New Developments February 2017

Surge in methane emissions threatens efforts to slow climate change

To save energy on heating and cooling, look at the shape of cities, not just their buildings  In North America and Europe, the greatest gains are likely to come from improving energy efficiency of buildings, especially retrofit of existing buildings. Efficiency gains matter relatively more in those regions that are already highly urban,” the researchers write. That’s because where cities are well established, their general form—compact or sprawling—is already set. Surprisingly, though, retrofitting buildings immediately doesn’t necessarily produce the greatest savings. Current technologies widely available for energy retrofits can save 20 to 40 percent of building energy use. But cutting-edge technologies could save 70 to 90 percent. Waiting five years or so for those new technologies to go mainstream and come down in cost could save more energy in the long term. And the picture is different in rapidly urbanizing regions like China, South Asia, Pacific Asia, the Middle East, North Africa, and Sub-Saharan Africa. There, changes in urban density will have the biggest effect on building energy use.

Storing solar power increases energy consumption and emissions, study finds Homes with solar panels do not require on-site storage to reap the biggest economic and environmental benefits of solar energy, according to research from the Cockrell School of Engineering at The University of Texas at Austin. In fact, storing solar energy for nighttime use actually increases both energy consumption and emissions compared with sending excess solar energy directly to the utility grid. The researchers estimated that adding energy storage to a household with solar panels increases its annual energy consumption by about 324 to 591 kilowatt-hours. "I expected that storage would lead to an increase in energy consumption," Fares said. "But I was surprised that the increase could be so significant -- about an 8 to 14 percent increase on average over the year." Storage -- done the right way and installed at large-scale -- can have beneficial impacts on the grid's emissions overall.

1000 times more efficient nano-LED opens door to faster microchips a nano-LED that is 1000 times more efficient than its predecessors, and is capable of handling gigabits per second. It is integrated into a silicon substrate on a membrane of indium phosphide.

Battling corrosion to keep solar panels humming "It's challenging to predict and even more challenging to design ways to reduce it because it's highly dependent on material and environmental conditions.” It's not easy deciding which environmental conditions to reproduce. "Along the coast of Florida, it's humidity and sea salt in the air. In Albuquerque, we have high ultraviolet (UV) radiation, so UV might be one of the important parameters here. The parameters driving corrosion shift with location and materials.” The team is developing nanocomposite films made from inexpensive materials as barriers against water vapor and corrosive gases.  Solar cells' electrical components are protected from corrosion by encapsulating polymers, sealants and glass, but water vapor and corrosive gases can permeate as materials and packaging degrade. Materials, for example, typically corrode faster in the higher temperatures and humidity of tropical coastal regions than in coastal Antarctica.

Toward all-solid lithium batteries  recent research has explored the possibility of all-solid-state batteries, in which the liquid (and potentially flammable) electrolyte would be replaced by a solid electrolyte, which could enhance the batteries' energy density and safety. the research team conducted the mechanical testing in a bath of mineral oil, protecting the sample from any chemical interactions with air or moisture. Using that technique, they were able to obtain detailed measurements of the mechanical properties of the lithium-conducting sulfide.

How India’s canals could help fast-forward its solar energy plans India aims for almost a nine-fold increase in solar capacity between between 2017 and 2022 to fulfil global climate-change commitments and reduce its dependence on coal-fired power plants. Installing solar-panels over 30% of Gujarat’s canals could be used to meet nearly a fifth of India’s solar power targets by 2022. Coal generates over 75% of India’s electricity and is among the cheapest energy sources available. Since the panels are placed on top of water, they are cooled from below, which also increases their efficiency and enhances output by 2.5% to 5%. Canal-top panels, by absorbing heat, help reduce water evaporation. A 1-MW canal-top plant can save the evaporation of up to 9 million litres of water per year. The supports on canal-top panels must be galvanised–given a protective layer of zinc–more thickly than normal because the water beneath increases rusting risks. However, these solar projects require levelling of the canal banks and shadow-free areas above panels. If canals are tree-lined, this would involve cutting trees. Construction could also contaminate the water in the canal, said Kuldeep.

Scientists lay foundations for new type of solar cell  Infrared radiation is converted into electrical energy using a different mechanism from that found in conventional solar cells. The mechanism relies on so-called polaron excitations, which combine the excitation of electrons and vibrations of the crystal lattice.

Ireland votes in favour of law to become world's first country to fully divest from fossil fuels The Irish Parliament passed the historic legislation in a 90 to 53 vote in favour of dropping coal, oil and gas investments from the €8bn (£6.8bn) Ireland Strategic Investment Fund, part of the Republic’s National Treasury Management Agency.

