Category: Solutions

Photo of the Week: the Wind Tree

If you are following the Photo of the Week series, you probably remember the Vortex bladeless wind turbine. This radical new way to harvest wind energy is bringing a new ehm… wind in the industry. The asparagus-like structure is an improvement for those who don’t like the large rotating fans in the countryside. But the Wind Tree  (originally called the Arbre à Vent by its inventor Jérôme Michaud-Larivière) is raising wind energy to a whole new level of aesthetics.

Further developed by French engineers, this tree has rotating leaves that generate electricity regardless the direction of the wind. Other advantages are its silent operation, the possibility to start generating at wind speeds of 2 m/s instead of 5 m/s as for most traditional systems and the ability to be installed in an urban environment. One tree costs around 35 000 euros and has a capacity of 3kW. That is enough to power a small household. The real innovation is to be found in the leaves, designed to rotate in both laminar and the turbulent air flow near buildings.

The Wind Tree harvests wind energy from slower and turbulent wind flows than traditional systems, making it a perfect solution for an urban environment (photo: Fred Tanneau)

The Wind Tree harvests wind energy from slower and turbulent wind flows than traditional systems, making it a perfect solution for an urban environment (photo: Fred Tanneau)

Sources

NewWind

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Photo of the week: century old technology meets Kalahri sun

Earlier in the Photo of the Week series, we saw how Vortex Bladeless is offering a radical new way to harvest wind energy. But in the solar energy sector a lot of innovation is going on as well. The Swedish firm Ripasso is building what it claims to be the most efficient solar electricity system. In the South African Kalahari desert, giant parabolic mirrors follow the track of the sun and focus the rays in a small point where it drives a Stirling motor. That’s an invention dating back to 1816, but up to now it has mainly been used in military submarines although it can have much higher inefficiencies than classical combustion motors. It has no exhaust or inlets and works solely on the heating and cooling cycle of an internal fluid. Ripasso took this Stirling motor to South Africa where it is now able to convert solar energy to electricity with an efficiency of 34%, significantly higher than the 23% at best of other solar systems available today. Although it was not easy to convey banks their technology can fulfill its promises, Ripasso has now enough funding to start its first commercial-scale installation.

Ripasso showed that their 100m² mirrors in combination with a Stirling motor can reach an efficiency up to 32% (photo: Jeffrey Barbee)

Ripasso showed that their 100m² mirrors in combination with a Stirling motor can reach an efficiency up to 32% (photo: Jeffrey Barbee)

Sources

Ripasso Energy
The Guardian

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Photo of the week: time for Ocean Cleanup!

We humans are very effective in one thing: ruining all the good things the planet has to offer. On this blog we’ve talked a lot about air pollution and greenhouse gas emissions, but the air is not the only place we use as trash can. Every year millions of tons of plastic debris end up in our oceans. In the so-called Great Pacific Garbage Patch, with an estimated density of plastic of 330 000 parts per square kilometer, debris is brought together by the circular ocean current in the higher Pacific Ocean.

Boyan Slat, now a 20-years old Dutch engineering student, presented an idea to clean up the mess a few years ago. At the time, it got a lot of publicity and with a kickstarter campaign he raised 2 billion dollars in no time. Last week, his ngo the Ocean Cleanup announced a first test system will be deployed in the second quarter of 2016 near Tsushima Island, between Japan and South Korea. Within five years, after other deployments of increasing scale and design updates, Slat plans to deploy a 100 km-long system to clean up about half the Great Pacific Garbage Patch, between Hawaii and California.

With the Ocean Cleanup system, Boyan Slat hopes  to put the sea currents at work to collect garbage (graphic: the Ocean Cleanup)

With the Ocean Cleanup system, Boyan Slat hopes to put the sea currents at work to collect garbage (graphic: the Ocean Cleanup)

Altough many people are excited about the idea, not everyone is convinced the system is going to work. Back in 2014, a very thorough technical and scientific review of Slat’s own feasibility study was published. Besides the enormous technical challenges such a floating device poses to engineers, the Ocean Cleanup seems to aim at collecting the larger plastic debris at the top water layer. In fact, the most harmful are the tiny particles floating in lower water layers that are swallowed by sea animals. How the device will cope with this and other feasibility questions remain largely unanswered until today. Let’s hope the test system in Tsushima will bring clarity on what is possible. In the meantime, we better try to reduce our waste footprint anyway.

Sources

the Ocean Cleanup
Review

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Photo of the week: Recycled printer toner roads

Sydney found a rather creative way to reduce their emissions and waste. The city’s road contractor teamed up with a cartridge recycling company to use printer toner waste to create asphalt. The toner partially replaces the bitumen and fine aggregates used in traditional asphalt production. By using the toner in combination with recycled oil, the production process is 40% more energy efficient. The asphalt is around the same price as the old version. The first streets of Sydney have been paved and now it’s looking forward to the results. Over a few years it will become clear whether this new pavement performs as good (or better) than traditional pavement.

Watkin Street in Newton, Australia, gets a new layer of asphalt made with recycled printer toner (photo: Jamie Williams/City of Sydney)

Watkin Street in Newton, Australia, gets a new layer of asphalt made with recycled printer toner (photo: Jamie Williams/City of Sydney)

 

Source

The Guardian

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Photo of the week: NYC’s fleet of eco-friendly street food carts

New York City is looking at several ways to reduce its carbon emissions. The city recently launched a pilot project together with MOVE Systems, an American start-up created to bring the mobile food industry into the 21st century. They’ve come up with the MRV, a food cart with cutting edge technology such as solar panels, batteries and alternative fuels. Nowadays, food carts mostly run on propane gas, both polluting and potentially dangerous in urban environments. The MRV carts are for free for vendors who sign up; the carts are paid for by donations and private funding. Yet, it will take some time before you will see them in the streets of the Big Apple, because the city only gives a limited amount of permits for food carts every year.

The MRV offers a 21th century update for the food carts in NYC (photo: MOVE Systems)

The MRV offers a 21th century update for the food carts in NYC (photo: MOVE Systems)

Sources
The Verge
Move Systems

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Photo of the week: Tidal lagoon to power Wales

Great Britain has a lot to win from its all-surrounding waters. And green energy company Tidal Lagoon Power knows that. They’re planning to build a 10 kilometers-long sea wall from Newport to Cardiff to create a artificial lagoon. At high tide the water can stream in via turbines in the wall. The lagoon is then closed until low tide, when it is opened again to let the water stream out via the turbines. The company claims it could generate enough energy to power Wales. The project would cost around 6 billion British pounds (8.3 billion euros). Governement has already said it supports the idea, although negotiations over subsidies over a pilot project in Swansea have yet to start. Consumer charity Citizens Advice has warned that the project is a “appalling value for money”. It would indeed be the most expensive green energy project in Great Britain so far. Tidal Lagoon Power says it will only be expensive in the first thirty years when they have to pay constructions bills and turn a profit, but afterwards the generated energy would become very cheap.

An impression of the pilot lagoon scheme in Swansea Bay (photo: Tidal Lagoon Power)

An impression of the pilot lagoon scheme in Swansea Bay (photo: Tidal Lagoon Power)

Source

The Telegraph

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