Wastholm.com

Är du förberedd om krisen kommer? Så här packar du en krislåda med grejer för att klara dig i upp till en vecka - till exempel om du drabbas av ett långvarigt strömavbrott.

The standard story about nuclear costs is that radiation is dangerous, and therefore safety is expensive. The book argues that this is wrong: nuclear can be made safe and cheap. It should be 3 c/kWh — cheaper than coal.

A nuclear salt-water rocket (NSWR) is a theoretical type of nuclear thermal rocket which was designed by Robert Zubrin. In place of traditional chemical propellant, such as that in a chemical rocket, the rocket would be fueled by salts of plutonium or 20 percent enriched uranium. The solution would be contained in a bundle of pipes coated in boron carbide (for its properties of neutron absorption). Through a combination of the coating and space between the pipes, the contents would not reach critical mass until the solution is pumped into a reaction chamber, thus reaching a critical mass, and being expelled through a nozzle to generate thrust.

It is one unintended consequence of the Fukushima nuclear disaster almost a decade ago, which forced Japan to all but close its nuclear power program. Japan now plans to build as many as 22 new coal-burning power plants — one of the dirtiest sources of electricity — at 17 different sites in the next five years, just at a time when the world needs to slash carbon dioxide emissions to fight global warming.

"I want to go off grid with solar and batteries!"

I hear this, or some variant, increasingly often. It seems to be a more and more popular concept, especially after some of the recent events in which people were left without power for long periods of time. And, quite often, I assume the people asking are genuinely interested in what they see as the benefits of off grid power. They're just not familiar with enough details to really have an understanding of what they're asking, or what it asks of them.

This post is my humble attempt to put a lot of information in one spot, such that I can link people to it when they ask about off grid power. There are quite valid reasons for off grid power, but it's not as easy or as simple as people tend to think. And it's certainly not as cheap as people assume it will be.

In fiscal 2010, just before the March 2012 disaster at Tokyo Electric Power Company Holding’s Fukushima No. 1 nuclear power plant, the national average CO2 emission was 416 grams per kilowatt-hour. In fiscal 2013, after all nuclear power plants were idled, the figure rose to 570 grams.

Fuel economy is about 10 km per liter for gasoline-powered passenger cars and a little over 20 km per liter for hybrid cars. The comparable figure for EVs is some 10 km per kilowatt-hour. Even with all nuclear power plants idled, an EV emits only about half as much CO2 as hybrid vehicles. Even if all power stations used coal, the CO2 emission per kilowatt-hour would be 864 grams, making CO2 emissions from an EV less than from a hybrid car.

It now aims to raise the density level of volcanic ash that can affect nuclear plants by 100 times the current level, while pressing utilities to upgrade their air filters.

Reactor No. 3 at the Ikata plant and reactors Nos. 3 and 4 at the Genkai plant top the list of those most likely to be affected by clogged filters.

The fly ash emitted by a power plant—a by-product from burning coal for electricity—carries into the surrounding environment 100 times more radiation than a nuclear power plant producing the same amount of energy.

The Row-bot has four tiny buoyant stabilizers for feet and two paddles that extend from the middle of its body. While the feet keep Row-bot afloat, the paddles send it skimming across the surface of a body of water. The device takes water into a cavity in its housing as it moves, where electrogenic bacteria digest pollutants found within the water. The byproducts of that digestion are carbon dioxide and electricity, which in turn fuels the Row-bot and keeps it moving.

Futurist Ray Kurzweil notes that solar power has been doubling every two years for the past 30 years — as costs have been dropping. He says solar energy is only six doublings — or less than 14 years — away from meeting 100 percent of today’s energy needs. Energy usage will keep increasing, so this is a moving target. But, by Kurzweil’s estimates, inexpensive renewable sources will provide more energy than the world needs in less than 20 years. Even then, we will be using only one part in 10,000 of the sunlight that falls on the Earth.

1–10 (68)   Next >   Last >|