NC Scientists Study Offshore Wind Energy Potential

This article by Jared Brumbaugh appears with the permission of Public Radio East. To view the original article and/or listen to the 5 minute broadcast click here.

Coastal scientists are hoping to deploy two buoys in April to explore wind energy potential off the coast of North Carolina.

Credit UNC Institute of Marine Sciences

It was the winds of coastal North Carolina that propelled Orville and Wilbur Wright to first in flight more than 110 years ago.  Soon, scientists will launch a one year study to determine if those same coastal winds can be used to power homes and businesses.  The University of North Carolina at Chapel Hill will deploy two – 3,000 lb. buoys to collect information on water and atmospheric conditions in the Atlantic.   Professor of Marine Sciences Harvey Seim says they’ll use the information to help identify viable lease block locations for offshore wind farms.

 “The intent here is to take a closer look at what the offshore wind energy resource is like and to carefully document its structure to help where and where not to consider deployment of offshore wind turbines.”

In 2008, the North Carolina State Legislature requested that a study be conducted to look at the viability of offshore wind energy in our state.

“The University played a big role in putting together a report for the state at that time over the next year.  And we found that there was reason to be encouraged that offshore wind energy might be feasible off of North Carolina.”

Seim says there has been a series of follow up projects conducted since the study, the most recent will be the placement of the two buoys 20 miles off the coast.  Below the surface of the water is a large, donut shaped flotation collar about 6 to 7 feet in diameter.  The visible section consists of a 12 foot super structure equipped with high-tech meteorological instruments.

Credit UNC Institute of Marine Sciences

“On the super structure are a number of sensors to measure properties of the atmosphere, the main one being the wind speed and direction.  We have a couple of anemometers, redundant, so we can make sure we’re getting the right measurements.  Air temperature, air humidity, air pressure, rainfall, things that tell us about how cloudy it is.  And in addition, a camera that will take a snap shot of the sea surface conditions every hour.”

Just below the water and at a depth of 50 feet, special instruments will record the ocean’s temperature and salinity.  The two buoys will be anchored to the seafloor about 80 miles apart.  One will be located north of Cape Hatteras and the other off Ocracoke Island.  Semin says the buoys will be placed in areas where there’s a lack of data indicating a favorable spot for wind energy development.

“The intent is to try to fill in the holes in the historical database in sites that look like they should be promising based on other data, but we’ve never taken measurements in those particular locations.”

Semin says the areas where they are conducting their research will be in non-conflict areas, which are places that don’t disrupt military, fishing, and ecological activities.  The purpose of the research project will focus mainly on collecting information about wind speed and direction.  Seim says they’ll study how the proximity of the Gulf Stream to the continental shelf creates a seemingly favorable environment for wind energy facilities.

“This is the Gulf Streams closest approach to the continent anywhere along the eastern sea board except for Florida. And when it comes close to the land, it essentially serves as an energy source and helps pump up the wind fields, we know that’s what happens during the wintertime and spinning up strong storms right off of our coast.”

Credit UNC Institute of Marine Sciences

The buoys are equipped with satellite communications, which will transmit data back to shore every hour.  According to Seim, the data will be available to the public, as well as local and commercial mariners, divers, weathermen, and scientists.  He says the National Oceanic and Atmospheric Administration will be the primary receiver of the data, and will help distribute the information globally.

“The data from the buoys will flow into the National Weather Service’s model systems and help with forecasting, we’ll also be hosting our own website to present the data to people as well.”

The original buoys were purchased nearly a decade ago.  After an extensive 100,000 dollar retrofit, the pair of buoys were deployed off the coast in 2011.  But before the research could be completed, the buoys were severely damaged either intentionally or by accident.  Over 200-thousand dollars in repairs have been made, and the buoys are set to be deployed next month. Semin is hoping to alert mariners to be on the lookout for the buoys and any suspicious activity.

“The buoys are marked with their identification numbers from NOAA, these NDBC numbers, and they have a website on them that’s fairly easy to access that you could just go in there and let us know if you think there’s something that’s not looking right. We’d also like to ask that people don’t tie off to the buoys.  They’re big and robust, but the instruments themselves are fairly delicate so if you try to throw a line on them, you might damage some of the equipment.”

