Tuesday, 15 April 2008

Intelligent Design? Utilities Embrace An Efficiency Evolution



 
 

Sent to you by vetkasi via Google Reader:

 
 


Energy Flow ChartKara Mertz tries to run an eco-conscious home. She buys wind energy credits to offset her electricity usage, and she owns a solar water heater. But her carbon footprint is still significant, thanks in part to the 20 gadgets her teenage son is constantly recharging.

Fortunately for Mertz, her hometown of Boulder, Colorado may soon have options that allow far greater control over energy use. Last month, power company Xcel Energy selected Boulder to become the world's first "Smart Grid City," an experiment in one of the latest efficiency technologies. If the new system generates enough savings to rationalize the high implementation cost, a revolution of energy-efficient power grids and improved renewable energy use may sweep the world.

"How much of [my son's electronics] are sucking off the grid and we don't realize it?" said Mertz, who serves as assistant to the city manager. "If all of a sudden we look at where money is going, it's very enlightening."

Grid of the Future

Smart grids rely on advanced metering systems to form a direct connection between residents and power companies. Based on a home's average electricity use, the meters calculate the next day's expected electric bill, identify how much power various appliances require, and provide homeowners with options to reduce their energy costs. The homeowner can then, for example, turn off the pool heater when electricity is most expensive, or use air conditioning when electricity is cheapest - making it possible to coast through the "peak" hours of high electricity demand.

The advanced meters also tell utility companies as soon as a power outage occurs. This instantaneous information allows the utility to address problems faster and prevent massive blackouts by rerouting electricity around the grid's troubled areas.

"One aspect [of a smart grid] is that it can help promote energy efficiency; another is it can help improve reliability...it's multi-dimensional," said Don Von Dollen, a smart grid program manager at the Electric Power Research Institute (EPRI) in Palo Alto, California. EPRI estimates that power outages and power quality disturbances alone cost U.S. businesses more than $120 billion a year.

The "grid of the future" may also fuel an increase in renewable energy demand. Currently, wind turbines or solar panels generally feed into the grid only when the wind blows or the sun shines. But with smart grids, a utility may be able to "turn off" natural gas or coal-fired power plants at times when renewably sourced energy is available-and re-route the power, Von Dollen explained. This is much more efficient for the power companies, he said.

For years, energy-efficiency education campaigns have struggled to motivate widespread reductions in energy use. Smart grids, in contrast, offer a way for consumers to directly realize the economic benefits of efficiency, potentially spurring greater action. To research the effects of smart grids on consumer purchasing behavior and energy use, Xcel Energy will collaborate with the University of Colorado at Boulder. "It's a case study of such an important environmental aspect," said Alison Peters, managing director of the university's Deming Center for Entrepreneurship.

The Challenge Ahead

Minnesota-based Xcel Energy selected Boulder for its pilot initiative due to the town's geographic isolation, population size, and technologically savvy and environmentally conscious residents. In recent years, Boulder has ratified the Kyoto Protocol, passed America's first city-wide carbon tax, and even purchased the URL http://www.environmentalaffairs.com/ to link to the municipality's Web site.

City officials are hoping the Smart Grid project will help Boulder meet its carbon-cutting goals. The city's 2006 greenhouse gas emissions inventory showed an increase in emissions over 2005, with as much as 61 percent of the total coming from electricity generation. "We love being the guinea pig," Mertz said. "There's a critical mass of people in this community who are interested in how they're using their energy."

Xcel's $100 million experiment in Boulder is the first city-wide showcase of the various smart grid technologies now available. In California and Texas, power companies are installing certain elements of smart grid technologies, such as updating millions of meters. Both states forced the changes and are compensating utilities for some of the immediate costs. The price of converting only portions of California residents' meters is estimated at $3 billion.

"Just changing millions of meters is a huge job," said Tom Nelson with the National Institute of Standards and Technology, who standardizes electricity meters. "It's not just changing out the meter. They have to communicate which meter is at which house for the billing department."

