15 Sep 2014:
Urban Air Pollution May
Affect Brains of Young Children, Study Says
Children living in areas with high air pollution are at increased risk for brain inflammation and for developing
Smog over Mexico City
neurodegenerative conditions such as Alzheimer's and Parkinson's disease, according to
a study by researchers at the University of Montana. The scientists compared brain and spinal fluids of children living in low-pollution areas to those of children living in Mexico City, an area notorious for its poor air quality. They found that children living in the city had significantly increased levels of combustion-related metals in their systems, as well as higher levels of antibodies related to inflammation. The antibodies are an indicator of autoimmune response and are possibly tied to higher risks for neurodegenerative conditions such as Alzheimer's and Parkinson's disease, according to the researchers. They say that a study following the Mexico City children as they age is needed to determine whether there is a relationship between their autoimmune responses and documented brain and cognition changes.
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.
08 Sep 2014:
U.S. Dietary Guidelines Would
Lead to Rise in Emissions, Study Says
Following U.S. federal guidelines for a healthy diet is likely to increase greenhouse gas emissions, even though the guidelines recommend a diet with less meat than the average American currently consumes, according to a recent analysis in the Journal of Industrial Ecology
. Compared to U.S. Department of Agriculture dietary guidelines, American's don't eat enough fruits, vegetables, seafood, and dairy, and they consume too much meat, eggs, nuts, soy, oils, solid fats, and added sugars. If the population were to shift its diet to match USDA guidelines, greenhouse gas emissions would actually rise by 12 percent, researchers found, because calories from meat, eggs, fats, and sugars would largely be replaced by dairy products. Methane emissions
from dairy and beef cattle contribute significantly to atmospheric greenhouse gas levels. The findings highlight a need to consider both environmental and health objectives when making dietary recommendations, the researchers say.
Interview: Calling for Moratorium
On Development of Tar Sands Oil
In a recent commentary in Nature
, aquatic ecologist Wendy Palen and seven colleagues were sharply critical of the way that Canada and the United States have gone
about developing Alberta’s vast tar sands deposits and the infrastructure needed to transport those fossil fuels to market. Rather than looking at the cumulative impact of this massive energy development on the climate and the environment, Palen and her co-authors wrote, major decisions have been made in piecemeal fashion. In an interview with Yale Environment 360
, Palen talks about why a moratorium on new tar sands developments is needed, how the decision-making process is biased in favor of short-term economic benefits, why the fate of the proposed Keystone XL Pipeline is critical, and what can be done to begin factoring in the real costs of exploiting the tar sands.
Read the interview.
28 Aug 2014:
Rail Transport of U.S. Oil Up
By 9 Percent, Creating Rail Car Shortage
The amount of U.S. oil shipped by rail rose 9 percent during the first seven months of the year compared to 2013, reaching 16,000 carloads per week in July,
according to the U.S. Energy Information Administration
(EIA). U.S. crude oil production reached an estimated 8.5 million barrels per day in June for the first time in 18 years and is driving the increase in rail transport
, the EIA said. Only 3 percent of petroleum shipped by rail in 2009 was crude oil; now crude accounts for more than half. Over the past three years, much of the oil has come from the Bakken Shale, primarily in North Dakota. Between 60 and 70 percent of the more than 1 million barrels per day of oil produced in North Dakota has been transported by rail so far in 2014, according to the North Dakota Pipeline Authority. The demand for rail cars has created a backlog that's been particularly worrisome for farmers, who say their grain is rotting before shipping space is available
to take it to market.
27 Aug 2014:
Obama Seeks Climate
Accord Without Congressional Approval
The Obama administration is aiming to forge a legally binding, international agreement that would cut fossil
fuel emissions and direct funds to poor nations dealing with climate change, without ratification from Congress, The New York Times
reports. The agreement would combine legally binding updates to an existing 1992 climate change treaty — allowing Obama to sidestep the constitutional requirement that treaties be ratified by two-thirds of the Senate — with voluntary pledges for specific emissions targets and aid to help poorer countries adapt to climate change. Nations would then be legally required to report progress toward their emissions targets at international meetings that would "name and shame" countries making slow or no progress, the Times
reports. Lawmakers from both political parties say that no climate agreement requiring congressional approval could be reached in the near future. Republican leaders are expected to oppose the agreement being worked on by the administration and say it would be an abuse of executive authority.
