Stories tagged efficiency

Nov
08
2010

That's actually a tear: The potato just received some horrible news. But it illustrates how full of fluid potatoes are.
That's actually a tear: The potato just received some horrible news. But it illustrates how full of fluid potatoes are.Courtesy ZooFari
Here’s my impression of the future:

“Um, hey. How was lunch? Italian dunkers, eh? Nice. Gotta love the dunkers. Ate those right up, I see. Pretty good sauce too, huh? Got some extra sauce there, actually. Were you going to… can I have that sauce? Yeah? Oh, it’s SO good.”

Yeah, that’s the future for you. Man, is he hungry. Stuff you wouldn’t touch, the future will pound back like Captain Haddock with a bottle of Loch Lomond (before that fiasco in San Theodoros).

But the future is smart, because it realizes that Italian dunker sauce is in short supply, and it’ll take perfectly good extra sauce wherever it can get it.

Are you following the metaphor still? Were you thrown by Captaion Haddock?

Here’s what I’m saying: in the next few decades, we’re going to be super hungry for energy, food, and water, because there will be about 9 billion of us on the planet. So, in addition to coming up with new ways to produce of all of these things, we’re going to have to look for areas where they’re being wasted right now, like all those puddles of Italian Dunker sauce being shoveled into the cafeteria trash bins.

Example: drinking potato chip water.

Potatoes, as it happens, are about 75% water. When we turn them into potato chips, we get rid of all that water—we bake it, dry it, and fry it away. Considering how much we love dried potato products, that’s a lot of water wasted.

But that doesn’t mean we should stop eating potato chips. (NEVER!) Instead, some factories have been installing equipment to reclaim water that would otherwise be vented out of potato processing facilities as steam. One of the factories where the technology is being tried may be able to recapture as much as 3,000 liters of water an hour (about 790 gallons an hour). This water, already clean and pure, can be reused in the factory, or even sent back into the municipal water system.

Although the article doesn’t mention it, I’d be willing to bet that there’s another product being recaptured with the water: energy. Steam, after all, is just water with a whole bunch of heat energy in it. With the right equipment, heat can be extracted from steam, and reused for anything from cooking to powering heating and cooling equipment.

Do you see now? The future, with its peanut butter covered fingers and greasy South Park t-shirt isn’t quite the loser you think it is. It’s using all that Italian Dunker sauce, in ways that you never imagined possible.

Sep
22
2010

NREL's membraine: There's so much science in his head it's projecting colorfully out into the air as a graph.
NREL's membraine: There's so much science in his head it's projecting colorfully out into the air as a graph.Courtesy NREL
You’re worried about the future again, aren’t you? You’re afraid that everything will taste like cardboard, and that most people will be robots, and that the robots will be too cool to hang with you, and that our trips to the bathroom with be confusing and abrasive, and something about bats, and that you will be hot all the time, even in your own homes.

And I wish I could tell you otherwise. But I can’t. I just don’t know enough about the future. Except on that last point—it looks like air conditioning may yet be an option in a necessarily energy efficient future.

Air conditioning can use up a lot of energy. An air conditioning unit typically cools air by blowing it over a coiled metal tube full of a cold refrigerant chemical. The refrigerant absorbs heat from the air in your house, and then it passes through a compressor, which squishes the refrigerant down, making it hot so that it releases heat outside your house. And then the refrigerant expands, and cycles back into the cool tube. (Here’s the explanation with some illustrations.)

Other cooling systems rely on evaporation. So called “swamp coolers” pull hot, dry air from outside, and blow it over water (or through wet fabric pads). The water evaporates to pull heat out of the air, so what is blown into your house is cool, humid air. Swamp coolers are more efficient, but they only work in very dry environments.

And then there’s another way to control your indoor climate: desiccant cooling. A lot of what makes warm air uncomfortable is the amount of moisture it can contain. Normal AC units remove moisture from the air, but they use a lot of energy in doing it. Another way is to use chemicals called desiccants. Desiccants suck up water. The little packs of “silica gel” crystals you might find in a new pair of shoes are full of desiccants. Blowing humid air over desiccants will result in the chemicals sucking the moisture out of the air, making it more comfortable.

Figuring out how to use the desiccants has been a challenge, however; desiccant chemicals can be corrosive to building materials, so they, and any dripping water, need to be contained. With this in mind, US government researchers at the National Renewable Energy Laboratory have developed a membrane for desiccant cooling systems that allows the water vapor in humid air to pass through it one way, but does not allow the liquid water removed from the air to pass back.

The researchers claim that this air conditioning process is up to 90% more energy efficient than standard AC. Every so often, the desiccant chemicals need to be “recharged” by heating them up so they release the trapped water (outside), a job that can be done by electric heating elements, or with a solar thermal collector. The University of Minnesota used a desiccant cooling system for their entry into the Solar Decathlon competition. Their system didn’t rely on a membrane—rather, humid air was pumped up through a drum of liquid desiccant—but they did recharge the desiccant using heat from solar thermal panels (which are basically big, flat, black boxes that collect heat from sunlight).