Credit UNC Institute of Marine Sciences

The Monitor National Marine Sanctuary vessel was set to deploy the buoys earlier this month, but a critical component failure will keep it in harbor until next week.  When the buoys are deployed, they will spend a year in the Atlantic collecting data.  Seim is hoping the project will receive more funding and can be extended so they’re able to document atmospheric and ocean conditions over a longer period of time.  You can see pictures of the research buoys at our website, publicradioeast.org.  I’m Jared Brumbaugh.

For more information:

climate.unc.edu/CoastalWind – Original UNC offshore wind energy feasibility study  – the full feasibility study generated by UNC for the state legislature

ndbc.noaa.gov – National Data Buoy Center -  the federal government site where the buoy data will be available to the public in a tabular format, along with many other observing platforms around the country

nccoos.org/platforms  -  the website maintained by Seim’s group at UNC that makes the buoy observations available in a graphical format.

2014 World Water Day: Water and Energy

Photo of Kerr-DamnThe theme of the 2014 World Water Day on March 22 is water and energy. As a teacher, you may be interested in seeing how many of the event’s key messages, designed to raise awareness about water and energy, are relevant to your teaching and perhaps that you are already incorporating into your instruction.

In recognition of World Water Day, today the United Nations released the 2014 World Water Development Report (pdf) that is divided into two volumes – Volume 1 – Water and Energy and Volume 2 – Facing the Challenges, which includes thirteen case studies from around the globe that illustrate “that an array of opportunities exists to exploit the benefits of synergies, such as energy recovery from sewerage water, the use of solar energy for wastewater treatment, and electricity production at ‘drinking water power plants’. These examples also showcase alternatives to fossil fuel-based energy production, including hydropower development, geothermal energy, solar power and biogas.” There is one US case study about Austin, Texas, which is at “the centre of energy-rich and water-stressed Texas” that highlights the city’s water and energy conservation programs, including a reclaimed water program. These case studies are brief and reader friendly and could be useful to students seeking not only to understand the interplay between water and energy but also to examine innovative solutions for conserving water and energy around the globe.

Information briefs to accompany 2014 World Water Day are also available and may be useful as you seek to update your instruction about the water and energy connection:

Water and Energy (pdf)
Water and Energy Efficiency (pdf)
Water and Energy Sustainability (pdf)

There is also a useful list of additional documents and information resources, which includes links to related infographics, activities for youth, and articles. Facts and figures from the 2014 report are also available.

I’d love to hear how you use any of this information with your students!

Wave energy conversion: the physics and the applications

Originally posted on UNder the C:

wavemotionanimation

Wave energy may be very important to the renewable energy industry as more traditional green energy sources meet more and more opposition in the political and economic arena. In this post, I’ll show you how ocean waves work, and some of the ways people have been attempting to harness wave energy for use by humans in the form of electricity.

An ocean wave behaves similarly to any other mechanical wave you may encounter, such as a sound wave or a wave you might make with a jump rope or slinky. The key element to any wave is the propagation of energy. That is, the wave serves as a means for energy to move from one place to the other. It’s important to recognize that it is the energy that is being moved, and not the matter. Take a look at the first GIF above. You can see that if you follow a…

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Sunshine on a Rainy Day: Using Molecules to Capture and Store Sunlight

Guest post by Ralph House of UNC’s Center for Solar Fuels

Developing a way to store solar energy when the sun is down, or not available, is a key element and the central mission of the University of North Carolina Energy Frontier Research Center: Center for Solar Fuels (UNC EFRC) which is funded by Basic Energy Sciences in the US Department of Energy. Inspired by natural photosynthesis where light is absorbed and stored as carbohydrates for later use, we designed an “artificial photosynthesis” device called a Dye Sensitized Photoelectrosynthesis Cell (DSPEC). Similar to photosynthesis, in the DSPEC, light is absorbed and used to drive chemical reactions leading to water splitting into its component parts, oxygen, protons and electrons, with the electrons and protons used to make a “solar fuel,” in this case hydrogen gas.

