Saturday, January 30, 2010

Post # 12: Your Life In Uranium and Coal

The average American consumes ~ 14000 kWh of electricity per year - among the highest in the world. That's roughly 1,120,000 kWh of electricity in an 80-year lifespan.

Let's examine how much fuel must be consumed in modern nuclear and coal-fired power plants to produce this amount of electricity – "your life in uranium and coal" so to speak...

Nuclear reactors are powered by fission process  ~ 51000 fuel pins (in a typical gigawatt-class nuclear power plant).  Each of these fuel pins is approximately 1/3-inch in diameter and ~ 12 feet in length (there are many variations, but these are reasonable average numbers.)

Based on the current once-through nuclear fuel cycle (which, by the way, extracts < 10% of the energy that is theoretically available in the fuel), the 14000 kWh of electricity each of us "consume" in a year is produced in only 2.6 inches of ONE nuclear fuel rod!  If you "run the numbers", this means that all of the electricity consumed by one American during their 80-yr life is produced by less than two of these small fuel pins !  In more familiar terms, that's about a soda can of nuclear fuel, or a cube of nuclear fuel a bit less than 4 inches on a side.  How's that for an efficient energy source?

Now compare these estimates to the amount of coal required to produce the same amount of energy.  The average energy content of coal is ~ 6150 kW(t)h / metric ton.  If we assume 40% overall thermal efficiency of the coal-fired plant (generous on average), that same American would consume ~ 455 metric tons of coal.  That's equivalent to a solid cube of coal 135-ft on a side.

So picture this... a soda can of nuclear fuel or a cube of coal 135 feet on a side:

That's "your life in uranium and coal"...


Monday, January 18, 2010

Post # 11: Putting A Lid On Bottled Water ?

Do you ever wonder about the energy consumption and CO2 footprint of a bottle of that cold, clear, water you pickup from the local quick-mart on the way to/from your kid's soccer game?  I became curious about this recently after noticing a beautiful bottle of south-pacific water in my hotel room.

After some digging, I found a very interesting short paper by Gleick and Cooley of the Pacific Institute ( that analyzed this exact question (well.. the energy consumption part of it anyway).  The paper, entitled, "Energy Implications of Bottled Water," is available online at .

Gleick and Cooley analyzed three scenarios for bottled water consumed in the Los Angles area: (1) water locally bottled, (2) water bottled in Fiji, and (3) water bottle in France.  The paper concludes that, depending on the bottling location, the energy required to purify, bottle, and deliver 1 liter of cold, clear bottled water to the consumer's lips is between 5.6 and 10.2 MJthermal/liter. (The larger number is associated with water produced in Fiji.  The energy demand would be even larger for an east-coast USA consumer.

According to Gleick and Cooley, the US consumed approximately 33 million liters of bottled water in 2007.  So if we extrapolate to the total effective energy required to meet the US market, 33E6 liters * 10 MJthermal/liter = 330E6 MJthermal.

The effective carbon footprint of this bottled water depends, of course on the source of the thermal energy.  If we assumed ALL of the energy required came from coal, and assuming a conversion factor of ~ 0.38 kg CO2 / MJthermal, the total CO2 footprint of our bottled-water addiction is approximately 330E6 MJthermal * 0.38 kg CO2 / MJthermal = 125,400,000 kg CO2 or 125,400 MT CO2.  Recalling our total annual US CO2 emissions is approximately 6,000,000,000 MT  CO2, this represents approximately 0.002% of our total annual CO2 emissions.

Significant?  You be the judge...


Tuesday, January 12, 2010

Post # 10: A Home For Life: Dynamic Energy-Sensitive Housing

My wife and I are at the stage in life where we are looking to "right-size", "down-size", and "optimize" our home.  Our kids are grown and out of the house.  Home functionalities that were important at one point in our life are no longer so important.  Functions we've never really considered important are now becoming important (like living on one floor).  We need to move.

Americans have an almost sacred attraction to the concept of "owning our own home".  Our federal policies promote it, our tax laws enable it, and we are taught from birth that home ownership is a major element of the "American Dream".  Our home also becomes a major element of our personal financial worth as we move through life.

