GeoIsla

Por: Mariana Muñiz Lara
De: www.vocero.com
Publicado: 30 de junio de 2008

Las alternativas de energía renovable más conocidas son la solar y la eólica, pero, además del sol y el viento, hay otro recurso rodeando a Puerto Rico que podría proveer electricidad: el agua, tanto a través de la fuerza de las olas o el cambio de temperatura en el océano como con las represas hidroeléctricas.

El profesor de Ingeniería Química de la Universidad de Puerto Rico, Recinto de Mayagüez (RUM), José Colucci, señaló que la costa Norte de la Isla tiene un oleaje alto y con buena frecuencia para producir energía, pero tienen que estudiarse aún los efectos ecológicos que tendría un sistema de energía en el área, así como si afectaría actividades como la pesca y el “surfing”. Indicó que para analizar la viabilidad de este proyecto, que se lleva a cabo en países como Inglaterra y estados como Oregon, se estarán colocando unas boyas que medirán la capacidad y el potencial del oleaje.

Asimismo, Colucci explicó que el caudal de los ríos en Puerto Rico es pequeño para considerarse producir energía a gran escala con la fuerza de la corriente, pero se pueden colocar turbinas para uso personal en fincas por las que crucen los ríos, siempre que se cuente con el permiso del Departamento de Recursos Naturales y se haya probado que no afecta aguas abajo.

Por su parte, el ingeniero Gerardo Cosme, de la empresa local Solartek, señaló que en Puerto Rico se han realizado estudios que indican que el área de Punta Tuna, en el Sureste, es un punto ideal para operar un sistema de energía oceanotermal, ya que tiene suficiente profundidad –unos 3,000 pies bajo el agua- a sólo dos millas de la tierra. Este sistema, que se coloca a más de 2,000 pies de profundidad, trabaja con las diferencias de temperatura en el océano, convirtiendo en electricidad la energía que produce el cambio entre las aguas cálidas de la superficie del mar y las frías de las profundidades. Cosme explicó que el ciclo de refrigeración con amoniaco que crea la fuerza para mover la turbina se logra instalando unas máquinas donde el agua de la superficie calienta el amoniaco hasta convertirlo en un gas que luego baja a un condensador donde el agua fría lo convierte otra vez en líquido para continuar el proceso. Un cable submarino transporta la electricidad generada.

Según Cosme, esta tecnología, conocida como OTEC, por sus siglas en inglés, no ha sido utilizada en la Isla, porque requiere una inversión de capital grande y los materiales de construcción que aguantan la hostilidad marina son difíciles de conseguir. Añadió que la energía oceanotermal, que se está utilizando en Hawai, sólo es viable para proyectos de producción a gran escala, y que el que se está estudiando podría generar energía comparable a la que brindan varias de las plantas de la Autoridad de Energía Eléctrica (AEE) combinadas.

Jorge Rodríguez, director ejecutivo de la AEE, informó que están analizando la viabilidad de un proyecto de energía oceanotermal en la costa entre Maunabo y Yabucoa, que proveería 75 megavatios de energía, con una fuente constante y renovable.

De otro lado, el presidente de la Unión de Trabajadores de la Industria Eléctrica y Riego (UTIER), Ricardo Santos, señaló que una opción para reducir los costos de energía de la Autoridad es rehabilitar las plantas hidroeléctricas que están abandonadas. Éstas producían un 2% de la energía del país y actualmente colaboran con menos del 1%. Santos considera que, rehabilitando los abastos de agua y utilizando las tecnología actuales, pueden llegar a producir un 4% de la demanda. “Esta energía es muy barata”.

¿Energía y agua potable?

Otro servicio básico por el cual el precio ha experimentado fuertes alzas es el agua para consumo. Colucci opinó que el costo de desalinizar el agua de mar es muy alto, pero podría considerarse la alternativa dado que hay muchos sectores que no cuentan con servicio de agua potable. Sin embargo, mencionó como puntos adicionales en contra que el agua tendría un sabor diferente y podría afectar la plomería metálica porque seguiría causando corrosión. Añadió que el problema del agua, en realidad, no es de abasto sino de distribución.

