Notas sobre Energías Renovables

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Re: Notas sobre Energías Renovables

Mensajepor Fermat » 19 Jul 2017 1:51 am

El hidrógeno como fuente de energía, a la vuelta de la esquina
Carlos Ferrer, 12-07-2017

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La última conferencia de la Convención Mundial de Tecnología de Hidrógeno se ha celebrado esta semana en Praga. Sobre las ventajas del hidrógeno como fuente de energía hemos hablado con uno de los ponentes, el español Carlos Fúnez.

Imagínense una ciudad del futuro, donde los automóviles no hacen ruido y no contaminan. No es ninguna fantasía. Muchas ciudades y países han anunciado ya una futura prohibición de los vehículos diésel, y el siguiente paso es la limitación de todos los automóviles de combustión. La alternativa, los vehículos eléctricos, viene de la mano con el uso de hidrógeno para producir electricidad.

Precisamente durante esta semana en Praga expertos de todo el mundo se han dado cita para compartir sus últimos avances en el marco de la séptima edición de la Convención Mundial de Tecnología de Hidrógeno. Uno de los participantes ha sido Carlos Fúnez, responsable de Consultoría y Medio Ambiente del Centro Nacional del Hidrógeno de España.

Como comenta, el uso del hidrógeno como fuente de energía hace tiempo que dejó de ser experimental.

“Es una tecnología fiable y segura, pero todavía queda un camino amplio en cuanto a reducción de costes y en cuanto a mejora de eficiencias y demás. El hidrógeno está ahora mismo como estaban los paneles fotovoltaicos en 2008”.

En su opinión es solo cuestión de tiempo que se convierta en una tecnología plenamente comercializable.

“Son tecnologías que ahora mismo están disponibles en el mercado, pero son incipientes, son nuevos desarrollos. Todavía son caros porque el hidrógeno está empezando a introducirse ahora en la sociedad y no hay un mercado como tal. En lo que es fabricación de pilas de combustible, hay tres cuatro empresas a nivel mundial, con lo cual producen poco, porque hay poca demanda, la producción es prácticamente manual y los costes son elevados. No hay un mercado que justifique la inversión en líneas de producción y demás”.

En este sentido las investigaciones las encabezan los países que cuentan fuertemente con el hidrógeno en sus políticas energéticas, como Alemania, Noruega, Gran Bretaña, Japón, China y el estado de California, en Estados Unidos. Otros países, como la República Checa, también hacen su aporte, incide Fúnez.

“Aquí en la República Checa también tienen sus investigaciones. Esta mañana estaba con la Plataforma Checa de Hidrógeno y Pilas de Combustible. La República Checa no está al nivel de los países punteros, pasa como en España. Pero la República Checa ha tenido el interés de acoger este tipo de congresos. Se celebran cada dos años, y hay diferentes ciudades que concursan para poder hospedarlos. Este año ha sido aquí y el siguiente será en Tokio, en Japón”.

De hecho Chequia presentó en la conferencia el TriHyBus, que combina batería convencional con tecnología de hidrógeno y un supercondensador, y que ya funciona regularmente en la ciudad de Neratovice. Otra de las novedades checas fue una pila de combustible portátil, de apenas 10 kilos, para ser utilizada en situaciones de emergencia por militares, bomberos o policías.

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http://www.radio.cz/es/rubrica/notas/el-hidrogeno-como-fuente-de-energia-a-la-vuelta-de-la-esquina
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Re: Notas sobre Energías Renovables

Mensajepor Fermat » 20 Jul 2017 8:36 am

New Solar Cells Capture Double the Amount of Energy from the Sun
Robby Berman, July 15, 2017

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A lot of people are excited about solar energy, and with good reason: It’s clean, renewable, and as manufacturing capabilities ramp up, an increasingly realistic way to power our world. On April 30th, 2017, Germany met 85% of its power needs from renewable energy sources including solar panels. Still, solar cells currently capture only about 25% of the available solar energy. Now a team from GW School of Engineering and Applied Science has produced a remarkably designed solar cell that collects nearly half of it. It’s been believed that the upper limit for the efficiency of conventional solar cells is about 30%, so this could be a big deal.

Scientists at GW School of Engineering and Applied Science have designed a multi-layered, stacked cell that operates as a sort of “solar sieve.” Each layer grabs a portion of the light spectrum as sunlight passes through on its way to the next layer down.

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As lead author of the just-published research Matthew Lumb explains, “Around 99 percent of the power contained in direct sunlight reaching the surface of Earth falls between wavelengths of 250nm (Editor's note: nm = nanometers) and 2500nm, but conventional materials for high-efficiency multi-junction solar cells cannot capture this entire spectral range. Our new device is able to unlock the energy stored in the long-wavelength photons, which are lost in conventional solar cells, and therefore provides a pathway to realizing the ultimate multi-junction solar cell.”

