On the left is a piece of glass plate, and on the right is the transparent solar cell. Credit: Rui Zhu, Ph.D
Scientists are reporting development of a new transparent solar cell, an advance toward giving windows in homes and other buildings the ability to generate electricity while still allowing people to see outside. Their report appears in the journal ACS Nano.
Yang Yang, Rui Zhu, Paul S. Weiss and colleagues explain that there has been intense world-wide interest in so-called polymer solar cells (PSCs), which are made from plastic-like materials. PSCs are lightweight and flexible and can be produced in high volume at low cost. That interest extends to producing transparent PSCs. However, previous versions of transparent PSCs have had many disadvantages, which the team set out to correct.
They describe a new kind of PSC that produces energy by absorbing mainly infrared light, not visible light, making the cells 66 percent transparent to the human eye. They made the device from a photoactive plastic that converts infrared light into an electrical current. Another breakthrough is the transparent conductor made of a mixture of silver nanowire and titanium dioxide nanoparticles, which was able to replace the opaque metal electrode used in the past. This composite electrode also allowed the solar cell to be fabricated economically by solution processing. The authors suggest the panels could be used in smart windows or portable electronics.
The authors acknowledge funding from the Engineering School of UCLA, the Office of Naval Research and the Kavli Foundation. The American Chemical Society is a nonprofit organization chartered by the U.S. Congress. With more than 164,000 members, ACS is the world's largest scientific society and a global leader in providing access to chemistry-related research through its multiple databases, peer-reviewed journals and scientific conferences. Its main offices are in Washington, D.C., and Columbus, Ohio.
Basing their work on decades of wind energy research and experience, Sandia engineers are creating several concept designs, running those designs through modern modeling software and narrowing those design options down to a single, most-workable design for a VAWTturbine-blade. Results aren’t in, but the early favorite for further testing is the Darrieus design. Credit: Illustration by Josh Paquette and Matt Barone
Sandia National Laboratories' wind energy researchers are re-evaluating vertical axis wind turbines (VAWTs) to help solve some of the problems of generating energy from offshore breezes.
Though VAWTs have been around since the earliest days of wind energy research at Sandia and elsewhere, VAWT architecture could transform offshore wind technology.
The economics of offshore windpower are different from land-based turbines, due to installation and operational challenges. VAWTs offer three big advantages that could reduce the cost of wind energy: a lower turbine center of gravity; reduced machine complexity; and better scalability to very large sizes.
A lower center of gravity means improved stability afloat and lower gravitational fatigue loads.
Additionally, the drivetrain on a VAWT is at or near the surface, potentially making maintenance easier and less time-consuming. Fewer parts, lower fatigue loads and simpler maintenance all lead to reduced maintenance costs.
Elegant in their simplicity
Sandia is conducting the research under a 2011 Department of Energy (DOE) solicitation for advanced rotor technologies for U.S. offshore windpower generation. The five-year, $4.1 million project began in January of this year.
Wind Energy Technologies manager Dave Minster said Sandia's wind energy program is aimed at addressing the national energy challenge of increasing the use of low-carbon power generation.
"VAWTs are elegant in terms of their mechanical simplicity," said Josh Paquette, one of Sandia's two principal investigators on the project. "They have fewer parts because they don't need a control system to point them toward the blowing wind to generate power."
These characteristics fit the design constraints for offshore wind: the high cost of support structures; the need for simple, reliable designs; and economic scales that demand larger machines than current land-based designs.
Large offshore VAWT blades in excess of 300 meters will cost more to produce than blades for onshore wind turbines. But as the machines and their foundations get bigger — closer to the 10 megawatt (MW) scale — turbines and rotors become a much smaller percentage of the overall system cost for offshore turbines, so other benefits of the VAWT architecture could more than offset the increased rotor cost.
Challenges remain
A Sandia team completes installation in the late 1980s of a vertical axis wind turbine test platform in Bushland, Texas. Photo by Randy Montoya
However, challenges remain before VAWTs can be used for large-scale offshore power generation.
Curved VAWT blades are complex, making manufacture difficult. Producing very long VAWT blades demands innovative engineering solutions. Matt Barone, the project's other principal investigator, said partners Iowa State University and TPI Composites will explore new techniques to enable manufacture of geometrically complex VAWT blade shapes at an unprecedented scale, but at acceptable cost.
VAWT blades must also overcome problems with cyclic loading on the drivetrain. Unlike horizontal axis wind turbines (HAWTs), which maintain a steady torque if the wind remains steady, VAWTs have two "pulses" of torque and power for each blade, based on whether the blade is in the upwind or downwind position. This "torque ripple" results in unsteady loading, which can lead to drivetrain fatigue. The project will evaluate new rotor designs that smooth out the amplitude of these torque oscillations without significantly increasing rotor cost.
Because first-generation VAWT development ended decades ago, updated designs must incorporate decades of research and development already built into current HAWT designs.
Reinvigorating VAWT research means figuring out the models that will help speed up turbine design work.