Other U.S. states and some parts of Europe are also developing smart grids. "A lot of other states are watching what goes on in Texas and California to see if they should follow them or learn from them," Von Dollen said. "There's a greater urgency within Europe than there is in the U.S. But as far as deployments, the U.S. is a little farther ahead."

According to Kurt Yeager, director of the Galvin Electricity Initiative, a campaign to improve the U.S. grid system, despite incentives provided in the recent energy bill, more government involvement is needed at the federal level. "The biggest impediment to the smart electric grid transition is neither technical nor economic," Yeager told a Congressional committee last year. "Instead, the transition is limited today by obsolete regulatory barriers and disincentives that echo from an earlier era."

In 2007, carbon dioxide emissions from U.S. power plants jumped 2.9 percent, the greatest single-year increase since 1988. They have risen 11.7 percent since 1997 as the demand for electricity continues to rise, according to U.S. Environmental Protection Agency data.

Ben Block is a staff writer at the Worldwatch Institute who covers everything environmental for Eye on Earth. He can be reached at bblock@worldwatch.org.


 
 
 
 
Posted by at No comments:

More Companies Discontinuing Farm Animal Confinement



 
 

Sent to you by vetkasi via Google Reader:

 
 


Veal crateMore companies around the world are adjusting their farm-animal confinement policies and requesting clarification of consumer labels to reflect these changes. The moves come largely in response to U.S. voter-led initiatives and the implementation of farm policy reforms in the European Union.

Animal confinement - forcing dense populations of chickens, pigs, or young cattle into cages, crates, or tight pens to more efficiently utilize farm space - is a common practice in the United States, Europe, and increasingly the developing world. Led by growth in China, Brazil, and India, industrial livestock production has grown at twice the rate of traditional forms of animal husbandry, according to a United Nations Food and Agriculture Organization report. The World Society for the Protection of Animals expects factory farming in those countries to "explode," placing billions more animals into confinement.

Growing public awareness of the environmental, public health, and animal welfare challenges associated with animal confinement has lead several major grocery stores, fast food chains, and meat producers to phase out some of these practices. U.S. companies that have responded to consumer concern in recent years include Safeway, North America's third largest grocery retailer; leading pork producer Smithfield Foods; and hamburger giant Burger King.

Mounting legislation is forcing companies to curtail confinement as well. The E.U. voted to ban veal cages, breeding pig crates, and windowless "battery cages" for hens, and the laws first went into effect last year. A campaign is now under way in the largest U.S. agricultural state, California, to hold an animal welfare referendum during the November election. A handful of other U.S. states have passed bans on veal and pregnant sow crates, but the California initiative would make it the first to outlaw all three confinement practices.

"There's a big ripple effect. These laws...send a signal to industry all across the country that accelerates progress nationwide," said Paul Shapiro, senior director of the factory farming campaign with the Humane Society of the United States. The Humane Society has been organizing several of the state ballot initiatives and pressuring companies to change their practices. "The problem isn't persuading Americans that crates are inhumane. The problem is getting bills through...agricultural committees that kill [the bills]."

At a time when 73 percent of emerging human diseases are derived from animals, placing farm animals in constant close contact has led to bacterial resistance and other health concerns. Concentrated animal waste can pollute waterways with high nitrogen and phosphorus loads, and both manure and livestock release methane, a greenhouse gas more potent than carbon dioxide. Close confinement can interfere with natural animal tendencies as well. "It's the lack of normal behavior in confinement that I find most disturbing: chickens pecking at each other, pigs gnawing on cages," said Alan Goldberg, a professor of toxicology at Johns Hopkins' Bloomberg School of Public Health.

Businesses that oppose animal confinement have requested that the U.S. Department of Agriculture (USDA) establish a "naturally raised" label for meat and other animal products, to differentiate from the current "natural" label, which they say is misleading. Chipotle Mexican Grill, the country's largest restaurant seller of naturally raised meat, is among businesses that note that while "natural" addresses how the meat is processed, it does not provide information on how the animals are raised, such as whether they are confined.

