05 Feb 2015:
Ultra-Efficient Solar Cells
Can Be Adapted for Rooftops, Research Finds
Extremely efficient solar cells similar to those used in space may soon be ready for installation on residential rooftops, according to a report
in Nature Communications
. Concentrated photovoltaic (CPV) systems, which use lenses and curved mirrors to focus sunlight onto small solar cells, produce energy much more efficiently than conventional solar panels — 40-percent efficiency compared to less than 20 percent for standard silicon systems. But they are typically the size of billboards and have to be positioned very accurately to track the sun throughout the day. Now researchers have overcome these obstacles by developing a CPV system that uses miniaturized gallium-arsenide photovoltaic cells, 3D-printed plastic lens arrays, and a moveable focusing mechanism. The new system is small and light enough to fit on a residential rooftop and should be inexpensive to produce, researchers say.
16 Jan 2015:
Solar a Better Investment Than
Stocks in Most Large U.S. Cities, Study Says
For homeowners in 46 of the 50 largest cities in the U.S., investing in a residential solar power system would yield better returns than putting money in the
stock market, according to an analysis
by the North Carolina Clean Energy Technology Center at North Carolina State University. For 21 million owners of single-family homes in the U.S., solar energy already costs less than current local utility rates, the report says, as long as the system can be purchased with low-cost financing of 5 percent interest over 25 years. Residents of New York City, Boston, and Albuquerque would likely see the largest benefits from investing in residential solar, the report says. The findings assume
, however, that government incentives encouraging solar investments — such as tax exemptions and policies allowing homeowners to sell excess solar power to utility companies — will continue, which is highly dependent on federal, state, and local politics.
14 Jan 2015:
Offshore Wind More Profitable
Than Drilling on U.S. East Coast, Report Says
Offshore wind would produce twice the number of jobs and twice the amount of energy as offshore drilling
Offshore wind turbines in the Irish Sea
near the U.S. East Coast
, according to
a new report from the advocacy group Oceana. The report contends that recent claims by the oil and gas industry about the economic potential of offshore drilling in the region are exaggerated because many of those oil and gas reserves are not economically viable to drill. Plans to build the nation's first offshore wind farm off Cape Cod have repeatedly failed to move forward
. But Oceana calculates that over the course of 20 years, offshore wind in the Atlantic could produce nearly twice as much energy as all of the economically recoverable oil and gas. Offshore wind installations also would likely create an additional 91,000 jobs — twice as many as offshore drilling would create, Oceana says.
12 Jan 2015:
Maasai Group Plans to Sell
Biogas Made From Slaughterhouse Waste
A group of Maasai farmers in southwestern Kenya has developed a profitable way to convert animal waste and
A Keeko Biogas cylinder prototype
blood from a local slaughterhouse into biogas that can power the facility as well as other local businesses, Reuters reports
. The Keeko Biogas project plans to start bottling the fuel and selling cylinders of it in March, once safety testing has been completed, project leaders say. At roughly $8 per 6-kilogram cylinder, the biogas is about half the price of liquefied petroleum gas, and it can be up to 40 percent more energy efficient than propane or butane, says the Kenya Industrial Research and Development Institute, which is providing technical support for the project. The facility will be able to produce 100 to 300 cylinders of biogas per week, organizers say. The project will not only offset the costs of waste management for the slaughterhouse, it will also likely help prevent deforestation in the region. "We cut down a lot of trees for charcoal and we hope to reduce that,” the chairman of the slaughterhouse told Reuters.
08 Jan 2015:
Land Disturbances Darken Snow
And Increase Melt Rate, Researchers Say
Land disturbances, such as agricultural practices and development, may have a big impact on snow purity and
Sampling snowpack in Montana
melt rates, according to
a large-scale survey of impurities in North American snow by researchers at the University of Washington. The researchers were particularly interested in the Bakken oil fields of northwest North Dakota. Before undertaking the study, they predicted that diesel emissions and air pollution associated with oil exploration would darken the snowpack, decreasing the amount of sunlight it reflects and increasing its melt rate. They found, however, that while these activities do add soot to the snow, the dirt they stir up adds an equal amount of impurities to the snowpack. Disturbances from clearing oil pads, new housing sites, agricultural activities, and extra truck traffic on unpaved roads add a significant amount of dirt to snowfields, they found.
