Vertical-Axis Wind Turbines

Sandia National Laboratories' wind energy researchers are re-evaluating vertical axis wind turbines (VAWTs) to help solve some of the problems of generating energy from offshore breezes.

Though VAWTs have been around since the earliest days of wind energy research at Sandia and elsewhere, VAWT architecture could transform offshore wind technology.

The economics of offshore windpower are different from land-based turbines, due to installation and operational challenges. VAWTs offer three big advantages that could reduce the cost of wind energy: 1) a lower turbine center of gravity; 2) reduced machine complexity; and 3) better scalability to very large sizes.

A lower center of gravity means improved stability afloat and lower gravitational fatigue loads.
Additionally, the drivetrain on a VAWT is at or near the surface, potentially making maintenance easier and less time-consuming. Fewer parts, lower fatigue loads and simpler maintenance all lead to reduced maintenance costs.

Large offshore VAWT blades in excess of 300 meters will cost more to produce than blades for onshore wind turbines. But as the machines and their foundations get bigger -- closer to the 10-20 megawatt (MW) scale -- turbines and rotors become a much smaller percentage of the overall system cost for offshore turbines, so other benefits of the VAWT architecture could more than offset the increased rotor cost.

However, challenges remain before VAWTs can be used for large-scale offshore power generation.
Curved VAWT blades are complex, making manufacture difficult. Producing very long VAWT blades demands innovative engineering solutions. (Science Daily, 7/30/2012)

Chicago Bridge & Iron Co. To Buy Rival Shaw Group Inc.

Chicago Bridge & Iron Company (CB&I) agreed to buy rival Shaw Group Inc. (SGI) in a $3 billion deal that will create one of the world's biggest energy infrastructure companies.  The combined company, to be called CB&I Shaw, will be involved in everything from building nuclear power plants in the U.S. and China to constructing gas-processing plants and oil storage tanks globally.

It will have a $28 billion order backlog of projects in the oil, gas and electric industries, including about $18 billion coming from Louisiana-based Shaw, one of that state's largest and most politically influential firms.  The acquisition will give CB&I, which is more focused on the oil-and-gas-business, better access to lucrative and potentially growing projects in the electric-power industry.

Utilities in coming years are expected to spend billions of dollars building new power plants and retrofitting coal-burning plants to meet tougher antipollution regulations.

The addition of Shaw also is expected to allow CB&I to reduce its revenue volatility, in part because Shaw gets more of its money from relatively stable and predictable work such as providing maintenance and retrofitting services to the power industry. Shaw supplies services to about 40% of the 104 nuclear reactors operating in the U.S. and many conventional power plants.Shaw is helping build four nuclear reactors in Georgia and South Carolina, for Southern Company and Scana Corporation. It also has a profitable division that furnishes disaster-recovery services to the federal government, such as work it performed following Hurricane Katrina.

CB&I was founded in 1889 in Chicago and pushed west, building tanks for the water storage that was needed by growing towns and expanding railroads. It soon branched into oil and refined product tanks as the oil and gas industry took off. Currently, about 80% of CB&I's revenues come from outside the U.S., but that will drop to about 50% with the addition of Shaw, which is more focused on the domestic market. (WSJ, 7/30/2012)

Green DMV Demos GM's 2013 Hybrid Escalade

Coqui Brand in association with GreenDMV got the privilege to showcase GM's 2013 Hybrid Escalade.

Taking Green a step further.

Song: The Recipe - Kendrick Lamar ft. Dr. Dre

Portable & Standby Generators

Portable generators are sold at home centers and tool companies and cost several hundred dollars to about $1,000. Most run on gasoline, though some run on propane in canisters, like backyard grills. With a portable generator, you can plug in heavy-duty extension cords (the number of outlets will depend on the generator) and run them directly to the equipment you consider most crucial. Or you can get by with a single extension cord if you install a power transfer switch in your house to direct the power to specific circuits.