"Underpinning this research effort will be a tool development effort that will synthesize and enhance existing aerodynamic and structural dynamic codes to create a publicly available aeroelastic design tool for VAWTs," Barone said.
Needed: aerodynamic braking
Another challenge is brakes. Older VAWT designs didn't have an aerodynamic braking system, and relied solely on a mechanical braking system that is more difficult to maintain and less reliable than the aerodynamic brakes used on HAWTs.
HAWTS use pitchable blades, which stop the turbine within one or two rotations without damage to the turbine and are based on multiple redundant, fail-safe designs. Barone said new VAWT designs will need robust aerodynamic brakes that are reliable and cost-effective, with a secondary mechanical brake much like on modern-day HAWTs. Unlike HAWT brakes, new VAWT brakes won't have actively pitching blades, which have their own reliability and maintenance issues.
VAWT technology: A long history at Sandia
In the 1970s and 1980s, when wind energy research was in its infancy, VAWTs were actively developed as windpower generators. Although strange looking, they had a lot going for them: They were simpler than their horizontal-axis cousins so they tended to be more reliable. For a while, VAWTs held their own against HAWTs. But then wind turbines scaled up.
"HAWTs emerged as the predominant technology for land-based wind over the past 15 years primarily due to advantages in rotor costs at the 1 to 5 megawatt scale," Paquette said.
In the 1980s, research focused more heavily on HAWT turbines, and many VAWT manufacturers left the business, consigning VAWTs to an "also ran" in the wind energy museum.
But the winds of change have blown VAWTs' way once more.
Sandia is mining the richness of its wind energy history. Wind researchers who were among the original wind energy engineers are going through decades of Sandia research and compiling the lessons learned, as well as identifying some of the key unknowns described at the end of VAWT research at Sandia in the 1990s.
The first phase of the program will take place over two years and will involve creating several concept designs, running those designs through modern modeling software and narrowing those design options down to a single, most-workable design. During this phase, Paquette, Barone and their colleagues will look at all types of aeroelastic rotor designs, including HVAWTs and V-shaped VAWTs. But the early favorite rotor type is the Darrieus design.
In phase two researchers will build the chosen design over three years, eventually testing it against the extreme conditions that a turbine must endure in an offshore environment.
In addition to rotor designs, the project will consider different foundation designs: Early candidates are barge designs, tension-leg platforms and spar buoys.
The project partners will work on many elements.
Another partner, the University of Maine, will develop floating VAWT platform dynamics code and subscale prototype wind/wave basin testing. Iowa State University will develop manufacturing techniques for offshore VAWT blades and subscale wind tunnel testing. TPI Composites will design a proof-of-concept subscale blade and develop a commercialization plan. TU-Delft will work on aeroelastic design and optimization tool development and modeling. Texas A&M University will work on aeroelastic design tool development.
"Ultimately it's all about the cost of energy. All these decisions need to lead to a design that's efficient and economically viable," said Paquette.
Sandia National Laboratories is a multi-program laboratory operated by Sandia Corporation, a wholly owned subsidiary of Lockheed Martin company, for the U.S. Department of Energy's National Nuclear Security Administration. With main facilities in Albuquerque, N.M., and Livermore, Calif., Sandia has major R&D responsibilities in national security, energy and environmental technologies and economic competitiveness.
Drexel engineers develop new technology for grid-level electrical energy storage
In the aftermath of the recent United Nations Rio+20 Conference on Sustainable Development, the focus of many industrialized nations is beginning to shift toward planning for a sustainable future. One of the foremost challenges for sustainability is efficient use of renewable energy resources, a goal that hinges on the ability to store this energy when it is produced and disburse it when it is needed.
A team of researchers from Drexel University's College of Engineering have taken up this challenge and has developed a new method for quickly and efficiently storing large amounts of electrical energy.
Electrical energy storage is the obstacle preventing more widespread use of renewable energy sources such as wind and solar power. Due to the unpredictable nature of wind and solar energy, the ability to store this energy when it is produced is essential for turning these resources into reliable sources of energy. The current U.S. energy grid system is used predominantly for distributing energy and allows little flexibility for storage of excess or a rapid dispersal on short notice.
The Drexel's team of researchers is putting forward a plan to integrate into the grid an electrochemical storage system that combines principles behind the flow batteries and supercapacitors that power our daily technology.
Existing Technology
Batteries store a large amount of energy, but are relatively slow in discharging it and they have a limited lifespan, or cycle-life, than their counterparts – electrochemical capacitors, which are commonly called "supercapacitors" or "ultracapacitors."
Conventional supercapacitors provide a high power output with minimal degradation in performance for as many as 1,000,000 charge-discharge cycles. The capacitor can rapidly store and discharge energy, but only in small amounts compared to the battery.
The obstacle in the way of using either a battery or a supercapacitor to store energy in the grid is that energy storage ability is inextricably tied to the size of the battery or the supercapacitor being used. Supercapacitors, similar to lithium-ion batteries, are manufactured in fairly small cells ranging in size from a coin to a soda can. Large amounts of expensive material, such as metal current collectors, polymer separators and packaging, would be required to construct a battery or supercapacitor of the size necessary to function effectively in the energy grid.