22 Aug 2014:
Drought in Western U.S.
Has Caused Land to Rise, Researchers Say
The western U.S. has lost so much water during the ongoing severe drought that the land has sprung up by
GPS station in California's Inyo Mountains
as much as 15 millimeters (0.6 inches), according to a study in the journal Science
. Water at the surface of the earth typically weighs down the land, but the region has lost enough water that the tectonic plate underlying the western U.S. has undergone rapid uplift, much like an uncoiling spring, researchers explain. California's water deficit over the past 18 months has caused some of its mountain ranges to rise by more than half an inch, and the West overall has risen by 0.15 inches, according to the study. Using ground positioning data from GPS stations throughout the region, researchers from the University of California, San Diego, estimate the water loss to be 240 gigatons (63 trillion gallons) — equivalent to a nearly four-inch layer of water spread out over the entire western U.S.
20 Aug 2014:
Exporting Coal to Korea Could
Slash Emissions by 21 Percent, Analysis Says
Exporting U.S. coal to South Korean power plants could cut greenhouse gas emissions by 21 percent compared to burning it at less efficient U.S. plants, according to
researchers at Duke University
. The strategy could also generate more than $25 billion in economic activity in the U.S. and cut emissions of sulfur dioxide, nitrogen oxide, and particulate matter, the researchers say. For those benefits to occur, however, U.S. plants would need to replace the exported coal with natural gas, and South Korea must use the imported coal to replace dirtier sources of coal. South Korea's coal-fired power plants are newer and significantly more efficient than those in the U.S. — efficient enough to offset emissions associated with shipping the coal across the globe, the researchers say. However, they also caution that further studies are needed to assess the scenario's full environmental impacts, including water use, land use, and the degradation of vital habitats.
19 Aug 2014:
Wind Energy Prices at
All-Time Low, According to U.S. Report
The cost of wind power in the U.S. is at an all-time low of 2.5 cents per kilowatt hour, according to a new report
from the U.S. Department of Energy, and utility companies are in some cases electing to use wind as an energy source over fossil fuels because of its low cost. Although wind power grew modestly in 2013 — installations were only 8 percent of those seen in the record year of 2012 — it now meets 4.5 percent of U.S. energy needs, producing enough electricity to power 16 million homes. The country ranks second only to China in installed wind capacity, the report says, and wind power accounts for 33 percent of all new U.S. electric capacity additions since 2007. That progress has been heavily dependent on federal, state, and local incentives, however, and wind power's growth could slow if those incentives expire. Its viability could also fall if natural gas becomes more affordable than wind, the report cautions.
13 Aug 2014:
New Maps Show Flooding
Risks for Critical U.S. Energy Facilities
A new mapping tool
shows critical energy infrastructure in the U.S., such as power plants, refineries, and crude oil rail terminals, that may be vulnerable to coastal and
inland flooding, as well as areas that may be prone to flooding in the future. The maps, created by the U.S. Energy Information Administration and the Federal Emergency Management Agency, let users see which energy facilities could be in danger of flooding caused by hurricanes, flash floods, and other weather events, including street-level results for a particular address. The maps show areas that have a 1-in-100 (1 percent) and 1-in-500 (0.2 percent) chance of flooding annually, as well as areas that might be identified in the future as having a 1-percent annual flood hazard.
11 Aug 2014:
Climate Effects of Keystone XL
Significantly Underestimated, Study Finds
The U.S. State Department's final environmental review of the Keystone XL Pipeline may have underestimated carbon dioxide emissions associated with the pipeline by as much as four times, according to
a new study published in Nature Climate Change
. The addition of Keystone XL crude oil to the market will drive global oil prices down, the authors say, which in turn will increase demand for oil worldwide — by as much as 0.6 barrels for every barrel of Keystone XL oil added to the market. The extra oil consumption could add up to 110 million tons of CO2 to the atmosphere each year, an amount four times larger than the State Department's estimate of up to 27 million tons annually, according to the study. President Obama has said he will let the pipeline proceed only if it will not "significantly exacerbate" greenhouse gas emissions. The State Department's final review determined that the pipeline's effect on climate change would be negligible, but that analysis did not take into account the increase in crude oil demand that could be sparked by Keystone XL, the authors of the new study say.
