Generation Technologies Assessment from EPRI

When I address the topic of electricity generation with teachers and students, a key message I aim to to convey is that every energy source used to generate electricity has its advantages and disadvantages.  This knowledge is key to evaluating both renewable and non-renewable energy sources for their potential to provide electricity to a growing population and in doing so  promotes critical thinking about electricity generation in the 21st century.

Coal, coal w/carbon capture and storage (CCS), natural gas, nuclear, hydro, wind, biomass, geothermal, and solar, are all sources for electricity generation.  The Electric Power Research Institute (EPRI) recently published  an Assessment of Relative Benefit / Impact webpage that visually ranks each energy source from more favorable to least favorable with regards to the following criteria:

Construction Cost
Electricity Cost
Land Use
Water Requirements
CO2 Emissions
Non-CO2 Emissions
Waste Products
Availability
Flexibility

Details are also provided about each of the above criteria and, by clicking on the energy source of interest, the user is taken to a summary page that further details the extent to which this energy source is used to generate electricity.  The Electric Generation Technologies by Region page shows the energy sources used to generate electricity in your region compared to the national average.  You can also compare the energy sources used to generate electricity in your region to those of other regions of the country.

Carbon Capture Utilizing Direct FuelCells

FuelCell Energy, Inc., a manufacturer of ultra-clean, efficient and reliable power plants, announced earlier this month that it had received $3 million  from the U.S. Department of Energy to evaluate the use of Direct FuelCells ® (DFC®) to”efficiently and cost-effectively separate carbon dioxide (CO2) from the emissions of existing coal-fired power plants.  Efficient and cost-effective carbon capture can then lead to sequestration of this greenhouse gas, preventing its release into the atmosphere.”

For those of you interested in teaching your students about fuel cells and their underlying chemistry, you may find it useful to teach about fuel cells in the context presented above: how might fuel cells be used to mitigate CO2 emissions from coal-fired power plants?

Perhaps start by introducing the basic parts of any fuel cell.  The Smithsonian Institution provides a nice overview of fuel cells on their website.

A two page pdf is available from FuelCell Energy, Inc that describes and diagrams the “unique chemistry of the high efficiency carbonate fuel cell.”  In this case, CO2-containing flue gas from coal-fired power plants is utilized as oxidant for the DFC® cathode.  Natural gas, propane, or syngas can be used as the fuel cell anode feed to provide H2 needed to complete the electrochemical power generation cycle.

To learn more about carbonate fuel cells and other types of fuel cells under development visit the DOE’s EERE website.

Fuel Cell Energy also has an 8 page white paper(pdf) about Fuel Cell Technology.

The website HowStuffWorks has a three minute video about fuel cells.

Carbon Stabilization Wedge Game

This small group activity was developed by the Carbon Mitigation Initiative at Princeton University “to convey the scale of effort needed to address the carbon and climate situation and the necessity of developing a portfolio of options.” By the end of the exercise, students should understand the magnitude of human-sourced carbon emissions and feel comfortable comparing the effectiveness, benefits, and drawbacks of a variety of carbon-cutting strategies including nuclear power. The students should appreciate that there is no easy or “right” solution to the carbon and climate problem.  Students will learn about the technologies currently available that can substantially cut carbon emissions, develop critical reasoning skills as they create their own portfolio of strategies to cut emissions, and verbally communicate the rationale for their selections. Working in teams, students will develop the skills to negotiate a solution that is both physically plausible and politically acceptable, and defend their solution to a larger group.”  Accompanying Slides and Graphics are available for download as well.

This game and its creator was also highlighted in chapter 2 of the recent NOVA special, Power Surge which can be viewed online in under 13 minutes.

DOE’s Fossil Energy Video Gallery

DOE’s Fossil Energy Video Gallery contains short videos pertaining to carbon capture and storage (CCS), geological sequestration of carbon, and gasification technology among others.

Coal without carbon?

What features of coal will enable it to remain part of our energy portfolio well into the future?  How can coal be acquired and/or burned in a more sustainable manner? These are questions addressed in  an article titled Dirty Coal, Clean Future in The Atlantic Magazine’s December 2010 issue.  The article  summarizes the pre- and post- combustion technologies being investigated, with much of the doing and learning occurring in China – a fossil energy “laboratory”.  Here’s an excerpt from the article:

“For the coal industry, the term “clean coal” is an advertising slogan; for many in the environmental movement, it is an insulting oxymoron. But two ideas that underlie the term are taken with complete seriousness by businesses, scientists, and government officials in China and America, and are the basis of the most extensive cooperation now under way between the countries on climate issues. One is that coal can be used in less damaging, more sustainable ways than it is now. The other is that it must be used in those ways, because there is no plausible other way to meet what will be, absent an economic or social cataclysm, the world’s unavoidable energy demands.”

One of the pre-combustion technologies mentioned in the article- a.k.a. coal without carbon – is underground coal gasification.

Additional Resources on Underground Coal Gasification (UCG):

Fire in the Hole This Science & Technology Review article describes how underground coal gasification may provide a secure energy supply and reduce greenhouse gas emissions. By Lawrence Livermore National Laboratory.

PowerPoint presentation: Underground Coal Gasification By Lawrence Livermore National Laboratory.

