Friday, July 28, 2006

Oil Exploration from the Sky: Fast and Wide

As time goes by, better and better methods for finding mineral wealth, including oil, will be developed. This TechReview article reports on a new method of aerial search for oil reserves:

A new airborne technology for mapping oil fields could locate new oil reserves by drastically cutting survey costs, and help companies identify untapped oil within new reserves.

Las Vegas, NV-based startup eField Exploration recently completed a survey of existing oil fields in Texas in which it revealed extensions of these fields into areas that traditional methods did not spot, according to company president Ed Johnson. Drilling to confirm the findings will likely begin soon, he says.

The new method uses existing electromagnetic imaging technologies in a novel airborne system that can quickly cover large areas, thus reducing costs. It also potentially reduces the environmental impact of exploration by eliminating the need to bulldoze wide roads for the heavy equipment used in seismic surveys.

According to Dan Burns, a research scientist in MIT's earth resources laboratory, while seismic surveys are currently by far the most common method of imaging oil fields, electromagnetic (EM) imaging is gaining in popularity because it is more reliable. Electromagnetic imaging is a more direct way to detect oil than seismic surveys, since it can measure differences between oil and water, something seismic methods can't do. "There's clearly a move more and more toward electromagnetics," Burns says. "In general, seismic techniques are responding to differences in the rocks themselves, as opposed to fluids, whereas EM methods are much more sensitive to fluids."

.....Because their method reduces costs, eField is also exploring another potential benefit: rapidly scouting for potential oil deposits in new areas or in areas that have already been mapped but with inadequate methods due to high costs. By quickly covering large areas (the Texas survey took in 3,100 miles) and generating maps in weeks instead of months, the new airborne technology can cut costs per "line mile" for large areas to about $100, Johnson says, rather than the hundreds of thousands of dollars per mile he says seismic surveys cost.

A person almost needs to be totally oblivious to the real world, to believe that most of the world's oil reserves have already been located, much less extracted. Fixation on earth-changing catastrophes is a natural stage in human development, but persons who get stuck in that fixation can easily lose touch with reality. This is true for religious apocalyptics as well as ideological apocalyptics.

There is plenty of room in the real world for those who want to solve problems.

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Thursday, July 27, 2006

OTEC---Energy From the Deep and Shallow

Solar energy is the most abundant form of energy available on Earth. But since sun energy is only available for part of the day, it is difficult to store that energy for use when it is needed. One way around that is to use solar energy that has already been stored. The oceans soak up the sun's energy and store it as heat in the surface layers. Deeper layers of ocean are much cooler. By using the heat differential between deep and surface layers, huge quantities of usable power could be extracted from tropical parts of the Atlantic, Pacific, and Indian Oceans.

This story from Technology Review
replays some of the history of the thinking about OTEC:

In the October 1978 issue of TR, William F. Whitmore invoked an idea from the 19th century: ocean thermal energy conversion, or OTEC. Exploiting the temperature difference between the sun-heated surface of tropical waters and the chilled depths thousands of feet below, Whitmore argued, could provide clean, renewable energy in the lower latitudes.

In the tropics, the oceans store an immense amount of energy from the sun. The band of surface water within 10º of the equator basks around at 80º F., while cold regions 3,000 ft. below are around 40º F. [OTEC] uses this thermal gradient, like the hot and cold terminals of a gas turbine, to generate electricity. The essence of the system is the circulation of a fluid such as ammonia or propane. Where it comes near the warm water it is brought to a boil and so expands; where it comes near the cold, it liquefies once again. In the course of its circulation from one place to another, it drives a power-generating turbine. A typical closed-loop system would include two exchangers (evaporator and condenser), a turbine, and a generator.

... The engineering challenges to be bridged demand solutions of scale rather than of technical innovation. Ship designs and structures used for offshore oil platforms have blazed the trail for the physical platform on which OTEC will be mounted. A general design goal is to isolate the platform as much as possible from the influence of the ocean surface, where the interaction of wind and wave can induce violent platform motions. A leading candidate is a large spar buoy configuration, with most of the platform mass several hundred feet underwater and a relatively small surfacepiercing mast for access; this would also give warning to marine traffic. The OTEC system, with power cabled to shore, is necessarily fixed in place. Both steel and concrete are considered as possible platform construction materials.