To guard against carbon monoxide poisoning, you must run a portable generator outside and well away from windows and doors. Running it in the garage is also out because the exhaust can work its way inside even if the big door is open. And don’t even think of modifying an extension cord so you can plug the generator into a house outlet. Generator power needs to bypass the house wiring completely (by running extension cords directly to appliances) or go through a transfer switch, which also acts as a one-way gatekeeper that prevents the current from energizing your home’s transmission line and shocking an electrician working to restore power to your neighborhood.

Built-in standby generators are permanently installed outside, like air conditioners. Instead of running off gasoline, these generators run off natural gas or, where that isn’t available, propane. Assuming the connection isn’t to a tiny propane tank, either option means that standby generators can essentially run as long as they’re needed. Standby units also switch on and off automatically. And they are always wired to a transfer switch, so you never have to snake out extension cords. You can set up the system to power just a few circuits, or all of them, meaning you can weather a long power outage almost without changing your routine. Running a generator does add noise, though, although standby units are quieter than portables because they are more enclosed. Locating the generator in an insulated enclosure reduces the sound even more.

But the convenience of automatic standby power comes at a price: Installed units often come to about $10,000, though you can shave off a few thousand dollars by going with a small unit that powers just a few circuits.

In general, a 5,000-watt portable generator is the minimum that’s worth getting to back up vital systems. That’s enough for a fridge, a few lights and even a room air conditioner. Built-in systems start about 7,000 watts, but to keep central AC running, you’ll probably need 17,000 watts to 20,000 watts. Above that, the price jumps because higher-power generators need liquid coolant, not air.
(Wash Post, 7/18/2012)

Obama Administration Roadmap To Solar on Public Lands

As part of President Obama’s all-of-the-above energy strategy, the Department of the Interior, in partnership with the Department of Energy, will publish the Final Programmatic Environmental Impact Statement (PEIS) for solar energy development in six southwestern states—Arizona, California, Colorado, Nevada, New Mexico, and Utah. The final Solar PEIS represents a major step forward in the permitting of utility-scale solar energy on public lands throughout the west.

When President Obama took office, there were no solar projects permitted on public lands; since 2009, Interior has approved 17 utility-scale solar energy projects that, when built, will produce nearly 5,900 megawatts of energy—enough to power approximately 1.8 million American homes.

The Solar PEIS will serve as a roadmap for solar energy development by establishing solar energy zones with access to existing or planned transmission, the fewest resource conflicts and incentives for development within those zones. The blueprint’s comprehensive analysis will make for faster, better permitting of large-scale solar projects on public lands.

The Solar PEIS planning effort has focused on identifying locations on Bureau of Land Management (BLM) lands that are most suitable for solar energy development. These areas are characterized by excellent solar resources, good energy transmission potential, and relatively low conflict with biological, cultural and historic resources.

The Final PEIS identifies 17 Solar Energy Zones (SEZs), totaling about 285,000 acres of public lands, as priority areas for utility-scale solar development, with the potential for additional zones through ongoing and future regional planning processes. The blueprint also allows for utility-scale solar development on approximately 19 million acres in “variance” areas lying outside of identified SEZs. In total, the Final PEIS estimates a total development of 23,700 megawatts from the 17 zones and the variance areas, enough renewable energy to power 7 million American homes.

Key elements of the Final Solar PEIS:

• Establishes an initial set of 17 Solar Energy Zones on 285,000 acres across 6 Western States;
• Outlines a process for industry, the public and other interested stakeholders to propose new or expanded zones; efforts already underway include California’s Desert Renewable Energy Conservation Plan and the West Chocolate Mountains Renewable Energy Evaluation, Arizona’s Restoration Energy Design Project, and other local planning efforts in Nevada and Colorado;
• Includes strong incentives for development within zones, including faster and easier permitting, improved mitigation strategies, and economic incentives;
• Sets a clear process that allows for development of well-sited projects on approximately19 million acres outside the zones;
• Protects natural and cultural resources by excluding 78 million acres from solar energy development;
• Identifies design features (best practices) for solar energy development to ensure the most environmentally responsible development and delivery of solar energy; and
• Establishes a framework for regional mitigation plans and a strategy for monitoring and adaptive management; the first mitigation pilot for the Dry Lake Solar Energy Zone is already underway.