05 Jan 2015:
U.S. Cities Are Significantly
Brighter than German Cities, Scientists Say
German cities emit several times less light per capita than similarly sized American cities, according to new research
published in the journal Remote Sensing
Berlin, Germany, at night
Moreover, the differences in light emission become more dramatic as city size increases: Light per capita increases with city size in the U.S. but decreases in Germany. Factors such as the type of lamps used and architectural elements like the width of the streets and the amount of trees are likely behind the differences, the researchers say. Energy-efficient LED street lighting
is currently being installed in many cities worldwide, and the researchers expect this to change the nighttime environment in many ways — for example, by reducing the amount of light that shines upward. The study also found that, in major cities in developing countries, the brightest light sources were typically airports or harbors, whereas the brightest areas in large European cities are often stadiums and city centers.
29 Dec 2014:
The Arctic Is Absorbing
More and More Sunlight, NASA Images Show
The Arctic has been absorbing significantly more sunlight since the year 2000, according to NASA satellite data
Changes in absorption of sunlight in the Arctic
a trend that mirrors the steady decrease in Arctic sea ice during that same period. These maps show changes in the amount of solar radiation absorbed over the Arctic from 2000 to 2014, as well as changes in sea ice cover during the same period. As sea ice cover declines and more dark ocean is exposed to the sun's rays, that decreases the reflectivity, or albedo, of the ocean's surface, meaning more heat is absorbed. Shades of red depict areas absorbing more sunlight and areas with less ice cover. The Arctic's rate of absorption has increased by 5 percent every June, July, and August since 2000. No other region on the planet has shown significant changes in albedo during that time, researchers say.
23 Dec 2014:
Madrid Announces Largest
Energy-Efficient Street Lighting Project
The city of Madrid has announced plans
to renew its entire street lighting system with 225,000 new energy-efficient
New energy-efficient street lighting in Madrid, Spain.
bulbs, the world’s largest street-lighting upgrade to date. The new lights, which will afford the city a 44-percent reduction in energy costs, will pay for themselves, according to Philips
, the company supplying the new system. In addition to drawing less overall power, the bulbs’ intensity will be controlled from a central command panel, resulting in less wasted energy. Of the 225,000 new lights, 84,000 will be locally manufactured LEDs, and the city is taking measures to ensure the safe recycling of heavy metals found in the old lamps. Similar, though smaller, projects have been undertaken in Argentina, Sweden, and the Netherlands.
A Green Dilemma for the Holidays:
Better to Shop Online or In-Store?
Various studies in recent years have suggested that online shopping typically packs a lower carbon punch than shopping at brick-and-mortar stores. But new research suggests the story is more complicated than that. The key, according to a report in the Journal of Cleaner Production
, is to minimize the number of miles driven per item — whether by the shopper, a local delivery van, or a FedEx truck.
17 Dec 2014:
Obama Protects Alaska's
Bristol Bay From Oil and Gas Development
President Obama yesterday announced protections for Bristol Bay, Alaska
A grizzly bear catches a salmon in Bristol Bay.
of the most productive fishing grounds in the nation, from future oil and gas development. The president's action is expected to benefit commercial fishermen and Native Alaskans and boost conservation efforts in the region, which is roughly the size of Florida. Noting that Bristol Bay is the world's largest sockeye salmon fishery and the source of 40 percent of U.S. wild-caught seafood — a catch worth $2 billion annually — Obama vowed to ensure long-term safeguards for the bay. The region has been under protection intermittently since 1989, when the Exxon Valdez spill prompted a federal moratorium on offshore drilling. "It is a natural wonder, and it’s something that’s just too precious to be putting out to the highest bidder," Obama said in a video message
. The federal government is still considering whether to allow development of what would be North America's largest open-pit mine
in the bay's watershed.