In the 1990s, 250-kilowatt test facilities in Hawaii's tropical waters demonstrated OTEC's feasibility. For a plant to be commercially viable in the United States, however, it would have to produce between 50 and 100 megawatts. Developing such plants would require "patient financing," according to Luis Vega, test director of the largest test plant operated by the Pacific International Center for High Technology Research, which ran the Hawaiian facilities. The first step would be a prototype plant of a few megawatts. Ultimately, Vega believes, not only would a commercial-scale OTEC plant be viable, but it could operate at six to eight cents per kilowatt-hour, making it competitive with other renewable energy sources and even with fossil-fuel plants.
More at Technology Review.

In international waters, an enterprising group able to install a permanent infrastructure incorporating a seastead community and resort, OTEC, international financial services, aquafarming, and perhaps ocean based space launch and recovery services, could go from a billion dollar conglomerate to a trillion dollar superpower in a very short time.

The oceans are a giant solar pond, storing the sun's energy for anyone willing and able to tap it. The OTEC news blog is one website that tries to keep up with developments in this area.


Sunday, July 23, 2006

Cellulosic Ethanol: Down to Micro-scale

Cellulose is nature's structural polymer. It is hard to break cellulose down into its constituents, otherwise there would be no tall trees. But now that the liquid fossil fuel supply is not flowing fast enough to meet world demand, industrialists find that they would like to be able to get at the energy stored inside cellulose--the individual sugar molecules that are polymerised into cellulose. If you can get to the sugar molecules, you can ferment them into a useful liquid fuel--ethanol, or perhaps butanol.

Here is a Technology Review article that deals with the engineering of micro-organisms that could aid people in the extracting of sugars from cellulose, and the further fermentation of these sugars into useful liquid fuels:

Producing ethanol fuel from biomass is attractive for a number of reasons. At a time of soaring gas prices and worries over the long-term availability of foreign oil, the domestic supply of raw materials for making biofuels appears nearly unlimited. Meanwhile, the amount of carbon dioxide dumped into the atmosphere annually by burning fossil fuels is projected to rise worldwide from about 24 billion metric tons in 2002 to 33 billion metric tons in 2015. Burning a gallon of ethanol, on the other hand, adds little to the total carbon in the atmosphere, since the carbon dioxide given off in the process is roughly equal to the amount absorbed by the plants used to produce the next gallon.

Using ethanol for auto fuel is hardly a new idea (see "Brazil's Bounty"). Since the energy crisis of the early 1970s, tax incentives have pushed ethanol production up; in 2005, it reached four billion gallons a year. But that still translates to only 3 percent of the fuel in American gas tanks. One reason for the limited use of ethanol is that in the United States, it's made almost exclusively from cornstarch; the process is inefficient and competes with other agricultural uses of corn. While it is relatively easy to convert the starch in corn kernels into the sugars needed to produce ethanol, the fuel yield is low compared with the amount of energy that goes into raising and harvesting the crops. Processing ethanol from cellulose -- wheat and rice straw, switchgrass, paper pulp, agricultural waste products like corn cobs and leaves -- has the potential to squeeze at least twice as much fuel from the same area of land, because so much more biomass is available per acre. Moreover, such an approach would use feedstocks that are otherwise essentially worthless.

Converting cellulose to ethanol involves two fundamental steps: breaking the long chains of cellulose molecules into glucose and other sugars, and fermenting those sugars into ethanol. In nature, these processes are performed by different organisms: fungi and bacteria that use enzymes (cellulases) to "free" the sugar in cellulose, and other microbes, primarily yeasts, that ferment sugars into alcohol.

In 2004, Iogen, a Canadian biotechnology company based in Ottawa, began selling modest amounts of cellulosic ethanol, made using common wheat straw as feedstock and a tropical fungus genetically enhanced to hyperproduce its cellulose-digesting enzymes. But Iogen estimates that its first full-scale commercial plant, for which it hopes to break ground in 2007, will cost $300 million -- five times the cost of a conventional corn-fed ethanol facility of similar size.

