Dec 30, 2008

Popular posts of 2008

This blog started from a discussion I had with Nari early this year. We wanted to see where the blog would be headed, and I am happy to report that our posts have generated meaningful discussion and interest. In this year, we have blogged on topics ranging from clean coal, coal-to-liquids, underground coal gasification, solar PV, biofuels, cement, and GHG emissions. The following posts have more than 50 unique pageviews, starting July 2008:


Dec 25, 2008

Happy Holidays!

Happy Holidays to our readers. Thanks for your support and comments! Look for my (Pradeep's) guest post on the short-term outlook for U.S. biofuel industry to appear online tomorrow on the The Big Biofuels Blog.
Update: My article on The Big Biofuels Blog is: U.S. Biofuels : Near-term challenges and prospects


Dec 19, 2008

X-Algae: Mutant algae for biofuel production?

Chlorophyll A structure showing the central magnesium atom in green, nitrogen in blue, oxygen in red, carbon in black and hydrogen in white. Image credits: Wikipedia

Researchers have found that genetic truncation of the size of chlorophyll arrays in algae leads to higher photosynthetic algal yields, by increasing light absorption/mass of algae. This article is available online. M. Mitra and A. Melis, "Optical properties of microalgae for enhanced biofuels production," Opt. Express 16, 21807-21820 (2008).

"Abstract: Research seeks to alter the optical characteristics of microalgae in order to improve solar-to-biofuels energy conversion efficiency in mass culture under bright sunlight conditions. This objective is achieved by genetically truncating the size of the light-harvesting chlorophyll arrays that serve to absorb sunlight in the photosynthetic apparatus."
Nature optimizes each algae to maximize its light absorption to survive in the wild. However, the large size of these light-absorbing chlorophyll arrays leads to sub-optimal light utilization when growing algae for biofuel production, because light has to be distributed as far as possible in the growth medium to ensure optimal light utilization and increased yields per unit time per unit area. When grown in the mass culture, the mutant algae evolved oxygen at a 2 to 3-fold higher rate compared to the wild-unmodified algae, indicating potential algal biofuel yield increases of 100% to 200%.

Implications for algal biofuel production:
Previous posts (yields, CO2 capture, economics) on this blog have focused on various aspects of algal biofuel production. Because algal yields significantly influence the economics, increasing the light absorption per unit volume in the algal growth medium would lead to accelerated commercialization.


Dec 18, 2008

Opinion: Are win-win solutions to our energy and environmental problems possible?

Image credits: Apollo Alliance
Folks at the Environmental Economics blog have a great ongoing discussion on whether "green policies" would create additional jobs in the long run. John Whitehead thinks that "Green government fiscal policy doesn't create jobs in the long run", whereas Mark Thoma thinks that green policies would create jobs in the short run and help stabilize the economy. Mark also argues that the lack of empirical evidence for green policies creating additional jobs does not apply to the current state of the economy.

My 2 ¢: I agree with Mark that green policies would create incentives for job creation in the short-run. However, this should be balanced against the job losses from the traditional sectors of the industry in the long-run. Examples include the potential job-losses in the U.S. (& Indian/Chinese) coal mining industry because of CO2 regulations. Various stakeholders (government, industry, workers and the public) should be involved in environmentally and economically-sound policy making.


Dec 8, 2008

Water, water everywhere.....

How is water related to energy?
For a start, the sun's energy sets the water cycle into motion. Perhaps more important is that climate change will likely lead to accelerated melting of glaciers which feed many of the Himalayan rivers such as the Indus, Ganges-Brahmaputra and the Yangtze. The Gangotri glacier shown in the figure to the left is the source of the Ganges. Therefore, climate change (greenhouse gas emissions) would directly affect ~1.3 billion people who live in the drainage basin of these Himalayan rivers. The first figure shows regions of the world which are currently facing water scarcity. As defined by the "Water for food Water for life" study, economic water scarcity occurs when human, institutional and financial capital limit access to water even where water is available locally. Physical water scarcity occurs when more than 75% a region's river flows are withdrawn for agriculture, industry, and domestic purposes. I am particularly interested in sub-Saharan Africa, South Asia and China, as these are the major population centers where water scarcity is prevalent. (An interesting way to visualize this is shown on the worldmapper site).

    The IPCC Technical Paper VI projects that:
  • The per capita availability of fresh water in India will drop from 1820 m3 currently to 1000 m3 (yearly basis) as a result of population growth and climate change. In comparison, the global average by 2025 is expected to be ~5000 m3. India's population will therefore be using 1/5th of the world average per capita water consumption.
  • More intense precipitation in Asia would result in a higher runoff and reduction in the portion recharging the groundwater aquifers.
  • Agricultural irrigation demands in arid and semi-arid regions of east Asia would be expected to increase by 10% for a 1 degree C increase in temperature.
  • Changes in snow and glacier melt will cause seasonal shortages and affect 1/4th of China's population and hundreds of millions of India's population. (~0.3-0.6 billion combined).
  • Arid and semi-arid land in Africa would increase 5-8% by 2080.
  • Current water stress in Africa will likely be increased by climate change.
  • Any changes in the primary production of large lakes (Lake Chad, Lake Tanganyika) will have important impacts on local food supplies.

My perspectives: Economic water scarcity is another dimension of the "Water, water everywhere.." problem. Low-cost means to treat water and responsible aquifer management are required to overcome economic water scarcity. Physical water scarcity will need similar measures, and various end-users (farmers, industry, households) must be encouraged to conserve and recycle where possible. Farm subsidies for water-intensive crops (ex: sugarcane, paddy), will likely have significant impacts on water conservation and scarcity. Balanced policy planning is therefore required to manage local, regional and national water resources. Finally, regional cooperation, as outlined in an earlier post will be necessary to ensure equitable distribution of water resources among different stakeholders.

Related articles:


Dec 4, 2008

Graphic of the week: U.S. CO2 sources and regional cap-and-trade agreements

Here is a map of U.S. CO2 sources (from the NETL carbon sequestration atlas) overlaid with the states which are participants/observers in) various regional GHG reduction initiatives. More information from the Pew Center on Global Climate Change. Briefly, the abbreviations in the figure are:
  1. WCI: Western Climate Initiative
  2. MGGA: Midwestern Greenhouse Gas Reduction Accord
  3. RGGI: Regional Greenhouse Gas Initiative
In addition, through House Bill 7135, pending legislative approval, Florida's EPA will develop a GHG cap-and-trade program.
Note: Some provinces of Canada also participate in these agreements, however, they are not shown here.


Dec 3, 2008

2007 US greenhouse gas emissions: cement, limestone, natural gas, and other industries

The Energy Information Administration (EIA) has released a report on U.S. greenhouse gas (GHG) emissions in 2007 (Note: ftp link).

What attracted my attention was the "other sources" category, of which cement contributed ~46 million metric tons (MMT) of CO2/year in 2007 (~0.8% of total U.S. greenhouse gas emissions). The next highest contributor was lime-making, which involves limestone calcination. Aluminium (3.8 MMT) production contributes much lesser to U.S. GHG emissions compared to cement production. Additionally, iron and steel production likely contributes ~45 MMT CO2/year. On the other hand, recent high-gas prices partly contributed to higher natural gas production (and higher CO2 co-produced from natural gas). CO2 emissions from natural gas-flaring in the U.S. were not projected to change from 2006 (7.8 MMT CO2/year). In the figure, the values for natural gas show a spike in 1995, from my data it appears to be due to significantly higher natural gas flaring, than CO2 production from natural gas.


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