The "naturally raised" label that is currently being proposed, however, refers mainly to how an animal is fed or medicated, and would still allow farms to utilize conventional confinement operations. Thousands of organic food companies and consumer advocates have submitted complaints that the label would be deceptive, which the USDA is now reviewing. "Review of consumer research and comments indicate that the prohibited use of antibiotics, growth promotants, and animal by-products are the main factors consumers associate with meat and meat products from livestock they perceive as naturally raised," said Martin O'Connor, chief of the agency's standards, analysis, and technology branch in their marketing service's livestock program, in a presentation he delivered last year to the meat industry. O'Connor said the agency should announce a decision by August 1.

To address the many concerns associated with factory farming, including confinement, the Pew Commission on Industrial Farm Animal Production will release suggested changes at the end of this month. Although the commission is focused on U.S. industries, as meat consumption increases internationally and as industrialized countries import more livestock from the developing world, the report could have implications for shaping sustainable animal welfare policies worldwide, said Emily McVey, the commission's science advisor.

"More of our food is coming from other parts of the globe: Asia and South America," said Michael Blackwell, a member of the commission and former U.S. chief veterinarian. "Better [U.S.] public policy is needed to improve other sources from around the world."

Ben Block is a staff writer at the Worldwatch Institute who covers everything environmental for Eye on Earth. He can be reached at bblock@worldwatch.org.


 
 
 
 
Posted by at No comments:

Wind Power Growth Blows Past Projections



 
 

Sent to you by vetkasi via Google Reader:

 
 


Washington, D.C.-Global wind power capacity rose 27 percent in 2007 to more than 94,100 megawatts, led by capacity additions in the European Union, the United States, and China, according to the latest Vital Sign Update from the Worldwatch Institute.

New wind installations were second only to natural gas in the United States as an additional source of power capacity and were the leading source of new capacity in the EU. In China, the estimated 3,449 megawatts of wind turbines added last year propelled China past the government's ambitious wind power target for 2010.

The addition of a record-breaking 5,244 megawatts of wind capacity in the United States in 2007-enough to power 4.5 million U.S. homes-was driven by the federal production tax credit and by renewable energy mandates in 25 states and the District of Columbia. The nation's wind capacity now totals 16,818 megawatts, second only to Germany. The production tax credit is set to expire at the end of this year. "If Congress acts quickly to extend the tax credit, the U.S. will likely pass Germany to lead the world in wind power within the next two years," according to Janet Sawin, a Worldwatch senior researcher and the author of the update.

Germany remains the world leader in wind power capacity, with almost 24 percent of the global total (22,247 megawatts), but it experienced a lackluster year in 2007. Still, renewable energy resources now generate more than 14 percent of Germany's electricity needs, with about half of this coming from wind. Spain led Europe in new installations in 2007, now ranking third worldwide in total wind capacity (15,145 megawatts). France, Italy, Portugal, and the United Kingdom all experienced significant growth last year as well. In all, EU wind power capacity rose 18 percent in 2007, and the region is home to 60 percent of global installed capacity.

China was the biggest surprise in 2007. Barely in the wind business three years ago, China trailed only the United States and Spain in new wind installations in 2007, and ranked fifth in total installed capacity (6,050 megawatts). However, an estimated one-fourth of this capacity remains unconnected to the grid due to planning problems.

This explosive growth occurred amidst a backdrop of serious turbine shortages, a challenge that is expected to be ameliorated sometime in 2009. Despite higher costs due to turbine shortages, rising material costs, and increased manufacturing profitability, wind power remains competitive with new natural gas plants, and all conventional power plants have seen similar construction-cost increases. Wind power will become increasingly competitive with coal as more countries put a commodity price on carbon.