The UNC EFRC led by scientist Thomas Meyer, made news recently with a major breakthrough in solar energy storage: demonstration of the first functional DSPEC for hydrogen fuel production.

Improving the molecular machinery of DSPECs
At the heart of the DSPEC is a molecular assembly made up of a light-absorbing molecule (called a choromophore) that converts light into high-energy electrons, and a catalyst for splitting (oxidizing) water into its component parts. The assembly is tethered to the surface of a semiconductor material, in this case titanium dioxide (TiO2), layered on top of nanoparticles in a film of a transparent conducting oxide. The steps required to generate solar fuels are illustrated in the figure below (click to enlarge). DSPEC Steps

There were two hurdles to using DSPECs that the EFRC recently overcame. First, the molecular assemblies were only stable on the electrode surface in acidic environments. Figuring out how to keep them on the surface at a more basic pH (pH=11), would make the rate of water splitting (oxidation) a million times faster! Second, before the high-energy electrons, freed upon absorption of light by transfer to the semiconductor, could be transferred to the other side to make hydrogen, they found their way back to the chromophore-catalyst assembly halting water oxidation in its tracks.

The answer to both lay in a technique called atomic layer deposition (ALD). It provides a way to build ultrathin films, one layer at a time, over complex three-dimensional surfaces. In collaboration with the Parsons Research Group at NC State University, the EFRC team used ALD to apply an ultrathin layer of TiO2 on a conducting oxide surface after attaching a catalyst. This effectively protected the bonds that attached the catalyst to the electrode surface where it stayed put allowing for water oxidation to occur at basic pH, a million times faster.  This solved problem number one.

The root cause of the second problem was the thickness of the semiconductor in the nanoparticle films – several microns – too thick to allow the injected electrons to escape to the other side. In this case, ALD was used to deposit an ultrathin layer of TiO2 to the surface of the conductor with the chromophore-catalyst assembly then tethered to it. The ultrathin layer of TiO2 reduced electron transit times significantly allowing them to escape to the other electrode where they made hydrogen.

Although these results look to be a major breakthrough in solar energy storage, much needs to be done to improve both efficiency and stability. A next step will be the use of ALD to simultaneously increase the stability of surface binding and enhance the rate of electron capture. Stay tuned….

Teaching about the recent Dan River coal ash spill

coal ash picture The coal ash spill from Duke Energy’s Dan River power plant in Rockingham County on February 2 resulted in approximately 80,000 tons of coal ash entering the Dan River and is being cited as one of the nation’s largest coal ash spills. This unfortunate event serves as a reminder that our energy choices often result in unintended consequences from waste and/or byproducts of energy use, much like coal tar was a remnant of coal gas production at former manufactured gas plants. This local event can be used to help students discover and evaluate the consequences of human activities on the lithosphere, hydrosphere, atmosphere and biosphere.

Coal Ash Ponds
At some coal-fired power plants, the resulting coal ash from power production is stored in large ponds. The practice of transporting and storing coal ash in on-site ponds is known as wet ash handling. According to Duke Energy’s solid waste section on its website, it manages 23 active ash ponds in the Carolinas. A fact sheet published by Duke Energy on its management of coal ash reveals that these ponds were “the customary storage method when many coal plants were built. Since then, [it has] invested in millions of dollars to transition to storing fly ash in a dry form [dry ash handling] in lined landfills at many of [its] larger coal plants. This provides additional protection to surface and groundwater, and more conversion projects are under way.”

Components of Coal Ash
Coal ash, also known as coal combustion residuals (CCRs), varies in its composition depending on the type and origin of the coal, how the coal was burned, and the type of air pollution control equipment utilized at the power plant. The EPA indicates that “about 80 to 90 percent of [coal ash] is non-radioactive minerals, typically silicon, aluminum, iron and calcium.” In addition, the EPA cites that coal ash can “contain contaminants like mercury, cadmium and arsenic associated with cancer and various other serious health effects.” Furthermore, naturally occurring radionuclides such as uranium can become concentrated in coal ash.