"Packing together thousands of conventional small devices to build a system for large-scale stationary energy storage is too expensive," said Dr. Yury Gogotsi, director of the A.J. Drexel Nanotechnology Institute and the lead researcher on the project. "A liquid storage system, the capacity of which is limited only by the tank size, can be cost-effective and scalable."
The team's research yielded a novel solution that combines the strengths of batteries and supercapacitors while also negating the scalability problem. The "electrochemical flow capacitor" (EFC) consists of an electrochemical cell connected to two external electrolyte reservoirs - a design similar to existing redox flow batteries which are used in electrical vehicles.
This technology is unique because it uses small carbon particles suspended in the electrolyte liquid to create a slurry of particles that can carry an electric charge.
Uncharged slurry is pumped from its tanks through a flow cell, where energy stored in the cell is then transferred to the carbon particles. The charged slurry can then be stored in reservoirs until the energy is needed, at which time the entire process is reversed in order to discharge the EFC.
The main advantage of the EFC is that its design allows it to be constructed on a scale large enough to store large amounts of energy, while also allowing for rapid disbursal of the energy when the demand dictates it.
"By using a slurry of carbon particles as the active material of supercapacitors, we are able to adopt the system architecture from redox flow batteries and address issues of cost and scalability," Gogotsi said.
In flow battery systems, as well as the EFC, the energy storage capacity is determined by the size of the reservoirs, which store the charged material. If a larger capacity is desired, the tanks can simply be scaled up in size. Similarly, the power output of the system is controlled by the size of the electrochemical cell, with larger cells producing more power.
"Flow battery architecture is very attractive for grid-scale applications because it allows for scalable energy storage by decoupling the power and energy density," said Dr. E.C. Kumbur, director of Drexel's Electrochemical Energy Systems Laboratory. "Slow response rate is a common problem for most energy storage systems. Incorporating the rapid charging and discharging ability of supercapacitors into this architecture is a major step toward effectively storing energy from fluctuating renewable sources and being able to quickly deliver the energy, as it is needed."
This design also gives the EFC a relatively long usage life compared to currently used flow batteries. According to the researchers, the EFC can potentially be operated in stationary applications for hundreds of thousands of charge-discharge cycles.
"This technology can potentially address cost and lifespan issues that we face with the current electrochemical energy storage technologies," Kumbur said.
"We believe that this new technology has important applications in [the renewable energy] field," said Dr. Volker Presser, who was an assistant research professor in the Department of Materials Science and Engineering at the time the initial work was done. "Moreover, these technologies can also be used to enhance the efficiency of existing power sources, and improve the stability of the grid."
This concept for energy storage was recently published in a special issue of Advanced Energy Materials focused on next-generation batteries. The team's ongoing work is focused on developing new slurry compositions based on different carbon nanomaterials and electrolytes, as well as optimizing their flow capacitor design. The group is also designing a small demonstration prototype to illustrate the fundamental operation of the system.
"We have observed very promising performance so far, being close to that of conventional packaged supercapacitor cells," Gogotsi said. "However, we will need to increase the energy density per unit of slurry volume by an order of magnitude, and achieve it using very inexpensive carbon and salt solutions to make the technology practical."
The industry is interested in establishing a biorefinery sector in Denmark that can replace oil-based products with biofriendly materials, chemicals, energy and fuel. But this requires a larger biomass production than we are currently achieving. Scientists from University of Copenhagen and Aarhus University have published an extensive report that shows how we can increase the production of biomass by more than 200% in an environmentally friendly way.
The report called "The ten-million-tonne plan" shows how we can increase the Danish production of biomass from agriculture and forestry by 10 million tonnes per year without affecting the current production of feed and food.
The plan also shows how we can substantially reduce the environmental impact compared with current levels.
"It sounds too good to be true, but it is quite realistic. By concentrating on a number of areas we can in practice double plant production and improve the utilisation of existing resources so there is enough both for food and feed production and for an additional 10 million tonnes of biomass in 2020," says Morten Gylling, senior advisor at the Faculty of Science, University of Copenhagen.
The report contains a number of specific subelements that combined provide a solution for how we can use sustainable biology and technology to get an additional 10 million tonnes of biomass a year by 2020 without incorporating more agricultural land.
"One of the options is to double crop yield per hectare in selected areas. This can be done by converting to cropping systems with improved perennial crops and break crops to extend the growing season and thus more fully exploit the solar radiation. This will be sufficient to meet the requirements for both feed and food production and for the biomass production for a number of biofriendly products," explains Uffe Jørgensen, senior scientist at Aarhus University.
The increased production of biomass means that it would be possible to establish a biorefinery sector in Denmark – a sector that is crucial for the establishment of a green growth economy in Denmark.
"A future Danish biorefinery sector would create around new 20,000 jobs in production and industry, primarily in the provinces," says professor Claus Felby from University of Copenhagen and continues:
"10 million tonnes of biomass actually corresponds to 20 percent of our current consumption of natural gas and to 30-50 percent of our consumption of petroleum and diesel. To this should be added a significantly higher feed production that to a large extent will be able to replace what we currently import from countries such as South America," says Claus Felby.