El profesor de Microbiología del RUM, Arturo Massol, afirmó que Puerto Rico cuenta con grandes abastos de agua, pero no son utilizados correctamente ni por el Gobierno ni por la ciudadanía. Explicó que las aguas subterráneas suplían hasta el 40% de la demanda de agua, pero se han cerrado más de 100 pozos –que brindarían 1,000,000 de galones diarios, una cifra mayor a la que provee el Superacueducto- a causa del desarrollo urbano desmedido y la sedimentación con basura. Massol, quien aprovecha el agua de lluvia para su uso en el hogar, mencionó que, con el cambio climático, los periodos de lluvia y sequía son más extensos, pero, aun así, habría suficiente agua para suplir la demanda si se maneja correctamente.

Vía El Vocero

By Nico Saie
From: www.archdaily.com
Published June 26, 2008

Dutch architecture office FARO architecten bv sent us this amazing experimental house, where the main idea was to give big spaces to the client. Be sure to check out the lounge hanging from the ceiling.

Architect: FARO architecten bv
Location: Steigereiland, Netherlands
Construction Year: September 2006 - February 2007
Contractor: Kerkhofs montagebouw
Finishing: Dick Caarls
Technical advice: Pieters BouwTechniek
“Whale” construction: Bosgraaf yacht-design
Climate Advice: TH
Floor Tiles: MOSA
PU floors: Sinck&Co
Fencing: Carl Stahl
Domotica System: Moeller
Budget: 320,000 EURO (US $498,816)
Constructed Area: 207 sqm

On the Steigereiland, near Amsterdam, Pieter Weijnen built his own experimental wooden home. The house is painted a vibrant blue, referring to the traditional dike houses of nearby Durgerdam. Spaciousness is the keyword in this design. The ground floor consists of a roomy live-in kitchen. Entering the home, the first thing you notice is the lounge hanging from the ceiling like a floating island. The bottom of this contraption is shaped like the belly of a whale and clad in copper. The shape has been interpreted as a boat or a basket, giving the space below a homely atmosphere. Together with the floating lounge, the 7 meter high space creates a vertical loft. To make the most use of the space, Weijnen wanted to avoid load bearing walls as much as possible. To ensure stability, he used old docking poles as diagonal braces behind the front wall. All the walls and floors are made of massive, laminated Lenotec spruce wood.

Sustainable use of energy is a leading principle for the house on Steigereiland. The glass façade facing South, lets in plenty of daylight and sun heat. The air-conditioning is based on an ancient Arabian system: the air from the dwelling is pumped through underground tubes. After the air has cooled down, it is led back into the building. A tank under the roof terrace collects rainwater, which is used for the washing machine and the toilets. Plenty of recycled materials were used building this wooden home. The large beams in the front are old docking poles from the IJ, and the furniture in the children’s room is made of used cheese shelves. The copper cladding on the floating lounge, used to be on top of the roof of a church.

Via ArchDaily

Tras comprometerse con el ambiente.

Por Gerardo E. Alvarado León / galvarado@elnuevodia.com

Los 78 alcaldes del País podrán afianzar su compromiso con el medio ambiente y convertir sus municipios en “ciudades verdes” a través de una campaña que les dará herramientas para reducir las emisiones de gases que producen el calentamiento global.

Se trata de un esfuerzo llamado “Ciudades cool: solucionando el calentamiento global pueblo por pueblo”, dado a conocer el lunes por una coalición de grupos ambientales y sociales quienes llamaron la atención sobre las amenazas del cambio climático y la escasez de fondos públicos a nivel municipal para combatirlas.

Camilla Feibelman, coordinadora de Sierra Club en Puerto Rico, indicó que la campaña ayuda a los alcaldes y a las comunidades a implementar un plan que responde al Protocolo de Kioto, firmado en 1997 con el fin de que los países industrializados reduzcan sus emisiones colectivas de gases que causan el calentamiento global.

“Ciudades cool” destacadas

1. Salem, Virginia
2. Santa Rosa, California
3. Richardson, Texas
4. Long Branch, New Jersey

Fuente: Sierra Club

Un estudio del Sierra Club entre 43 “ciudades cool”, que consideró únicamente el renglón energético, reveló ahorros de casi $140 millones y una reducción de más de 500,000 toneladas en las emisiones de gases a la atmósfera.

Al día de hoy, 750 alcaldes de Estados Unidos han firmado el acuerdo, incluyendo tres de la Isla: Aguadilla, Camuy y Yauco.