The global wind market was worth an estimated $36 billion in 2007, accounting for almost half of all investment in new renewable electric and heating capacity. As many as 200,000 people are now employed in the wind industry worldwide. These numbers will only rise in the coming years as the EU seeks to meet aggressive 2020 targets for renewables and as the United States, China, and other nations realize their enormous potential for wind power.

"The wind industry has consistently blown by past projections," says Sawin, "and it will likely continue to do so for years to come."


 
 
 
 
Posted by at No comments:

Can Amazonian Beef Be Sustainable?



 
 

Sent to you by vetkasi via Google Reader:

 
 


The second article in a three-part series exploring the growing pressures facing the Amazon forest and its people. Read part one, "In Brazil, Violence Looms at the Forest Edge".

Amazonian cattle ranchingOne of Brazil's largest beef-export companies is expanding its Amazon operations, thanks in part to funding from the World Bank's private sector arm, the International Finance Corporation. The IFC says its investment is part of an historic effort to make cattle ranching in the region more sustainable, but many environmentalists are skeptical.

The $90 million investment will help Bertin Ltda., Brazil's leading beef and hide processor, expand its slaughterhouse in the southern Amazonian state of Pará-an area marred by illegal deforestation and ranch expansions, some of which have turned violent in recent years. To ensure that the cattle are not raised on illegally acquired land and without harm to the forest, Bertin has agreed to demand environmental permits for each lot of livestock that enters the facility.

"This will result in more efficient use of pasture land, and ultimately raise suppliers' income and reduce pressure on critical forest resources," said Karina Manasseh, an IFC spokeswoman.

Environmentalists, however, have raised concerns that the project lacks transparency and that the investment will only worsen deforestation, exploitative labor, greenhouse gas emissions, and illegal land grabbing. The IFC has acknowledged that these issues are potentially problematic with Bertin's operations, but it says the new system will prohibit the processing of cattle purchased from ranches that do not follow the strict regulations.

The debate comes as Brazil's livestock industry is booming, especially in the Amazon. In 2003, Brazil became the world's largest exporter of beef, and second in overall beef production according to a report from Amigos da Terra, the Brazilian affiliate of Friends of the Earth. Ten million Amazonian cattle were slaughtered last year, 46 percent more than during 2004.

The growth in global demand for beef was the primary cause of a 60 percent increase in deforestation during the later months of 2007. And as the ranches have expanded over the past decade, forest clearings contributed between 9 and 12 billion tons of greenhouse gas emissions, the Amigos da Terra report said.

Bertin's ability to monitor whether its suppliers comply with the IFC's environmental and labor criteria is dependent on an internal tracking system that the slaughterhouse will administer. A pilot project has begun that will include about 500 ranchers, but it is not yet clear how Bertin will ensure that each ranch is accurately disclosing the origins of its cattle, including how and where it was raised.   

Critics of the IFC scheme say it will be near impossible to determine whether ranchers are selling cattle raised on sustainable pastures. "Bertin has many potential suppliers of beef; it's very difficult to keep track of all these small ranchers, even the big ones," said Robert Goodland, a former World Bank advisor and now a senior fellow at the World Resources Institute. "And Bertin doesn't really want to check up too thoroughly, otherwise it wouldn't be able to get all the beef it needs. So there's no incentive to follow the law."

Amigos da Terra director Roberto Smeraldi also criticized the IFC investment, saying the sites chosen for the Bertin project's environmental assessment did not accurately reflect the potentially wide-sweeping damage to the region that the expanded operation could bring. "[The IFC] cannot just have this type of superficial approach to what's the end use of their money when...you have all sorts of issues of legality for the environment, labor rights, land tenure," Smeraldi said.

Daniel Nepstad, an ecologist with the U.S.-based Woods Hole Research Center, disagrees. Nepstad is organizing the sustainable purchasing operations for Bertin through the Amazon Institute for Environmental Research, and he said the slaughterhouse could easily have found non-IFC funding. But Bertin opted to follow the IFC guidelines to better position itself as a responsible producer in a competitive global market, Nepstad said. "Capital for this company is insignificant."

