New Material Harvests Energy from Water Vapor

[ScienceRocks]

New Material Harvests Energy from Water Vapor
Published: January 10, 2013. by Massachusetts Institute of Technology

CAMBRIDGE, MA -- MIT engineers have created a new polymer film that can generate electricity by drawing on a ubiquitous source: water vapor.

New Material Harvests Energy from Water Vapor - ScienceNewsline

The new material changes its shape after absorbing tiny amounts of evaporated water, allowing it to repeatedly curl up and down. Harnessing this continuous motion could drive robotic limbs or generate enough electricity to power micro- and nanoelectronic devices, such as environmental sensors.

"With a sensor powered by a battery, you have to replace it periodically. If you have this device, you can harvest energy from the environment so you don't have to replace it very often," says Mingming Ma, a postdoc at MIT's David H. Koch Institute for Integrative Cancer Research and lead author of a paper describing the new material in the Jan. 11 issue of Science.

"We are very excited about this new material, and we expect as we achieve higher efficiency in converting mechanical energy into electricity, this material will find even broader applications," says Robert Langer, the David H. Koch Institute Professor at MIT and senior author of the paper. Those potential applications include large-scale, water-vapor-powered generators, or smaller generators to power wearable electronics.

 

[waltky]

Turning humidity into drinkable water...

Advert turns air into drinking water
22 March 2013 - Just outside Lima, Peru, a billboard provides drinking water to whomever needs it - mainly, its neighbours.

The panel produces clean water from the humidity in the air, through filters. Researchers at the University of Engineering and Technology (UTEC) in Lima and advertising agency Mayo Peru DraftFCB joined forces to launch it. UTEC says it wanted to put "imagination into action" and show that it is possible to solve people's problems through engineering and technology. "A billboard that produces drinking water from air," says the billboard up high. And it does what it says on the tin: so far, the billboard has produced over 9,000 litres of drinking water - 96 litres a day. The panel is strategically located in the village of Bujama, an area south of the capital city that is almost a desert, where some people have no access to clean water.

The billboard serves a dual purpose, acting to draw students to the newly established engineering university UTEC

Access to all

Despite tough conditions with little rain, air humidity reaches 98%, says UTEC. "The panel traps humidity in the air and transforms it into water. It's that simple," said Jessica Ruas, a spokesperson from the university. "There is a lot of water. It is right there in the sea, but it is not suitable for drinking purposes, and costs a lot of money to process it." Ruas says the system might become a wider solution for the problem. "It doesn't have to come in the shape of a billboard, but ingenuity is key to development". Internally, the panel consists of five devices that extract water vapour from the air using a condenser and filters.

The billboard has become something of a local attraction as well as a local resource

Water is stored in tanks at the top of the structure. Once filtered, it flows down a pipe connected to a tap, accessible to everybody. The internal system costs some US$1,200 (£790) to set up. On the publicity side, the panel itself seeks to attract the "creative minds that Peru needs" to the young UTEC, which was founded only a year ago. "We want to change the minds of future engineers and inspire them," said Ms Ruas. The neighbours have given the billboard a warm welcome. It has become a local attraction for and motorists and an indispensable part of life in the local village. "We hadn't realised how big the impact would be," said Ms Ruas.

BBC News - Advert turns air into drinking water

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Will There be Enough Water for Everyone?
March 22, 2013 > As the global population grows, so does the need for water. The Worldwatch Institute says increased demands for food, energy and industry, along with climate change, could lead to water scarcity in some places. The warning comes on World Water Day, March 22.

Worldwatch says billions of people are already facing some kind of water scarcity or shortage. Spokesperson Supriya Kumar said that it’s only expected to get worse as the population increases. “Over 1.2 billion are basically living in areas of physical water scarcity. And almost 1.6 billion face economic water shortage. And these are really extreme numbers. And as our population continues to grow there’s just going to be more problems. And we’re going to really have to face drastic measures in order to make sure the people have access to water.” There are several types of water scarcity. The first is called “physical.” “Physical water scarcity really just means that there’s not enough actual water to meet all demands. Water is not distributed evenly. Areas in the Middle East, in northern China, in northwestern India – very arid regions – where there’s just not enough water. And so there’s just not physical availability,” said Kumar.

An Indian ragpicker boy drinks water from a tap at an automobile yard on the outskirts of Jammu, India.

And then there’s economic water scarcity. “Economic water scarcity refers to just the lack of investment in water programs and water capacity. And that’s something seen in large parts of Africa, where there’s actually physical water available, but just not enough investment made to make sure that water is available and accessible to the people that live in that region,” she said. Kumar said that action to relieve these problems can be taken on the local, national and regional levels. “In terms of the local level,” she said, “we could put more investment into water harvesting – into better methods of reusing water that’s wasted -- treating it to be reused for agriculture or for other industries.”

On the national level, the Worldwatch Institute recommends that governments develop better water policies, which could include fewer or revised agricultural subsidies. “For example, in India, a lot of farmers have subsidies that provide them with the use of electricity for 24 hours without any fees. And so, that leads them to pump water constantly, which is really depleting the ground water,” she said. Worldwatch says, globally, 70 percent of what’s called “water withdrawals” is for agriculture; 19 percent for industry and 11 percent for municipal demands. Some of the countries with very high withdrawals include India, China and the United States.

More http://www.voanews.com/content/water-scarcity-22mar13/1626505.html

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For Half of South Sudanese, No Clean Water
March 22, 2013 — On World Water Day, Margret Kiden was able to find enough water near her home in Nyakuron East, a Juba suburb, to do her domestic chores – including the laundry for her husband and three kids.

“We face many problems, there is no water here in Juba. It’s normally the water tanks which bring us water. At times, these water tanks are delayed, at times they bring dirty water and at times they don’t come” at all, said Kiden. The international community is funding several projects around South Sudan to improve access to clean water. But the country’s under-developed infrastructure means that water resources are still strained in most areas.

Only around half the population has access to clean water. In Juba, rapid growth has further strained the water supply. The South Sudanese capital has grown from population of around 60,000 in 2005 to nearly 400,000 in 2011. The city’s water resources have not been able to keep up. Residents of Juba usually get their water from tankers or from men who push bicycles through the streets with plastic containers, full of water, strapped to both sides.

A young woman carries a plastic container to collect water in Gudere, near Juba in South Sudan. Only half the population of South Sudan has access to clean water.

Any water from the public water works is used exclusively for government buildings, leaving residents to look for other sources, according to a study by the Japan International Cooperation Agency (JICA). JICA has launched a $40 million project to more than double water treatment capacity in Juba. The project is currently in the drafting stage, but once it is completed, another 350,000 people will have easier access to clean water. When the three boreholes in Nyakuron East stopped working two years ago, residents were left with only unclean nearby streams, which can carry diseases, or the traveling water tanks as their source of water.

Abale Keji says some residents have turned to another, more expensive solution. "We buy maybe one or two bottles from a shop to at least cook for the children," Keji says. A one-and-a-half-liter bottle of water can cost three South Sudanese pounds, slightly less than a dollar -- but exponentially more expensive by volume than the cost of a large tank On a normal day, Keji needs at least 1,000 liters of water to cook for her family, wash their clothes and bathe. That amount of water is not only hard to come by, it also eats into families' small incomes. Gross national income in South Sudan in 2011 was $984 per capita, or less than $3 a day.

http://www.voanews.com/content/south-sudan-clean-water/1626848.html