The GW team’s solar cell works with concentrator photovoltaic panels that focus sunlight onto micro-scale solar cells of about one millimeter square. Being so small opens up the possibilities for using them in sophisticated structures that can eventually be manufactured at a reasonable cost.

Aside from its stacking aspect, the GW solar cell incorporates a couple of other innovative touches.

What allows a GW panel to collect longer wavelengths is a material more commonly used with infrared lasers and photodetectors called gallium antimonide (GaSb). Cells made of this complement standard high-efficiency solar cells grown on conventional substrates.

The manner in which the GW solar cell is constructed is also a bit different. Its layers are stacked with extreme precision using a method called “transfer printing” that allows tiny three-dimensional structures to be assembled.

The GW solar cell is a one-off built to demonstrate the potential for far greater efficiency in solar energy collection. The technology it introduces is currently too expensive for cost-effective manufacture. But solar cells that are twice as effective at capturing energy from the sun? Sign us up for that.

http://bigthink.com/robby-berman/new-solar-cells-capture-double-the-amount-of-energy-from-the-sun
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Re: Notas sobre Energías Renovables

Mensajepor Fermat » 23 Ago 2017 7:11 am

Cyborg bacteria can harvest solar energy to produce fuel
Photosynthesis provides energy for the vast majority of life on Earth. However, chlorophyll, the green pigment that plants use to harvest sunlight, is relatively inefficient.

August 23, 2017, 15:16 IST

Los Angeles: Scientists have created cyborg bacteria - microbes covered with tiny, highly efficient solar panels - that are better than plants at harvesting the Sun's energy to produce fuel from carbon dioxide and water.

Photosynthesis provides energy for the vast majority of life on Earth. However, chlorophyll, the green pigment that plants use to harvest sunlight, is relatively inefficient.

To enable humans to capture more of the Sun's energy than natural photosynthesis can, scientists have taught bacteria to cover themselves in tiny, highly efficient solar panels to produce useful compounds.

"Rather than rely on inefficient chlorophyll to harvest sunlight, I have taught bacteria how to grow and cover their bodies with tiny semiconductor nanocrystals," said Kelsey K Sakimoto, from University of California, Berkeley in the US.

"These nanocrystals are much more efficient than chlorophyll and can be grown at a fraction of the cost of manufactured solar panels," said Sakimoto.

Humans increasingly are looking to find alternatives to fossil fuels as sources of energy and feedstocks for chemical production.

Many scientists have worked to create artificial photosynthetic systems to generate renewable energy and simple organic chemicals using sunlight.

Progress has been made, but the systems are not efficient enough for commercial production of fuels and feedstocks.

The new research focuses on harnessing inorganic semiconductors that can capture sunlight to organisms such as bacteria that can then use the energy to produce useful chemicals from carbon dioxide and water.

The scientists worked with a naturally occurring, nonphotosynthetic bacterium, Moorella thermoacetica, which, as part of its normal respiration, produces acetic acid from carbon dioxide (CO2).

Acetic acid is a versatile chemical that can be readily upgraded to a number of fuels, polymers, pharmaceuticals and commodity chemicals through complementary, genetically engineered bacteria.

Researchers fed cadmium and the amino acid cysteine, which contains a sulfur atom, to the bacteria, they synthesized cadmium sulfide (CdS) nanoparticles, which function as solar panels on their surfaces.

The hybrid organism, M thermoacetica-CdS, produces acetic acid from CO2, water and light.

"Once covered with these tiny solar panels, the bacteria can synthesize food, fuels and plastics, all using solar energy," Sakimoto said.

"These bacteria outperform natural photosynthesis," he said.

The bacteria operate at an efficiency of more than 80 per cent, and the process is self-replicating and self- regenerating, making this a zero-waste technology.

"Synthetic biology and the ability to expand the product scope of CO2 reduction will be crucial to poising this technology as a replacement, or one of many replacements, for the petrochemical industry," said Sakimoto.

http://energy.economictimes.indiatimes.com/news/renewable/cyborg-bacteria-can-harvest-solar-energy-to-produce-fuel/60190639
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Re: Notas sobre Energías Renovables

Mensajepor Fermat » 15 Sep 2017 3:57 am

Geothermal energy: Why hasn't it caught on yet?
Dave Keating, 13.09.2017

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One of the most famous tourist sites in Iceland is the Blue Lagoon, a man-made lake close to Reykjavík Airport that is fed and heated by a nearby geothermal power plant.