The results of the report also show that the aquatic environment will improve with a focus on biomass: The loss of nitrogen from farmland can be reduced by more than 20,000 tones:
"A focus on biomass production alone will help meet our obligations in the EUWater Framework Directive, which is one of the most important tasks of Natur og Landbrugskommissionen (Agriculture and Nature Council) at the moment. It is particularly a better utilisation of animal manure that will help us to significantly reduce nitrate leaching," emphasizes Morten Gylling.
Biodiversity in Denmark will also be enhanced:
"We can increase biodiversity by harvesting the grass from approx. 70,000 ha of lowland meadows so they do not become smothered in nettles and willow as a result of nutrient overloads. Another option is to increase the area with natural woodland by 47,000 ha, and it is also possible to cut and remove the biomass and nutrients from approx. 7,000 ha of road verges to increase floral diversity," adds Uffe Jørgensen.
In order to realise the biomass potential, a massive investment in research and development will be needed in future years, particularly within agriculture and forestry, but also within the biological and chemical conversion of biomass.
The project is part of the collaboration between University of Copenhagen, Aarhus University and DONG set up in December 2011 to help launch special initiatives within research and education in green energy.
The energy generated from our oceans could be doubled using new methods for predicting wave power. Research led by the University of Exeter, published (27 June) in the journal Renewable Energy, could pave the way for significant advancements in marine renewable energy, making it a more viable source of power.
The study was carried out by a team of mathematicians and engineers from the University of Exeter and Tel Aviv University. They devised a means of accurately predicting the power of the next wave in order to make the technology far more efficient, extracting twice as much energy as is currently possible.
Marine energy is believed to have the potential to provide the UK with electricity twice over. However, technologies to extract and convert energy from the sea are relatively immature, compared with solar or wind, and are not yet commercially competitive without subsidy. Very substantial progress has been made by the leading device developers, but key challenges remain: preventing devices being damaged by the hostile marine environment; and improving the efficiency of energy capture from the waves. This research addresses both problems by enabling control over the devices that extract wave energy. The key to this is to enable devices to accurately predict the power of the next wave and respond by extracting the maximum energy.
The research focused on point absorbers, commonly-used floating devices with parts that move in response to waves, generating energy which they feed back to the grid. Point absorbers are already known to be much more efficient in the amount of energy they produce if their response closely matches the force of the waves and previous research has looked at trying to increase this efficiency. However, this is the first study that has focused on increasing the device's efficiency by predicting and controlling internal forces of the device caused by forthcoming waves.
The team devised a system, which enables the device to extract the maximum amount of energy by predicting the incoming wave. This information enables a programme to actively control the response required for a wave of a particular size. Because the device responds appropriately to the force of the next wave, it is far less likely to be damaged and would not need to be turned off in stormy conditions, as is currently the case.
Lead author Dr Guang Li of the University of Exeter said: "Our research has the potential to make huge advances to the progress of marine renewable energy. There are significant benefits to wave energy but progressing this technology has proved challenging. This is a major step forward and could help pave the way for wave energy to play a significant role in providing our power."
Co-author Dr Markus Mueller of the Environment and Sustainability Institute at the University of Exeter's Cornwall Campus said: "The next step is for us to see how effective this approach could be at a large scale, by testing it in farms of Wave Energy Converters."
The University of Exeter is collaborating with Ocean Power Technologies, a leading wave energy device developer, to exploit and further develop the results from this research. This further activity is supported by the European Union Seventh Framework Programme (FP7/2007-2013) in a project called 'WavePort'.
In a study that could solidify the trend toward construction of gigantic windmills, scientists have concluded that the larger the wind turbine, the greener the electricity it produces. Their report appears in ACS' journal Environmental Science & Technology.
Marloes Caduff and colleagues point out that wind power is an increasingly popular source of electricity. It provides almost 2 percent of global electricity worldwide, a figure expected to approach 10 percent by 2020. The size of the turbines also is increasing. One study shows that the average size of commercial turbines has grown 10-fold in the last 30 years, from diameters of 50 feet in 1980 to nearly 500 feet today. On the horizon: super-giant turbines approaching 1,000 feet in diameter. The authors wanted to determine whether building larger turbines makes wind energy more or less environmentally friendly.
Their study showed that bigger turbines do produce greener electricity — for two main reasons. First, manufacturers now have the knowledge, experience and technology to build big wind turbines with great efficiency. Second, advanced materials and designs permit the efficient construction of large turbine blades that harness more wind without proportional increases in their mass or the masses of the tower and the nacelle that houses the generator. That means more clean power without large increases in the amount of material needed for construction or fuel needed for transportation.
The American Chemical Society is a nonprofit organization chartered by the U.S. Congress. With more than 164,000 members, ACS is the world's largest scientific society and a global leader in providing access to chemistry-related research through its multiple databases, peer-reviewed journals and scientific conferences. Its main offices are in Washington, D.C., and Columbus, Ohio.