Nepstad says the project will ultimately force ranchers who follow illegal practices to sell their cattle to slaughterhouses that are located farther away, and that often offer lower compensation, than Betin's operation. He says this will provide further incentives for ranchers to comply with the IFC's and other guidelines.

Yet in the Amazon, as elsewhere, it may still cost more to play by the rules. If ranchers want to convert already-cleared land into pasture, this requires the use of fertilizer and significant water resources, at a price tag four times higher than if they were to illegally clear new land. "It's cheaper to deforest new areas than to invest in recuperating," Smeraldi said.

Nepstad said proper incentives need to be made available to convince ranchers to stop deforestation, such as national or international conservation funds. "We need to make it viable for land owners to legalize their operations," he said.

Ben Block is a staff writer at the Worldwatch Institute who covers everything environmental for Eye on Earth. He can be reached at bblock@worldwatch.org.


 
 
 
 
Posted by at No comments:

Tuesday, 8 April 2008

Pursuing Conservation Tillage Systems - George Kuepper (2001)


This takes a brief look at conservation tillage as it may be applied to organic cropping systems. It describes a number of the most promising strategies and technologies with focus on annual cropping systems.
Posted by at No comments:

Nitrogen & Phosphorus Removal

Biological Nitrogen Removal
Nitrogen appears in organic wastes in various forms. In wastewater, four types of nitrogen are common: organic nitrogen, ammonia nitrogen, nitrite nitrogen, and nitrate nitrogen. These different forms constitute the total nitrogen content. The predominant forms of nitrogen in wastewater are organic nitrogen and ammonia (NH3). Organic nitrogen is converted to ammonia in the first step of the nitrogen cycle. In order to remove nitrogen from wastewater, the ammonia must be oxidized to nitrate (NO3). This process is commonly referred to as nitrification. An oxic environment must be maintained for a sufficient period of time to promote nitrification.At the Water Reclamation Facility, oxic conditions are maintained by a number of rotor surface aerators. In the presence of dissolved oxygen, the microorganisms convert stored BOD (biochemical oxygen demand) to CO2, water, and increased cell mass. Biological nitrification occurs, producing nitrite in an intermediate step and ultimately producing nitrate. Following nitrification, nitrogen can be removed from the wastewater by reducing the nitrate to nitrogen gas (N2), which is released to the atmosphere. This process is commonly referred to as denitrification. Denitrification requires anoxic conditions, as well as an organic carbon source, to proceed. Introducing an anoxic zone into the flow scheme provides for denitrification of nitrate. In this zone, operated with no dissolved oxygen (DO), the endogenous oxygen demand of mixed liquor suspended solids (MLSS) plus the carryover of BOD (biochemical oxygen demand) from the anaerobic zone causes denitrification of the nitrate produced in the aerobic zone. During anoxic conditions, dissolved oxygen is not available to the microorganisms for respiration. Because of this, the oxygen molecules are stripped from the nitrate, causing the production of nitrogen gas(N2) . Carbon dioxide and water are also produced in the process, which results from the degradation of BOD. In addition, a portion of the alkalinity consumed during the nitrification process is restored through the denitrification process. When the mixed liquor flows to the secondary anoxic zones, there will be a relatively small concentration of extra cellular BOD in the wastewater. However, denitrification will still proceed since the microorganisms utilize internal storage products to reduce nitrate (endogenous denitrification).
Biological Phosphorous Removal
