green tech


An expedition team on a carbon emission-free trip to Greenland, relying solely on sail, solar and man power to promote climate change awareness, has been rescued by an oil tanker.

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Spains newest solar tower

Spain's newest solar tower

A second solar tower is now in operation near Seville, Spain.

Wikipedia says “a solar tower configuration uses a field of mirrors to concentrate sunlight onto a receiver held in the tower. The heat creates steam which turns a turbine to make electricity”.

This new Spanish solar tower, called PS20, is the largest in the world with a capacity of 20 megawatts. It will surely be a hit on Google Earth.

For comparison, that is as much as the Salton Sea Geothermal power plant produces in Imperial County CA, or the Copco #1 Hydroelectric plant up in the Klamath river.

Detroit Electric. Yes, there is such thing.

Detroit Electric was an automobile brand in Detroit, Michigan, from 1907 to 1939. They manufactured electric cars, powered by a rechargeable lead acid battery, and advertised as reliably getting 80 miles between battery recharging. The company was in business until the stock market crash of 1929, when filed for bankruptcy and was acquired and kept in business on a more limited scale for some years building cars in response to special orders.

Then in February 2008 , almost 100 years later, China’s Youngman Automotive Group said they were reviving the 100 year-old electric car brand.

And an year later, in March 2009, Detroit Electric announced a partnership with Proton, Malaysia’s largest automobile manufacturer, to mass produce the E63, an all-electric sedan. Under the agreement, Detroit Electric will license two Proton vehicle platforms and contract the company to assemble the electric vehicles that will be marketed under Detroit Electric’s brand, providing Detroit Electric with a cheap manufacturing base.

The E63 will be a four-door sedan with two range options: either 111 miles for $23,000 to $26,000 or 200 miles for $28,000 to $33,000. The company plans to introduce the car in Europe and Asia in February 2010 and then in the U.S. a few months later. The quick turnaround will be possible by outfitting Proton’s existing car models with Detroit Electric’s engine design instead of designing a whole new model.

Old Detroit Electric ad

Old Detroit Electric ad

A Florida county plan of vaporizing garbage with a plasma torch is fading away. Budget and fear are behind the delays.

Vaporize *this*

Vaporize *this*

The initial proposal, scaled back by 80%, would have created the largest plasma arc gasification plant in the world. The county hoped to not only avoid further landfill, but completely empty their existing landfill — 3.9 million metric tons of waste collected since 1978 — within 18 years.

Something similar, albeit not of the same size, already operates in Japan, UK and Canada. The idea is to run inert gas through a high voltage electrical arc, reaching temperatures over 13,000 °C, and breaking down waste into basic gaseous elements. Sounds so good even the TreeHugger is sold on it.

Sweden once again jumps ahead of everybody else when the subject is alternative energy. The resourceful Swedish came up with a new energy source, recycling energy that would otherwise be wasted.

The town of Halmstad will connect its local crematorium to the heating system:

“To start with we’re planning on heating our own facilities, but hopefully we can connect to the district heating network in the future,” said Halmstad cemetery administrator Lennart Andersson to the Aftonbladet newspaper.

“After all this talk about the environment we realized we should take advantage of the heat created during cremation,” he said.

“There won’t be anything different about the ashes,” he said.

The phrase “four-wheel drive” might become literal. Michelin has come up with a new electric car where the engine is in the wheels: the Active Wheel.

Packing in a sophisticated active shock absorption system, with its own dedicated motor, and disk braking brings the wheel to a hefty 43 kg (95 pounds). Together, the two front wheels deliver a steady 41 horsepower, which can spurt up to 82 hp for short sprints. The Will should do 0-100 km (0 – 62 mph) in 10 seconds and will have a max speed of 140 km/h (87 mph).

Lithium ion batteries will be delivered in three modular configurations, offering ranges of 150, 300 and 400 km (93, 186 and 248 miles). Just like hybrids, the Active Wheels recover energy during braking to extend vehicle range. The in-wheel motors are reported to be 90% efficient, compared to about 20% efficiency for a conventional vehicle in city driving.

With battery packs on board, the prototype Heuliez Will weighs in at just 900 kg.

Active Wheel

Active Wheel

How to extract energy from the ocean

How to extract energy from the ocean

All that water in the ocean holds a lot of heat, but it’s not spread out. Just a few feet down below the temperature drops considerably, and it gets even colder at a few hundred feet. Scientists want to tap on this huge thermal differential to power energy plans.

This is how it works:

Surface water heats a fluid with a low boiling point, such as ammonia. The resulting gas drives a power-generating turbine. The gas is then cooled by passing it through cold water pumped up from the bottom of the ocean via massive fibreglass tubes that suck up cold water. The gas condenses back into a liquid that can be used again, and the water is returned to the deep ocean.

Scalability seems to be a problem:

“A 100 MW plant might have a pipe 30 feet in diameter suspended 3000 feet. That’s not a small challenge. You’ve got this huge structure vertically suspended. You’ve got a lot of stresses and strains from current, from the movement of platform on the surface”.

And small designs also had trouble in the past:

In 2003, Indian engineers building a 1 MW ocean thermal plant attempted to lower an 800-metre cold water pipe into the ocean from a barge in the Bay of Bengal only to lose the pipe in 1100 metres of water. A new pipe met the same fate the following year.

Besides the obvious technical issues (how to keep these massive pipes in place in the ocean, etc), I see problems with the energy used to pump cold water from the bottom to condensate the working fluid. How does that fit in with Conservation of Energy principles? If we want to break the laws of Physics and build a perpetual machine, might as well go with a known, guaranteed source like magnetic motor.

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