In support of more detailed system-level analyses of transmission needs, the BLM is engaged in ongoing transmission planning efforts, including through the Transmission Expansion Planning Policy Committee and the Western Electricity Coordination Council’s transmission study.
The July 27 Federal Register Notice of Availability for the Final PEIS will begin a 30-day protest period, after which Secretary Salazar may consider adopting the document through a Record of Decision. The BLM released the Draft Solar PEIS in December 2010, and in response to the over 80,000 comments received from cooperating agencies and key stakeholders, issued a Supplement to the Draft Solar PEIS in October 2011.

Click here to access the Final Solar PEIS.
Click here for a list of the 17 Solar Energy Zones.
Click here for a map of the six-states (individual state maps available upon request).
Click here for the Executive Summary of the Solar PEIS.

Green Roofs in Washington, DC

In 2011, the Washington area led the nation, installing 800,000 square feet of green roofs (doubling the amount in 2010), and for the first time surpassed Chicago, which is known for its green roof initiatives. The District now has more than 1.2 million square feet of green roofs, according to the Green Roofs for Healthy Cities survey. DC Greenworks,, a nonprofit helping build green roofs,  believes 2012 probably will surpass 2011.

Commercial roofs form the bulk of green roofs because they generate the most return in terms of insulation and offsetting District stormwater and impervious surface area fees. Residential green roofs are increasing due to their ability to insulate against weather and noise, as well as for aesthetic benefits.

The District gives permits for three types of roofs:

1) Extensive Design, which is usually approved quickly, according to DC Greenworks. The roof has a shallow bed of growing medium (three to four inches deep), consisting mostly of expanded shale and slate and only 30 percent organic material. A higher percentage would make the roof heavier and potentially lead to rot.

2) Semi-Intensive, which contain deeper growing mediums that support plants with deeper roots.

3) Intensive systems, , which contain vegetables, bushes and even trees can be grown

In all three types, the green roof components (the plants, growing medium, drainage system, irrigation, root barrier and insulation), can either be laid down in layers across the roof, or they can come pre-installed in small modular trays that hook together.

The benefit of the former is that you can easily include or exclude different components, such as irrigation, to customize to a user’s need. A modular system, on the other hand, allows one to easily take up different sections to look for leaks or to replace dead plants. Also, modules usually come pre-planted, and thus the new roof has complete plant coverage sooner. A modular system is heavier and more expensive.
  
Resources on green roof design and function can be found on the District Department of the Environment, DC Greenworks and Green Roofs for Healthy Cities. (Wash Post, 7/23/2012) 

EPA Funds Stormwater Mangement Programs

EPA Provides $950,000 to Improve Water Quality Using Green Infrastructure in 17 Communities
  The U.S. Environmental Protection Agency (EPA) announced today that it is providing $950,000 to help 17 communities expand green infrastructure use to improve water quality and protect people’s health and benefit communities. Green infrastructure uses vegetation and soil to manage rainwater where it falls, keeping polluted stormwater from entering sewer systems and waterways in local communities. The EPA funding is intended to increase incorporation of green infrastructure into stormwater management programs, protect water quality, and provide community benefits including job creation and neighborhood revitalization.

EPA is awarding the funds to diverse communities across 16 states. Some communities – like Beaufort, South Carolina and Neosho, Missouri – are small towns in urban growth areas interested in preserving and protecting their healthy waterways. Others – such as Camden, New Jersey and Pittsburgh, Pennsylvania – are large cities interested in adding green infrastructure into their redevelopment projects to restore degraded urban waters and help revitalize their communities. The selected communities also provide an opportunity to demonstrate the potential of green infrastructure across a range of climate zones.

