Sunday, October 14, 2012

Cleantech News from CleanTechnica

Cleantech News from CleanTechnica

Link to CleanTechnica

Black Silicon Solar Cell Hits 18.2% Efficiency, Should Help to Reduce Costs

Posted: 13 Oct 2012 07:30 AM PDT

Black-silicon solar cells with 18.2% efficiency have been created by researchers from the U.S. Department of Energy’s National Renewable Energy Laboratory (NREL). These don’t need extra anti-reflection layers (like typical solar cells do), which should help to significantly lower the cost of solar energy.


The specially designed nanostructured surface ensures that the light-generated electricity is still collectable in an efficient way from the solar cell, while still conferring the inherent advantages of a ‘black silicon‘ material.

“The researchers made nano-islands of silver on a silicon wafer and immersed it briefly in liquids to make billions of nano-sized holes in each square-inch of the silicon wafer surface,”an NREL news release states. “The holes and silicon walls are smaller than the light wavelengths hitting them, so the light doesn’t recognize any sudden change in density at the surface and, thus, don’t reflect back into the atmosphere as wasted energy. The researchers controlled the nanoshapes and the chemical composition of the surface to reach record solar cell efficiencies for this ‘black silicon’ material.”

Regularly, solar cell manufacturers need to add an additional anti-reflection layer, sometimes even more than one, to their cells; this raises the manufacturing costs considerably.

In previous research, NREL has shown that its nanostructures reflect significantly less light than even the best anti-reflection layers currently used. It had previously been unable to achieve overall conversion efficiencies that could challenge other solar cells with these ‘black-silicon’ solar cells, however.

To reach these efficiencies, the researchers first needed to resolve why having an increased surface area on the nanostructure-featuring solar cells drastically reduced the gathering of electricity current.

“Their experiments demonstrated that the high-surface area, and especially a process called Auger recombination, limit the collection of photons on most nanostructured solar cells. They concluded that this Auger recombination is caused when too many of the dopant impurities put in to make the cell work come through the nanostructured surface,” NREL states.

“This scientific understanding enabled them to suppress Auger recombination with lighter and shallower doping. Combining this lighter doping with slightly smoother nanoshapes, they can build an 18.2%-efficient solar cell that is black but responds nearly ideally to almost the entire solar spectrum.”

Branz added: “The next challenges are to translate these results to common industrial practice and then get the efficiency over 20%. After that, I hope to see these kinds of nanostructuring techniques used on far thinner cells to use less semiconductor material.”

The research was just published on the website of Nature Nanotechnology.

Source: NREL
Image Credits: Black Silicon via Wikimedia Commons

Reposted from Solar Love with permission.

India Needs Concentrated Solar Power to Achieve Safer, More Reliable Energy Future, NRDC Report Finds

Posted: 13 Oct 2012 07:10 AM PDT

In the wake of historic summer blackouts that left more than 700 million Indians without power, a new report released this week by the Natural Resources Defense Council (NRDC) and the Council on Energy, Environment and Water (CEEW), an India-based independent research organization, shows that concentrated solar power can play an essential role in achieving a secure and diversified energy future for India.

"After experiencing the world's largest blackout this summer, the Indian government knows the urgent need to improve grid stability and provide affordable electricity to hundreds of millions of people," said Anjali Jaiswal, Senior Attorney for the Natural Resources Defense Council's India Initiative. "As India enters Phase 2 of the National Solar Mission, we are looking to the Indian government to support flexibility in the domestic solar industry by fostering confidence, investment, and innovation in concentrated solar power."

According to the new report, "Concentrated Solar Power: Heating Up India's Solar Thermal Market under the National Solar Mission," India has jumpstarted its solar energy industry in just over two years thanks to Phase 1 of the government's National Solar Mission. A major contributor to this growth is solar thermal power, including seven large-scale concentrated solar power (CSP) projects now underway in India.

