insulated cavity to produce saturated
steam. The steam produced in the
receivers is collected in a series of pipes,
routed to steam drums, and then to the two
turbine generators. Steam used by the steam
turbines is condensed back to water and
returned to the solar field. The advantage of this design is that lenses are cheaper
than mirrors. Furthermore, if a material is chosen that has some flexibility,
then a less rigid frame is required to withstand wind load
Prototypes of Fresnel lenses concentrators have been produced for the collection of thermal energy
by
International Automated Systems. No full-scale thermal systems using Fresnel
lenses are known to be in operation.
I am surprised that some organizations will
back and finance up to $500,000,000 in this system considering that there is no real prototype in
existence. It seems to me that the panels on the desert floor are so
close together that power washing them will be very difficult. Also stainless
steel tubes are selected as the tube material to receive the sun's energy and heat the steam-water in the over
head Fresnel tubes arranged horizontally. In the US we do not
use stainless steel to receive heat and transport steam- water
mixtures because stainless steel cannot withstand impurities such as caustics in the water-steam systems.
I think they should have arranged the tubes
in a vertical direction with the down comer tubes in the center and
the heated tubes around the out side and also he seam drums at the top. This would provide a natural
circulation steam-water system and it does not require multiple steam
drums in series. And they could control the water level tin the steam drums.
I cannot envision what kind of heat
transfer-heat balance they will get with the steam water mixture flowing
horizontally in the tubes. Boiling water is not a simple matter. I wonder
what kind of steam quality mixture they will get at the end of the Fresnel
tubes? But the saturated steam going the turbine is a good idea and the only way
this system has a chance of working. And at the beginning and and end of
the daily cycle they may not get any steam at all.
Well I have given them a lot of free advice.
They will not listen to it anyway. The folks at Daggett did not listen
either and it was a total failure. Where is the NREL when we need them? They
should weigh in on these matters also. PG&E does not care. They do not
have to pay dime for the system. They pay only for the energy if they ever
get any.
Financial Backer of this project.
Khosla is an Indian-American venture
capitalist. He is an influential personality in Silicon Valley. He was one of
the co-founders of Sun Microsystems and became a general partner of the venture
capital firm Kleiner, Perkins, Caufield & Byers in 1986. Knosla may be a lot
poorer when this is over.
Although the plant capacity is only 177 MWe,
I think it is large enough to show what a loser it will be. But we will
see in no experience yet. about 10 years.
Here is a blurb abut the Fresnel solar
system. No experience yet, but system is being tried in Spain.
To date there has
been no experience of using Fresnel collectors under actual operating
conditions. In order to ensure and prove that this technology is ready for use
in later commercial plants, we decided to build a complete demonstration plant -
the same size as a collector module, which would be used in a solar power
station. In this way the Fresnel design concept can be validated in an
experiment. Reliable figures and data are essential to examine the very
promising future of the technology and therefore confidence with customers and
investors in the new technology. The technology should be ready for market by
2008 in large-scale
Here is a request for information about the
CARRIZO SOLAR FARM. It concerns only the environmental information. Whether or
not the system will produce energy is not a concern of the CEC. In my opinion it
will produce very little electric energy. Don Lutz
SUBJECT: DATA
REQUEST SET 4 - NUMBERS 113 THROUGH 134
CARRIZO ENERGY
SOLAR FARM APPLICATION FOR CERTIFICATION (07-AFC-8)
Dear Mr. Fontana,
Pursuant to Title 20, California Code of Regulations,
section 1716, the California Energy Commission staff is asking for the
information specified in the enclosed data requests related to the Carrizo
Energy Solar Farm (CESF) Application for Certification (AFC)
(07AFC-8). The information requested is necessary to: 1) more fully
understand the project, 2) assess whether the facility will be constructed
and operated in compliance with applicable regulations, 3) assess whether
the project will result in significant environmental impacts, 4) assess
whether the facilities will be constructed and operated in a safe,
efficient and reliable manner, and 5) assess potential mitigation
measures.
This fourth set of data requests (#s 113-134) is being
made in the area(s) of biological resources, cultural resources, soil and
water resources, traffic and transportation, and waste management. Written
responses to the enclosed data requests are due to the Energy Commission
staff on or before September 29,2008.
PG&E makes huge solar deal
UTILITY PROJECT WOULD PUT FIVE POWER PLANTS IN MOJAVE
DESERT
Article Launched: 04/01/2008 01:34:35 AM PDT
Pacific Gas & Electric today will announce the
largest series of solar-power contracts in the utility's history. The deal, to
buy as much as 900 megawatts of electricity - or enough to power
540,000 California homes each year - involves five plants to be built during
the next decade.
If the solar-thermal power plants designed by
Oakland's BrightSource Energy become operational, a significant amount of
power for PG&E customers could come from the sun that beats down on the Mojave
Desert.
"From what I know, this is the biggest
commitment ever in the history of solar," said John Woolard, BrightSource
Energy's chief executive officer and president. "It's a fairly significant
undertaking on both sides."
Building all five plants in the Mojave will
cost $2 billion to $3 billion, Woolard said. The project, which faces
regulatory and financing hurdles, could mean 2,000 construction jobs, and
employ about 1,000 workers to operate the plants. PG&E didn't disclose
the financial details of the contracts
My comments: Matt Nauman is a fine
fellow, but as is true of most newspaper reporters, he knows nothing about
energy. In the first place PG&E did not buy 900 megawatt of electricity because
this is only the power rating of the 900 MWe facility, it is not
electrical energy. PG&E bought nothing, and has taken no financial liability.
PG&E will pay for the energy kWh produced by the BrightSource company's solar
power plant, if there ever is any. And the rate PG&W will pay has not been
determined.