Green infrastructure captures and filters pollutants by passing stormwater through soils and retaining it on site. Effective green infrastructure tools and techniques include green roofs, permeable materials, alternative designs for streets and buildings, trees, rain gardens and rain harvesting systems. Communities are increasingly using green infrastructure to supplement or substitute for single-purpose “gray” infrastructure investments such as pipes, filters, and ponds.

In April 2011, EPA renewed its commitment to green infrastructure with the release of the “Strategic Agenda to Protect Waters and Build More Livable Communities through Green Infrastructure.” The agenda identifies community partnerships as one of five key activities that EPA will pursue to accelerate the implementation of green infrastructure and EPA announced partnerships with 10 “model communities.”

In February 2012, EPA announced the availability of $950,000 in technical assistance to a second set of partner communities to help overcome some of the most common barriers to green infrastructure. EPA received letters of interest from over 150 communities across the country. (EPA)

More information
 

Demographics of Fracking Areas in North Carolina

Fracking Counties By Zip Code
Durham
27517, 27519, 27560, 27613, 27701, 27703, 27704, 27705, 27706, 27707, 27708, 27709, 27710, 27711, 27712, 27713
Granville
27509, 27522, 27525, 27565, 27581,
Lee
27330, 27332
Chatham
27252, 27312, 27330, 27502, 27517, 27519, 27523, 27559, 27562, 27713, 27312
Moore
27281, 28327, 27376, 27330, 27325,
Wake
27502, 27511, 27513, 27518, 27519, 27522, 27523, 27539, 27540, 27560, 27562, 27587, 27617, 27713
Montgomery
27229, 27281, 27306
Richmond
28091, 28338, 28379
Anson
28091, 28133, 28135, 28170
Rockingham
27025, 27027, 27048, 27288
Stokes
27019, 27025, 27052,
Yadkin
27055
Davie
27028

Companies Interested in Fracking in North Carolina

Nine companies have an interest in fracking in North Carolina. They are:

Natural gas companies 1) PSNC Energy and 2) Piedmont Natural Gas; Electric utilities Progress Energy,

3) Duke Energy (Duke & Progress Energy merged) and 4) Dominion Resources, which are expanding their use of natural gas to produce power;

5) General Electric, which has invested in natural gas reserves in other states and introduced a mobile evaporator to help gas drillers recycle water;

6) Weyerhaeuser, a major landowner that has invested in shale deposits;

Natural gas producer 7) Koch Industries; and

Railroad companies 8) Norfolk Southern and 9) CSX, which are seeing an increase in fracking-related shipping.

(Indy Week, 5/30/2012)

Over 100,000 Protest Nuclear Restart in Tokyo

On hottest day of the year, protesters call for Prime Minister Noda to quit

Over 100,000 protesters took to the streets in central Tokyo on Monday to protest the country's return to nuclear power. The demonstration was one of the largest of its kind since Prime Minister Yoshihiko Noda announced that the country would restart its nuclear reactors last month. Protest organizers estimated the crowd at 170,000 people. Demonstrators marched through the streets in Tokyo's record setting heat chanting: "Don't resume nuclear power operation. Prime Minister (Yoshihiko) Noda should quit."

Public anger over the handling of last year's Fukushima disaster has continued to swell. Earlier this month a damning report released by a parliamentary panel investigating the government's handling of the disaster found that plant owner TEPCO and government regulators intentionally ignored key warnings and preparations that should have been implemented before the tsunami. The subsequent nuclear disaster to follow was "clearly man-made," according to the panel.

