Power Roof: A roof-integrated solar cooling and heating system

Solargenix tiene colectores parabólicos para calentar y enfriar agua en "Hogares"
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Solargenix

Artículo en una de las empresas que contribuyó a construir Saguaro (Arizona).

Duda: En el artículo dice entre 250 y 500 degrees pero no especifica las unidades. Se suponen Fahrenheits al ser EEUU.

Empresa constructora Saguaro

EERE: Mencion a la tecnología

link

Articulo planta de Saguaro

APS TO CONSTRUCT SOLAR TROUGH POWER PLANT

First Such Project in U.S. Since 1990 RED ROCK, ARIZ. – APS today broke ground on Arizona’s first commercial solar trough power plant and the first such facility constructed in the United States since 1990. Located at the company’s Saguaro Power Plant in Red Rock, about 30 miles north of Tucson, the APS Saguaro Solar Trough Generating Station will have a 1-megawatt (MW) generating capacity, enough to provide for the energy needs of approximately 200 average-size homes. APS has contracted with Solargenix Energy to construct and provide the solar thermal technology for the plant, which is expected to come online in April 2005. Solargenix, formerly Duke Solar, is based out of Raleigh, North Carolina. Solargenix has partnered with ORMAT who will provide the engine to convert the solar heat, collected by the Solargenix solar collectors, into electricity. “The APS Saguaro Solar Trough Power Plant presents a unique opportunity to further expand our renewable energy portfolio,” said Peter Johnston, manager of Technology Development for APS. “We are committed to developing clean renewable energy sources today that will fuel tomorrow’s economy. We believe solar-trough technology can be part of a renewable solution. Solargenix is sure too. The company’s solar-trough technology uses parabolic shaped reflectors (or mirrors) to concentrate the sun’s rays to heat a mineral oil between 250 and 570 degrees. The fluid then enters the ORMAT engine passing first through a heat exchanger to vaporize a secondary working fluid. The vapor is used to spin a turbine, making electricity. It is then condensed back into a liquid before being vaporized once again. Historically, solar-trough technology has required tens of megawatts of plant installation to produce steam from water to turn generation turbines. The significant first cost of multi-megawatt power plants had precluded their use in the APS solar portfolio. This solar trough system combines the relatively low cost of parabolic solar trough thermal technology with the commercially available, smaller turbines usually associated with low temperature geothermal generation plants such as the ORMAT unit being used for this project. In addition to generating electricity for APS’ customers, the solar trough plant will help APS meet the goals of the Arizona Corporation Commission’s Environmental Portfolio Standard, which requires APS to generate 1.1 percent of its energy through renewable sources – 60 percent through solar – by 2007. APS owns and operates approximately 4.5 megawatts of photovoltaic solar
generation around the state and has partnered on a 3-megawatt biomass plant in Eager, which came online in February, and a 15-megawatt wind farm to be constructed near St. Johns. APS, Arizona’s largest and longest-serving electricity utility, serves about 902,000 customers in 11 of the state’s 15 counties. With headquarters in Phoenix, APS is the largest subsidiary of Pinnacle West Capital Corp. (NYSE: PNW). March 26, 2004

Puede que haya encontrado algo

En este link, dice:

APS' 1 MW solar trough plant at the Saguaro power plant will heat mineral oil to between 250° and 500°F, lower temperature than used in other plants. Flowing through a heat exchanger, the heated oil will vaporize pentane, a hydrocarbon, which in turn will drive the turbine. The vapor then will condense back into liquid form and the cycle will repeat. This approach represents a departure from existing solar thermal plants, which use steam driven turbines. The capital cost for a steam turbine would be too great for such a small plant, instead, APS will use a 1-MW turbine similar to a geothermal plant’s.

Esto significan entre 121ºC y 260ºC. Con aceite térmico.
Voy a ver si encuentro una Web de dicha planta.

Información sobre la planta:

Saguaro
The natural gas-fueled Saguaro Power Plant, north of Tucson, Arizona, has two steam units and three combustion turbine units. APS operates and owns all five of the generating units that have a combined capacity of about 395 megawatts available to the APS system.

Posibles mejoras : Parabolic-trough technology

Oportunidades de mejora para las actuales plantas parabólicas:

Alto porcentaje sobre los costes los supone la estructura.