16 Dec 2014:
Falling Gasoline Prices Have
Little Effect on Car Travel, Analysis Shows
Although the average retail price of gasoline in the U.S. has fallen 28 percent from its peak in June 2014,
Gas prices vs. miles driven
the decline may not have much effect on automobile travel and gasoline consumption, according to an analysis by the U.S. Energy Information Administration
(E.I.A.). Typically, an increase in the price of a product leads to lower demand, and vice versa — a concept known as price elasticity. Air travel, for example, tends to be highly elastic: A 10-percent increase in the price of air fares leads to an even greater decrease in air travel. Automobile travel tends to be much less elastic, however. According to E.I.A. data, it takes a 25- to 50-percent decrease in the price of gasoline to increase automobile travel by just 1 percent. One reason for this is that the distance people drive to work and for daily errands is relatively fixed, analysts say. Increased vehicle fuel economy also balances out increases in miles traveled, leading to more stability in gasoline consumption.
Beyond Lima: Major Investors
Must Fund Global Green Initiatives
Much of the discussion at the recent U.N. climate talks in Lima, Peru, was about the financing that
Climate talks in Lima stretched into Sunday.
will be needed to decarbonize the world’s energy supply, improve efficiency, and redesign cities and transportation systems to reduce greenhouse gas emissions. As journalist Isabel Hilton reports for e360
from Lima, moving the broader financial markets toward green investments is critically important in order to avoid the worst impacts of climate change. The key, Hilton writes, is to get major institutions to invest in sustainable growth, particularly renewable energy, and to get major companies and the industrial sector to understand that they must revise their strategies to address the risks of climate change.
Read Hilton's analysis.
05 Dec 2014:
U.S. Natural Gas Fracking Boom
May Be Shorter Than Predicted, Study Says
Estimates of the amount of natural gas that can be extracted from U.S. reserves is much too high and the boom may last just half as long as predicted, says a new report
in the journal Nature
. Official government estimates by the Energy Information Administration (EIA) suggest that peak natural gas production, driven by the rapid growth of hydraulic fracturing, will likely last until 2040 before tapering off. The new analysis suggests that that estimate is too high. Instead, researchers say, the peak will likely come in 2020, and after that production will fall off dramatically. The findings are based on higher-resolution, finer-scale estimates of oil and gas reserves — in units of a single square mile — compared to the EIA's method, which lumps together all land within a single county. The EIA's method also fails to account for the realities of economics, the reseachers say: Fracking companies tend to look for "sweet spots," which they quickly abandon as soon as the reserves become depleted and extraction costs rise.
26 Nov 2014:
Aerodynamic Upgrades to
Large Trucks Would Cut Fuel Use Steeply
The fuel consumption of the 2 million tractor-trailer trucks hauling cargo across the U.S. — which currently
Airflow patterns around a tractor-trailer truck
burn 36 billion gallons of diesel fuel per year — could be cut by billions of gallons through the use of drag-reducing devices, according to
researchers at Lawrence Livermore National Laboratory. In wind tunnel tests, researchers fitted a scale-model truck with two types of devices designed to reduce drag and improve aerodynamics: a trailer skirt, which consists of panels affixed along the lower side edges of a trailer, and a boat tail fairing, which is affixed to the back of the trailer to reduce the size of its wake. The researchers found that using the devices in combination — technology currently installed on only 3 to 4 percent of the nation’s large trucks — reduced the aerodynamic drag by as much as 25 percent, which translates to a 13-percent decrease in fuel consumption. If the U.S. tractor-trailer fleet were to improve its fuel economy by 19 percent, which the researchers say is achievable, 6.5 billion gallons of diesel fuel would be saved each year, avoiding 66 million tons of carbon dioxide emissions.
21 Nov 2014:
U.S. Can Cut Greenhouse Gas Emissions 80 Percent by 2050, Study Says
The United States can reduce greenhouse gas emissions by 80 percent by 2050, using existing or near-commercial technologies, according to researchers with the Deep Decarbonization Pathways Project
. The study analyzed scenarios with four types of decarbonized electricity: renewable energy, nuclear energy, fossil fuel with carbon capture and storage, and a mixed case. The scenarios achieved reductions of 83 percent below 2005 levels and 80 percent below 1990 levels, according to the study, which was released ahead of next month’s climate talks in Lima, Peru, and negotiations in Paris in December 2015. The energy efficiency of buildings, transportation, and industry would need to increase through the use of smart materials and energy-efficient designs, and vehicles will need to be fueled with electricity generated from wind, solar, or nuclear, as opposed to coal, the researchers said. They project the net costs would be on the order of 1 percent of gross domestic product per year. The 80-percent reduction by 2050 is a long-standing goal of the Obama administration, in line with global commitments to limit warming to less than 2 degrees C.