Global Trends in Renewable Energy Investment 2012 (fs-unep-centre.org) is the fifth edition of the UNEP report, based on data from Bloomberg New Energy Finance (bnef.com), and has become the standard reference for global clean energy investment figures.
This year it shows that despite an increasingly tough competitive landscape for manufacturers, total investment in renewable power and fuels last year increased by 17% to a record $257 billion, a six-fold increase on the 2004 figure and 94% higher than the total in 2007, the year before the world financial crisis.
Although last year's 17% increase was significantly smaller than the 37% growth recorded in 2010, it was achieved at a time of rapidly falling prices for renewable energy equipment and severe pressure on fiscal budgets in the developed world.
The REN21 Renewables 2012 Global Status Report (ren21.net/gsr), which has become the most frequently referenced report on renewable energy market, industry and policy developments, notes that during 2011 renewables continued to grow strongly in all end-use sectors - power, heating and cooling and transport. Renewable sources have grown to supply 16.7 % of global energy consumption. Of that, the share provided by traditional biomass has declined slightly while the share sourced from modern renewable technologies has risen.
In 2011, renewable energy technologies continued to expand into new markets: around 50 countries installed wind power capacity, and solar PV capacity moved rapidly into new regions and countries. Solar hot water collectors are used by more than 200 million households as well as in many public and commercial buildings worldwide.
The two publications were launched jointly by Achim Steiner, UNEP Executive Director, Mohamed El-Ashry, Chairman of REN21, Michael Liebreich, Chief Executive of Bloomberg New Energy Finance, and Professor Dr. Udo Steffens, President and CEO of the Frankfurt School of Finance & Management, host of the Frankfurt School - UNEP Collaborating Centre for Climate & Sustainable Energy Finance.
Highlights
Total investment in solar power jumped 52% to $147 billion and featured booming rooftop photovoltaic (PV) installations in Italy and Germany, the rapid spread of small-scale PV to other countries from China to the UK and big investments in large-scale concentrating solar thermal (CSP) power projects in Spain and the US.
The United States surged back to within an inch of the top of the renewables investment rankings, with a 57% leap to $51 billion, as developers rushed to cash in on three significant incentive programs before they expired during 2011 and 2012. After leading the world for two years, China saw its lead over the US shrink to just $1 billion in 2011, as it recorded renewable energy investment of $52 billion, up 17%.
India's National Solar Mission helped to spur an impressive 62% increase to $12 billion, the fastest investment expansion of any large renewables market in the world. In Brazil, there was an 8% increase to $7 billion.
Competitive challenges intensified sharply, leading to sharp drops in prices, especially in the solar market -- a boon to buyers but not to manufacturers, a number of whom went out of business or were forced to restructure.
Renewable power, excluding large hydro-electric, accounted for 44% of all new generating capacity added worldwide in 2011 (up from 34% in 2010). This accounted for 31% of actual new power generated, due to lower capacity factors for solar and wind capacity.
Gross investment in fossil-fuel capacity in 2011 was $302 billion, compared to $237 billion for that in renewable energy capacity excluding large hydro.
The top seven countries for renewable electricity capacity excluding large hydro - China, the United States, Germany, Spain, Italy, India and Japan - accounted for about 70% of total non-hydro renewable capacity worldwide. The ranking among these countries was quite different for non-hydro capacity on a per person basis: Germany, Spain, Italy, the US, Japan, China and India. By region, the EU was home to nearly 37% of global non-hydro renewable capacity at the end of 2011, China, India and Brazil accounted for roughly one quarter.
Renewable technologies are expanding into new markets. In 2011, around 50 countries installed wind capacity; solar PV capacity is rapidly moving into new regions and countries; interest in geothermal power has taken hold in East Africa's Rift Valley and elsewhere; interest in solar heating and cooling is on the rise in countries around the world; and the use of modern biomass for energy purposes is expanding in all regions of the globe.
In the power sector, renewables accounted for almost half of the estimated 208 gigawatts (GW) of electric capacity added globally during the year. Wind and solar photovoltaic (PV) accounted for almost 40% and 30% of new renewable capacity, respectively, followed by hydropower (nearly 25%). By the end of 2011, total renewable power capacity worldwide exceeded 1,360 GW, up 8% over 2010; renewables comprised more than 25% of total global power-generating capacity (estimated at 5,360 GW in 2011) and supplied an estimated 20.3% of global electricity.
At least 118 countries, more than half of which are developing countries, had renewable energy targets in place by early 2012, up from 96 one year before, although some slackening of policy support was seen in developed countries. This weakening reflected austerity pressures, particularly in Europe, and legislative deadlock in the US Congress.
Despite all the additional investments, share prices in the renewable energy sector had a dismal 2011 in the face of overcapacity in the solar and wind manufacturing chains and investor unease about the direction of support policies in both Europe and North America.
"There may be multiple reasons driving investments in renewables, from climate, energy security and the urgency to electrify rural and urban areas in the developing world as one pathway towards eradicating poverty-whatever the drivers the strong and sustained growth of the renewable energy sector is a major factor that is assisting many economies towards a transition to a low carbon, resource efficient Green Economy" says Mr. Steiner.