US Department of Energy’s Coal Gasification page.

What is Clean Coal Technology?

According to the US Department of Energy’s (DOE) Fossil Energy Office, “clean coal technology” describes a new generation of energy processes that sharply reduce air emissions and other pollutants from coal-burning power plants.  Learn more about the clean coal and natural gas initiatives being pursued by the DOE which include carbon capture and sequestration (CCS) technologies and coal gasification.

You can also visit the National Energy Technology Laboratory to learn more about the “large-scale demonstrations of clean coal technologies” that they are funding in partnership with the US Department of Energy as part of their Clean Coal Power Initiative (CCPI). Click on “Coal 101″ in the right-hand tool bar to learn more about coal and clean coal technologies in a reader friendly format.

 

What fossil energy technologies are local scientists investigating?

This four page brochure provides a glimpse at what scientists participating in the Energy Technology Research Program at RTI, International, in NC’s Research Triangle Park, are doing to advance energy technologies.  These technologies include post-combustion carbon capture technologies that rely on either sorbent-based technology to remove CO2 or  CO2 separation based on a novel membrane technology – perhaps of interest to those of you who teach chemistry or want to expose your students to chemistry careers related to energy.

What I am reading now: Sustainable Energy – Without the Hot Air

I have started reading this 2008 book by David MacKay, a Professor in the Department of Physics at the University of Cambridge in preparation for a book club discussion and want to share this finding with you!

http://www.withouthotair.com/

The author wants his book to be read so it is available for FREE as a pdf download and also in a browser friendly format online! A 10-page synopsis is also available for download. And you are free to use all the material, including images and graphs, except for the cartoons and the photos with a named photographer.

Although the book is focused for the most part on the UK’s energy demand and supply what I like about this book is the attention given to NUMBERS (both for the UK and for the globe).

“We need simple numbers, and we need the numbers to be comprehensible, comparable, and memorable.” - David McKay

In keeping with the fossil energy theme for this month’s blog postings below is an excerpt from a chapter titled Sustainable Fossil Fuels?

“Take the known reserves of fossil fuels, which are overwhelmingly coal: 1600 Gt of coal. Share them equally between six billion people, and burn them “sustainably.” What do we mean if we talk about using up a finite resource “sustainably”? Here’s the arbitrary definition I’ll use: the burn-rate is “sustainable” if the resources would last 1000 years. A ton of coal delivers 8000 kWh of chemical energy, so 1600 Gt of coal shared between 6 billion people over 1000 years works out to a power of 6 kWh per day per person. A standard coal power station would turn this chemical power into electricity with an efficiency of about 37% – that means about 2.2 kWh(e) per day per person. If we care about the climate, however, then presumably we would not use a standard power station. Rather, we would go for “clean coal,” also known as “coal with carbon capture and storage”– an as-yet scarcely-implemented technology that sucks most of the carbon dioxide out of the chimney-flue gases and then shoves it down a hole in the ground. Cleaning up power station emissions in this way has a significant energy cost – it would reduce the delivered electricity by about 25%.
So a “sustainable” use of known coal reserves would deliver only about 1.6 kWh(e) per day per person.

We can compare this “sustainable” coal-burning rate – 1.6 Gt per year – with the current global rate of coal consumption: 6.3 Gt per year, and rising.

Our conclusion is clear:

Clean coal is only a stop-gap.

If we do develop “clean coal” technology in order to reduce greenhouse gas emissions, we must be careful, while patting ourselves on the back, to do the accounting honestly. The coal-burning process releases greenhouse gases not only at the power station but also at the coal mine. Coal-mining tends to release methane, carbon monoxide, and carbon dioxide, both directly from the coal seams as they are exposed, and subsequently from discarded shales and mudstones; for an ordinary coal power station, these coal-mine emissions bump up the greenhouse gas footprint by about 2%, so for a “clean” coal power station, these emissions may have some impact on the accounts.”

I encourage you to check out this resource which can help you and your students to view our energy future in a more realistic light.

Webinar: Can Carbon Capture and Storage Clean up Fossil Fuels?

Carbon capture and storage (CCS) entails capturing carbon dioxide from sources such as coal burning power plant emissions,  injecting compressed carbon dioxide gas into geologic reservoirs for long term storage to remove it from the atmosphere.

While geologic sequestration of carbon is not considered to be economically or technically feasible within North Carolina due to its geology, carbon capture is still an option and exposing your students to the technical, geologic and policy implications of CCS can inspire critical thinking about future energy options in general.

This recent (Nov 2010)  webinar by Geoff Thyne of the University of Wyoming provides an overview of CCS, highlights some of the challenges of this technology, and discusses the potential of CCS to offset carbon emissions.

Enhance your teaching of photosynthesis: algal biofuels!

As a former biology teacher, I always loved teaching photosynthesis but struggled to make it interesting and relevant to students and found that although students could learn the overall equation for photosynthesis many could not identify what a plant did with the sugars it produced!  The PBS NOVA interactive From Pond Scum to Power describes the process of photosynthesis, tells what plants and algae do with the sugars created, and discusses why algae and other plants make oil and how algae oil gets converted to biodiesel. Perhaps learning about algal biofuels will help your students better understand photosynthesis and the potential for algae to help meet our future fuel needs.