The last of the country's nuclear reactors had been shut down in May, following public pressure; however, the first reactor at the Oi plant in Fukui prefecture was restarted July 1, 2012 despite widespread criticism. Noda now plans to eventually restart all 50 of Japan's reactors, a campaign that has seen large scale protests since its announcement. (Common Dreams, 7/16/2012)

Obama Administration Reports on Everglades Progress

Obama Administration Releases Report on Progress and Next Steps in Restoring the Everglades, Announces Additional $80 Million in Project Funding

  Over $1.5 Billion Invested in the Everglades Since 2009; USDA To Fund Fourth Year of Easements for Water Quality, Wildlife Habitat Improvements in the Northern Everglades Watershed

The Obama Administration today released a report outlining the historic Federal investments and progress made in Everglades restoration under the leadership of President Obama, and announced $80 million in additional funding to support farmers and ranchers who voluntarily conserve wetlands on agricultural land in the Northern Everglades Watershed. This new investment, part of the U.S. Department of Agriculture’s Wetlands Reserve Program (WRP), will restore an additional 23,000 acres of wetlands vital to water quality and wildlife habitat in the Everglades system.

President Obama has made restoring the Everglades a national priority. Using the partnerships and community-led approach that is a hallmark of the President’s America’s Great Outdoors initiative, the Administration has reinvigorated Federal leadership in Everglades restoration, investing $1.5 billion in Everglades projects and initiatives that will make a measurable impact on the ground, including nearly $900 million to jump start key construction projects that will restore water flow and essential habitat. These projects already have generated 6,600 Florida jobs and are expected to generate more. President Obama also has requested an additional $246 million in the Fiscal Year 2013 Budget to build on this progress and continue the investments, partnerships and projects that will return the Everglades to health.

Working in partnership with the State of Florida, Tribes and local leaders, since 2009, the Administration has restored more than 3,000 acres of the floodplains along the Kissimmee River; worked with landowners to improve habitat and water quality on more than 400,000 agricultural acres; begun constructing the first mile of bridging for the Tamiami Trail to restore water flow to Everglades National Park; begun implementing key components of the Comprehensive Everglades Restoration Plan to make more water available for environmental, urban and agricultural use; and reached an historic agreement with the State of Florida to make essential water quality improvements, including $879 million in State commitments for water quality projects.

Today’s investment in the WRP also builds on other significant Obama administration accomplishments to conserve habitat in the greater Everglades ecosystem. Earlier this year, the Department of the Interior’s Fish and Wildlife Service (FWS) established the 150,000-acre Everglades Headwaters National Wildlife Refuge and Conservation Area. Assistant Secretary Jacobson today announced that FWS has received $1.5 million in reprogrammed 2012 funding to begin securing additional conservation easements on priority parcels of some of the last remaining grass-land savannahs in the Northern Everglades – working with private land-owners to conserve the land, water and wildlife of the Everglades Headwaters.

National Strategic & Critical Minerals Production Act

The House on Wednesday afternoon approved a rule setting up debate and a vote on a bill aimed at streamlining the permitting process for the mining of rare-earth minerals. Members voted 245-180 in favor of the rule, and the House is expected to approve the bill Thursday.

Republicans say the bill is needed because the United States is increasingly reliant on imported minerals that are widely seen as key to manufacturing health and national security. The National Strategic and Critical Minerals Production Act, H.R. 4402, notes that 67 key minerals are obtained mostly through imports, more than twice the number from 25 years ago. The GOP says permitting delays in the name of environmental protection have delayed the domestic development of these minerals.

The bill streamlines the permitting approval process, and is aimed at putting limits on lawsuits against efforts to mine these minerals, which Bishop said are often "frivolous law suits" meant to delay the permitting process.

Most Democrats are likely to oppose the bill, in part because of the possible environmental consequences.  Dems believe the bill appears to streamline the permitting process for mining that does not involve strategic minerals.  (The Hill, 7/11/2012)

Senate Confirms MacFarlane as Chair of Nuclear Regulatory Commission

Allison Macfarlane

The Senate confirmed the nomination of Allison Macfarlane to head the Nuclear Regulatory Commission and Kristine Svinicki for a second term on the commission (on Friday, June 29, 2012).
Macfarlane takes over from outgoing Chairman Gregory Jaczko, whose tenure on the panel was tumultuous.