"This sends yet another strong signal of opportunity to world leaders and delegates meeting later this month at the Rio+20 Summit: namely that transforming sustainable development from patchy progress to a reality for seven billion people is achievable when existing technologies are combined with inspiring policies and decisive leadership," he said.
"It is essential to continue government policies that support and nurture the sector's growth, and to de-escalate damaging trade disputes. Otherwise," he warned, "the low-carbon transition could weaken just at the point when exciting cost reductions are starting to transform the economics."
Says Dr. El-Ashry: "Despite the continuing economic crisis in some key traditional markets, and continuing political uncertainties, more renewable energy was installed last year than ever before. Policies helped to drive renewable energy forward. Policy development and implementation were stimulated by the Fukushima nuclear catastrophe in Japan, along with improvements in renewable energy costs and technologies. As a result, renewable energy is spreading to more countries and regions of the globe. Globally there are more than 5 million jobs in renewable energy industries, and the potential for job creation continues to be a main driver for renewable energy policies."
Bumpy road for renewable energy firms recalls early auto industry
Faced with plunging green energy technology prices and economic austerity measures, many governments slashed their renewable subsidies and allowed other support schemes to expire. The result was a succession of company failures and factory closures in 2011-2012, including five significant solar manufacturers in the US and Germany.
According to Mr. Steiner, "Today's over-capacity situation in some renewables sectors, particularly solar, provides the opportunity to upscale deployment in new markets at costs few thought possible only a few years ago. This is particularly attractive to the many developing countries where much of the population has little or no access to modern energy services."
Says Prof. Dr. Steffens: "Renewables are starting to have a very consequential impact on energy supply, but we're also witnessing many classic symptoms of rapid sectoral growth -- big successes, painful bankruptcies, international trade disputes and more. This is an important moment for strategic policymaking as winners in the new economy form and solidify."
Adds Mr. Liebreich: "We are entering a fascinating period, with clean energy's costs starting to be competitive with fossil fuels. The challenge for policy-makers is to reduce support mechanisms at just the right pace - too fast and the long-term future of the industry will be harmed. Too slow and you do the world's taxpayers and energy consumers a great disservice."
"Right now we are seeing a lot of pain on the supply-side as prices are being compressed, but it is important to remember than installers, generators and consumers are benefiting. It is all part of the maturing of the sector," he says.
"In 1903, the United States had over 500 car companies, most of which quickly fell by the wayside even as the automobile sector grew into an industrial juggernaut. A century ago, writing off the auto industry based on the failures of weaker firms would have been foolish. Today, the renewable energy sector is experiencing similar growing pains as the sector consolidates."
The industry's image in the investor community has been harmed by a number of high-profile supply-chain company failures, he says. At the same time, he points out, Germany's solar installations hit a new record peak output of 22GW at the end of May - equivalent to around one quarter of the country's total power demand.
Renewables: an increasingly important contributor to world energy supply
In more and more countries, renewable energy represents a significant and rapidly growing share of total energy supply.
In the United States, renewable energy (including large hydro) provided 12.7% of total domestic electricity in 2011, up from 10.2% in 2010, and 9.3% in 2009. An estimated 39% of electric capacity added in 2011 was from renewable sources, mostly wind power. Renewable energy sources accounted for about 11.8% of U.S. domestic primary energy production, for the first time surpassing the 11.3% from nuclear power).
China again led the world in the installation of wind turbines and was the top hydropower producer and leading manufacturer of PV modules in 2011. Wind power generation increased by more than 48.2% during the year.
In the European Union, renewable energy accounted for more than 71% of total electricity generating capacity additions in 2011, with solar PV alone representing nearly half (46.7%) of new capacity coming on stream.
Germany remained the third biggest market for renewable energy investment. Renewable sources met 12.2% of total final energy consumption and accounted for 20% of electricity consumption (up from 17.2% in 2010 and 16.4% in 2009).
As the world marks the UN "International Year of Sustainable Energy for All," the REN21 Renewables 2012 Global Status Report includes a special focus on rural renewable energy, based on input from local experts working from around the world. Renewable energy is seen increasingly as a means for providing millions of people with a better quality of life through access to modern cooking, heating/cooling and electricity.
The impressive deployment of all renewable energy technologies combined with dramatic cost reductions and significant technology advances in recent years create an important opportunity for rural renewable energy development that points to a brighter future. However, further efforts will be necessary to reach the UN's outlined objectives: annual investment in the rural energy sector needs to increase more than fivefold to provide universal access to modern energy by 2030.
Closing the gap with fossil fuels
The price of all major renewable energy technologies continued to fall in 2011 -- to the point where they are challenging fossil-fuel sources, even before climate, health and other benefits are factored in.
The dominant reason for the price declines was that manufacturer margins were compressed as the industry continued the shift from a period of under-capacity a few years ago, to overcapacity now as growing demand failed to keep up with a surge in supply.