America may not have the power to deal with future hot days The real issue is the increased intensity of peak demand, the researchers say—the extreme needs for electricity on the hottest days. Under a modest warming scenario, there will be a 2.8 percent increase in average electricity demand across all regions of the US, and a 3.5 percent increase in peak demand.

Protecting bulk power systems from hackers The fundamental problem is a gap between physical equipment and intangible software. Advances in smart grid technology -- such as smart meters in homes, management systems for distributed energy resources like wind and solar production along with instrumentation systems in power plants, substations or control centers -- create both improvements in monitoring and entry points for hackers.

Material can turn sunlight, heat and movement into electricity -- all at once This kind of material would likely supplement the batteries on your devices, improving energy efficiency and reducing how often you need to recharge. One day, Bai said, multi-energy harvesting may mean you won't have to plug in your gadgets anymore. Batteries for small devices may even become obsolete.

New, long-lasting flow battery could run for more than a decade with minimum upkeep 

New engineered material can cool roofs, structures with zero energy consumption  It has the ability to cool objects even under direct sunlight with zero energy and water consumption. In addition to being useful for cooling of buildings and power plants, the material could also help improve the efficiency and lifetime of solar panels. In direct sunlight, panels can overheat to temperatures that hamper their ability to convert solar rays into electricity.

"Just by applying this material to the surface of a solar panel, we can cool the panel and recover an additional one to two percent of solar efficiency," said Yin. "That makes a big difference at scale."

JAPAN IS BUILDING THE WORLD’S LARGEST FLOATING SOLAR POWER PLANT The 13.7 megawatt (MW) floating solar power plant will be built on the Yamakura Dam reservoir. 51,000 Kyocera solar modules will be installed in the waters of the Yamakura Dam reservoir which is an 180,000 square meter area. The project is expected to generate an estimated 16,170 MWh of electricity per year, enough to power up 4,700 typical households. The Yamakura Dam project is set to complete by March 2018. Kyocera has built four floating solar power plant in Japan so far since 2014. Floating solar plant are actually very beneficial. Solar panels in water perform better than that of the land. Algae growth in water can be slowed down by the solar panels which stop sunlight from hitting the water.

Who’s the typical solar power user? You’d be surprised. A new Australian study has found that, at least in that country, families with low and medium incomes in the suburbs are buying the most solar power right now. In Australia, the government has used incentives such as feed-in tariffs to encourage solar uptake. The number of Australians installing solar photovoltaic (PV) technology grew from 8,000 to more than one million between 2008 and 2013. In the past, high income and education as well as home ownership were the defining features of those who bought solar power. The vast majority of people acquiring solar are in outer suburbs that often have lower average incomes.

One thing hasn’t changed: home ownership is still a feature of a solar user. The researchers found that solar homes were most likely to have three or more bedrooms and were occupied by a family of two or more. What’s more, those over 55 years of age are big solar purchasers, probably because they want to control electricity costs.

Tackling climate change through cleaner cookstoves In recent years, we’ve become aware of the health impacts of cookstoves: by burning fuels ranging from cow dung to coal and wood, cookstoves both contaminate people’s homes and pollute the outside air, causing ailments like lung cancer and heart disease that kill 4.3 million people prematurely every year. Cookstoves are known to produce an estimated 2.3 percent of global CO₂emissions. They also expel other impactful greenhouse gases like methane, as well as aerosols, a class of substances that includes black carbon (otherwise known as soot). Aerosols complicate matters further because their effects can vary: some cause warming, and others have a cooling effect thanks to the particulate matter they contain, which can block sunlight. Because they have a relatively short lifespan in the atmosphere, aerosols’ largest impact is at a more localized country-level—which can lead to regional variability. They modeled the outcome of a hypothetical 20-year cookstove eradication program in each country. It showed that by 2050, global temperatures would decrease 0.08°C, primarily as the short-term impacts of aerosols are removed. By 2100, that climbs to 0.12°C, as the benefits of eradicating lingering greenhouse gases—like carbon dioxide and methane—start to kick in. It’s a fairly significant decline, especially considering the Paris Agreement’s 2°C warming limit for the globe. Researchers estimate that the decrease would also stop over 10 million premature deaths by 2050. The study authors note that eradication in this timeframe is a tall order, what with so many people dependent on this mode of food preparation.

Nevertheless, with the spread of improvements and replacements for traditional cookstoves—like solar-powered cookers, cleaner-burning fuels, and solar energy—the research does provide a necessary roadmap for where to leverage these technologies, for the greater global good.