Such power plants are common across Iceland -.but little-known in the rest of the world. For many of the swimmers in the lagoon, it is the first time they have ever heard of this power source.

Political leaders from 25 countries gathered at a sumptuous palace in Florence, Italy, this week are hoping to change that.

Yesterday, governmental ministers and 29 partner institutions from the private sector signed the Florence Declaration, committing to a 500-percent increase in global installed capacity for geothermal power generation by 2030.

Although that may sound like a lot, it's starting from a low baseline. Geothermal energy today accounts for just 0.3 percent of globally installed renewable energy capacity.

This is despite its huge potential - for both lowering greenhouse gas emissions and saving money. Geothermal is one of the lowest-cost energy sources available, after startup costs are met. The global potential for geothermal is estimated to be around 200 gigawatts.

"Geothermal's vast potential is currently untapped," said Italian Environment Minister Gian Luca Galleti at the Florence summit. "We must develop new technologies and encourage new investments to ensure we cover this gap."

The summit was organized by the Global Geothermal Alliance, which was launched at the United Nations climate summit in Paris in 2015.

Run by the International Renewable Energy Agency (IRENA), it is bringing governments and companies together to try to speed up deployment. But significant hurdles remain.

To get heat from the layer of hot and molten magma under the Earth, water is pumped down an injection well. Then it filters through the cracks in the rocks where they are at a high temperature. The water then returns via the "recovery well" under pressure in the form of steam. That steam is captured and is used to drive electric generators or heat homes.

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http://p.dw.com/p/2jsWb
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Re: Notas sobre Energías Renovables

Mensajepor Fermat » 21 Oct 2017 7:21 am

Scientists Have Created a Concrete Roof That Generates Solar Power
Block Research Group/ETH Zürich/Michael Lyrenmann
Brad Jones, October 19, 2017

Researchers at the Swiss Federal Institute of Technology in Zurich have developed a new form of ultra-thin, curved roofing that’s capable of producing solar power. The design will allow a residential structure that’s part of the school’s living lab facility, NEST, to generate more energy than it consumes.

The roof is made up of several layers; an inner sheet of concrete, which acts as a foundation for heating and cooling coils and insulation, which are in turn covered by more concrete. Thin-film photovoltaic cells used to harvest solar energy are then installed on the exterior of the building.

The prototype for the roof was some 7.5 meters high, and had a total curved surface area of 160 square meters. It’s now been dismantled, ahead of the same design being implemented next year on the HiLo apartment building that’s part of the NEST project.

The unique shape of the roof would typically be constructed with non-reusable materials like specially fabricated timber or milled foam. Instead, this project used a net constructed from steel cables which was covered with a polymer textile, producing a form that the concrete could adhere to. This facilitated the unusual design, but it made the project considerably cheaper in terms of the the cost of materials.

The Block Researcher Group and the Swiss National Centre of Competence contributed an algorithm to the project to ensure that the roof would take on its desired form when the weight of wet concrete was applied to the net. The concrete was sprayed onto the net using a technique developed specifically for this application.

Raise the Roof With Solar Power
Roof-mounted solar panels are nothing new, but various advanced versions of the technology have emerged in the past few years. As well as being incredibly efficient, this new hardware is typically a lot cheaper than previous iterations.

Tesla’s well-publicized solar roof project is perhaps the most prominent example. If the finished product is as effective and inexpensive as Elon Musk has suggested, it could potentially bring a method of harnessing solar energy to more homes than ever before.

However, Tesla isn’t the only company innovating when it comes to solar power. The roll-up solar panels developed by Renovagen demonstrate another way that solar technology is being implemented in ways that were unheard of even a decade ago.

Solar power is an increasingly viable way to produce energy, and more and more countries are investing in solar infrastructure on a large scale. Thanks to projects like the HiLo roof, individuals are set to have more ways to implement the technology in their own homes than ever before.

Fuente y video:
https://futurism.com/scientists-have-created-a-concrete-roof-that-generates-solar-power/
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Re: Notas sobre Energías Renovables

Mensajepor Fermat » 23 Oct 2017 5:33 am

Primer parque eólico flotante del mundo ya está en funcionamiento: ¿Cómo es y dónde está?

El proyecto Hywind tiene cinco turbinas que flotan a 25 kilómetros de la costa de Peterhead y se estima que proveerá electricidad a más de 20.000 hogares.

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22 de Octubre de 2017 | 08:16 | Bloomberg

BLOOMBERG.- El primer parque eólico marítimo flotante comenzó a entregar electricidad a la red en el norte de Escocia.