But, in a mobile society, home ownership can also impede the periodic relocations that are becoming the norm in today's world.  Further, in a world of limited energy resources, living in a home that is larger than we need is a wasteful.

Our housing needs (size and type of space) change as we move through life.  A single person becomes a couple.  A couple becomes a family.  A family becomes a couple, and often, a couple becomes a widow or widower.  The mobility of youth is traded for the fragility of old age.

This got me to thinking...

What if we pursued a very different approach to home ownership?  Imagine a model in which you purchase the land upon which you will live, but then had the option to add, in a modular fashion, the space you need as you need it, and reduce the space you no longer need as your needs diminish.

How might we accomplish this?

Imagine inter-connecting standardized panels for floors, walls, ceilings, and roofs.  When you need more space (extra bedrooms, bathrooms, etc), you run down to the local Home Depot and purchase more panels or modules.  When you no longer need that second story, that extra bedroom or bath, or that extra garage space, you conveniently disassembly the unneeded modules, truck them back to the local "housing" co-op, and sell them  Voila!  Less space to clean, less space the heat and cool, and a less real estate tax to pay!

How would such a model impact our society and our culture?  Our lifetime energy consumption?  Personal wealth strategies?  Worker mobility?  Community stability?  Governmental fiscal policies,  our banking system, etc.?

My guess is the impacts would be profound in ways we can predict, and in some we cannot.



Thursday, January 7, 2010

Post # 9: Disruptive Technologies and Our Energy Future

I have long been intrigued by the phenomenon of "disruptive technology" (DT). The term was originated by Clayton Christensen in the mid-1990s. Put simply, disruptive technology (also referred to as "disruptive innovation") is a technical innovation that profoundly changes society by providing either a paradigm shift in functionality, delivering existing functionalities at dramatically lower cost than current options, or extending functionalities in to new markets and cultures.

DTs are usually unexpected by the market, and often (but not always) accompanied by rapid rates of societal adoption and market penetration. Recent examples of DT include digital photography, iPods, and cell phones (now merged in many platforms). Other examples might include LEDs, transistors, internal combustion engines, the telephone, the telegraph, and (no doubt) the wheel.

I've given some thought to a "wish list" of disruptive energy technology innovations that would fundamentally change our world and our energy/society/environment dialog. Some of these DTs are in the energy supply sector, some in energy distribution, and some in energy use.

So here goes, "Greene's Wish List of Disruptive Energy Innovations"

1. Carbon capture and storage: Effective, economic carbon capture and storage technologies. This innovation opens the door to continued use of fossil fuels. ScottishPower recently announced a "breakthrough" in carbon capture - 90% carbon capture with a 1/3 reduction in energy consumption relative to current best practice. (See: However, the cost of this technology is still undesirably-high, and then there's the possibly more difficult issue of what to do with all that carbon once you've captured it. (There's got to be a Nobel prize in this for someone.)

2. Energy Storage: Deep-cycle battery or other electrical energy storage technologies with 10 times the current energy storage densities of consumer batteries. Today's lithium-ion batteries are at ~ 0.5 MJ/kg. So we're going for ~ 5 MJ/kg. (Recall crude oil is about 50 MJ/kg energy content. So even such a revolutionary change as I'm describing here would still only move "man-made" energy storage to 10% of that found in nature.) Such technology would open the door to greater production and use of wind and solar electricity, and major reductions in petroleum consumption in the transportation sector by enabling wide-scale adoption of electric vehicles. Without this, it's difficult to see how wind and solar can ever provide more than 25-30% of our electricity because of their destabilizing impact (time and frequency domains) on the grid. An interesting recent (brief) overview by House and Johnson can be found at: A second Nobel for someone.

3. Energy Conservation: Heating and cooling of buildings accounts for almost 40% of total U.S. primary energy consumption. I'm thinking user-installed, mass-market (think Home Depot and Lowes), low-cost, technologies to reduce residential and commercial energy consumption. How about attractive insulating panels that could be backfit to the interiors of homes and office buildings to cut through-wall energy-loss by 50%?

