Expert says big energy picture must balance security, sustainability, and supply

Expert says big energy picture must balance security, sustainability, and supply

The world has no choice but to build more energy-producing plants--and find new sources of energy--but the build out process will not happen overnight, a government expert recently told an MIT audience.

A worldwide boost in demand for energy, coupled with environmental concerns, will force a huge U.S. increase inthe number of nuclear power plants--but it will take more than two decades to come to fruition, according to Carl O. Bauer, director of the U.S. Department of Energy's National Energy Technology Laboratory (NETL).

Bauer's Feb. 26 colloquium, "Energy Supply and Demand, Economics and Greenhouse Gas Management: Are They Related?" was sponsored by the MIT Energy Initiative. The discussion focused on the intertwined aspects of security, sustainability, supply and the environment in relation to the world's energy production.

Bauer said blackouts in California, Texas and New England by 2016 are just some of the challenges facing decision makers as they tackle America's energy future.

"I happen to believe we're right on the cusp of a huge energy build out because we have no choice," Bauer said. But, he added, the lack of U.S. nuclear plant construction in recent decades has led engineers to turn to other fields, and construction companies to commit resources to building plants overseas.

In facing the U.S. energy challenge, decision makers, he said, must juggle three "co-dependent" entities: the economic sustainability of energy sources; energy supply and security; and the effect of solutions on the environment and climate change. But "too often we divorce the circles and make a decision in policy that we can't live with," he said.

Coal, natural gas and oil use will remain largely unchanged in the United States over the next two decades, projections show, while the use of renewables is likely to increase from 6 to 9 percent of the total. Nuclear is slated to remain constant at 8 percent because old plants will shut down and new plants can't come on line fast enough to make a big dent in usage patterns by 2030.

And while U.S. energy use is expected to increase by 25 percent in that time frame, worldwide energy demand is expected to leap 50 percent, further straining resources.

"Do we think the oil supply can grow by 50 percent? The challenge for increasing the oil supply is increasingly onerous, and many believe peaking will happen in this decade," Bauer said. We will become increasingly dependent on coal and natural gas, which have their own supply and production problems, he said.

A state-by-state North American Electric Reliability Corp. long-term reliability assessment questioned states' capacity to generate electricity for the hottest days of summer in coming years.

Besides possible peak-usage brownouts and blackouts, the shortfall could bump up electricity prices in states neighboring high-demand regions by 30 to 40 percent.

While alternatives such as wind look promising, even the country's windiest states--such as North Dakota and South Dakota--don't have enough consistently windy days to meet high demand. Nights--when demand is down for air conditioning--tend to be windiest.

Managing public electricity use--limiting use during peak times or setting allowances--could become a reality.

If so, Bauer predicted that Americans might be in for some unfamiliar discomfort.

"How much are we willing to sweat or shiver?" he said. "How much are we going to allow someone to manage our own use through a meter on our house to control the flow of electricity and shut us down if demand goes too high?"

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Team probes mysteries of oceanic bacteria

Wee creatures are key to Earth's environment

Microbes living in the oceans play a critical role in regulating Earth's environment, but very little is known about their activities and how they work together to help control natural cycles of water, carbon and energy.

A team of MIT researchers led by Professors Edward DeLong and Penny Chisholm is trying to change that.

Borrowing gene sequencing tools developed for sequencing the human genome, the researchers have devised a new method to analyze gene expression in complex microbial populations. The work could help scientists better understand how oceans respond to climate change.

"This project can help us get a better handle on the specific details of how microbes affect the flux of energy and matter on Earth, and how microbes respond to environmental change," said DeLong, a professor of biological engineering and civil and environmental engineering.

"The new approach also has other potential applications, for example, one can now realistically consider using indigenous microbes as in situ biosensors, as well as monitor the activities of human-associated microbial communities much more comprehensively," DeLong said.

Their technique, which has already yielded a few surprising discoveries, is reported in the March 3 issue of the Proceedings of the National Academy of Sciences.

The work was facilitated by the Center for Microbial Oceanography: Research and Education (C-MORE), a National Science Foundation Science and Technology Center established in 2006 to explore microbial ocean life, most of which is not well understood.

The traditional way to study bacteria is to grow them in Petri dishes in a laboratory, but that yields limited information, and not all strains are suited to life in the lab. "The cast of characters we can grow in the lab is a really small percentage of what's out there," said DeLong, who is research coordinator for C-MORE.

The MIT team gathers microbe samples from the waters off Hawaii, in a part of the ocean known as the North Pacific Gyre.

Each liter of ocean water they collect contains up to a billion bacterial cells. For several years, researchers have been sequencing the DNA found in those bacteria, creating large databases of prevalent marine microbial genes found in the environment.

However, those DNA sequences alone cannot reveal which genes the bacteria are actually using in their day-to-day activities, or when they are expressing them.

"It's a lot of information, and it's hard to know where to start," said DeLong. "How do you know which genes are actually important in any given environmental context?"

To figure out which genes are expressed, DeLong and colleagues sequenced the messenger RNA (mRNA) produced by the cells living in complex microbial communities. mRNA carries instructions to the protein-building machinery of the cell, so if there is a lot of mRNA corresponding to a particular gene, it means that gene is highly expressed.

The new technique requires the researchers to convert bacterial mRNA to eukaryotic (non-bacterial) DNA, which can be more easily amplified and sequenced. They then use sequencing technology that is fast enough to analyze hundreds of millions of DNA base pairs in a day.

Once the sequences of highly expressed mRNA are known, the researchers can compare them with DNA sequences in the database of bacterial genes and try to figure out which genes are key players and what their functions are.

The team found some surprising patterns of gene expression, DeLong said. For example, about half of the mRNA sequences found are not similar to any previously known bacterial genes.

Lead authors of the paper are Jorge Frias-Lopez, research scientist in MIT's Department of Civil and Environmental Engineering (CEE), and CEE graduate student Yanmei Shi. Maureen Coleman, graduate student in CEE, Gene Tyson, postdoctoral associate in CEE, and Stephan Schuster of Pennsylvania State University also authored the paper with Chisholm and DeLong.

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