Concentrated solar power involves systems of mirrors that concentrate a large area of sunlight onto a small area. The concentrated light is converted to heat, with a turbine and electrical power generator converting the heat to electricity. Because CSP allows for storage of electricity, large-scale CSP presents several potential benefits for India's energy profile. These include supplying electricity to help India meet its base-load needs, providing supplemental electricity during times of peak usage, and ensuring grid stability.

Building on the April 2012 report from NRDC and CEEW, which discussed the tremendous growth of the domestic solar market under Phase 1 of India's National Solar Mission, this new report focuses on the progress of CSP projects during Phase 1, identifying the benefits of and barriers to CSP growth in India.

Phase 1 of the National Solar Mission sparked India's CSP market, as the government allocated power production evenly between CSP and photovoltaic (PV) technologies. The large-scale CSP projects now underway in India will provide a projected 500 megawatts (MW) in energy capacity, a huge jump from the 8.5 MW of energy capacity under CSP projects before the National Solar Mission began in 2010.

Despite the anticipated acceleration of CSP in India, several barriers exist that challenge the long-term sustainability of India's CSP industry. These include the length of time required to develop CSP projects, high initial capital costs, and a lack of confidence in the CSP market as a whole. NRDC and CEEW's report provides recommendations for the Indian government, private sector, and other stakeholders to ensure a robust CSP ecosystem develops to support the long-term feasibility of CSP. These recommendations include:

Develop a Clear Roadmap: To reach India's Phase 2 targets, and continue to build India as a prime destination for solar, the sector needs long-term signals about the direction of the market, policy priorities, and support measures. India's Ministry of New and Renewable Energy (MNRE) can help ramp up India's solar mission by laying out a clear roadmap for Phase 2, without locking in one technology.

Increase Transparency: With doubt lingering among investors, MNRE should increase information publicly available on the bid selection process, the status of project commissioning, and power being produced.

Investigate Delays and Monitor Timeline Extensions: The government should enforce commissioning timelines for Phase 1 projects to avoid setting a precedent of leniency on delays. Looking ahead, the government should assess the appropriateness of commissioning timelines for projects, taking into account foreseeable causes of delay, and determine which unforeseeable delays merit deadline extensions.

Facilitate Innovative Financing: In order to attract CSP investment, MNRE should coordinate stakeholders to develop financiers' comfort with nonrecourse project financing, such as government-backed loan guarantees.

Enforce Renewable Purchase Obligations (RPOs): The Indian government should continue to analyze effective approaches to enforce renewable purchase obligations, the renewable energy mandates that energy distribution companies in India must meet.

Offer Incentives for Innovation: In order to fully exploit the potential of CSP technologies, the Indian government should offer incentives to project developers to adopt storage technologies (by extending commissioning timelines) and water-efficient plants, involving technologies like dry-cooling (by offering tariff premiums).

"It is essential that under Phase 2 of the Mission, the Indian government not force a false choice between concentrated solar power and photovoltaic technologies," said Dr. Arunabha Ghosh, CEO for the Council on Energy, Environment and Water, an independent think-tank based in New Delhi. "With greater confidence, investment, and transparency, both sectors have the potential to strengthen India's energy profile while creating new business opportunities for domestic developers, manufacturers and suppliers, and technology innovators."

NRDC and CEEW's report draws from extensive discussions with stakeholders, and research and analysis of national, state and international programs.

The full report and fact sheet can be found online here:

Read more about concentrated solar power in India and the Jawaharlal Nehru National Solar Mission in Anjali Jaiswal's blog:

Reposted from NRDC’s Media Center.

UK Empowers Electricity Storage Systems with Fund Amount of 20 Million

Posted: 13 Oct 2012 07:00 AM PDT

The UK Government is about ready to hit the “go” button on the work of leading innovators in the electricity and energy storage systems sector. It has directed £20 million for two energy storage competitions, which, in return, will reportedly fetch a yield of £10 billion every year (if an Imperial College London report is correct).

energy storage

Applicants are invited to register through the internet this week. The goal is to have the projects starting at the beginning of next year.