Phosphorus is an essential element in the metabolism of organic organisms. A minimal concentration is necessary to achieve optimum operation of biological treatment systems. The BioDenipho process incorporates anaerobic selector technology to promote biological phosphorous removal from the wastewater. It combines the flexibility and energy efficiency of the BioDenitro Process with the advantages offered by an anaerobic selector. This results in a highly-efficient Biological Nutrient Removal (BNR) system. A three-stage anaerobic selector is incorporated prior to the distribution chamber. The anaerobic residence time is approximately 3 hours based on a flow of 3.0 MGD for U.F. Water Reclamation Facility. This is not long enough to promote the buildup of sulfides or other noxious products associated with anaerobic treatment processes. Each stage of the anaerobic selector contains a submerged mixer designed to provide gentle agitation of the mixed liquor while minimizing turbulence at the liquid surface. The mixer is driven by a gear-reduced, waterproof submerged motor. Aeration of the mixed liquor in the oxidation ditch can be provided in a number of ways. The most common method is to intensely agitate the surface of the liquid, which is open to the atmosphere, with a large brush aerator. There are many variations in the type of equipment employed; however, all aeration systems have the common purpose of vigorously mixing an oxygen-containing gas with the mixed liquor. Submersible mixers are used in the anaerobic zones, oxidation ditches and secondary anoxic zone. Maxi-rotors are used for aeration in the oxidation ditches. Centrifugal pumps are used for return activated sludge pumping. The anaerobic selector separates activated sludge metabolism into two steps: BOD uptake and BOD oxidation. The return activated sludge (RAS) enters the anaerobic selector, where it is mixed with influent wastewater. By passing the RAS and influent through the anaerobic selector, microorganisms capable of using stored polyphosphate as an energy source are proliferated. This energy is used to transport BOD into their cellular structure when free or combined forms of oxygen are not available for respiration. In the anaerobic zone, where substrate (BOD) concentration is high, the absence of oxygen causes the microorganisms to release the stored intracellular polyphosphates by decomposition to simple orthophosphates. The decomposition of polyphosphate to orthophosphate results in an increase of soluble phosphorus in the mixed liquor and also releases energy. The energy is used by the microorganisms to transport soluble BOD through the cell wall and store the soluble BOD inside the cell. Thus, the BOD concentration in the mixed liquor is reduced without the use of oxygen. Typically, the anaerobic selector is a three-or-four stage reactor equipped with submersible mixers to maintain biosolids in suspension. Return activated sludge (RAS) is discharged to the first stage selector, while raw influent is directed to the second stage. By staggering the RAS and raw wastewater influent location, the volatile fatty acids and soluble BOD, which promote phosphorous release, are not consumed during RAS denitrification. As an added benefit, the anaerobic selector inhibits the growth of filamentous bacteria that cause bulking sludge. In the subsequent anoxic phases, nitrates are present from prior oxic phases. Microorganisms capable of biological denitrification are favored in this phase. The carbon source required for biological denitrification is provided by the BOD in the influent wastewater; no additional carbon source is required. In the oxic phase, the organisms in the presence of dissolved oxygen convert the stored and extracellular BOD to CO2, water, and increased cell mass. A portion of the energy from this reaction then goes to recreating the intracellular polyphosphate using the orthophosphate released in the anaerobic zone. Since new cells are grown, the amount of phosphate removed from solution is greater than the amount previously dissolved in the anaerobic zone, thus affecting net phosphate removal. In the second stage, denitrified RAS is contacted with the influent wastewater in the absence of free or combined forms of oxygen. The anaerobic environment stresses the microorganisms, which begin to break down stored polyphosphate into orthophosphate. Throughout the remainder of the anaerobic selector, orthophosphate is expelled from the microorganisms releasing energy that is used to absorb BOD into their cells. In subsequent anoxic and oxic phases, the BOD is oxidized and the cells reproduce. In the oxic phases, these new cells, along with old cells, replenish the phosphorous reserved within their cells. This results in a net phosphorous uptake. Phosphorus removal from the wastewater is ultimately achieved by wasting phosphorous-rich sludge from the system. Phosphorous is removed from the system as a fixed biological material in the waste sludge. The amount of phosphorous in the sludge will be dependent upon the amount of BOD and phosphate in the influent and the volume of sludge produced.
Next: BioDenipho Phases
Posted by at No comments:
Subscribe to: Posts (Atom)