It’s reassuring to know that in the future, even as we’re covered in flesh eating bacteria, and spam advertisements for Spam are being beamed directly into our brains, we’ll at least be able to relax in pleasantly dry, cool air, without worrying too much about the energy we’re using to do it.

Dec
20
2009

Old refrigerators guzzle energy: Newer refrigerators use 75% less energy
Old refrigerators guzzle energy: Newer refrigerators use 75% less energyCourtesy Rich Anderson

More efficient refrigerators have a huge impact

Refrigerators today are bigger than in the 70s but use 75% less energy. This happened because of stricter energy efficiency standards. Efficiency standards can save more energy than current wind, solar, and geothermal energy sources combined!

United Nations summit on climate change

This week at the United Nations' summit on climate change, U.S. Department of Energy (DoE) Secretary, Steven Chu, unveiled a $350-million investment plan to bring to the developing world everything from efficient refrigerators to solar lanterns.

Climate REDI

Climate Renewables and Efficiency Deployment Initiative (Climate REDI) is a $350-million investment by major economies, including $85 million from the U.S., to bring everything from efficient refrigerators to solar lanterns to the developing world.

"The energy savings from refrigerators is greater than all U.S. renewable energy generation—all the wind, solar thermal and solar photovoltaics—just the refrigerators," Chu said in a speech announcing the initiative, noting the refrigerators also cost less. "Energy efficiency is truly a case where you can have your cake and eat it too. [But] it was driven by standards; it didn't happen on its own."

Learn more about the UN energy-efficiency initiative

Source: Scientific American
U.S. Unveils a $350-Million Energy-Efficiency Initiative at Copenhagen

Jun
22
2008

My Geo Metro: 47 miles per gallon
My Geo Metro: 47 miles per gallonCourtesy Art Oglesby
Guess the answer to this word problem before doing the math.

  • Car A (a compact) gets 34 mpg
  • Car B (a hybrid) gets 54 mpg
  • Car C (an S.U.V.) gets 18 mpg
  • Car D (a sedan) gets 28 mpg

Which would save more gasoline?

  • (a)replacing Car A with Car B
  • (b)replacing Car C with Car D
  • (c)both would save the same

Can you do the math?

I drive my car about 10,000 miles each year. One way to look at this problem would be to calculate how many gallons of gas each of the four cars would use to go 10,000 miles. Can you do the math? If gas costs $4 per gallon what is the cost for each car to go the 10,000 miles?

Show me your answers in the comments

I will do the math for my Geo Metro as an example. It now has over 100,000 miles on it. Until recently it got 50 miles per gallon. Two gallons would take me 100 miles, 20 gallons would take 1000 miles. 100,000 miles would take 2000 gallons. With $4 gas that 2000 gallons would cost $8000.

Save the world's gas

I once owned a Ford pickup truck. If it got 20 mpg and if I drove it 100,000 miles I would need 5000 gallons which would cost me $20,000. By replacing my pickup with the Metro I use less than half the gas and save over $1000 a year. I used to commute to work and put on 30,000 miles per year. That figures out to a $36,000 saving over 10 years.

John Kanzius discovered that salt water when bombarded with radio waves burns. You can learn more and see salt water burn in this video(You Tube).

Jun
13
2007

A British design firm, Sheppard Robson, has unveiled a plan for a new house that produces zero emissions, making it carbon neutral. Their home is the first design to meet the highest level of energy efficiency set by the UK government for some new laws that go into effect in 2016.

The Science Museum of Minnesota has its own Zero Emissions Building right here by the Mississippi River, Science House. Next time your in our Big Backyard, make sure the check it out.

Aug
12
2005

Is that a contradiction in terms?

Approximately 330 million tons of garbage filled landfills in the United States last year alone, according to Solid Waste Digest, a trade publication for the waste industry. However, remarkably, the capacity of these landfills has been increasing even though very few new dumps are being built. How is this possible?

It turns out that landfill managers have been using methods that allow them to pack more trash into a landfill then what was previously thought possible. Some landfills pile tons of dirt on top of sections of their dumps and then six months later scrape the dirt aside. Like stomping your foot into the waste bin to make more room, this system works to create 30 to 40 more feet of depth — more space for more trash.

Other methods to increase landfill capacity include blowing water and air into the dumps to quicken decomposition and therefore reducing the size of buried garbage. Or, they are using other methods, such as giant 59-ton compacting machines, to bury trash more tightly.

The good news here is that this efficiency will help to reduce the need for new landfills. The bad news is, again, the United States produces 330 million tons of garbage a year! New York City produces so much garbage that it exports 25,000 tons of trash every day to other states and other cities.

So, while I think this new efficiency is great, I also think that we (you and I) still play a significant role in reducing the amount of trash put into landfills. Reduce, reuse, recycle!