Concern about Coal Ash Release to Dan River
During a Feb 17th, 2014 presentation to the General Assembly’s Environmental Review Commission (ERC) officials from NC’s Department of Environment and Natural Resources (DENR) stated that drinking water supplies were not adversely impacted. DENR officials have acknowledged that their primary concern is the settling of the ash onto the bottom of the Dan River and its longer-term impact on the aquatic habitat and to people who use the river for recreation.  On February 12, 2014, the N.C. Department of Health and Human Services’ Division of Public Health issued two health advisories to minimize human exposure to contaminants downstream of the spill site.  DHHS advises against the consumption of fish and shellfish and asks people to avoid recreational contact with water and sediment. To learn more about specific human health effects associated with many of the components of coal ash visit the Agency for Toxic Substances and Disease Registry and search for the chemical of interest.

The Connection between Coal Ash and Clean Air
An interesting aside on this topic that illustrates the link between water and air pollution management is worth noting.  Some media stories correctly reported that a portion of the toxic materials found in the state’s coal ash ponds were a result of efforts to reduce air pollution through the passage of the Clean Smokestacks Act (CSA).  Following passage of the CSA, which required significant emission reductions from the state’s coal-fired plants, scrubbers were placed on the facilities to keep ash from being discharged into the atmosphere.  After capture by the scrubbers, the ash was subsequently disposed of into the coal ash ponds resulting in cleaner air “but the trade-off is significant enrichments of contaminants in solid wastes and wastewater discharged from power plants” according to a 2012 research study funded by the North Carolina Water Resources Research Institute.

Background Information and Teaching Resources

Dan River Coal Ash Spill, NC DENR

The Dan River Coal Ash Release: Description & Timeline of Events (PPT presentation from Feb 17th, 2014 DENR presentation to the ERC). This presentation includes graphics and photos that can be useful in helping students understand how coal ash is produced and captured in ponds.

Response to Release of Coal Ash Into the Dan River, US EPA

Response to Dan River, Duke Energy

North Carolina coal ash spill raises questions about enforcement of environmental regulations, 7 minute video excerpt from PBS NewsHour, Feb 17, 2014

Coal Ash: Characteristics, Management and Environmental Issues (pdf), Electric Power Research Institute

EIA updates its state energy portal

eia

The U.S. Energy Information Administration’s (EIA) state energy portal has been updated to include “new analytical narratives on the energy sectors of each of the 50 states, the District of Columbia, and 5 U.S. territories.” The narrative for NC can be found here.

In addition, there is an interactive mapping tool available that enables users to create customized   maps and charts, ideal for classroom use. The map for NC can be found here. By clicking on the “Layers/Legend” tab and selecting one of five available base maps, maps can be created to show availability of energy sources, transmission lines, major power plants as well as renewable energy potential for North Carolina.  Electricity, nuclear, natural gas and renewable energy profiles for the state are available along with supporting data tables in Microsoft Excel. Also, by clicking on a specific power plant, the portal links users directly to data for that particular plant in EIA’s electricity data browser (see corresponding blog post).

This tool also shows how NC ranks in comparison to the other 49 states in terms of energy production, consumption, prices for electricity and natural gas, and carbon dioxide emissions.

Inside Energy iPad app by Shell

This free iPad app from Shell “explores the role innovation plays in producing energy to power and sustain our lives.”  Stories with interactive features are organized into four sections: Innovative Thinking, Meeting Demand, Energy Efficiency and People and Planet.  A two minute video about this app can be viewed here.

While this app can be useful to teachers and students, teachers will want to be sure to remind students to be mindful of who is presenting this information and teach them how to identify potential bias when reviewing scientific information. It would be valuable to have students investigate a particular story presented in the app from different perspectives by gathering related news articles, press releases, etc.

I would love to hear from those of you who have used this app with students – what stories have you found useful in your teaching? How do you prepare your students to critically evaluate what they read and look for evidence of bias?



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