Vía El Nuevo Día

Global interest in couple’s pioneering project to live off-grid - including their car

Severin Carrell
The Guardian, Monday May 19, 2008

Michael and Dorothy Rea outside their home on Unst. Photograph: Murdo Macleod

Life on the most northerly inhabited island in Britain can be very tough indeed. On Unst the winters are harsh, and the winds brutal and relentless, regularly sweeping across the treeless landscape at more than 100mph.

But Unst is the island chosen by a retired couple from Wiltshire to build one of the world’s greenest houses - a “zero carbon” home powered entirely by the wind and the sun. It sits on the same latitude as southern Greenland, but will soon boast lemon trees, grapevines and green pepper plants in its greenhouse, an electric car powered by the wind, and floors heated by drawing warmth from the air.

The three-bedroom home designed by Michael and Dorothy Rea, near the shoreline of a secluded bay, has become a test bed for living “off-grid”: generating all their power from renewable sources, growing most of their food at home, and running a car without a petrol station.

Their home - built for just over £210,000 from an off-the-shelf timber framed house - has quietly become famous. The Scottish executive in Edinburgh is using it as a benchmark for new sustainable house-building rules; officials in the prime minister’s office watch its progress and Chinese officials are studying its innovative technologies for a new 5,000-home eco-town in Guangzhou, in southern China.

Last year, the Reas learned that their website - zerocarbonhouse.com - was the fourth most popular site worldwide on Google. Michael Rea is often up at 5am answering emails from PhD students, green activists and even Canadian senators.

The Reas believe their home is the first of its kind. “If we can do this here, anyone can do it anywhere,” said Dorothy, a former headteacher. “It’s just an ordinary house. It could be in Edinburgh; it could be in Chigwell.”

“It’s definitely significant,” said Duncan Price, a director of one of the world’s largest green energy consultancies, ESD, and an advisor to the Reas. “What’s very special is they’re trying to address the carbon impact of their whole lifestyle. It’s a microcosm of how the world would be in a carbon-constrained future.”

It is one of several pioneering off-grid projects in remote areas of Scotland, where communities such as the islanders on Eigg in the inner Hebrides and another living on Scoraig, a remote peninsula near Ullapool in north-west Scotland, have developed their own independent green power sources.

Around 80 people living on Scoraig, which is only accessible by boat or with a five-mile trek overland, power their homes and businesses chiefly using small hand-made wind turbines designed by local resident Hugh Piggott, a guru of self-sufficient off-grid living. Solar panels and diesel generators supplement the turbines.

In February, the islanders of Eigg, just south of Skye, switched on the UK’s first independent “green grid”. It provides power to all the 45 homes and 20 businesses by combining electricity from wind turbines, solar panels and two small hydro-electric dams into a single supply. For the first time, islanders can run fridges, electric kettles, satellite TVs and computers without using unreliable oil-powered generators.

Forced by their isolation to become self-sufficient, many observers believe these communities prove that micro-generation and home energy schemes are viable UK-wide. Nick Rosen, author of How to Live Off-Grid, a handbook on off-grid communities, said: “It doesn’t mean we should all live like Scoraig but we should be fostering communities like it all over the place. It increases the self-reliance of our society overall, in the event of sudden energy price hikes, the Russians cut off the gas or strikes in the oil industry.”

The Reas are not naive about the severity of Shetland’s weather or the scale of the challenge. They erected the timber frame for their new home during a gale in November 2006; the strongest gusts threw heavy roof sections through the air, smashing one to the ground.

Shetland, the Reas note wryly, has the strongest and most reliable winds of any inhabited part of the world, closely followed by the Falkland islands. But then they have striking views over a south-facing bay across to the low-slung, mottled green islands of Uyea, Fetlar and Yell. In midsummer, the temperature can hit 30C and the sun never sets.

“I could foresee the time when energy would be very, very expensive,” Michael Rea said. “But at first what we were doing was viewed as the black arts, but we weren’t cranks. We were ordinary people.”

Although they describe their home as normal, it will use advanced low-carbon technologies, many of which are being fitted this summer. With help from Dundee University and Duchy College in Cornwall, they are building a greenhouse which uses hydroponics where their vegetables, fruit and herbs will be grown in a liquid with specially controlled lighting to create artificial “seasons”. The University of Delaware is refitting a Toyota Yaris car with an electric engine.