The most spectacular price plunge was in PV cells, whose average price fell from $1.50 per Watt in September 2010, to $1.30 per Watt by January 2011 and $0.60 per Watt by the end of the year, according to the Bloomberg New Energy Finance Solar Price Index. This fed into a fall in PV module prices of nearly 50% between the start of 2011 and the beginning of this year.
Onshore wind turbines showed a similar, although less dramatic, trend. In 2011, prices for turbines to be delivered in the second half of 2013 were 25% lower than for devices delivered in the first half of 2009, according to the Bloomberg New Energy Finance Wind Turbine Price Index.
While 2011 saw significant falls in the costs of generating a MWh of power from onshore wind (down 9%), and from PV technologies (down more than 30%), the cost of electricity generated by fossil-fuel sources changed less in most parts of the world - despite the sharp falls in US natural gas prices due to the increased use of "fracking," a hotly contested form of resource extraction.
Based on current trends, it is predicted that the average onshore wind project worldwide will be fully competitive with combined-cycle gas turbine generation by 2016 even in the US, as gas prices are expected to rebound to a point where they cover the cost of extraction. At present, this is true only of a minority of wind projects, those that use the most efficient turbines in locations with superior wind resources.
In solar, analysis suggests that the cost of producing power from rooftop PV panels for domestic use is already competitive with the retail (but not the wholesale) daytime electricity price in several countries including Germany, Denmark, Italy and Spain, as well as the state of Hawaii.
Policy environment drives development
REN21's analysis found that stable renewable energy policies continue to be a driving force behind the development of green power capacity.
At least 118 countries - more than half of them in the developing world - have now established renewable energy targets. These include shares of total primary energy, total end-use energy, electricity generation (typically 10-30%), heat supply, biofuels as shares of road transport fuels, and total installed capacities for specific technologies.
Support for renewable power generation remains the most popular policy option with at least 65 countries and 27 states now having feed-in-tariffs (FITs).
Most policy activities in 2011 involved revisions to existing FITs, at times under controversy and involving legal disputes.
FIT payments vary widely among technologies and countries but are generally trending downwards, mostly due to lower technology costs than expected.
This graph shows power density of GaInP and crystalline silicon cells, underwater, as a function of depth. Credit: US Naval Research Laboratory
Scientists at the U.S. Naval Research Laboratory (NRL), Electronics Science and Technology Division, dive into underwater photovoltaic research to develop high bandgap solar cells capable of producing sufficient power to operate electronic sensor systems at depths of 9 meters.
Underwater autonomous systems and sensor platforms are severely limited by the lack of long endurance power sources. To date, these systems must rely on on-shore power, batteries or solar power supplied by an above water platform. Attempts to use photovoltaics have had limited success, primarily due to the lack of penetrating sunlight and the use of solar cells optimized more towards the unimpeded terrestrial solar spectrum.
"The use of autonomous systems to provide situational awareness and long-term environment monitoring underwater is increasing," said Phillip Jenkins, head, NRL Imagers and Detectors Section. "Although water absorbs sunlight, the technical challenge is to develop a solar cell that can efficiently convert these underwater photons to electricity."
Even though the absolute intensity of solar radiation is lower underwater, the spectral content is narrow and thus lends itself to high conversion efficiency if the solar cell is well matched to the wavelength range. Previous attempts to operate solar cells underwater have focused on crystalline silicon solar cells and more recently, amorphous silicon cells.
High-quality gallium indium phosphide (GaInP) cells are well suited for underwater operation. GaInP cells have high quantum efficiency in wavelengths between 400 and 700 nanometers (visible light) and intrinsically low dark current, which is critical for high efficiency in lowlight conditions.
The filtered spectrum of the sun underwater is biased toward the blue/green portion of the spectrum and thus higher bandgap cells such as GaInP perform much better than conventional silicon cells, states Jenkins.
Preliminary results at a maximum depth of 9.1 meters reveal output to be 7 watts per square meter of solar cells, sufficient to demonstrate there is useful solar power to be harvested at depths commonly found in nearshore littoral zones.
In an address at Green Week in Brussels on 24 May, Karl Falkenberg, Director General of DG Environment, said that integrated projects which co-ordinate actions with other funding streams represent the way forward for the LIFE programme.
Speaking at the session, ’20 years of LIFE – the past, present and future of water policy funding’, Mr Falkenberg said that the limited LIFE budget means that projects will have to use “multiplier effects” to achieve an impact that is not merely local but one that spreads across Member States, he said. The EU will favour cross-border initiatives, while partnerships for research will give access to additional finances, he added.
Mr Falkenberg praised those who set up the LIFE programme 20 years ago, saying that they had a “good understanding of the demonstration potential” of the instrument.
Speaking ahead of the Director General, Dr Lynne Barratt, ASTRALE (external monitoring team for the LIFE programme) gave an overview of the strengths and opportunities of the programme. “LIFE projects excel in policy implementation but not in all areas of the policy lifecycle,” she said.