En el archivo Parabolic-trough technology Roadmap encontrado en la dirección:
http://www.nrel.gov/docs/fy99osti/24748.pdf

Se encuentran entre otros posibles puntos de mejora, los del siguiente fragmento de texto:

• Advanced Trough Collector

As illustrated above, the structure constitutes about 40% of the solar field cost, whereas the
reflectors and receivers each cost from 20%–25% of the total. In the SEGS design, steel
provides the major strength, with thick glass mirror panels giving the parabolic shape to the
reflecting surface. Lower-cost designs can be explored for the steel structure, with a possible
alternative of a lighter aluminum or composite structure integrated with a front surface
reflector on film, thin glass, or structural member. Evolutionary improvements in the receivers
are also possible.

• Ø Direct Steam Generation (DSG)

In the DSG concept, steam is generated directly in the parabolic-trough collectors. This saves
cost by eliminating the need for the heat transfer fluid (HTF) system and reduces the efficiency
loss involved with using a heat exchanger to generate steam. DSG should also improve the
solar field operating efficiency due to lower average operating temperatures and improved heat
transfer in the collector receiver. The trough collectors would require some modification due to
the higher operating pressure and lower fluid flow rates. Control of a DSG solar field likely
will be more complicated than the HTF systems and may require a more complex design layout
and a tilted collector. DSG also makes it more difficult to provide any thermal storage. A pilot
demonstration of DSG technology is in progress at the Plataforma Solar de Almería (PSA) in
Spain.

• The Integrated Solar Combined-Cycle System

Exitosa busqueda (primeros pasos)

Parabolic trough collectors (buscando en Google)

TroughNET
http://www.eere.energy.gov/troughnet/technology.html

Third Annual Parabolic Trough Workshop Proceedings
http://www.eere.energy.gov/troughnet/documents/workshop3rd.html

En este Web he encontrado las diferentes plantas de producción de E.Electrica mediante
el captador solar parabólico, pero ninguna aplicación menor.

De momento ya se que la denominación es : Parabolic trough collectors o similar. Donde la clave es trough

Sigo buscando posibles investigaciones en internet (sin resultado)

Encontrada posible bibliografía en la nasa:
http://adsabs.harvard.edu/abs/1976STIN...7720607K
Esta página contiene posibles denominaciones del espejo en inglés:
"The cylindrical parabolic mirror as reflector for solar collectors. Efficiencies and optimization.
ENERGY TECHNOLOGY, PARABOLOID MIRRORS,FUNNELS, PARABOLIC REFLECTORS SOLAR COLLECTORS, DYNAMIC RESPONSE, ENERGY BUDGETS, FOCUSING, OPTIMIZATION, POWER EFFICIENCY, RADIANT FLUX DENSITY, SOLAR ENERGY CONVERSION, STEADY STATE"

Encontrado alguien que patenta algo parecido:

http://www.freepatentsonline.com/4106480.html

Un libro sobre el espejo pero para centrales térmicas.

http://adsabs.harvard.edu/abs/1978real....2.....P

He encontrado una caché de una página que hace referencia a esto
Utilization of a cylindrical parabolic reflector for desalination of saline water:
http://www.google.com/search?q=cache:YIdJwtIjUHYJ:else.hebis.de/cgi-bin/sciserv.pl%3Fcollection%3Djournals%26journal%3D01968904%26issue%3Dv38i0007++heat+water+Solar+OR+Energy+OR+Sun+%22cylindrical+parabolic+reflector+%22+-dish+-dishes+-cook+-cooker&hl=es

Utilization of a cylindrical parabolic reflector for desalination of saline water
701 -- 704
A.N. Minasian, A.A. Al-Karaghouli, S.K. Habeeb
http://www1.elsevier.com/cdweb/journals/01968904/viewer.htt?iss=7&vol=38&viewtype=issue

Buscaré pues en google con :
"cylindrical parabolic reflector" + desalination

Busqueda en internet

En el apartado de ´"Das Parabolschüsselkonzept" explica diferentes tipos de espejos
http://www.htwm.de/cclaus/Jahres/solar.htm

Un ingeniero alemán habla sobre la instalación de generación electrica en Almeria 50MW
http://www.baupool.com/pressemitteilungen/welt020924b.htm

Objetivo del Proyecto