Day: September 29, 2017

Having enough clean drinking water has been a challenge in many parts of the world, whether it’s a place where water is scarce or abundant. The World Health Organization finds 3 in 10 people globally still lack safe drinking water at home.

The U.S. Department of Energy has just announced it is providing up to $15 million in funding for projects to develop solar desalination technology to create freshwater at a lower cost. Even before the announcement, researchers had been working on better ways to desalinate water.

“We can take any quality of water that we’re starting with and we can turn it into any quality of water that we desire at the end, and the only real challenge or limitation has to be overcome is how much does it cost and how much energy does it take to go from here to here,” said Eric Hoek, co-founder and Chief Executive Officer of Water Planet Inc.

Cheaper energy

Water treatment plants are largely driven by electricity. A cheaper source of energy is the sun.

“What’s changed in the last five to 10 years, solar has gotten cheap,” Hoek said.

“The only reason that that has not taken over the world at this point is that it’s still intermittent. The sun goes up and it comes down. You have power when it’s up and don’t when it’s down. What you need to make that a continuous base load is you need batteries, which you can charge up during the day, discharge at night, and the cost of batteries is still currently pretty high.”

Household system

Qilin Li at Rice University is building a desalination system that uses solar energy with broad drinking water applications for “individual households or small communities that live in remote locations, especially those who don’t have access to municipal water supply, don’t have a stable supply of electricity. This technology can be an ideal technology,” Li said.

Her solar-powered desalination system can “also benefit megacities in developing countries that don’t have the extensive water and power infrastructure we enjoy here in developed countries, and that kind of relief perhaps in not providing all the water for the whole city, but can relieve some of their need or dependency on the power grid,” Li said.

The goal of Li’s system is to make it modular and cost efficient so it could either meet the needs of a small household or a large community.

Li and her team created a reactor to distill water using heat from the sun. Water turns into vapor, goes through a porous membrane and becomes pure water. Li says a low cost coating on the membrane developed at Rice University makes this unique.

“So it (membrane) harvests the sunlight, converts the photon energy in the sunlight to heat highly efficiently to generate water vapor, and it also serves a separation function to keep the contaminants on the dirty side of the membrane and only allow pure water vapor to go through,” Li said.

Waste heat

The sun is not the only low cost source of energy. Amy Childress’ lab at the University of Southern California (USC) looks at how waste heat that comes from manufacturing can be used as a resource.

“With waste heat you’re going to have cycles and spikes. We’ve gone out to the field, measured waste heat at an industrial site. We come back. We plug that into our system, so that we can repeat that waste heat curve over and over and watch the response of membranes to the waste heat,” said Childress, who directs USC’s Civil and Environmental Engineering Department’s environmental engineering program.

Her lab looks at how waste heat would impact the longevity and properties of a membrane.

Childress says the work in her lab will be helpful in the development of better membranes.

Filters in demand

There is high demand for membranes that help produce clean water. Water Planet’s PolyCera® membrane used to treat wastewater, is finding broader applications.

“We have a lot of interest now around the world, not just in industrial wastewater, but we’re actually making point-of-use under-the-sink water filters for applications in India, in China and here in the U.S. We’re making membranes that are being tested now for deployment offshore in sea water desalination to produce drinking water in barges and in platforms,” Hoek said.

With nearly 30 percent of the world’s population lacking safe drinking water at home, researchers will continue to work on harnessing free energy to clean water.
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Having enough clean drinking water has been a challenge in many parts of the world, whether it is a place where water is scarce or abundant. The U.S. Department of Energy has just announced it is providing $15 million in funding for projects to develop solar desalination technology at a lower cost. But even before this announcement, researchers had been working on better ways of desalinating water. VOA’s Elizabeth Lee has the details.
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A long-running effort to build one of the world’s largest telescopes on a mountain sacred to Native Hawaiians is moving forward after a key approval Thursday, reopening divisions over a project that promises revolutionary views into the heavens but has drawn impassioned protests over the impact to a spiritual place.

Hawaii’s land board granted a construction permit for the $1.4 billion Thirty Meter Telescope atop the state’s tallest mountain, called Mauna Kea, but opponents likely would appeal the decision to the state Supreme Court. Protesters willing to be arrested were successful in blocking construction in the past.

“For the Hawaiian people, I have a message: This is our time to rise as a people,” said Kahookahi Kanuha, a protest leader. “This is our time to take back all of the things that we know are ours. All the things that were illegally taken from us.”

No construction soon

Telescope officials don’t have any immediate construction plans and will consider its next steps, said Scott Ishikawa, a project spokesman. Officials previously have said they want to resume building in 2018.

“In moving forward, we will listen respectfully to the community in order to realize the shared vision of Mauna Kea as a world center for Hawaiian culture, education and science,” TMT International Observatory Board Chairman Henry Yang said in a statement.

Richard Ha, a Native Hawaiian farmer who supports the project, urged opponents to avoid confrontation.

“The possibility of getting the best telescope in the world … I don’t feel is the right battle to fight,” he said. “It will hurt our own people.”

While opponents say constructing the telescope will desecrate Mauna Kea, supporters tout the instrument’s ability to provide long-term educational and economic opportunities.

“This was one of the most difficult decisions this board has ever made,” state Board of Land and Natural Resources Chairwoman Suzanne Case said in a statement about the 5-2 decision.

Plans for the project date to 2009, when scientists selected Mauna Kea after a five-year around-the-world campaign to find the ideal site for what telescope officials said “will likely revolutionize our understanding of the universe.”

The project won a series of approvals from Hawaii, including a permit to build on conservation land in 2011. Protesters blocked attempts to start construction. Then in 2015, the state Supreme Court invalidated the permit, saying the board’s approval process was flawed, and ordered the project to go through the steps again.

​Protests from the beginning

Protests disrupted a groundbreaking in 2014 and intensified after that. Construction stopped in 2015 after 31 demonstrators were arrested for blocking the work.

A second attempt to restart construction a few months later ended with more arrests and crews retreating.

Mehana Kihoi said being arrested while praying on the mountain was one of the most traumatic experiences of her life. She started going there to help heal from domestic violence, Kihoi told the land board earlier this month.

“For years, I carried grief and pain … until I went to the mauna,” she said, using the Hawaiian word for mountain.

Culture over money

Kanuha, a protest leader, dismissed the millions that telescope officials have paid toward educating youth on the Big Island in science, technology, engineering and math. So far, $3.5 million has been paid into the educational fund, even while the project’s construction permit was invalid.

That money isn’t the answer to improving the lives of Native Hawaiian youth, Kanuha said. Revitalization of language and culture through Hawaiian-focused education is what’s important, he said.

A group of Native Hawaiian telescope supporters formed a group called Perpetuating Unique Educational Opportunities. Some members had been against the telescope in the past, said the group’s attorney, Lincoln Ashida.

“We believe that with increased opportunities for children, that results in stronger families, which in turn benefits our community,” Ashida told the board.

A group of universities in California and Canada make up the telescope company, with partners from China, India and Japan. The instrument’s primary mirror would measure 98 feet (30 meters) in diameter. Compared with the largest existing visible-light telescope in the world, it would be three times as wide, with nine times more area.

Mauna Kea, a dormant volcano, has been the first choice, telescope officials said, calling it the best location in the world for astronomy. Its summit provides a clear view of the sky for 300 days a year, with little air and light pollution. They selected an alternate site in Spain’s Canary Islands if the telescope couldn’t be built in Hawaii.
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