The more one can fiddle with the ethanol-producing microbes to reduce the number of steps in the conversion process, the lower costs will be, and the sooner cellulosic ethanol will become commercially competitive. In conventional production, for instance, ethanol has to be continually removed from fermentation reactors, because the yeasts cannot tolerate too much of it. MIT's Greg Stephanopoulos, a professor of chemical engineering, has developed a yeast that can tolerate 50 percent more ethanol. But, he says, such genetic engineering involves more than just splicing in a gene or two. "The question isn't whether we can make an organism that makes ethanol," says Stephanopoulos. "It's how we can engineer a whole network of reactions to convert different sugars into ethanol at high yields and productivities. Ethanol tolerance is a property of the system, not a single gene. If we want to increase the overall yield, we have to manipulate many genes at the same time."

The ideal organism would do it all -- break down cellulose like a bacterium, ferment sugar like a yeast, tolerate high concentrations of ethanol, and devote most of its metabolic resources to producing just ethanol. There are two strategies for creating such an all-purpose bug. One is to modify an existing microbe by adding desired genetic pathways from other organisms and "knocking out" undesirable ones; the other is to start with the clean slate of a stripped-down synthetic cell and build a custom genome almost from scratch.

Lee Lynd, an engineering professor at Dartmouth University, is betting on the first approach. He and his colleagues want to collapse the many biologically mediated steps involved in ethanol production into one. "This is a potentially game-changing breakthrough in low-cost processing of cellulosic biomass," he says. The strategy could involve either modifying an organism that naturally metabolizes cellulose so that it produces high yields of ethanol, or engineering a natural ethanol producer so that it metabolizes cellulose.

This May, Lynd and his colleagues reported advances on both fronts. A team from the University of Stellenbosch in South Africa that had collaborated with Lynd announced that it had designed a yeast that can survive on cellulose alone, breaking down the complex molecules and fermenting the resultant simple sugars into ethanol. At the same time, Lynd's group reported engineering a "thermophilic" bacterium -- one that naturally lives in high-temperature environments -- whose only fermentation product is ethanol. Other organisms have been engineered to perform similar sleights of hand at normal temperatures, but Lynd's recombinant microbe does so at the high temperatures where commercial cellulases work best. "We're much closer to commercial use than people think," says Lynd, who is commercializing advanced ethanol technology at Mascoma, a startup in Cambridge, MA.

Others are pursuing a far more radical approach. Soon after the State of the Union speech, Patrinos left the DOE to become president of Synthetic Genomics, a startup in Rockville, MD, founded by Craig Venter, the iconoclastic biologist who led the private effort to decode the human genome. Synthetic Genomics is in hot pursuit of a bacterium "that will do everything," as Venter puts it. With funding from Synthetic Genomics, scientists at the J. Craig Venter Institute are adding and subtracting genes from natural organisms using the recombinant techniques employed by other microbial engineers. In the long run, however, Venter is counting on an approach more in keeping with his reputation as a trailblazer. Rather than modify existing organisms to produce ethanol and other potential biofuels, he wants to build new ones.

Natural selection, argues Venter, does not design life forms to efficiently perform the multitudinous functions their genes encode, much less to carry out a dedicated task like ethanol production. Consequently, a huge amount of effort and expense goes toward figuring out how to shut down complex, often redundant genetic pathways that billions of years of evolution have etched into organisms. Why not start with a genome that has only the minimal number of genes needed to sustain life and add to it what you need? "With a synthetic cell, you only have the pathways in there that you want to be in there," he says.
Much more at Technology Review.

When you consider that biomass derived liquid fuels stand to replace a significant amount of oil-based fuels, you can begin to understand the type of money that is at stake. It is not inconceivable that in the future a biomass entrepreneur might easily have a higher personal worth than Bill Gates. That is not as much as future outer space entrepreneurs will be worth, but that will be then, this is now.

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Tuesday, July 18, 2006

More on Thermoelectrics: Thermophotovoltaics

Last week I posted on Rennselaer's active building envelope technology, utilising thin-film thermoelectric heat pumping combined with thin film photovoltaics. The ABE technology could effectively replace conventional heating and air conditioning systems, and provide electricity to the building at the same time.