PG&E must commit to buying energy
from solar plants as required by the State of California. If the rate is too
high the State must reimburse PG&E for part of the cost of energy. This means
you the tax payer will chip in.
As for a 900 MWe power plant. it
probably will never get built because it requires many financial backers for
such a project. Are there that many suckers out there? I think not.
Moreover, 900 MWe plant capacity
will only provide enough electric energy for 160,000 homes, not 540,000. And
they will have to power wash the panels every 10 days or so.
It appears that these these
plants will be the Tower power configuration. Perhaps the Brightsource Energy
Co. should visit the Tower Power Plant at Daggett, CA. They did not work
at all.
Review Process Begins for Solar Thermal Project in Kern
County
Sacramento - 5/22/08
The California Energy Commission today accepted an application to
build a 250-megawatt solar thermal generating complex in Kern County.
By a vote of 5-0, the Commission said it has enough information to
begin the review of the Beacon Solar Energy Project proposed by a wholly owned
subsidiary of Florida Power and Light Company. After finding the application for
certification (AFC) from Delaware-based Beacon Solar LLC "data adequate," the
Commission assigned a committee of two to lead the 12-month review of the
proposed plant. Commission staff will now begin the data discovery and analysis
phase of the licensing process. Commissioner Karen Douglas will head the
committee that will ensure that the project meets the requirements of the
California Environmental Quality Act. Commissioner Jeff Byron will serve as the
Associate Member.
Beacon Solar LLC plans to develop the project on
the western edge of the Mojave Desert along the California State Route 14
corridor, about four miles from California City and 15 miles from the town of
Mojave. The Beacon Solar Energy Project would be situated on 2,012-acres of
private land that used to be an agricultural site. The project would produce
electricity using parabolic trough solar thermal technology. Thousands of
parabolic mirrors assembled in rows would receive and concentrate the solar
energy to produce steam for powering a steam turbine generator. If approved by
the Commission the project will begin construction in the third quarter of 2009,
with commercial operations targeted for the third quarter of 2011.
My Comments: They did not say what
utility would get the energy from this plant. The parabolic trough is what I
think will be the most successful. Perhaps we will see some day how much energy
this plant will produce.
Stirling Engines Mirror- Solar Systems
Pictures are
two views of fields of Stirling Engines mounted on a mirror which focuses
the sun's photons onto the the engines mounted on the mirror assembly. The
mirrors will track the suns movement throughout the day.
 
On
August 11, 2005,
Southern California Edison
announced an agreement to purchase
solar powered Stirling engines from
Stirling Energy Systems[5]
(SES)
over a twenty year period and in quantity (20,000 units) sufficient to generate
500 megawatts of electricity. These systems - to be installed on a 4,500 acre
solar farm - will use mirrors to direct and concentrate sunlight onto the
engines which will in turn drive generators. Each Stirling engine-mirror module
assembly has a power capacity of 25 kWe (33.4 hp)
Stirling Energy Systems
(SES) is a systems
integration and project management company that is developing equipment for
utility-scale renewable energy power plants and distributed electric generating
systems ("gensets"). SES is teamed with Kockums Submarine Systems, NASA-Glenn
Laboratories, the U.S. Department of Energy (DOE), and The Boeing Company for
solar power plants. SES is positioned to become a premier worldwide renewable
energy technology company to meet the global demand for renewable electric
generating technologies through the commercialization of its own Stirling cycle
engine technology for solar and genset applications.
Stirling engines are powered by the expansion of a gas when
heated, followed by the compression of the gas when cooled. The Stirling engine
contains a fixed amount of gas which is transferred back and forth between a
"cold" and a "hot" end. The gasses used inside a Stirling
engine never leave the engine. There are no exhaust valves that vent
high-pressure gasses, as in a gasoline or diesel engine.
The Stirling engine receives the solar
heat focused on the outside of the hot piston wall and it is supplied to the
inside working fluid by conduction. The cold piston gas inside transfers its
heat through the wall to the outside heat sink. In this case the desert air.
The SES Solar Dish Stirling
system is shaped much like large satellite dishes (approximately 37’ in
diameter) and covered with curved mirrors. These solar dishes are programmed to
always face the sun and focus that energy on a collector in much the same way
that a satellite dish focuses radio waves on a tuner. This collector is
connected to a Stirling engine which uses the thermal power generated by the
focused solar energy to heat liquid hydrogen in a closed-loop system. The
expanding hydrogen gas creates a pressure wave on the pistons of the Stirling
engine which spins an electric motor creating electricity with no fuel cost or
pollution. This technology is referred to as solar thermal or concentrating
solar power.
The SES Solar Dish Stirling
system is shaped much like large satellite dishes (approximately 37’ in
diameter) and covered with curved mirrors. These solar dishes are programmed to
always face the sun and focus that energy on a collector in much the same way
that a satellite dish focuses radio waves on a tuner. This collector is
connected to a Stirling engine which uses the thermal power generated by the
focused solar energy to heat liquid hydrogen in a closed-loop system. The
expanding hydrogen gas creates a pressure wave on the pistons of the Stirling
engine which spins an electric motor creating electricity with no fuel cost or
pollution. This technology is referred to as solar thermal or concentrating
solar power.
SES maintains that the dish
Stirling system is technologically ready for use today. They have spent the last
17 years in research and development, and are ready for mass deployment as soon
as sufficient investments and/or execution of power agreements makes mass
production possible.
SES expects that one dish on
an annual basis can produce 60,000 kWh of electricity. Using these data supplied
I calculate a capacity factor of 27% for the system. There is only a
few hours in the winter season to generate energy and not a lot more in the
Spring and Fall seasons. Three months of Summer is the most productive
hours and that is not a lot. No system that only produces a capacity factor of
25% will be a serious contender for energy production.
|