Dr Barratt emphasised that the programme could play a greater role than it has done in influencing policymaking. Mr Falkenberg concluded his address by reaffirming this point. We need to work towards making LIFE a source of knowledge that can help revise policy, he said.
Mr Falkenberg concluded the session by presenting the two winners of the ‘Best of the Best’ and three winners of the ‘Best’ LIFE Environment projects with their plaques.
‘Best of the Best’:
‘INSU-SHELL – Environmentally Friendly Facade Elements made of thermal insulated Textile Reinforced Concrete’ (LIFE06 ENV/D/000471) This German project demonstrated a new technology to minimise the amount of concrete necessary in the construction of the facades. The beneficiary, the Rheinisch - Westfaelische Technische Hochschule Aachen, developed a high-tech, thermally insulated textile reinforced concrete (TRC) technology, which reduces the C02 produced by more than half.
In Botswana, leaders from ten African nations open the inaugural Summit for Sustainability in Africa, the first convening of African leaders dedicated to valuing renewable natural capital in development; expected outcome includes Gaborone Declaration.
His Excellency Lt. Gen. Seretse Khama Ian Khama, President of the Republic of Botswana, opened the Summit for Sustainability in Africa today with a welcoming address to heads of state and other esteemed guests, underscoring both the opportunities and responsibilities of African nations to join together to design a new economic path toward sustainable development throughout the continent. The multi-national Summit, a first of its kind in Africa, is being held in the Botswana capital of Gaborone over two days, where His Excellency is co-hosting the event in partnership with Conservation International before a live audience of more than three hundred dignitaries and ten African nations.
In highlighting the role of renewable natural capital in Africa, or the goods and services provided to people, economies and businesses from healthy ecosystems, HE President Khama emphasized, “We need to pay more attention to what is economically feasible, socially desirable and environmentally sustainable.”
“In hosting this Summit on Sustainability in Africa, our aspirations are to discuss common African perspectives on sustainable development and to find consensus about how some of us in Africa and its peoples represented here may use their natural resource wealth and transform their resources into drivers of inclusive economic growth and people-centered development," Khama said. "However, for us to do so, we need to take stock and attach value to our natural resources and ecosystems such that we may include their value in planning and decision making processes as well as in our national accounts and balance sheets.”
Also on day one of the Summit, Her Excellency Ellen Johnson Sirleaf, President of the Republic of Liberia, Dr. Achim Steiner, the Executive Director of the United Nations Development Programme (UNEP), and His Excellency Hifikepunye Pohamba, President of Namibia, supported opening sentiments, calling for more leaders of African nations to take interest and control of the future of development while also protecting the continent’s renewable natural capital.
Explaining a concept she described as “economic invisibility” in natural capital valuation, President Johnson Sirleaf told summit audiences, “Our ecosystems, biodiversity, and natural resources underpin economies, societies, and individual well-being, but the values of its benefits are often overlooked or poorly understood. We are running down our natural capital stock without understanding the value of what we are losing.”
“Increasingly, one of the imperatives of any sustainable development is to strike the right balance between our current needs and our global future. The question before us is, how do we ensure that we do not deplete our natural capital to satisfy our daily needs? I hope this summit is when Africa speaks with one voice on how we can manage our natural capital for future generations.”
The Summit, which was born of conversations between President Khama, a board member of Conservation International and that organization’s Chairman and CEO Peter Seligmann, was designed to initiate new dialogues, form new partnerships and create a framework for the public and private sectors to collaboratively incorporate the immediate and long term value of natural capital in their national, regional and corporate accounting systems.
A relatively new concept, “natural capital” is a term for the limited stocks of physical and biological resources found on Earth. It refers to the limited capacity of ecosystems to provide ecosystem services, or the direct and indirect contributions of natural ecosystems to people.
“We will not have harmonious futures if we destroy the treasure of our forests, rivers, oceans, and grasslands, that we have inherited,” Seligmann said. “This is what historians refer to as an open moment, when people come together because they understand there is a common purpose they have to address. Ultimately, we must ask ourselves: how do we take care of our future and children if we don’t take care of nature?”
His Royal Highness The Prince of Wales addressed attendees via a pre-recorded video message which emphasized that conservation of renewable natural capital does not need to come at the expense of economic development.
“It is seen in a widely held view that there is a somehow a choice to be made between protecting the environment and sustaining nature on the one hand, and on the other hand, promoting economic growth and reducing poverty. All economic development is in the end dependent on natural capital, in some form or other. Soil fertility, fresh water replenishment, clean air, waste recycling, flood protection, disease prevention, genetic diversity and climatic stability all enable development in different ways. And it is scarcely possible to think of an economic activity that would carry on for very long without these things being available.”
It is expected that the summit will conclude with the announcement of the Gaborone Declaration, which will embody a series of principles committing participants to integrating natural capital into economic development plans and policies. Attending leaders will then take these messages to the meeting of the United Nations Convention on Sustainable Development in Brazil in late June.
“We in Africa are determined to show leadership. Let us indeed lead by example in valuing and using our abundant natural resources for the health, education, and sustainable future of current and next generations,” Khama concluded.