Researchers at MIT are working on a novel form of thermoelectric technology for use in automobiles. Called thermophotovoltaics, it involves using heat to generate light at specific wavelengths, which is then used to generate electricity with photovoltaics. Multiple energy conversions are involved--from chemical to heat to light to electricity--which risks introducing inefficiencies into the process. Regardless, it is quite clever, and may eventually find an economical fit in tomorrow's automobiles, in replacing mechanical devices such as alternators and compressors.

According to Kassakian, the system could potentially be a more efficient way to power electrical systems in a vehicle than the current alternator-based one, which wastes energy in two stages: the internal combustion engine converts only about 30 percent of the energy in fuel into movement, and then the alternator is only 50 percent efficient in converting the mechanical energy into electricity. He says a small prototype thermophotovoltaics device that could confirm the system's improved efficiency might be ready in a year.

The researchers modified the surface structure of the light emitter, etching into it nano-sized pits to tune the wavelengths of light emitted to precisely those a photovoltaic cell can convert most efficiently into electricity. They further refined the device with the use of filters that allow the desired wavelengths of light to pass through to the photovoltaic cells, but reflect other wavelengths back to the light emitter. The reflected light carries energy that helps keep the emitter hot, reducing the amount of fuel needed.

In addition to replacing the alternator with a thermophotovoltaic module, says Kassakian, the technology could be part of an air-conditioning system for vehicles that doesn't require a compressor. Because this would significantly decrease the load on an engine, it could make it possible to turn off the engine when the vehicle stops in traffic and easily restart it.

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Tuesday, July 11, 2006

Active Building Envelope from Rennselaer

Every day, the sun bathes the planet in energy--free of charge--yet few systems can take advantage of that source for both heating and cooling. Now, researchers are making progress on a thin-film technology that adheres both solar cells and heat pumps onto surfaces, ultimately turning walls, windows, and maybe even soda bottles into climate control systems. On July 12, 2006, Rensselaer Polytechnic Institute (RPI) researcher Steven Van Dessel and his colleagues will announce their most recent progress--including a computer model to help them simulate the climate within their test structure atop the RPI Student Union--at the Solar 2006 Conference in Denver, Colo. For 4 years, the researchers have been working on their prototype Active Building Envelope (ABE) system. Comprised of solar panels, solid-state, thermoelectric heat pumps and a storage device to provide energy on rainy days (literally), the ABE system accomplishes the jobs of both cooling and heating, yet operates silently with no moving parts. NSF is supporting the team to determine if a microscale version of the technology will function effectively. According to Van Dessel, thin-film advances could potentially lead to functional thermal coatings composed of transparent ABE systems. Such systems might vastly improve the efficiency of temperature-control systems. "The ease of application would make it possible to seamlessly attach the system to various building surfaces," he added, "possibly rendering conventional air conditioning and heating equipment obsolete."

Here is more information on the ABE system from Physorg

Thermoelectric heating, cooling, and electrical generation, are ways in which sunshine can be used directly for temperature control and power production. Van Dessel and the Rennselaer team are dedicated to integrating this powerful technology into all new construction. The team has made a great deal of progress in the past three or four years, in miniaturizing the technology, converting it into a thin film. Eventually, molecular scale coatings will probably accomplish the same hat trick.


Monday, July 10, 2006

Making Solar Energy More Usable

The rate of solar energy intercepted by the earth is about 5,000 times greater than the sum of all other energy sources, but less than 0.5 percent is represented in the kinetic energy of the wind, waves and in photosyntheticstorage in plants. The amount of the solar energyintercepted by earth is only one thousandth of one millionof the total released energy in the sun. Source.

One of the main problems with harvesting solar power on earth, is the limited number of hours per day that sunlight reaches the surface. Using photovoltaics, you are limited to an average of six hours per day of usable energy production, minus time for bad weather. Often the periods of heaviest usage of energy are times that the sun does not shine.