Making sodium-ion batteries that last scientists have developed an anode material that enables sodium-ion batteries to perform at high capacity over hundreds of cycles. Lithium and sodium have similar properties in many ways, but sodium ions are much larger than lithium ions. This size difference leads to the rapid deterioration of a key battery component. The researchers developed a simple approach to making a high-performance anode material by binding an antimony-based mineral onto sulfur-doped graphene sheets. Incorporating the anode into a sodium-ion battery allowed it to perform at 83 percent capacity over 900 cycles.

Wireless power transmission safely charges devices anywhere within a room The researchers demonstrated their method, called quasistatic cavity resonance (QSCR), inside a specially built 16-by-16-foot room at their lab. They safely generated near-field standing magnetic waves that filled the interior of the room, making it possible to power several cellphones, fans and lights simultaneously. “There's no reason we couldn't scale this down to the size of a toy chest or up to the size of a warehouse.” The QSCR method involves inducing electrical currents in the metalized walls, floor and ceiling of a room, which in turn generate uniform magnetic fields that permeate the room's interior. This enables power to be transmitted efficiently to receiving coils that operate at the same resonant frequency as the magnetic fields. The induced currents in the structure are channeled through discrete capacitors, which isolate potentially harmful electrical fields. Though the demonstration room was specially constructed, Sample said it likely will be possible to reduce the need for metalized walls, ceilings and floors in the future. It may be possible to retrofit existing structures, for instance, with modular panels or conductive paint.

Efficient power converter for internet of things The "internet of things" is the idea that vehicles, appliances, civil structures, manufacturing equipment, and even livestock will soon have sensors that report information directly to networked servers, aiding with maintenance and the coordination of tasks. Researchers have presented a new power converter that maintains its efficiency at currents ranging from 500 picoamps to 1 milliamp, a span that encompasses a 200,000-fold increase in current levels.

Looking for the next leap in rechargeable batteries  they developed an alteration to the lithium-sulfur battery that could make it more than competitive with the industry standard lithium-ion battery. Currently the lithium-sulfur battery can be recharged 50 to 100 times -- impractical as an alternative energy source compared to 1,000 times for many rechargeable batteries on the market today.

Stabilizing energy storage Chemists predict a better future for these types of batteries, called redox flow batteries. Using a predictive model of molecules and their properties, the team has developed a charge-storing molecule around 1,000 times more stable than current compounds. "If you want to increase the capacity, you just put more material in the tanks and it flows through the same cell," says University of Michigan chemist Melanie Sanford. "If you want to increase the rate of charge or discharge, you increase the number of cells."

US grid can handle more offshore wind power, cutting pollution and power costs The researchers consulted with PJM Interconnection -- a grid operator supplying electricity to more than 60 million people in 14 states -- to develop a computer model that simulates how the electric grid would respond to injections of wind power from offshore wind farms along the East Coast at five build-out levels, between 7 and 70 gigawatts of installed capacity. They also found that the PJM grid could in the future handle twice that amount, up to 70 gigawatts, as wind forecasting improves, allowing the power operator to better predict and harness more wind. "We saw up to a 50 percent reduction in carbon and sulfur dioxide and up to a 40 percent reduction in nitrogen oxides emissions at the highest build-out level, a 70-gigawatt set of wind farms. Plus, the costs of electricity would go down every month except in July when air conditioning is at a peak.”

New hydronium-ion battery presents opportunity for more sustainable energy storage It's the world's first battery to use only hydronium ions as the charge carrier. Hydronium, also known as H3O+, is a positively charged ion produced when a proton is added to a water molecule. Hydronium ions can be reversibly stored in an electrode material consisting of perylenetetracarboxylic dianhydridem, or PTCDA. The hydronium ions also migrate through the electrode structure with comparatively low "friction," which translates to high power. "It's not going to power electric cars," Ji said. "But it does provide an opportunity for battery researchers to go in a new direction as they look for new alternatives for energy storage, particularly for stationary grid storage."

Liquid hydrogen may be way forward for sustainable air travel Transport makes up around 20 percent of our energy use around the world -- and that figure is set to grow. "It is a defect that kerosene is so irrationally cheap, which triggers much unnecessary air travel," he writes. "A worldwide tax on kerosene -- if at all politically possible -- should be something to pursue." For road transport, Hermans argues that liquid hydrogen is not a viable option due to safety issues around handling it. He finds that electric vehicles offer the most promising solution. However, the challenge is to improve the performance of batteries to prolong the driving time for electric cars, as well as improving the performance of supercapacitors for more rapid charging of the batteries, he argues. The most efficient way for us to reduce energy use in future is to reduce our mobility, for example, by having shorter distances between the workplace and home. "In other words, urban planning provides an important key," he concludes.