4. Energy Production: Flexible, low-cost, super-efficient solar-PV panes for roof-top (and other surface) mounting. I'm talking efficiencies > 40% at mass-market (think Home Depot and Lowes) prices. Today's best multi-junction concentrating solar cells have run at ~ 40% efficiency in idealized laboratory tests. Moving this efficiency into affordable mass-market products would be revolutionary. There is hope. Researchers at Idaho National Laboratory have recently developed a "nanoantenna" technology that might someday achieve efficiencies as high as 80% according to their reports. See:

5. Energy Production: Small (say 100 - 300 MWe), high-temperature (800-900 C) nuclear process heat and electricity systems. I'm talking factory-fabricated power and process heat systems for less than $2B/kWe. These affordable high-temperature systems will enable 50% efficient electric power conversion systems and high-temp process heat for a wide variety of industrial uses.

These five Disruptive Innovations would fundamentally change the nature of our energy/environment challenge, reduce global greenhouse gas emissions, and improve the energy security of the U.S. It is an interesting reality that most of these "wish list" items will require solution to long-standing challenges in the materials engineering and science arena.

Let's get cracking ....


Monday, January 4, 2010

Post # 8: The Carbon Footprint of Electricity Production

I've been searching for credible information on the "life-cycle" carbon footprint of electricity generation from different sources. By "life-cycle", I mean the total effective carbon footprint ( CO2 emitted / unit of electricity generated) including resource extraction, power plant and equipment manufacturing and construction, and power production operations. Reliable information is difficult to come by - principally because it is devilishly hard to calculate these life-cycle CO2 footprints in a consistent manner.

The five studies I've chosen to summarize here are referenced at the end of this post. The studies were conducted by a variety of organizations for different purposes over a 9-year period between 1998 and 2006. I've summarized the results of the five studies in the graphic below, which displays the range and the average value of the emissions estimates from the five studies for each of the generation types. All generation types were not evaluated by each study, and in some cases (Wave/Tidal and Oil) only point estimates were give. (Note to reader: g CO2/kWh = kg CO2/MWh = MT CO2/GWh). You'll probably need to click on the image to see the expanded version if you want to read the values from the chart.

Several conclusions can be drawn from the chart above and from a more detailed review of the actually reports from which the data are taken:

(1) there is no significant difference between the life-cycle carbon footprint of hydro, nuclear, and wave/tidal power; and all three electricity generation sources are substantially better (by two orders of magnitude or more) than coal and natural gas.

(2) wind and biomass have ~ twice the CO2 emission footprints of hydro, nuclear, and wave/tidal - but still far superior to natural gas, coal, and oil

(3) solar-PV appears to have a significantly higher CO2 emission footprint than hydro, nuclear, wave/tidal, wind and biomass. There's some interesting details in the analysis. While the majority of studies place it's CO2 footprint near that of hydro, nuclear, and wave/tidal, some studies estimate a significantly higher footprint (hence the range shown the plot). Some of this may be due to different assumptions regarding the specific solar-PV technologies employed, differing assumptions regarding the deployment location of the solar-PV systems,and some may be due to the specific analysis methodologies employed.  I find it difficult to believe solar-PV's CO2 footprint could be even close to that of natural gas, but I need to understand this better.

(4) the three fossil sources (natural gas, coal, and oil) are all problematic unless/until we overcome the carbon capture/storage challenge . Breakthroughs in carbon capture and sequestration technologies for these fossil-driven electricity sources would tremendously improve our chances of achieving the global green house gas emission reductions we need.

Last words... if you're interested in reducing CO2 emissions, and you believe in dealing with the facts, you must give serious thought to the "low-carbon portfolio": hydro, nuclear, wave/tidal, geothermal, and biomass. I'm not putting solar in this category just yet. Solar probably belongs in the low-carbon portfolio, but I want to understand the wide variation in CO2 emissions footprints noted above, before I draw that conclusion..