06 Aug 2014:
Western U.S. In Its Quietest
Fire Season In A Decade, Officials Report
The western U.S. is in the midst of its quietest wildfire season
in a decade, according to data from the National
Interagency Fire Center (NIFC). With 1.7 million acres burned through August 4, the 2014 fire season has destroyed well below the average of 4.4 million acres for the previous nine years through the same date. Fire season still has a few months left, however, and the year's good fortune may not last: Above normal fire potential is expected to continue
over most of California, Nevada, Oregon, Washington, and Idaho, according to the NIFC. Average temperatures have been 2 to 4 degrees above normal for most of the West; portions of the western Great Basin, northern California, and Pacific Northwest were 6 to 8 degrees warmer than normal; and exceptional drought conditions continue in California, western Nevada, and the Texas Panhandle, the center says.
04 Aug 2014:
California Takes Steps to
Curb Lawn Watering During Severe Drought
In the midst of a severe, long-term drought, California is taking unprecedented steps to discourage watering of
A drought-resistant yard
residential lawns, with some areas offering residents substantial cash incentives for installing water-saving landscaping, AFP reports
. The "Cash in Your Lawn" program in Los Angeles offers residents up to $6,000 ($3 per square foot) for replacing their lawns with drought-tolerant plants, rocks, and pebbles. Throughout the state, Governor Jerry Brown recently prohibited lawn watering more than two times per week and banned fines for brown lawns, which homeowner associations sometimes impose with the intent of improving a neighborhood's appearance. The drought, currently in its third year, threatens the water supply of California's 38 million residents. Agricultural regions
have already seen severe water reductions, placing extra pressure on the state's groundwater reserves.
31 Jul 2014:
U.S. Public and Congress Similarly
Split on Environmental Spending, Study Says
American citizens are increasingly divided over the issue of environmental protection and seem to be taking their cue primarily from Congress, according to
new research from Michigan State University. The gap between conservatives who oppose environmental protection and liberals who support it has risen drastically in the past 20 years, the study found. A national poll from 2012 (the most recent data in the study) with a question on environmental spending indicated that 68 percent of Democrats believe the country has spent too little on the environment, versus only 40 percent of Republicans. The polling data, which reach back to 1974, indicate the gap started growing particularly wide in 1992, a year after the fall of the Soviet Union. At that point, the researchers say, the conservative movement replaced the “Red Scare” with the “Green Scare” and became increasingly hostile toward environmental protection, a trend amplified in recent years by the Tea Party.
Interview: Making the Rights of
Farm Animals a Basic Green Issue
Conservation organizations have long sought to protect pandas, polar bears, and pelicans, but the welfare of
farm animals has largely been left to activist animal-welfare groups like the Humane Society of the United States
. For the past 10 years, that organization has been headed by the politically savvy Wayne Pacelle, who has greatly increased its visibility and influence. Under his leadership, the society has lobbied successfully to curb what it calls the worst excesses of “factory farms.” In an interview with Yale Environment 360
, Pacelle talked about how treatment of farm animals is linked to greenhouse gas emissions, why his group is promoting “meatless Mondays,” and why consumers should be willing to pay more for products from animals that are sustainably raised.
28 Jul 2014:
Trees Save Lives and Billions in
Health Costs Annually, Forest Service Finds
Trees are saving more than 850 human lives each year and preventing 670,000 cases of acute respiratory symptoms in the U.S., according to the first broad-scale
estimate of trees' air pollution removal by U.S. Forest Service
researchers. Looking at four common air pollutants — nitrogen dioxide, ozone, sulfur dioxide, and particulate matter with a diameter less than 2.5 microns — researchers valued the human health benefits of the reduced air pollution at nearly $7 billion annually in a study published in the journal Environmental Pollution
. The benefits of trees vary with tree cover across the nation, the researchers note. Tree cover in the United States is estimated at 34.2 percent overall, but varies from 2.6 percent in North Dakota to 88.9 percent in New Hampshire. While the pollution-removal capabilities of trees led to an average air quality improvement of less than 1 percent, the impacts are substantial, the study found.