The “Energy Storage Technology Demonstration Competition,” which is supposed to be the first competition, will enable the organisations to acquire funds from the government, which will help them build up and exhibit their innovations in energy preservation and their technological prowess. The goal is to improve utility-scale storage for the UK’s electricity grid.

As for the second competition, the DECC's Energy Storage Component Research and Feasibility Study Competition, a funding grant will be offered in order to ”support component level research in relation to storage technologies.”

Andrew Jones who is the S&C Electric Company's managing director for Middle East, Africa, and Europe, said to BusinessGreen that the organisation would let in up to 3 projects.

He further added that S&C is in talks with several clients that have the potential to develop storage demonstrations schemes for solar or wind farms, and another to support massive commercial constructions in order to make them independent of the grid (simply running on renewables and energy storage). Of course, competitively priced electricity storage is key to the UK’s (and other countries’) long-term renewable energy goals.

Jones said: “We are delighted with DECC’s announcement to support the progression of electricity storage. This will certainly help contribute towards the government’s overall understanding of its benefits and hopefully enable the market reforms required to facilitate its adoption. This will provide the much-needed impetus to improve the efficiency of our electricity grid and help boost the integration of renewable energy sources.”

Image: batteries via Shutterstock

New Obama Solar Energy Blueprint Paves Way for Additional 23.7 GW of Green Power

Posted: 13 Oct 2012 04:23 AM PDT

Interior Department Secretary Ken Salazar on Friday announced a federal blueprint for large-scale solar power project developments spanning six Western states. The Obama Administration’s Solar Programmatic Environmental Impact Statement (PEIS) refines the approach that’s been taken previously — the Interior Department is now first identifying solar energy development zones in Arizona, California, Colorado, Nevada, New Mexico, and Utah with access to existing or planned transmission capacity and where utility-scale solar PV installations would pose minimal risks to wildlife and ecosystems.

Announced at a press conference in Las Vegas, the PEIS for utility-scale solar energy permitting also establishes incentives for project development and a process through which to consider additional zones and solar projects, according to a Department of Interior press release.



New Solar Power Development Roadmap for the US West

Interior’s announcement demonstrates further follow-through on President Obama’s "all-of-the-above energy strategy" and pledge to boost renewable energy and green economic growth in the US.

Interior on Tuesday reached the President’s goal of authorizing 10,000 megawatts (MW) of renewable power on public lands with the approval of the Chokecherry and Sierra Madre Wind Energy Project sites in Wyoming. At a combined rated capacity of up to 3,000 MW, the two southeastern Wyoming wind farms could generate enough clean, green renewable power for nearly 1 million US homes and create an estimated 1,000 green jobs.

Interior has authorized 33 renewable energy projects on public lands since 2009. These include 18 utility-scale solar power facilities, seven wind power farms, and eight geothermal power plants, along with associated transmission corridors and infrastructure, the Department noted. Taken together, these projects will produce enough clean electricity to power more than 3.5 million US homes, support some 13,000 construction and operations jobs, and potentially avoid a massive amount of carbon and greenhouse gas emissions over their useful lives.

"Energy from sources like wind and solar have doubled since the President took office, and with today's milestone, we are laying a sustainable foundation to keep expanding our nation's domestic energy resources," Secretary Salazar stated. "This historic initiative provides a roadmap for landscape-level planning that will lead to faster, smarter utility-scale solar development on public lands and reflects President Obama's commitment to grow American made energy and create jobs."

New PEIS Paves Way to Potential 23.7 GW of New Solar Power

The new Solar PEIS establishes an initial set of 17 Solar Energy Zones (SEZs) spanning some 285,000 acres of public lands to "serve as priority areas for commercial-scale solar development. If fully built out, projects in the designated areas could produce as much as 23,700 MW of solar energy, enough to power approximately 7 million American homes," according to Interior.

The Solar PEIS also comes with some built-in flexibility in that it allows for evaluation on a case-by-case basis of solar power project proposals on carefully selected sites outside the SEZs. Interior in the new Solar PEIS has identified some 19 million acres in such so-called "variance" areas.