One way around that problem is to place photovoltaic panels in earth orbit, well above the shadow of the earth. Generated power can be beamed to earth by microwave, and collected by large rectenna farms on the surface. Here is a link to a blog, Power From Space, devoted to this topic.

Another method is to collect the sun's energy while it shines, and store the energy for later use. This method does not collect nearly as much energy as the orbiting solar satellites, but the sun provides so much extra energy to earth that it will suffice. What is the best method of storing solar energy?

Batteries are no good, because the energy density of batteries is too low, given their cost and short lifetimes. The only possible exception in terms of current battery technology would be redox flow cells. In five or ten years, redox flow cells might be ready for the challenge.

Electricity is hard to store at the present time. But energy comes in many forms, and is convertible from one form to another. I would like to suggest that with present technologies, the best form of solar energy storage is thermal storage--heat. Below are several links providing more information about thermal storage. In future posts, I will provide more detail regarding current efforts to utilise this important energy storage method.

Open Directory Thermal Energy Links
Ionic Thermal Storage
Dissertation on Phase-Change Heat Storage Systems

Thermal storage is a type of energy averaging. Rather than being forced to use all the six hours of sunlight at one time, the energy can be used over the entire 24 hour period. Solar Ponds are one form of thermal storage. OTEC is another, and in that sense the ocean itself could be thought of as a huge thermal system.

Humans need heating and cooling, and in that sense thermal storage will always be useful for human buildings and infrastructure. Eventually, for electric power purposes, redox flow cells and other newer electrical storage methods will eliminate the need for thermal-electric conversion losses.

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Sunday, July 09, 2006

Like I Have Been Saying . . . . News from the Fuel Cell Forum in Lucerne

The annual fuel cell conference of the European Fuel Cell Forum was held in Lucerne, Switzerland, last week. Much of the sentiment from the conference in regard to hydrogen energy storage was compiled in this Reuters newsreport:

When environmentally friendly wind electricity is used to generate hydrogen, only one-quarter of the energy generated by the wind turbine is eventually used to move a car. The rest is lost during transport and energy conversion, said Ulf Bossel of the European Fuel Cell Forum, which held its annual fuel cell conference in Lucerne, Switzerland, last week.

"With hydrogen energy you only have 25 per cent efficiency to turn wind power to [car] wheel power," he said. It's much more efficient to transport that electricity directly into a car battery, via the grid, and use 90 per cent of its power."

Hydrogen is being discussed at the conference because it is one of the fuels for cells that can generate electricity and heat in an electrochemical conversion.

....Bossel said most renewable energy will be harvested as electricity through wind and solar power and should be used directly.

But he accepted that today's economy is based on fuels and cars will need some liquid fuel for long journeys, rather than recharging batteries every few hundred kilometres.

Even when this liquid energy is made from biomass, it makes sense to turn it into a biodiesel rather than hydrogen, said Wim van Swaaij, professor of thermo-chemical conversion at Netherlands' Twente University.

Biofuels are easy to handle, like today's fuels. Hydrogen, in its pure form, needs to be stored under high pressure which also consumes energy. Biofuels themselves contain hydrogen but in a much more stable form.

"Through steam reforming technology we can turn 40 to 50 per cent of the original fuel content in biomass into biofuel. The percentage is even higher for hydrogen, 50 to 60 per cent, but we will also have to store it and biofuels are the easiest and most efficient way to store it," Van Swaiij said.

The carbon particles in the biofuel will not make a net contribution to heating up the Earth through the greenhouse effect if the fuel is harvested from biomass, because the plants consume carbon dioxide as they grow, Van Swaaij added.

Bossel also said that producing hydrogen, either through electrolysis using nuclear or renewable electricity, or refined from biomass or fossil fuels, requires massive amounts of water. One kilogram of hydrogen requires nine litres of water.

In capitalist countries, the market will decide efficiencies based upon pricing--supply and demand--within the context of government regulation. We should all hope that government does not chase the wild albatross of hydrogen storage too much farther. Eventually nanotechnology and materials technologies may make hydrogen viable, economically. At present it would be smarter to bank on alternatives, such as batteries, supercapacitors, and biofuels such as bio-butanol and biodiesel.

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