25 Jul 2014:
Southwestern U.S. Aquifers
Are Extremely Low, NASA Data Show
Groundwater reserves in the U.S. Southwest are severely low and prospects for their long-term viability are bleak as persistent drought continues to parch the
land and prevent recharging, according to an assessment from NASA
. As shown in this map, many underground aquifers in the Southwest are extremely dry compared to average conditions over the past 60 years. Deep red areas on the map, such as in southern California and Nevada, depict aquifers that are so dry there's less than a 2 percent chance they could have experienced such levels of drought-related depletion since 1948. Although the Pacific Northwest is experiencing drought-related wildfires, its aquifers appear to be well-stocked, according to the map. The discrepancy is likely due to the long lag between dry conditions at the surface and depletion of groundwater reserves, researchers say.
16 Jul 2014:
Politics and Education Affect
When People Search for Climate Information
People across the United States search the Internet for information on climate change when they experience unusual or severe weather events, but the timing of their searches differs based on political ideology and education levels, according to
research published in the journal Climatic Change
. An analysis of Google searches and weather patterns between 2004 and 2013 found that Democratic-leaning regions and those with higher education levels were more likely to seek information about climate change when average summer temperatures were above normal, whereas those in Republican and less educated areas sought climate change information when they experienced extreme heat. Searches peaked during weather consistent with climate change as well as during cold snaps, the study found. This could indicate that people who observe unusual extreme weather conditions are genuinely interested in learning more about climate change, or that climate deniers, when experiencing unusually cool weather, go online to confirm their skeptical views, the researcher speculated.
15 Jul 2014:
California Agriculture Relying
Too Heavily on Groundwater in Drought
California's agriculture industry is relying too heavily on groundwater to irrigate drought-stricken farmlands — a trend that will not be sustainable long-term, according
Central Valley orchard
to a study
by the University of California, Davis. The drought, which is the third most severe on record, is responsible for the greatest water loss ever seen in California agriculture, with river water for Central Valley farms reduced by roughly one-third, the study found. Groundwater pumping will likely replace most river water losses, and some areas have more than doubled their pumping rate over the previous year. If the drought continues for two more years, the report says, groundwater reserves will continue to be depleted to replace surface water losses and pumping ability will slowly decrease, which could affect crop production. So far in the current drought, 428,000 acres of cropland — roughly 5 percent — has been made fallow across the Central Valley, Central Coast, and Southern California.
26 Jun 2014:
Major U.S. Retailers to Limit
Pesticides That May Be Harmful to Bees
Home Depot and other U.S. retailers announced new policies to help limit the use of a group of pesticides suspected of contributing to widespread declines in bee
New warnings on plants aim to protect bees.
populations, Reuters reports
. Under the new rules, suppliers will be required to label any plants treated with neonicotinoid pesticides, or "neonics," that are sold in home and garden stores. Home Depot will require labeling by the fourth quarter of 2014, a company vice president said, and the retailer is testing to determine whether it's feasible to eliminate neonics altogether without compromising plant health. Another retailer, BJ's Wholesale Club, which has more than 200 East Coast locations, said it will ask suppliers to eliminate neonics by the end of the year, or label plants treated with them as requiring "caution around pollinators." An analysis of 800 peer-reviewed studies released this week by an international group of scientists found that neonics have been a key factor in bee declines
25 Jun 2014:
Blizzard Helps Scientists
Visualize Airflow Around Wind Turbines
A Minnesota blizzard has helped scientists understand airflow patterns around large wind turbines, paving the way for more efficient turbine designs and wind farm
Airflow patterns are visible during blizzard.
configurations, researchers report
in Nature Communications
. Wind farms lose roughly 10 to 20 percent of the potential energy they could harvest, and complex airflow patterns play the largest role in those energy losses. Studying airflow around large turbines, which can be more than 100 meters tall, is not feasible in lab settings, so scientists typically test smaller turbine models in wind tunnels and use tracer particles to visualize airflow patterns. Researchers from the University of Minnesota realized they could scale up their experiments to real-world conditions by using heavy snowfall during a blizzard to trace airflow patterns, as shown in this video. Their findings show that airflow patterns under real-world conditions differ from smaller-scale laboratory tests in important ways, and those differences should be taken into account when designing turbines and wind farms.
