Michael Misha's List: Energy

• During torrefaction, woodchips go through a machine – almost like an industrial-sized oven – to remove the moisture and toast the biomass. The machine, called a torrefier, changes more than just the appearance of the woody biomass. The chips become physically and chemically altered – through heat in a low-oxygen environment
• The torrefied wood is lighter than the original woodchips but retains 80 percent of the original energy content in one-third the weight.
• woodchips are a carbon neutral source of energy
• nearly half of the state's forests are not adequately thinned because landowners lack a market for small diameter trees, rotten or unusable trees and logging residue. That land could be producing more valuable wood products if it was managed more effectively

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• Desertec has been arguing for remote electricity generation based largely on concentrating solar power (CSP) in North Africa and the Middle East. CSP is relatively expensive, but has one big advantage: some of the heat captured during the day can be stored in molten salts and used to generate electricity overnight.
• The problem with renewable electricity is that the wind doesn't always blow, nor the sun always shine, at the one spot where you build your renewable energy generator. Yet the wind is always blowing somewhere, just as the sun is always shining on half the globe. So with a large enough grid, variations in generation should even out, giving a reliable supply.

  • ...and since HVDC efficiently transmits power over very long distances, generators from across the globe could could share their energy harvest.
• The numbers look daunting: the project would cost more than €1.5 trillion, of which €128 billion would go on the lines and equipment for the supergrid itself, and around €1.4 trillion on renewable-generating capacity. To put this in context, the International Energy Agency forecasts that the global power industry will have to invest $13.6 trillion on fossil-fuel-based power generation by 2030. Under Czisch's plan, investment in clean technologies would displace spending on dirty ones so costs would not escalate.

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• The surface area of each array is 250 times greater than that of a conventional capacitor of comparable size. The arrays' storage capacity is about 100 microfarads per square centimeter.
• But surface area isn't the only determinant of energy density. The Maryland group's nanocapacitors also benefit from the very small spacing between their electrodes
• If the electrodes are far apart, the like charges on their surfaces strongly repel each other. When the electrodes are placed closer together, the negative and positive charges on either side balance out these repulsive forces, and more total charge can be stored in a given area.

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• To generate fusion, 192 laser beams are generated, amplified, converted from infrared to ultraviolet light, and then aimed at a small gold canister the size of a pencil eraser. Inside that canister is a sphere containing the fuel: two isotopes of hydrogen called deuterium and tritium. The lasers are positioned all around the sphere to create the temperatures and pressures needed to ignite a fusion reaction. If all goes as planned, some of the hydrogen atoms should fuse, producing helium and releasing energy. This should, in turn, cause more fusion reactions until the fuel runs out. The whole process will take just a few billionths of a second.

• Other experts, however, are more skeptical. "If NIF is successfully, they'll still be a very long way from turning this into a practical energy source," says Ian Hutchinson, professor and head of nuclear science and engineering at MIT. For example, he says, a power plant would require the lasers to fire much more frequently than the NIF lasers--5 to 10 times a second, rather than once every couple of days, as is possible now. (Each burst would release energy equivalent to about five kilowatt-hours of electricity: by comparison, an average nuclear power plant generates 12.4 billion kilowatt hours a year, while an average house requires about 1,000 kilowatt-hours per month.)

   

  In contrast, ITER will use magnetic confinement of hot plasma to produce fusion, a system that produces a continuous stream of energy that could be more suited to generating electricity than the very short bursts of energy produced by NIF, he says.

• Other experts, however, are more skeptical. "If NIF is successfully, they'll still be a very long way from turning this into a practical energy source," says Ian Hutchinson, professor and head of nuclear science and engineering at MIT. For example, he says, a power plant would require the lasers to fire much more frequently than the NIF lasers--5 to 10 times a second, rather than once every couple of days, as is possible now. (Each burst would release energy equivalent to about five kilowatt-hours of electricity: by comparison, an average nuclear power plant generates 12.4 billion kilowatt hours a year, while an average house requires about 1,000 kilowatt-hours per month.)

   

  In contrast, ITER will use magnetic confinement of hot plasma to produce fusion, a system that produces a continuous stream of energy that could be more suited to generating electricity than the very short bursts of energy produced by NIF, he says.

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