03 Nov 2014:
Climate Impacts To Be Severe and Irreversible Without Emission Cuts, UN Says
Climate change will have “severe, widespread, and irreversible impacts” on society and the environment
The U.N. climate panel's synthesis report was released on November 2.
unless nations swiftly and drastically cut carbon emissions — a goal that, while difficult, still remains within reach, according to a comprehensive new United Nations climate report released this week. Failure to curb emissions by the end of the century will likely lead to food shortages, refugee crises, the flooding of major coastal cities and entire island nations, and dangerous yet routine heat waves, among other impacts, the analysis concluded. But the panel also said for the first time that combating climate change is economically feasible. The new U.N. report synthesizes the findings from a series of analyses released over the past year by the Intergovernmental Panel on Climate Change — the panel's first major update since 2007.
30 Oct 2014:
China Is Top Developing Nation for Clean Energy Investment, Analysis Finds
China is the most attractive among developing nations for low-carbon investment and deployment, according to an analysis by the Climatescope project
, a partnership among various international development agencies and Bloomberg New Energy Finance. China received top marks because it is the largest manufacturer of wind and solar equipment in the world, has the largest demand market for wind and solar energy, and has taken major strides to improve its domestic policy framework score, the analysis said
. Brazil ranked second, largely due to the country's aggressive approach to clean energy development and the availability of low-cost capital through its national bank, the report said. South Africa ranked third, and the analysis noted the nation had attracted $10 billion in clean energy investments in 2012 through 2013. The project ranked 55 developing countries on their past, present, and future ability to attract investment for clean energy companies and projects.
28 Oct 2014:
Scientists Find Seafloor Fallout Plume of Oil from Deepwater Horizon Spill
Researchers say they have found a large fallout plume of oil on the seafloor from the 2010 Deepwater Horizon
Deepwater Horizon oil at the surface of the ocean
disaster in the Gulf of Mexico. According to a report in the Proceedings of the National Academy of Sciences
, a portion of the 2 million barrels of oil thought to be trapped in the deep sea after the spill appears to have settled across a 1,250-square-mile patch of the seafloor centered around the Macondo Well, which discharged an estimated 5 million barrels of oil in the nearly three months between its blowout in April and eventual capping in July. The oil is concentrated in the top half-inch of the seafloor, and mostly distributed in patchy deposits to the southwest of the well, the study found. These deposits account for between 4 and 31 percent of the Macondo oil sequestered in the deep ocean, researchers estimate. The rest has likely been deposited outside this area, they say, but has evaded detection so far because of its patchiness.
24 Oct 2014:
New Mapping Tool Shows U.S. Geothermal Plants and Heat Potential
A new mapping tool from the U.S. Department of Energy
lets users see how geothermal power plants
Geothermal power plants and heat flow potential
across the country are taking advantage of the heat stored within the earth’s crust. Most of the nation’s 154 operational and planned geothermal plants are clustered in western states, where geothermal heat potential is especially high (red areas). Notably, the map identifies two areas that appear ripe for new geothermal development: one in the Great Plains and another at the border of Virginia and West Virginia. The bulk of the facilities are conventional geothermal plants, which generate power using fluid found naturally deep below earth's surface. Steam captured at the surface spins a turbine, which then powers an electric generator. A newer type of technology, called enhanced geothermal, forces cold water from the surface down into the hot crust. Both types are generally considered clean sources of energy.
20 Oct 2014:
Electricity Access Has Small
Effect on Emissions in India, Study Says
Expanding electricity to the homes of 650 million people in India over the past 30 years had minimal
A third of all households in India lack electricity.
direct impact on the country’s greenhouse gas emissions, according to a study published in Nature Climate Change
. Although many humanitarian and development organizations have stressed the importance of improving electricity access in low-income countries, it has been unclear how this would impact overall emissions levels. An analysis of trends in India between 1981 and 2011 shows that expanding household electricity access by roughly 45 percent contributed only 3 to 4 percent to the nation's overall growth in carbon dioxide emissions. When the indirect effects of greater electricity access, such as increased wealth and consumerism, are taken into account, household electricity use raised India’s emissions by 11 to 25 percent over that period, the study found.