Dogged and single-minded, Michael Rea has cajoled builders, banks and even the window firm Velux into sponsoring the project. Eventually, the house will be lit by very low energy LED lights, the greenhouse will use electricity from its own wind turbine and the chief source of heating will be a heat pump which draws warmth from the air into an under-floor system.

“I have been waiting 24 years for this house to be built,” said Dorothy, 65. “But it’s just a standard house, an honest house, nothing fancy. It’s a serious project in renewable design and energy efficiency, an experiment in joined-up technology, but it’s also a house we intend to grow old in.”

Explainer: How heat is harnessed

The house is very heavily insulated and its under-floor heating uses warmth drawn from the outside air and stored in a giant “water battery”. Heat inside the house is captured by a ventilation system and reused. Rainwater is harvested for toilets and the washing machine. Large windows capture warmth from the sun.

Power for dishwasher, cooker, toaster, fridge, computers and lights comes from a wind turbine, which charges fuel cells able to store power for four days. The house’s LED lights will use the same power as one 100W bulb.

The greenhouse will have its own wind turbine. Plants will grow in high-nutrient hydroponic liquids, with special LED lights to create artificial seasons and daylight. A converted battery-powered Toyota Yaris will be charged from the fuel cells.

Via guardian.co.uk

From: www.biomimicrynews.com
Published May 21, 2006

Researchers have been unable to build an ideal “photonic crystal” to manipulate visible light, impeding the dream of ultrafast optical computers. But now, University of Utah chemists have discovered that nature already has designed photonic crystals with the ideal, diamond-like structure: They are found in the shimmering, iridescent green scales of a beetle from Brazil.

This inch-long beetle from Brazil accomplished a task that so far has stymied human researchers. University of Utah chemists determined the beetle glows iridescent green because it evolved a crystal structure in its scales that is like the crystal structure of diamonds. Such a structure is considered an ideal architecture for ‘photonic crystals’ that will be needed to manipulate visible light in ultrafast optical computers of the future. - Photo Credit: Jeremy Galusha

“It appears that a simple creature like a beetle provides us with one of the technologically most sought-after structures for the next generation of computing,” says study leader Michael Bartl, an assistant professor of chemistry and adjunct assistant professor of physics at the University of Utah. “Nature has simple ways of making structures and materials that are still unobtainable with our million-dollar instruments and engineering strategies.”

The study by Bartl, University of Utah chemistry doctoral student Jeremy Galusha and colleagues is set to be published later this week in the journal Physical Review E.

The beetle is an inch-long weevil named Lamprocyphus augustus. The discovery of its scales’ crystal structure represents the first time scientists have been able to work with a material with the ideal or “champion” architecture for a photonic crystal.

“Nature uses very simple strategies to design structures to manipulate light - structures that are beyond the reach of our current abilities,” Galusha says.

Bartl and Galusha now are trying to design a synthetic version of the beetle’s photonic crystals, using scale material as a mold to make the crystals from a transparent semiconductor.

The scales can’t be used in technological devices because they are made of fingernail-like chitin, which is not stable enough for long-term use, is not semiconducting and doesn’t bend light adequately.

The University of Utah chemists conducted the study with coauthors Lauren Richey, a former Springville High School student now attending Brigham Young University; BYU biology Professor John Gardner; and Jennifer Cha, of IBM’s Almaden Research Center in San Jose, Calif.

Quest for the Ideal or ‘Champion’ Photonic Crystal

Researchers are seeking photonic crystals as they aim to develop optical computers that run on light (photons) instead of electricity (electrons). Right now, light in near-infrared and visible wavelengths can carry data and communications through fiberoptic cables, but the data must be converted from light back to electricity before being processed in a computer.

The goal - still years away - is an ultrahigh-speed computer with optical integrated circuits or chips that run on light instead of electricity.

“You would be able to solve certain problems that we are not able to solve now,” Bartl says. “For certain problems, an optical computer could do in seconds what regular computers need years for.”

Researchers also are seeking ideal photonic crystals to amplify light and thus make solar cells more efficient, to capture light that would catalyze chemical reactions, and to generate tiny laser beams that would serve as light sources on optical chips.

“Photonic crystals are a new type of optical materials that manipulate light in non-classic ways,” Bartl says. Some colors of light can pass through a photonic crystal at various speeds, while other wavelengths are reflected as the crystal acts like a mirror.