20 Jun 2014:
Summer Temperatures in U.S.
Have Risen Up To 5 Degrees Since 1970
Summer temperatures in the U.S. have been rising on average 0.4 degrees F per decade since 1970, or about
2 degrees F overall, but the Southwest and West regions have borne the brunt of those increases, according to an analysis by Climate Central
. In the Southwest, temperatures have risen an average of 0.6 degrees per decade, with a few localized areas warming as much as 0.9 degrees per decade. In the West, some parts of California and Nevada have warmed 1.32 degrees F per decade, or more than 5 degrees total since 1970. On the other end of the spectrum, the Upper Midwest has seen the lowest increases. Temperatures in that region have increased only 0.1 degree F per decade on average. The National Climate Assessment
, released last month, found that annual average temperatures in the U.S. could increase by 10 degrees F before the end of the century if the rate of greenhouse gas emissions doesn't slow.
13 Jun 2014:
U.S. Energy System Depicted
In New Mapping Tool from Federal Agency
The U.S. Energy Information Administration (EIA) recently launched a mapping system
that allows users to
explore the landscape of energy sources and power plant distribution across the nation. Among the most striking visualizations is this map showing the widespread distribution of natural gas power plants, marking the fossil fuel's growing use as an energy source. The U.S. had 1,714 natural gas power plants in 2012, accounting for 30 percent of the country's electricity generation, Vox reports
. Natural gas plants are easier to build and emit fewer pollutants and roughly half as much CO2 as coal-fired plants. The EIA maps depict numerous aspects of the U.S. power system, including the distribution of wind turbines, solar installations, nuclear power plants, coal-fired plants, hydropower stations, and pipelines. More energy maps
are available at Vox, or users can create their own with the EIA's tool.
12 Jun 2014:
U.S. Breweries Cut Water
Use Amid Widespread Drought Conditions
Major breweries in the U.S. are cutting back on the amount of water they use to brew beer as drought threatens their water supplies, the Associated Press
reports. MillerCoors, headquartered in Chicago, has reduced its water use by 9.2 percent since 2012, a company sustainability report said. Earlier this month St. Louis-based Anheuser-Busch, the largest U.S. brewer, reported that it has cut water use by 32 percent in the last five years. Employing strategies such as fueling boilers with wastewater, recycling water used to clean bottles and cans, and installing sensors to fine-tune irrigation in hop and barley fields, MillerCoors has cut water use to 3.48 barrels of water for each barrel of beer, the company says. The company is also giving $700,000 to landowners in the watershed of its Fort Worth brewery who make efforts to curb erosion and runoff by, for example, planting native grasses or rotating cattle grazing lands. Craft breweries typically use twice as much water as major breweries per barrel of beer, the AP notes, because they are smaller in scale and don't have access to the same technology.
11 Jun 2014:
Group Will Pay Farmers
To Create Temporary Migratory Bird Habitat
started by The Nature Conservancy aims to enlist California farmers in creating temporary habitats for migrating birds — a partnership that could become
more important as the state's long-term drought continues and the birds' wetland habitats dwindle. Using crowdsourced data, The Nature Conservancy (TNC) tracks the paths of migratory birds on their annual journey from Canada to South America to determine where and when the birds will need suitable wetland habitat for stop-overs in California's Central Valley. Then, in a sort of reverse auction, TNC asks farmers how much they would charge to temporarily flood their land to accommodate the birds, and pays farmers with the lowest bids to do so for a few weeks or months. The Nature Conservancy says the year-old program has been a success, enabling the organization to rent habitat for roughly 0.5 to 1.5 percent of what permanent protection costs. The program's budget is $1 million to $3 million annually. Forty farmers flooded roughly 10,000 acres last year, and sightings of key migratory bird species were 30 times above average, according to TNC.