10 Oct 2014:
Natural Gas Production Causing
Large Methane Hotspot Over U.S. Southwest
A single methane “hotspot” in the U.S. Southwest accounts for 10 percent of the nation’s total estimated
Coalbed natural gas field in northwest New Mexico
methane emissions, according to an analysis
by researchers at the University of Michigan and Caltech. The area is centered in New Mexico's San Juan Basin near the shared borders of Colorado, Utah, and Arizona — the site of the largest and most active coalbed natural gas production operation in the U.S. Natural gas from the basin is more than 95 percent methane, a significantly more potent heat-trapping gas than carbon dioxide. Satellite measurements collected over seven years showed natural gas production operations in the area released roughly 650,000 tons of methane to the atmosphere each year. The methane emissions are not associated with hydraulic fracturing operations in the region, which began after the measurements were collected.
09 Oct 2014:
Investment in Energy Efficiency
Outpaces the Renewable Energy Sector
Global investments in energy-efficiency measures have reached $310 billion annually — nearly $100 billion more
than investments in renewable energy last year, according to a new report from the International Energy Agency
. Efficiency measures saved the equivalent of 2 billion tons of oil between 2001 and 2011 in the 18 countries evaluated in the report, which is more than the annual energy demand of the U.S. and Germany combined. The residential sector saw the largest improvement in efficiency, with energy demand falling 5 percent from 2001 levels, according to the report. Homes and businesses are commonly turning to efficiency measures
such as low-energy lighting, smart thermostats, and improved insulation to lower energy costs. To limit global temperature increases to no more than 2 degrees Celsius, the largest share of emissions reductions — 40 percent — will need to come from improvements in energy efficiency, the agency said.
Interview: Still Bullish on Hybrids,
But Skeptical about Electric Cars
As one of the principal designers of the gasoline-electric hybrid Prius, Bill Reinert has never been shy about sharing his views on what
he considers the poor prospects for fully electric vehicles — and on just about anything related to alternative fuels and the future of transportation. For Reinert, who recently retired from the Toyota Motor Corporation, the physical and performance limitations of battery technology are the key stumbling blocks for electrics. In an interview with Yale Environment 360
, he talks about the potential he sees in other low-emissions vehicle technologies now in development, particularly fuel cells, and the state of the global effort to find efficient and affordable alternatives to gasoline-powered cars. Read the interview.
29 Sep 2014:
Inexpensive Solar Cell
Makes Hydrogen Fuel from Sunlight
Researchers have developed a device that can store solar energy by inexpensively converting it to hydrogen —
Electrodes split water to hydrogen and oxygen.
an important step
toward making solar power available around the clock. The technology, which which was recently described in the journal Science
, is a type of "water splitter," a device that can efficiently divide water into its constituent parts: hydrogen and oxygen. The concept is important for solar energy storage because hydrogen gas can be used directly as fuel and is relatively easy to store, the researchers say. The device can convert 12.3 percent of the energy in sunlight to hydrogen, according to the report; conventional solar cells, in comparison, convert roughly 16 percent of energy from sunlight to electricity, but a significant portion of that energy is lost when converting it to a form that is easily stored. The design of this water splitter is an improvement over previous iterations, the researchers say, but the device's longevity and reliability will need to improve before it becomes a practical, large-scale solar energy storage option.
25 Sep 2014:
World's Largest Coal Company
Plans Billion-Dollar Solar Project in India
Continuing its push to increase investment in renewable energy, India’s energy ministry is working with the
Gevra mine, operated by Coal India Limited
state-controlled coal mining company Coal India Limited — the largest coal mining operation in the world — to install solar power projects worth $1.2 billion. The company is in the process of selecting sites for solar plants, which are expected to have a combined total energy-generating capacity of 1,000 megawatts, the Times of India reports
. India currently has roughly 2,200 megawatts of grid-connected solar power capacity, so Coal India Limited's contribution would be a substantial increase
. When prime minister Narendra Modi took office earlier this year, he pledged to bring electricity to the homes of the nation's entire population of 1.2 billion — 400 million of whom lack any access to electricity — within the next five years, largely through solar projects.