Así, el proyecto Hywind, construido por la empresa petrolera estatal noruega Statoil ASA y Masdar Abu Dhabi Future Energy Co., tiene cinco turbinas que flotan a 25 kilómetros de la costa de Peterhead, cerca de Aberdeen. El proyecto tiene una capacidad de 30 megavatios y su construcción costó alrededor de US$263 millones.

"Esto constituye un desarrollo estimulante para la energía en Escocia", señaló la primera ministra Nicola Sturgeon. "Hywind proveerá electricidad limpia a más de 20.000 hogares y nos ayudará a cumplir con nuestros ambiciosos objetivos en materia de cambio climático".

En el transcurso de la historia, las turbinas eólicas se instalan en el lecho marino desde la década de 1990. Su instalación en el mar normalmente eleva la velocidad de los vientos y reduce las quejas de los vecinos, pero también se ha visto limitada a aguas relativamente poco profundas.

Por eso, se prevé que las turbinas flotantes abrirán el sector a nuevos mercados como Japón, la costa oeste estadounidense y el Mediterráneo, donde los fondos marinos caen abruptamente desde la costa.

"Hywind puede emplearse en aguas con una profundidad de hasta 800 metros, lo cual permite abrir zonas que hasta el momento fueron inaccesibles para la energía eólica offshore", dijo Irene Rummelhoff, vicepresidenta ejecutiva del área de negocios de New Energy Solutions en Statoil.

Baterías que almacenan la electricidad
Parte de la electricidad generada por las turbinas marinas se almacenará en baterías. Statoil ha instalado uno de sus dispositivos de litio Batwind, que pueden almacenar 1 megavatio/hora de electricidad. Esto ayudará a estabilizar el flujo de electricidad generado por el parque eólico.

El costo de los parques eólicos offshore convencionales viene cayendo en los últimos años. En la subasta de energía renovable más reciente del Reino Unido los precios cayeron hasta US$75 el megavatio/hora, menos de un tercio del costo de la nueva energía nuclear en ese país. Rummelhoff prevé que la energía eólica flotante offshore seguirá una trayectoria similar.

"Statoil tiene la ambición de reducir los costos de la electricidad proveniente del parque eólico flotante Hywind hasta US$48 a US$70 el megavatio/hora para 2030", dijo en un comunicado.

"Sabiendo que un 80% de los recursos eólicos offshore está en aguas profundas donde las instalaciones fijadas al fondo no son adecuadas, la energía eólica flotante offshore desempeñará de aquí en más un papel significativo en el crecimiento del sector".

El proyecto Hywind cuenta con apoyo gubernamental en forma de certificados de energías renovables (ROC por sus iniciales en inglés). Recibe 3,5 ROC, lo cual equivale actualmente a unas us$184 por megavatio-hora, según la portavoz de Statoil Elin Isaksen. Esto está por encima del precio mayorista de la electricidad del Reino Unido, que ha promediado US$64 por megavatio/hora en los últimos 12 meses.

http://www.emol.com/noticias/Economia/2017/10/22/880047/Primer-parque-eolico-flotante-del-mundo-ya-esta-en-funcionamiento-Como-es-y-donde-esta.html
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Re: Notas sobre Energías Renovables

Mensajepor Fermat » 24 Nov 2017 11:21 am

Hydrogen-Powered Trains Are Coming to Germany in 2021

In Brief
Germany and French company Alstom have signed an agreement that will see 14 hydrogen-powered trains built and used in the country by 2021. On a single hydrogen tank, the trains can travel 1,000 kilometers and reach a top speed of 140 km/h (87 mph).



All Aboard the Hydrogen Train
As the shift from diesel engines to clean energy continues, German and French engineering company Alstom have signed a deal that will see the latter building a series of hydrogen-powered trains that will go into service starting in 2021.

Alstom stated it will build 14 emissions-free trains, called Coradia iLint, that can travel 1,000 kilometers (621 miles) on one full hydrogen tank, and can reach a maximum speed of up to 140 km/h (87 mph).

Germany Choosing Hydrogen Over Diesel
As noted by Reuters, the agreement and subsequent announcement arrives around the same time as climate change discussions were taking place in Bonn, Germany. During these talks, nearly 200 countries came together in an attempt to improve their climate change plans and develop a a global climate accord.

“This day represents a real breakthrough in rail transportation and a big step change [sic] towards a clean mobility system,” said Gian Luca Erbacci, senior vice president for Europe at Alstom. “For the first time worldwide, a hydrogen-fueled passenger regional train will replace diesel trains, generating zero emission with the same performance as a regular regional train and up to 1,000 km autonomy.”

