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Posts Tagged ‘storage’

Radio show Living on Earth did a segment in February on new technology to store and release solar heat. Here is host Steve Curwood on his outing to MIT to learn about the breakthrough.

“A team of researchers at MIT has come up with a chemical that would let windshield glass directly store solar energy and then release it on demand as heat to melt the ice. … The same chemical could be woven into clothing fibers to capture the sun’s energy and then give you some added warmth when you ask for it, even days later.

“I paid a visit to the lab where the MIT team has been working on this breakthrough and met up with researchers David Zhitomirsky and Eugene Cho, who work in the lab of professor Jeffrey Grossman.”

To Curwood’s question about the difference between the familiar electrical, battery-enabled solar technology and the MIT lab’s chemical version, Zhitomirsky replies,”We use these molecules that can absorb UV light and instead of generating charges, what they do is that they change shape, and by changing shape, they can store chemical energy …

“CURWOOD: OK, so sunlight hits this molecule, it changes shape and can storage its energy. And how do you get the energy out?

“ZHITOMIRSKY: So you can figure the material in several ways. One way is to add a small amount of heat, and the material will release more heat than you add in. The other methods are triggering it with light or you can apply an electrical field to the material. …

“The way we envision using it is to integrate into fibers that you then make clothing out of.” More here.

Release solar heat from my coat in a blizzard? Where do I sign up?

Photo: Helen Palmer
Living on Earth host Steve Curwood, right, in the MIT lab with Eugene Cho and David Zhitomirsky.

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I was thinking about “evaporative cooling” as I got out of the shower this morning and shivered.

In summer’s heat it’s nice how the evaporation of water on your skin cools you down, but in winter, the process is not so welcome.

Still, the principle is something that innovators in hot climates think about a lot, applying it to keeping produce cool so it lasts longer.

Stephanie Buglione, at Nourishing the Planet, has a story on this concept. She focuses on a nonprofit group called Practical Action and how it is using something called zeer pots to reduce food waste.

She explains, “Practical Action, a nongovernmental organization that works with farmers in Southern Africa, Latin America, and South Asia, encourages the use of earthenware refrigerators called zeer pots to help prevent post-harvest food waste. The pot-in-pot refrigerator design keeps fruits and vegetables cool by harnessing the principle of evaporative cooling. These pots can extend the shelf life of harvested crops by up to 20 days by reducing storage temperature.

“The design consists of a large outer pot and a smaller inner pot, both made from locally available clay. Wet sand is added between the two pots and is kept moist. Evaporation of the liquid in the sand draws heat out of the inner pot, in which food can be stored. …

“Zeer pots can provide flexibility for farmers by enabling them to store crops and sell in response to market demand, which can translate into greater income. Extended shelf life also translates into longer-term food sources for farmers and their families. Ultimately, this inexpensive and low-tech system can help farmers and low-income households save food and prevent waste.” More.

Sometimes the best technology is the simplest.

Photo: Noor Khamis/Reuters
Nairobi, Kenya. Many Africans are challenged to keep their fruits and vegetables fresh if they lack electricity for refrigeration. Zeer pots are a low-tech solution that uses the principle of evaporative cooling.

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