Archive for the 'Electricity' Category

Guest Post: Evolving Electric Industry Represents New Career Opportunities by Jordan Kern, PhD

Eliminating greenhouse gas emissions in the electric power industry might require it to change from top to bottom – the technologies that are used, the business models employed, the number and scope of market participants, and the regulatory oversight required. The only thing that we can safely say won’t change are the laws of physics that impose constraints on the operation of power systems.

The good news (at least for folks who are concerned about climate change) is that the electric power industry is changing quickly, largely due to technological advances and policy pressure. What that means for conventional, vertically integrated electric power utilities – companies like Duke Energy— is a little uncertain, but they’re spending a lot of time thinking about how they can be successful players in the grid of the future.

As the electric power industry evolves, another thing we’re learning is that there is a big need for an influx of new workers with a broader set of expertise. Some of this need is related to the facts of life: baby boomers who worked their whole careers at power companies are retiring. Some industry estimates project that 50% of the workforce at electric power utilities will retire over the next several years, and these folks will need to be replaced.

Image from Utility Dive

But perhaps more importantly, the types of skills needed in the electric power industry are changing in a number of ways:

  • For one, the future of the industry may not be dominated by conventional electric utilities or for that matter, even by suppliers of energy.
  • In a grid dominated by renewables, demand side management (i.e., managing and reacting to customers’ behavior) and storage will become critical components.
  • Even at big utilities, the pathway to a job is no longer limited to mechanical and electrical engineering. Increasingly, utilities need workers with skills in data science, software development, business, and marketing.

In a lot of ways, this shift benefits UNC students. Even though the technical rigor necessary for a career in the energy industry has been available at UNC for a long time, without a significant undergraduate engineering presence on campus, some doors have been closed to our graduates.

The shifting nature of energy industry means new doors are springing open. We just need to make sure UNC grads are walking through them.

Part of that means exposing students to the benefits of marrying their intellectual and philosophical interest in sustainability to tangible career pathways. For more on the incredible strides UNC has taken in this regard, you should read UNC professor Greg Gangi’s recent blog post.

Another important aspect of preparing students for new opportunities in the energy industry is adapting undergraduate curriculums. At UNC, the Curriculum for the Environment and Ecology (ENEC) is doing just that, having recently hired a new lecturer in Energy.

I’ve tried to do my own small part too, by developing an Energy Modeling and Analytics course (ENEC 490), which is offered in the fall. The course uses a “flipped classroom” approach, with formal lectures delivered online via YouTube, and in-class time used to develop coding and modeling skills through the completion of industry case studies.

One of the things I’ve been most impressed with over the last several years is how these shifts in focus at UNC and within ENEC have been spurred by student interest.

On the part of the university and ENEC, this shows not only a willingness to adapt quickly (not always a strength of big institutions), but also a recognition that, in terms of defining societal priorities and creating new areas of economic and intellectual growth in the future, the students are often the teachers.

Jordan Kern is a Research Assistant Professor at the UNC Institute for the Environment. You can learn more about his research and teaching portfolio at http://jdkern.web.unc.edu/

Guest Post: How much energy is in your water bottle? by Ryan Kingsbury

We don’t often think about the energy it takes to satisfy our thirst, but where we get our drinking water has huge consequences for how much energy is needed. In many parts of the world, fresh water sources like lakes or aquifers are becoming scarce, forcing residents to settle for supplies that aren’t as clean. And the dirtier the water, the more energy it takes to purify.

Salt is especially hard to remove. In desert or coastal regions with limited sources of freshwater, residents must use a process called desalination to turn salty groundwater or seawater into drinking water. We’ve already covered how mixing saltwater with freshwater releases a lot of energy,  so, to do the reverse– to remove salt from water– consumes a lot of energy.

Exactly how much energy is required depends on the method of desalination. Distillation (which involves boiling)  is a simple way to desalinate water, but it’s also one of the most energy-intensive. By using a technology called reverse osmosis, we can desalinate water using about 1/10th as much energy as distillation. So compared to boiling the water, using reverse osmosis is much more efficient. But reverse osmosis still requires about 100x more energy than treating fresh surface water or groundwater. In fact, you could charge your smartphone with the energy it takes to desalinate just 1 gallon of seawater!

Despite its energy demands, desalination is widely used around the world. There are more than 18,000 desalination plants in 150 countries, including about 250 in the U.S. About half of these plants use reverse osmosis, and about a third use distillation.

In the U.S., most plants are located in Florida, Texas, and California (shown on this cool map), but there are about a dozen here in North Carolina. If you’ve ever visited the Outer Banks, your drinking water probably came from a reverse osmosis desalination plant.

There are so many reverse osmosis plants in the world, that together they produce 4x as much water in one year as refineries do oil! But virtually all of these plants were built as a “last resort,” in areas where there simply isn’t enough freshwater to meet the needs of consumers, industry, and agriculture. When it’s available, treating freshwater is always preferable to desalination.

The more we have to rely on seawater and other salty water resources, the more energy it will take to slake our thirst. So next time you take a drink of water, remember that you’re not just drinking ounces, you’re drinking watts.