09 Jun 2014:
Air Conditioning Can Raise
Urban Nighttime Temperature by 2 Degrees
Excess heat from air conditioners raises outdoor temperatures at night by nearly 2 degrees F (1 degree C), worsening the urban heat island effect and increasing cooling demands, according to research
from Arizona State University. Studying the Phoenix metropolitan area, researchers found that air conditioning systems pumped more waste heat into the air during the day, but the effect on near-surface temperatures was negligible. The same was not true for nighttime temperatures, however, when waste heat significantly boosts air temperatures because of nighttime atmospheric conditions. Air conditioning systems can consume more than 50 percent of total electricity
during extreme heat, the researchers note, and summertime extreme-heat days are projected to become more frequent and intense as a result of climate change. Redirecting waste heat from air conditioning systems to household appliances such as water heaters, for example, could help alleviate the problem, the scientists say. They project that such strategies would save at least 1,200 to 1,300 megawatt-hours of energy per day in the Phoenix metropolitan area alone.
Interview: The Small College That
Launched Fossil Fuel Divestment
When Stanford University announced in May that it would divest its endowment of coal mining companies, it was following the lead of a tiny college in rural Maine
that dubs itself “America’s environmental college.” A year and a half earlier, Stephen Mulkey, the president of Unity College
stood on a stage with Bill McKibben, the founder of 350.org and lead cheerleader for the divestment movement, to announce that his college would be the first institution of higher learning to rid its endowment of all fossil fuel holdings. In an interview with Yale Environment 360
, Mulkey, a climate scientist, talks about the ethical imperative behind the decision to divest, and his vision for, as he puts it, a re-engineering of the way the environmental sciences are taught.
05 Jun 2014:
Coating for Roof Tiles Could
Help Clear Smog-Causing Air Pollutants
Engineering students have created a roof tile coating
that, when applied to an average-sized residential roof,
Coated tiles (left) and an uncoated tile (right).
breaks down the same amount of smog-causing nitrogen oxides per year as a car driven 11,000 miles makes. If applied to one million roofs, the titanium-dioxide based coating, which costs roughly $5 per roof, could clear 21 tons of nitrogen oxides each day, the team calculated. That could put a noticeable dent in atmospheric levels of the pollutant; in Southern California, for example, an average of 500 tons of nitrogen oxides are emitted daily. The team, which was recently recognized in a U.S. Environmental Protection Agency student design contest, showed that their tiles could remove 88 to 97 percent of nitrogen oxides in laboratory tests — a feat that other roof tile prototypes have not demonstrated.
02 Jun 2014:
New U.S. Coal Plant Rules
Could Lead to a Steep Drop in Emissions
The Obama administration today unveiled a sweeping new plan
that aims to cut carbon dioxide emissions from the nation’s 600 coal-fired power plants by roughly a third. Gina McCarthy, administrator of the U.S. Environmental Protection Agency, said the new rules would give states maximum flexibility
to achieve the goal of reducing power plant emissions 30 percent below 2005 levels by 2030. Hundreds of coal-fired power plants are expected to close under the EPA plan. But rather than immediately shutting down plants, states would be allowed to reduce emissions by making changes across their electricity systems — by installing new wind and solar generation or energy-efficiency technology, continuing to expand the use of natural gas, and by starting or joining state and regional “cap and trade” programs. “There is no one-size-fits-all solution ... so each state’s path can be different,” said McCarthy. The proposed regulations could be held up by legal challenges. Obama administration officials said the rules would lift the U.S. into a clear global leadership position
on combating global warming.
30 May 2014:
New Battery Technology
Could Offer Cheap Renewable Energy Storage
New battery technology that uses cheaper and safer materials to store large amounts of energy may soon enable utility companies to use more renewable power,
Iron-chromium flow battery technology
MIT Technology Review. The new device is a type of flow battery, and it uses liquid materials that rely on iron-chromium chemical reactions to store energy. California-based startup Enervault, developer of the new battery, figured out how to use materials that had been tried in batteries decades ago; Enervault overcame a key technical challenge that had caused the earlier batteries to quickly degrade. The new battery is large — it can store one megawatt-hour of electricity, or enough to run 10,000 100-watt light bulbs for an hour — and the materials last more than 20 years, according to its developer. Although the battery is inefficient compared to conventional batteries — it loses 30 percent of the energy used to charge it — it is still economically viable, the company says. The iron-chromium flow battery costs 80 percent less than vanadium flow batteries, a competing technology. The batteries are currently in use at a small power plant near Modesto, California.