1. "ExtremE - Externalities of Energy. National Implementation In Germany,"Krewitt, Mayerhofer, Friedrich, et al., IER, Stuggart, 1998

2. "Hydropower-Internalized Costs and Externalized Benefits," Frans H. Koch, International Energy Agency (IEA), Implementing Agreement for Hydropower Technologies and Programs, Ottawa, Canada, 2000

3. "A guide to life-cycle green house gas (GHG) emissions from electric supply technologies", Daniel Weisser, PESS/IAEA, IAEA Bulletin 2000

4. "Life-Cycle Assessment of Electricity Generation Systems and Applications for Climate Change Policy Analysis," Paul J. Meier, University of Wisconsin - Madison, August, 2002 (

5. "Carbon Footprint of Electricity Generation", Science and Technology Postnote # 268, UK Parliamentary Office of Science and Technology, October 2006 (

Friday, January 1, 2010

Post # 7: My 2010 Reading List

I've been giving some thought to my personal reading list for 2010. I have rather eclectic interests and resultant reading habits. (I like classical english novels, a few english-language poets, and the Bible - but that's a different reading list.) When it comes to energy/society/environment issues, I like to read penetrating analysts by broad thinkers - even if I don't agree with them. (Why waste my time only reading authors who think like me?) I believe our reading should stretch us, enrich us, inform us, and stir us to action.

With this as background, here' s my current 2010 energy/society/environment reading list:

The GeoPolitics of Energy: Achieving a Just and Sustainable Energy Distribution by 2040 by Judith Wright and James Conca. I've met Jim Conca. He's an articulate and passionate communicator of our global energy plight, and its connection to quality-of-life issues for the 2/3 of the world population who are suffer through their days and nights with little of no access to energy.

The Long Emergency by James Howard Kunstler: A controversial hit that sparked an intense debated among businessmen, environmentalists, and bloggers when it was published 2005 and 2006. Kunstler is a strong critic of rural sprawl in America, and a strong believer in peak oil. (I'm already into this one...)

Sustainable Energy - Without the Hot Air by David JC MacKay: A recent, very popular book on low-carbon energy options. MacKay is getting high marks for his pragmatic, penetrating analysis of our options.

Whole Earth Discipline: An Ecopragmatist Manifesto by Stewart Brand. Brand is the founder of the Whole Earth Catalog. In recent years, he (like Patrick Moore, the co-founder of Greenpeace) has evolved away from his earlier narrow solution set to our global energy/environment problems, to a broader "portfolio" approach to solving our complex problems.

Blackout by Richard Heinberg. Heinberg is a well-known advocate of our need to move away from fossil energy sources. Has a sharp focus on global, systems-level solutions. From what I know of him, he also has a refreshing tendency not to sugar-coat the warts of any of the energy sources and solutions.

Two books by Vaclav Smil: (1) "Energy in Nature and Society: General Energetics of Complex Systems", and (2) the more recent "Global Catastrophes and Trends: The Next Fifty Years". Smil, a Distinguished Professor in the Faculty of Environment at the University of Manitoba has a reputation as a provocative and thoughtful analyst. However, from my limited exposure to his writings, his position on nuclear energy appears dated and unbalanced. Nevertheless, he tends to be a mind-stretcher.

Guns, Germs, and Steel by Jared Diamond: Pulitzer Prize winning book on the fate of human societies (His more recent book, "Collapse" is one of my favorites.)

A Short History of Nearly Everything by Bill Bryson. Bryson is a great science writer. This book, which was originally published in 2003, is supposed to be one of his best.

A Road More or Less Traveled by Otis & Roberts. A book recently published by two young men who hiked the Appalachian Trail from Maine to Georgia. It's full of hilarious stories, thought provoking introspective, and reflective criticism about our society and our culture. (Yes, I'm already well into it...)

What Jesus Demands From the World by John Piper. Piper is one of my favorite modern Christian writers. Always thought-provoking, hard hitting, and always focused on bringing the reader to a personal engagement with Jesus Christ and personal obedience to His Word.

I told you it is an eclectic list .... :)

Cheers, and Happy New Year!