The nominations of Macfarlane and Svinicki were cleared by the Environment and Public Works Committee last week. At a hearing earlier this month, committee Chairman Barbara Boxer (D-Calif.) said Macfarlane was the right person to take over the NRC and put it back on track to fulfill its mission of ensuring nuclear safety. Macfarlane also had the backing of Harry Reid, in part because of her opposition to building a nuclear waste repository at Yucca Mountain, Nevada. Jaczko, a former Reid staffer, also opposed the project.

Lawmakers agreed by unanimous consent to confirm the nominations of Allison Macfarlane.  Svinicki will serve a five-year term on the NRC. Svinicki is a supporter of Yucca Mountain.  Boxer opposed Svinicki nomination for a second term.  Macfarlane will complete the one-year term for the current chairmanship. 

The nomination of Kristine Svinicki, a Republican, was packaged together with Macfarlane to ensure the confirmation of both.  (Roll Call, 6/29/2012)

Does Fracking Pollute Groundwater?

ProPublica posted a story yesterday entitled, “New Study: Fluids From Marcellus Shale Likely Seeping Into PA Drinking Water,” which describes how new research has concluded that salty, mineral-rich fluids deep beneath Pennsylvania’s natural gas fields are likely seeping upward thousands of feet into drinking water supplies.

Another paper published on Monday by Duke University researchers found that gas drilling in northeastern Pennsylvania did not contaminate nearby drinking water wells with salty water, which is a byproduct of the drilling.

So which is it? Is fracking polluting groundwater or not? The answer depends on how you want to frame it. (Grist, 7/10/2012)

Department of Labor Proposes Contractors Hire Veterans

Special Projects: Doc Sloan

Support Job Goals For Veterans in Federal Contracting

The U.S. Department of Labor's Office of Federal Contract Compliance Programs is proposing a new equal-opportunity employment rule that would require all contractors -- construction companies as well as IT firms to airplane manufacturers -- doing business with the government "to set a hiring goal of having 7 percent of their employees be qualified workers with disabilities." Another amendment to federal contracting policy would require government contractors and subcontractors to make a "fair and reasonable" effort to hire veterans and meticulously document efforts to recruit and hire former military personnel.

The new rules would set "goals" -- not quotas -- by the federal government's description.

The Center is interested in promoting employment for veterans in energy and environmental sector contracting.  This is huge area for federal government contracting, from oil and gases public land leasing to subsidies for energy projects.

According to the executive director of the National Disability Rights Network, the protections now in place haven't been working.  The Network believes the federal government, as an enormous employer and contracting agent, bears the responsibility to set an example for the rest of the nation's businesses.

The veterans "quota" is not a set-in-stone percentage, but a "hiring benchmark" that the contractor itself must come up with and try to meet. It would be based on a number of factors, including the prevalence of veterans living in the area where the company does business.  (Pittsburgh Post-Gazette, 6/30/2010)

The Department of Labor proposals on hiring disabled workers and veterans

We Commend PEPCO For Excellent Performance After Storms

The Center is located in the heart of Washington, DC and we would like to thank the local utility, PEPCO, for its excellent electricity delivery service.  We also think the utility does an incredible job of getting the power back on after very violent storms.  Our area recently experienced a derecho, which is a widespread, long-lived, straight line windstorm that is associated with a fast-moving band of severe thunderstorms.  PEPCO, and other American utilities, get the power back up for everyone in no more than a week, when such events appear that they could easily cause enough damage to keep the power off for a month.

American utilties provide the best electricity delivery service in the world.  Americans have become so accustomed to having electricity at their beck and call that we panic when it is not available to us.  We adjust for a day or two, but become apoplectic if it goes on for 3-5 days.  Yet we are amazed that the utility company can get the power back up in a week after various sections of the distribution system are downed by massive trees.  The utility also must be careful, when repowering the system, that no trees are laying on lines because that can cause fires.

So we agree with the PEPCO ombudsman who stated:

“This was a regional event, a severe weather event. We are gonna have to let the process play out. I am comfortable that we will be able to demonstrate that our performance, considering the event, that we performed well considering the severity of the event.”