Want to learn more about reverse osmosis desalination? Check out this animated video from the Seven Seas Water Corporation.

Ryan Kingsbury, P.E., is a PhD student at the University of North Carolina at Chapel Hill where he is a member of the Coronell Research Group.  Orlando Coronell, PhD, and his research team study membrane-based processes for water purification and energy production and storage, with applications in municipal, industrial, and household systems. Ryan studies salinity gradient energy which you can read more about here.

What do pickles have to do with generating electricity?

Earlier this year I heard University of North Carolina (UNC) at Chapel Hill doctoral student Ryan Kingsbury, a member of Orlando Coronell’s lab discuss his research and was introduced to the term “blue energy” for the first time.  Ryan studies energy storage and generation from salinity gradients.  Salinity gradient energy or “blue energy” refers to the energy released when water with different concentrations of salt mix (this is essentially the reverse of what happens during desalination).  For those of you who teach about diffusion, here is an opportunity to show your students how selective diffusion of positive and negative ions across membranes can drive the production of  electricity!

Salinity gradient energy is at the cutting edge of research on renewable energy.  Using ion-selective membranes and a process known as reverse electrodialysis (RED), natural and industrial waters (e.g. seawater, desalination brine, etc.) can be used to store energy, generate electricity and even treat wastewater!  Ryan recently described the physics behind blue energy and RED in a bit more detail in his own blog post.

And now for the pickle part.  It turns out one of the industrial wastewaters being investigated by researchers is the leftover salt water from making Mt. Olive pickles!  Researchers from NC State University, UNC-CH, East Carolina University and the Coastal Studies Institute are developing a process that uses salinity gradient to release energy from Mt. Olive wastewater. There is a 6 minute video describing this multi-institutional collaboration and a transcript of the video also available. The project PIs (Dr. Coronell from UNC and Dr. Call from NCSU) also participated in a February 2016 radio interview about salinity gradient energy which explains their project more broadly.

In addition to pickles, NC is also known for its estuaries; the mixing of salt and fresh water that occurs in estuaries is an untapped source of blue energy!  In fact, I learned from reading Ryan’s blog post that where rivers flow into the sea and fresh and salt water mix, the amount of energy created  is equivalent to the river falling into the ocean from the height of the Eiffel tower!

You can also learn more about blue energy in this June 2015 BBC article Blue energy: How mixing water can create electricity.

 

 

 

 

Accessing local, regional and national data on electricity supply and demand

I am an advocate for having students engage with real data and when that data is locally relevant, even better!  Access to real data about the electrical grid is what I like about the newly released U.S. Electric System Operating Data tool from the U.S. Energy Information Administration. This tool provides “analysis and visualizations of hourly, daily, and weekly electricity supply and demand on a national and regional level for all of the 66 electric system balancing authorities that make up the U.S. electric grid.”

There are three Duke Energy balancing authorities (BAs) in NC – Duke Energy Carolinas (DUK), Duke Energy Progress West (CPLW) and Duke Energy Progress East (CPLW).  From the tool’s interactive Status Map, you can view demand (actual & forecasted) and supply data for the BA that is servicing your school.  Hourly, daily, weekly and monthly demand data is available and can even be downloaded in excel should you want your students to conduct a graphing activity.

Map showing balancing authorities in North Carolina

Status map showing NC’s three Duke Energy BAs in blue, with data for Duke Energy Carolinas (DUK) shown (Sept 7, 2016). The size of the circle roughly corresponds to the system size.  By clicking on the corresponding blue dot you will find hourly, daily, weekly and monthly demand curves with these data available for download into excel for a graphing activity.

There is also a live feed that runs across the top of the tool that shows how many total megawatthours the US (the lower 48 states) consumed yesterday (approximately 9.77 million MWh on September 6th, 2016) as well as the latest US hourly demand and yesterday’s peak demand values.

From the Grid Overview home page students can also examine national or regional demand curves, like the weekly demand curve shown here for the Carolinas (CAR) region.

Weekly demand curve for the Carolinas (CAR) region.

What can students learn by examining a  daily or weekly demand curve?  In addition to seeing how many megawatt hours of electricity the Carolinas (CAR) region or a specific BA requires in any given day or week, students may also be able to examine and explain trends in electrical consumption over time and even seasonally.  For example, students could be tasked with examining the extent to which electrical consumption is tied to the weather and recent weather events. For example, the recent hurricane that passed through this region on Sept 3rd brought cooler weather and perhaps some power outages that reduced demand for electricity compared to the days before the hurricane.

This tool also enable users to assess the demand-supply balance for a given region (see below) or balancing authority such as Duke Energy Carolinas.  What can students learn by examining a visualization of demand and supply?  They will observe that  demand and supply closely match (they need to!) and that energy transfers (interchanges) occur to address any differences between demand and supply. The EIA’s About the Grid page in addition to the glossary may also be useful as you familiarize yourself with this tool and the terminology encountered.

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Comparing demand and supply for the Carolinas region.

 

 

 

 

Don’t forget the infrastructure!