Hydrogen-powered vehicles, much like Toyota’s hydrogen trucks, only emit water vapors during operation, making them an incredibly eco-friendly alternative to diesel that won’t produce harmful emissions and worsen global warming. Alongside the efforts of other automakers like Honda, and projects like Project Hesla, it’s become apparent that people want to invest in hydrogen fuel cells, as its both cheaper and better for our environment.

Fuente y video:
https://futurism.com/hydrogen-powered-trains-are-coming-to-germany-in-2021/
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Re: Notas sobre Energías Renovables

Mensajepor Fermat » 25 Nov 2017 7:28 am

Combining Solar Panels With Agriculture Makes Land More Productive
November 24th, 2017 by Steve Hanley

Solar panels are wonderful things, but they do take up a lot of space, especially for larger, utility-scale systems. In some densely populated countries like China and India, where loss of farmland can lead to hungry people, floating solar farms are being built to take advantage of the surface area of lakes and rivers. Researchers at the Fraunhofer Institute For Solar Energy Systems have conducted an experiment near Lake Constance — which borders Germany, Lichtenstein, and Switzerland — regarding another solution.

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According to a Fraunhofer press release, the experiment involves 720 bi-facial solar panels covering about a third of a hectare of agricultural land (on the Demeter farm cooperative Heggelbach). The panels are mounted high enough to allow the crops planted below to receive almost as much sunshine as they would if the panels were not there and to permit farm machinery to operate beneath them. After a year of trials, the research showed the dual use system increased the total productivity of the land by 60%.

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https://cleantechnica.com/2017/11/24/combining-solar-panels-agriculture-makes-land-productive/
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Re: Notas sobre Energías Renovables

Mensajepor Fermat » 30 Nov 2017 9:35 am

Solar Energy Prices Continue to Plunge While Coal Prices Climb Higher

In Brief
Costs for solar power and other forms of renewable energy continue to dip. Falling prices can be attributed to more efficient technology and auction practices, which ensure the lowest-possible price for building.


Solar-Powered Revolution
Studies investigating the price of solar power have revealed some surprising results. Prices for new solar energy installations are continuing to fall by 26 percent in the last year, according to data compiled by Bloomberg New Energy Finance. Prices have fallen by even wider margins in some of the most important emerging markets like India and China.

Prices have fallen so much that it is now cheaper to build new commercial renewable energy sources than it is to keep existing coal and nuclear power plants running. The annual Levelized Cost of Energy Analysis from Lazard shows that prices for these traditional sources of power generation have risen in the past year, while renewable sources such as solar and wind continue to see costs lowering dramatically.

Imagen
Image credit: minoru karamatsu/Flickr

We can point to two basic factors that contribute to the lowering prices, improving technology and the increased use of auctions to drive competitive pricing.

The technology developed to capture renewable energy is able to generate more electricity with the same amount of light. In the case of wind power, Alberto Gandolfi, the head of European Utilities Research for Goldman Sachs, explains that today’s wind turbines can generate the same amount of power from 11 mph winds that wind turbines built ten years ago would generate from winds blowing at 22 mph.

Solar Energy for Better Business
Gandolfi said, “What started as a decarbonization process, thanks to better technology, is about to become a process driven by cost and economics.” In other words, environmental concerns are no longer the only driving force behind a push toward clean energy. Governments and businesses are beginning to see renewable energy as a way to save money. The environmental benefit can now be considered a side effect of better business practices.

Competitive auctions allow the prices paid to build new renewable installations to be closest to the actual cost. This practice is allowing installations to go up with the least amount of overhead, driving costs to their lowest levels in history.

Government subsidies are no longer essential for the building of new installations. While they are certainly welcome and can continue to help renewable energy proliferate, large scale projects are able to move forward without them. For example, we can look to the UK, which did away with government subsidies back in 2016. A new proposal for a 350 MW solar farm was recently submitted to the Department for Business, Energy and Industrial Strategy and would be the first brand new subsidy-free solar farm built since subsidies were discontinued. The scale of the installation will allow it to be economically viable even without the government funds.

Lowering costs and higher efficiency are giving renewable energy critics even less room to stand. Restoring defunct coal operations is often used by politicians as a way to restore lost jobs. However, in actuality, the solar industry alone is responsible for creating jobs at a rate seventeen times faster than the rest of the U.S. economy.

Environmental responsibility may not be the most important factor when many consider the future of energy generation. Even so, there continue to be more and more factors aside from a cleaner planet to drive the shift toward renewable energy adoption. Better technology and lower costs have allowed renewables to draft economics to continue this vital drive to save the planet and its inhabitants.

https://futurism.com/solar-energy-prices-continue-plunge-coal-prices-climb-higher/
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