Also included in the new Solar PEIS is "a framework for regional mitigation plans, and to protect key natural and cultural resources the program excludes a little under 79 million acres that would be inappropriate for solar development based on currently available information."

"The Solar PEIS sets forth an enduring, flexible blueprint for developing utility-scale solar projects in the right way, and in the right places, on our public lands," said David J. Hayes, Deputy Secretary of the Interior. "Never before has the Interior Department worked so closely and collaboratively with the industry, conservationists and sportsmen alike to develop a sound, long-term plan for generating domestic energy from our nation's sun-drenched public lands."

For those interested in learning more, Interior has put a fact sheet on the new Solar PEIS online.

Solar Cell Degradation Research Can Improve Thin Film Solar Panels

Posted: 12 Oct 2012 11:53 PM PDT

The Laboratory for Photovoltaics at the University of Luxembourg has recently devised a new method to observe the causes of and prevent solar cell degradation before solar cell production is even finished. This will have huge effects on the solar cell manufacturing industry because of how fast chemical damage to solar cells can happen, and the large costs such damage incurs.

Solar panels convert the sun’s light into electrical current through the use of solar cells, which are the generators responsible for the energy solar panels produce. A specific type of solar cells, thin film solar cells, possess a special coating that is what actually absorbs the sun’s energy — this film can be easily degraded during the solar panel production process though.

“A thin film solar cell is a stack of several layers. The main one is the layer that absorbs the light and transforms it into electricity. If these absorbers are not processed immediately they lose part of their ability to convert light energy,” says researcher David Regesch of the Laboratory for Photovoltaics, Physics Research Unit at the University of Luxembourg.

For the new research, a laser was shone onto a solar cell and the light that was released by this was measured, which led to the finding that the degradation usually occurs within the first few minutes. And, importantly, it was found that the degradation was reversible and could be prevented, by immediately putting another layer on top of the solar cell. This stabilizes the solar cell.

“In the photovoltaics industry, solar cells are processed as fast as possible for economic reasons, and now scientists have shown a physical reason why this process should be completed quickly.”

The new research was just published in Applied Physical Letters.

Source: Université du Luxembourg
Image Credits: GE

Reposted from Solar Love with permission.

Tidal Power Capacity Potential in the UK Estimated at 153 GW

Posted: 12 Oct 2012 11:20 PM PDT

There are 153 GW of potential tidal and wave power capacity in the UK, according to a new report from the Crown Estate. The new report was commissioned to help predict the future of the technology.


The report from the Crown Estate underlines the enormous energy potential in the UK’s marine environment. To harness this enormous 153 GW of tidal power capacity, there are three primary types of technology that will be needed — tidal stream devices, tidal range barrage schemes, and tidal range lagoon schemes.

“The report predicts tidal stream devices could produce 95 terawatt hours (TWh) a year from 32GW of installed capacity, tidal range barrage schemes could supply 96 TWh/year from 45GW of capacity, and tidal range lagoon schemes could produce 25TWh/year, drawing on 14GW of capacity.”

And there is also the potential for “27GW of wave energy capacity, which could produce 69TWh of electricity a year.”

The authors of the report say that the figures for the different technologies should be interpreted separately, and that all of the results remain theoretical for now.

According to Rob Hastings, the director of the Crown Estate energy and infrastructure portfolio, the report is intended to be a reference to help in the development of the industry and associated policies.

“While the science of wave and tidal resource assessment is still emerging, and future work will clarify the resources that are practically available, it is clear that wave and tidal energy could contribute substantially to the UK’s electricity needs,” he said.

“Improving understanding about the extent and locations of resources will help to accelerate development in a sustainable way.”

The UK’s Secretary of State for Energy and Climate Change, Ed Davey, recently visited the European Marine Energy Centre (EMEC) in Orkney and had this to say:

“[EMEC is a huge asset to the development of wave and tidal energy in the UK and has helped secure UK leadership in the global market.

“The UK has the largest wave and tidal resource in Europe, which could produce 20 per cent of current UK electricity demand and cut carbon emissions.”

Source: The Guardian
Image Credits: Pelamis

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