Earlier this month I conducted a teacher workshop devoted to the topic of electricity for science teachers from North Carolina’s coastal region. During the workshop I asked the teachers to tell me about the kinds of local energy issues they are confronting with their students and what questions arise in the classroom as a result.  One teacher remarked that in light of the Desert Wind Power Project being constructed in the northeastern part of the state, he asks his students to consider the infrastructure needed to build a wind farm.  His comment was timely, given that roads are currently being built to enable construction of the wind farm. When we evaluate the different energy sources that can be used to generate electricity we want our students to consider the accompanying infrastructure and land use change that results from the acquisition, management and use of those energy sources.eagleford_vir_2016046

NASA’s recent Image of the Day titled Shale Revolution featured the infrastructure and land use change brought about by oil and gas acquisition in the Eagle Ford Shale Play in Texas. The speckles of light in the nighttime satellite image below are “the electric glow of drilling equipment, worker camps, and other gas and oil infrastructure combine with flickering gas flares.” Comparing daylight satellite imagery from the years 2000 and 2015 revealed a “bustling network of roads and rectangular drill pads had completely transformed the landscape.”  Furthermore, this visual transformation invites the viewer to also consider the societal impacts of such development as well; Cotulla, Texas saw its population more than double in a very short time period!  Thus, these images could be used to prompt a class discussion about the implications of oil and gas development, including the accompanying infrastructure and land use changes, on the local community.

It will be interesting to compare satellite images of the land that will house the Desert Wind Power Project before and after the project is complete and to use these images to prompt student thinking about the environmental, economic and societal impacts of a land-based wind farm in rural North Carolina.

Interactive infographics from the IEA | World’s energy system through 2050

IEA World Energy 2012

The World’s Energy System in 2012

The International Energy Association’s publication Energy Technology Perspectives 2015, is accompanied by a set of interactive visualizations that utilizes the data and figures behind its publication on energy technologies.  I am an advocate for having students visualize the entire energy system – the diversity of energy sources used to provide electricity to homes and industry and to power our various modes of transportation.  I also find it useful to examine how the system is changing over time as our demand for energy grows in light of the need to limit society’s carbon dioxide emissions. These interactive infographics from the IEA illustrate how the world’s energy system will evolve through 2050.  There are three parts to this online tool: an energy flow visualization, an emissions reduction visualization and a transportation visualization. Here I am featuring the energy flow visualization where the  user can hover over a specific energy source, transformation or end user to study a particular energy flow.  The diagram below shows the global energy flow for coal in 2012 and for 2050 (projected); one can easily compare the two graphics to see that coal use will decrease while global energy demand will increase.  Have you considered asking your students to evaluate and explain energy flow diagrams?

IEA World Energy 2012 and 2050_coal

Global energy flow for coal in 2012 and for 2050 (projected).

The emissions reduction visualization tool allows the user to assess how individual countries or regions can reduce carbon dioxide emissions via deployment of technologies and energy efficiency measures under three different warming scenarios (2°C, 4°C and 6°C). The transport visualization tool enables the user to select an “indicator” such as annual road energy consumption for a specific country, region or the world to visualize the extent to which the selected indicator needs to change to limit Earth’s average global temperature to either 2°C, 4°C or 6°C.  According to the IEA website. “the 2°C Scenario is the main focus of ETP 2015. It lays out the pathway to deploy an energy system and emissions trajectory consistent with what recent climate science research indicates would give at least a 50% chance of limiting average global temperature increase to 2°C.”  You can read the Executive Summary of the ETP 2015 here.

And if you want to read more about energy flow diagrams, check out this post.

Duke Energy 2050 Vision | Online Challenge

I recently learned about this interactive online “Energy Challenge” by Duke Energy where users create a plan to meet the energy demand of  a carbon constrained world in the year 2050. Duke Energy aggregated data from across its entire U.S. service territory and created a visual representation of its service area and power generating facilities which sets the stage for the user who is tasked with making choices about how to meet a growing energy demand while working towards CO2 reduction goals.  Choices that can be made by the user include: building new power plants, including solar and wind farms, upgrading existing power plants to produce more energy, retrofitting existing plants to reduce emissions, closing inefficient power plants and implementing energy efficiency programs.

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As users make decisions, such as retiring a set of aging coal plants or adding a wind farm, they get instant feedback regarding cost (in billions of dollars), impact on CO2 emissions (tons per year) and the extent to which their plan meets the predicted energy demand for the year 2050.  The energy demand meter displayed on the right side of the screen makes it easy to visually monitor the extent to which a decision helps to meet energy demand and the extent to which this demand is met through non-renewable energy sources, renewable energy sources and energy efficiency measures.

Duke Energy intends for this tool to “demonstrate the trade-offs and cost implications of choosing an energy generation mix that will meet future energy demand while minimizing CO2 emissions and keeping costs as low as possible.” I could easily see small groups of students competing to see which group can come up with a strategy that reduces CO2 emissions, meets projected energy demand for 2050 and costs the least amount of money.

To learn more about the game, click here.

One Indiana science teacher created a worksheet to accompany this game that could be used with your students.

If you have your students play this game, please share your experience by leaving a comment!

 

 



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