Congratulations PEPCO.  Keep up the good work

Renew Wind Production Tax Credit Now

The wind production tax credit is set to expire on December 31, 2012.  The production tax credit was signed into law by President George H.W. Bush in 1992 (Energy Polity Act of 1992 - H.R. 776) currently gives operators of wind farms a credit of 2.2 cents per kilowatt-hour of electricity they generate. Without the credits, wind power generally can't compete on price with electricity produced by coal- or natural gas-fired plants. Analysts predict that if the tax credit expires on Dec. 31, as it is scheduled to, installations of new equipment could fall by as much as 90% next year, after what is expected to be a record increase in capacity in 2012.

The credit now is caught in the congressional gridlock of an election year, and a vote on renewal isn't likely until after November. The credits for wind have expired three times before, most recently in 2004, with new construction slowing sharply each time before the credit was later renewed.

Wind's share of U.S. electricity output has grown to 2.9% last year, from about 1.3% in 2008, according to the Energy Information Administration.  (WSJ, 6/8/2012)

EPA Hearings on Proposed Particle Pollution Standards

The U.S. Environmental Protection Agency (EPA) will hold two public hearings on the proposed updates to the national air quality standards for fine particle pollution (PM2.5). A federal court ruling required EPA to update the standards based on best available science. The proposed updates, which meet that requirement, build on steps already taken by EPA to reduce pollution in communities across the country.

WHAT: Public hearings on proposed updates to national air quality standards for fine particle pollution.

WHEN:

July 17, 2012 (Philadelphia) 9:00 a.m. - 9:00 p.m. EDT
July 19, 2012 (Sacramento) 9:00 a.m. - 9:00 p.m. PDT

WHERE:

July 17, Philadelphia
William J. Green Federal Building
600 Arch Street
Philadelphia, Pa. 19106

July 19, Sacramento, Calif.
California Air Resources Board
1001 "I" Street
Sacramento, Calif. 95814

To register to speak at the hearings, contact Alan Rush at rush.alan@epa.gov or 202-564-1658. Members of the public also may register in person at the hearing and will be accommodated as time allows. EPA also will accept written comments on the proposed standards until Aug. 31, 2012. EPA will issue the final standards by December 14, 2012.

Note: Please bring picture identification and allow additional time to enter the buildings and go through security.

More information on the hearings and instructions for submitting written comments:

How Do Coal Scrubbers Work?

Coal Pollution

• Coal is not a clean-burning substance. It produces sulfur dioxide, which causes acid rain; nitrogen oxide, which causes smog; carbon dioxide, which contributes to the greenhouse effect; particles of dirt, which can cause respiratory distress; and many other pollutants. Scrubbers are currently used in most coal plants. They do not prevent air pollution, but they do reduce it by filtering out some of the most harmful pollutants.

Wet Coal Scrubbers

• There are two types of scrubbers used: wet and dry. Both use limestone, which reacts with sulfur to remove it from the air. In wet scrubbers, limestone powder is mixed with water and sprayed into the smokestack. As hot gasses from the coal plant blow through it, they come in contact with the water vapor. Dust clings to the water, and sulfur dioxide reacts with the limestone trapped in the vapor. The water vapor then precipitates out of the stack, where it can be filtered out, removing some of the worst pollutants. Some of the water vapor actually remains in the smokestack, which is why many stacks release white plumes. Those plumes are composed of steam and hot gasses.

Dry Coal Scrubbers

• 
  Dry coal scrubbers are a different way to do the same thing. Instead of being mixed with water a lot of water, the limestone is blown into the stack dry or with a bit of moisture. Sulfur dioxide still reacts with the particles of limestone, which trap the chemical. The hot gas then flows through a filter. The limestone particles with their trapped sulfur are too big to get through the filter, as are particles of dust. This removes them from the air stream before it leaves the smokestack. (eHow. com)