sustainable

The Return of Rich Ocean Farming

- Adam Clare

Using the bounty of ocean to feed people is nothing new, but with a new spin on ocean farming we can have a sustainable food source (currently fishing is quite destructive) that also helps slow down the rate of climate change. We can use the very plants and animals that we are farming in the ocean to absorb carbon!

Seaweed is one of the fastest growing plants in the world; kelp, for example, grows up to 9-12 feet long in a mere three months. This turbo-charged growth cycle enables farmers to scale up their carbon sinks quickly. Of course, the seaweed grown to mitigate emissions would need to be harvested to produce carbon-neutral biofuels to ensure that the carbon is not simply recycled back into the air as it would be if the seaweed is eaten. The Philippines, China, and other Asian countries, which have long farmed seaweed as a staple food source, now view seaweed farms as an essential ingredient for reducing their carbon emissions.

Oysters also absorb carbon, but their real talent is filtering nitrogen out of the water column. Nitrogen is the greenhouse gas you don’t pay attention to — it is nearly 300 times as potent as carbon dioxide, and according to the journal Nature, the second worst in terms of having already exceeded a maximum “planetary boundary.” Like carbon, nitrogen is an essential part of life — plants, animals, and bacteria all need it to survive — but too much has a devastating effect on our land and ocean ecosystems.

Read more here.

Thanks to Greg!

Sterilizing Medical Equipment with the Sun

- Adam Clare 2 Comments

When people think of solar power they tend to look at solar heating or solar electricity which makes a lot of sense. Now some researchers at Rice University have found a way to harness the power of the sun for sterilizing medical equipment in the developing world.

The Capteur Soleil, a device designed decades ago by French inventor Jean Boubour, was modified at Rice two years ago for use as a solar-powered cookstove for places where electricity — or fuel of any kind — is hard to get.

This year, Team Sterilize modified it further. When a set of curved mirrors and an insulated box containing the autoclave are installed, the steel A-frame sitting outside Rice’s Oshman Engineering Design Kitchen becomes something else entirely — a lifesaver

The system produces steam by focusing sunlight along a steel tube at the frame’s apex. Rather than pump steam directly into the autoclave, the Rice team’s big idea was to use the steam to heat a custom-designed conductive hotplate.

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Solar Power with Salt

- Adam Clare

Thermal solar power plants uses energy from the sun to heat up water and then run the resulting steam to power turbines. Simple enough, but now Siemens is looking to make that whole process more efficient by using salt.

Solar thermal power plants that produce hotter steam can capture more solar energy. That’s why Siemens is exploring an upgrade for solar thermal technology to push its temperature limit 160 °C higher than current designs. The idea is to expand the use of molten salts, which many plants already use to store extra heat. If the idea proves viable, it will boost the plants’ steam temperature up to 540 °C—the maximum temperature that steam turbines can take.

Siemens’s new solar thermal plant design, like all large solar thermal power plants now operating, captures solar heat via trough-shaped rows of parabolic mirrors that focus sunlight on steel collector tubes. The design’s Achilles’ heel is the synthetic oil that flows through the tubes and conveys captured heat to the plants’ centralized generators: the synthetic oil breaks down above 390 °C, capping the plants’ design temperature.

Startups such as BrightSource, eSolar, and SolarReserve propose to evade synthetic oil’s temperature cap by building so-called power tower plants, which use fields of mirrors to focus sunlight on a central tower. But Siemens hopes to upgrade the trough design, swapping in heat-stable molten salt to collect heat from the troughs. The resulting design should not only be more efficient than today’s existing trough-based plants, but also cheaper to build. “A logical next step is to just replace the oil with salt,” says Peter Mürau, Siemens’s molten salt technology program manager.

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Iceland Thinking of Electrifying Europe

- Adam Clare

Iceland uses sustainable geothermal energy production to provide power and hot water to its people and now they are thinking of exporting surplus power to Europe. They are wrapping up their research into the feasibility of running so much electricity underwater to Europe and if it’s completed even more people can benefit from renewable energy.

Plus, just imagine how rich Iceland can become from supplying cheap renewable energy to the rest of Europe.

The project aims for the exportation of some five terawatt-hours (or five billion kilowatt-hours) each year, Jonsdottir said.
At current power prices in Europe, that corresponds to between 250 and 320 million euros ($350-448 million) in exports annually, and is enough to cover the average annual consumption of 1.25 million European households.
“The idea is to meet demand during peak hours in Europe, as well as some base load,” Jonsdottir said, refusing to estimate how much the project might cost to implement.
Landsvirkjun, which is state-owned, produces about 75 percent of all electricity in Iceland

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Plants Eat Pollution

- Adam Clare

We all know that plants are really good at cleaning the air and that’s absolutely a good thing. Nowadays more and more research is looking at using plants to clean more than just the air. Recently, a researcher in Ontario has used plants to clean up pollutants in a brown field site.

“Traditionally, we dig up the contamination and take it to a hazardous-waste dumpsite or incineration facility, but then the soil is lost,” she says. “But, in using phytoextraction … after we pull all the contaminants out, you’ve still got this natural resource of the soil itself.”

The composted material may still need to be disposed of as hazardous waste, but the volume of contaminated matter has been greatly reduced, says Dr. Zeeb.

Read the rest here.

Thanks Mike!

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