Bartl says there are many proposals for how light could be manipulated and controlled in new ways by photonic crystals, “however we still lack the proper materials that would allow us to create ideal photonic crystals to manipulate visible light. A material like this doesn’t exist artificially or synthetically.”

The ideal photonic crystal - dubbed the “champion” crystal - was described by scientists elsewhere in 1990. They showed that the optimal photonic crystal - one that could manipulate light most efficiently - would have the same crystal structure as the lattice of carbon atoms in diamond. Diamonds cannot be used as photonic crystals because their atoms are packed too tightly together to manipulate visible light.

When made from an appropriate material, a diamond-like structure would create a large “photonic bandgap,” meaning the crystalline structure prevents the propagation of light of a certain range of wavelengths. Materials with such bandgaps are necessary if researchers are to engineer optical circuits that can manipulate visible light.

On the Path of the Beetle: From BYU to Belgium and Brazil

The new study has its roots in Richey’s science fair project on iridescence in biology when she was a student at Utah’s Springville High School. Gardner’s group at BYU was helping her at the same time Galusha was using an electron microscope there and learned of Richey’s project.

This microscopic image shows individual scales attached to the exoskeleton of the beetle Lamprocyphus augustus, and how the scales glow iridescent green because the fingernail-like material in the scales has a diamond-like crystal structure that reflects green light. University of Utah chemists are among researchers seeking to create a material with the same structure, which is considered ideal for future optical computers that would run at ultrahigh speeds on light rather than electricity. - Photo Credit: Michael Bartl

Richey wanted to examine an iridescent beetle, but lacked a complete specimen. So the researchers ordered Brazil’s Lamprocyphus augustus from a Belgian insect dealer.

The beetle’s shiny, sparkling green color is produced by the crystal structure of its scales, not by any pigment, Bartl says. The scales are made of chitin, which forms the external skeleton, or exoskeleton, of most insects and is similar to fingernail material. The scales are affixed to the beetle’s exoskeleton. Each measures 200 microns (millionths of a meter) long by 100 microns wide. A human hair is about 100 microns thick.

Green light - which has a wavelength of about 500 to 550 nanometers, or billionths of a meter - cannot penetrate the scales’ crystal structure, which acts like mirrors to reflect the green light, making the beetle appear iridescent green.

Bartl says the beetle was interesting because it was iridescent regardless of the angle from which it was viewed - unlike most iridescent objects - and because a preliminary electron microscope examination showed its scales did not have the structure typical of artificial photonic crystals.

“The color and structure looked interesting,” Bartl says. “The question was: What was the exact three-dimensional structure that produces these unique optical properties?”

The Utah team’s study is the first to show that “just as atoms are arranged in diamond crystals, so is the chitin structure of beetle scales,” he says.

Galusha determined the 3-D structure of the scales using a scanning electron microscope. He cut a cross section of a scale, and then took an electron microscope image of it. Then he used a focused ion beam - sort of a tiny sandblaster that shoots a beam of gallium ions - to shave off the exposed end of the scale, and then took another image, doing so repeatedly until he had images of 150 cross-sections from the same scale.

Then the researchers “stacked” the images together in a computer, and determined the crystal structure of the scale material: a diamond-like or “champion” architecture, but with building blocks of chitin and air instead of the carbon atoms in diamond.

Next, Galusha and Bartl used optical studies and theory to predict optical properties of the scales’ structure. The prediction matched reality: green iridescence.

Many iridescent objects appear that way only when viewed at certain angles, but the beetle remains iridescent from any angle. Bartl says the way the beetle does that is an “ingenious engineering strategy” that approximates a technology for controlling the propagation of visible light.

A single beetle scale is not a continuous crystal, but includes some 200 pieces of chitin, each with the diamond-based crystal structure but each oriented a different direction. So each piece reflects a slightly different wavelength or shade of green.

“Each piece is too small to be seen individually by your eye, so what you see is a composite effect,” with the beetle appearing green from any angle, Bartl explains.

Scientists don’t know how the beetle uses its color, but “because it is an unnatural green, it’s likely not for camouflage,” Bartl says. “It could be to attract mates.”

The study was funded by the National Science Foundation, American Chemical Society, the University of Utah and Brigham Young University.

Note: This story has been adapted from a news release issued by the University of Utah

Via Biomimicry News