If you’re reading this with a laptop sitting on your legs, you might have noticed that computers tend to warm up as they work, turning electrical energy into thermal energy. In fact, two-thirds of all the energy we use is lost as waste heat. Maybe, instead of just using the heat from your computer to keep your lap toasty, we should be harnessing that heat by turning it back into electricity. But the thermoelectric materials that convert thermal to electrical energy aren’t very good at their job. While they have some applications, the expense and inefficiency of current thermoelectric materials make them impractical for implementing at a large, power-saving scale. Until now: a new thermoelectric material might finally let us recover the energy lost to waste heat—at a reasonable price.
Nuclear power depends on a steady supply of uranium. The good news is that we have at least a hundred years worth of uranium. The bad news is that both demand for uranium and the price of production are rising—and a hundred years isn’t all that long. To reinforce our stock of uranium, researchers have proposed a backup plan: gather it from the sea.
For every billion pounds of water in the ocean, there are 3.3 pounds of uranium—we just need to figure out how to extract it. Over at IEEE Spectrum, Dave Levitan describes an effective technique for harvesting the diluted uranium:
So. Tired. From reading email.
A day of hard mental labor—writing emails, taking the SAT, competing in the national crossword competition—can leave you beat. But how, exactly, is that possible? You haven’t done any heavy lifting, at least not with your muscles.
Ferris Jabr at Scientific American MIND takes a crack at investigating this phenomenon, exploring the science on whether thinking really hard burns calories, or whether the exhaustion is coming from something else. He writes:
Although the average adult human brain weighs about 1.4 kilograms, only 2 percent of total body weight, it demands 20 percent of our resting metabolic rate (RMR)—the total amount of energy our bodies expend in one very lazy day of no activity.RMR varies from person to person depending on age, gender, size and health. If we assume an average resting metabolic rate of 1,300 calories, then the brain consumes 260 of those calories just to keep things in order. That’s 10.8 calories every hour or 0.18 calories each minute. (For comparison’s sake, see Harvard’s table of calories burned during different activities). With a little math, we can convert that number into a measure of power.
Despite increasing worry about what our energy consumption is doing to the planet, we’re also increasingly tied to power-hungry electronic devices. To keep reliable, renewable energy flowing, some suggest, we must give the power grid a makeover. And one method that could change it is a breath of fresh air. Danielle Fong and her company, LightSail Energy, want to store renewable energy in tanks of compressed air. Because wind and solar can be unpredictable energy sources, the ability to save any surplus for a windless or cloudy day makes them more reliable.
Caleb Garling has written about Fong’s unusual method of storing power for Wired’s World’s Most Wired feature.
A geothermal plant in Iceland
Iceland’s gigantic energy reserves, generated from renewable sources like geothermal vents, are all dressed up with nowhere to go—it’s too expensive to get power from the chilly island to anywhere else. But transporting data to and from the island is a different story. Iceland is starting to attract companies that build giant server farms, lured by the cheap electricity and the possibility of being able to market “green” power.
Each of us, just sitting in our chairs, is a little heat energy factory. So why not harness that body heat to power our phones and flashlights? Researchers have invented a thin, flexible “power felt” that can be worn as clothes, converting heat into an electric current. Dead batteries are so out in the future.
The thermoelectric fabric is made by stacking layers of plastic insulation with carbon nanotubes, one-atom-thick cylinders of carbon that are showing up everywhere from x-rays to fuel cells. The current version only makes about 140 nanowatts of power, so it’ll need some improvement before it becomes practical.
The only thing worse than a huge stinking pit of manure may be a huge stinking and foaming pit of manure that blows up the barn. Over the past few years, explosions have destroyed several Midwestern pig farms, killing thousands of hogs and causing millions of dollars of damage. Pig farmers and scientists have been at a loss to explain these explosions. Could the culprit be a small microbe?
Joshua trees in the Mojave Desert
Solar energy has been enjoying its day in the sun with massive federal subsidies, but the energy taken from sunlight also has a dark side. Building these plants in the American West destroys large swathes of the desert ecosystem. Cacti must be mowed down and local wildlife displaced to make room for the giant mirrors that will essentially carpet the desert. The LA Times has a great feature on the Ivanpah project in the Mojave that began construction in October 2010.
Far from an empty stretch of sand, the Mojave supports diverse wildlife. No one knows exactly how the new solar power plant will affect the tortoises, eagles, and Joshua trees that currently inhabit the area. Is it okay to sacrifice the desert in the fight against larger climate change? The situation has put environmental groups in a bind, as Times reporter Julie Cart explains:
The national office of the Sierra Club has had to quash local chapters’ opposition to some solar projects, sending out a 42-page directive making it clear that the club’s national policy goals superseded the objections of a local group. Animosity bubbled over after a local Southern California chapter was told to refrain from opposing solar projects.
A tower for removing gas at the Marcellus Shale Formation in Pennsylvania.
When it was revealed in November that several small earthquakes in northwestern England had been caused by fracking, the controversial process of extracting shale gas from bedrock by cracking the rock with pressurized water, the gas company responsible stated that it was an extremely unlikely occurrence. True as that may be, residents of Youngstown, Ohio, can now testify that something similar has happened again. This time, it wasn’t the removal of shale gas that triggered the earthquakes, but apparently the subsequent cracking of sandstone in order to store the wastewater produced by fracking.
What’s the News: Computers are hot. Too hot, really, for their own good—not only can laptops burn users’ thighs, but big clusters of servers require constant air conditioning, leading cloud-computing companies to consider situating them in places like Iceland to save on costs.
On the other hand, for part of the year in a good chunk of the globe, humans are cold. Analysts at Microsoft Research wondered whether they couldn’t somehow make these two things match up.