The Overview: Alberta Tar Sands
These satellite images, taken from July 1984 through May 2011, reveal the development of the Athabasca oil sands, commonly called "tar sands," which lie at the heart of Alberta’s oil deposits. Tar sands mining, which has become a significant issue for environmentalists, has been rapid and extensive, growing to cover nearly 260 square miles of the Canadian province by 2011. Nearly 2 million barrels of oil are produced every day, according to the Alberta government, with production expected to grow to nearly 4 million barrels per day over the next decade.
View the images.
17 Sep 2014:
Shift to Mass Transit Could
Have Major Economic and Climate Benefits
Expanding public transportation and infrastructure that promotes walking and biking throughout the world's
cities could save $100 trillion and cut transportation-related carbon emissions by 40 percent by 2050, according to
an analysis by researchers at the University of California, Davis, and the Institute for Transportation and Development Policy. Urban transportation-related emissions could double by 2050 as growth continues in major cities in China, India, and other developing countries. But if China alone were to develop extensive bus rapid transit and commuter transit networks, its predicted transportation-related emissions in 2050 could be cut by 40 percent, the analysis found. The U.S. — currently the world's largest contributor to urban transportation-related emissions — is seeing declines in that sector as population growth slows, vehicle fuel efficiency improves, and people drive less. But those emissions cuts could accelerate sharply if urban mass transit were improved, the report said.
16 Sep 2014:
Tackling Climate Change Could
Pay Off in as Little as 15 Years, Report Finds
Limiting greenhouse gas emissions globally over the next 15 years is both economically feasible and likely to save money, according to a new report
from the Global Commission on the Economy and Climate. Between 2015 and 2030, nations are expected to invest roughly $90 trillion in urban land-use and energy infrastructure, the analysis estimated. Steering those investments toward renewable energy, efficiency improvements, and other low-emission technologies would make that global investment more costly, the panel of government and business leaders conceded. But these costs could eventually be offset by the lowered operating costs associated with renewable power, the report suggested. Although they are difficult to quantify, health care savings associated with improved air quality would also offset costs. According to the report, the biggest challenges for governments will be enacting stronger rules and policies that favor low-carbon development, such as cutting the $600 billion currently spent on fossil fuel subsidies.
12 Sep 2014:
New High-Resolution Maps Show
Greenhouse Gas Emissions at City-Level
Researchers have developed a new method for mapping global carbon emissions for individual cities on an
hourly basis — a major improvement over previous techniques, which quantified greenhouse emissions less accurately and at coarser scales, according to researchers at Arizona State University
. The maps are derived from worldwide databases of population, power plants, and national fuel use statistics, and they encompass 15 years of data. Among other findings, the analysis revealed increased emissions in China, India, Europe, and the northern U.S. in 2010, after the peak of the global financial crisis. The researchers say this reflects faster recoveries from the crisis in those regions compared to, for example, the southeastern U.S., where emissions lagged in 2010. The results of the analysis match ground-level measurements, confirming the accuracy of the maps, the researchers say.
10 Sep 2014:
U.S. Renewable Energy Growth
In 2014 Dwarfs Fossil Fuel Plant Additions
The U.S. this year has significantly scaled back coal and natural gas power plant additions compared to 2013,
and solar and wind power capacity is far outpacing the 2013 installation rate, according to
the U.S. Energy Information Administration. No utility-scale coal plants were added in the first six months of 2014, whereas more than 1,500 megawatts of coal-fired power capacity had been added during the same period last year. Natural gas additions were cut roughly in half compared to the first half of 2013, while wind additions more than doubled and solar power increased by 70 percent. The only coal plants scheduled to come online in 2014 are the Kemper plant in Mississippi, which will capture its own carbon emissions
, and a small conventional steam coal plant in North Dakota, reflecting the challenging market for coal due to impending federal environmental regulations
and competition from natural gas.