Small, clean, green machines

MIT CityCarWhile mass transportation systems such as trains or busses are hailed as the solution for urban mobility, there is often the problem with the last mile. MIT Media Lab (with support from GM) has developed a small car, the CityCar, specifically to be used in an urban context and for car sharing.The 2-seater cars are fully electric and also stackable. They work a bit like shopping carts in when the behind car touches a parked one in front, the front car lifts its body enabling stacking. When you want to drive off again, you merely touch a button and the front car disengages and moves slightly forward. The idea is that anyone uses any car.

A further feature is that the cars are capable of 360° steering, making parking a dream.

Because the cars are part of a single, computerized network, their placement can be coordinated to reduce traffic congestion or make transportation options available at peak times and places. Rental charges could fluctuate to encourage alternate routes. Commuters could keep track of where and when cars and parking spaces are available in real time, using cellphones or other hand-held devices to track the cheapest or the most convenient car, spot, or route.

Ryan Chin, one of team working on this project, said: “When you think of this, you shouldn’t think of a car. You should think of it as a new personal and sustainable mobility system and service. This is a clean and green machine.”

MIT has submitted a proposal to a government in Asia that is interested in building a network of these cars in one of their cities. The CityCar was part of the plan submitted by MIT that also recently won the 2009 Buckminster Fuller Challenge.

Waste material becomes very efficient insulation

Your next refrigerator might be sheathed in renewable rice, if a team of students from the University of Michigan have anything to do with it. With just 12.5mm of rice husk ash they reckon they can achieve the equivalent of over 100mm of conventional petroleum-based insulation.

With claims that the 11 million fridges sold annually in the US could be made 50% more efficient, the judges of the Massachusetts Institute of Technology Clean Energy Prize obviously saw the potential in such technology. Such that they awarded the students first prize, which came with a cheque for $200,000. That will now no doubt help them as they launch a start-up company, Husk Insulation, to commercialise their product.

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Dyeing for more solar power

The main impediment to the widespread use of solar power – clouds and nightfall aside – is the cost of the silicon cells that actually convert the sun’s rays into electricity. To keep the expense down, people have been searching for ways to minimise the size of solar panels relative to the amount of light they can harvest. Often, this is done using clunky pieces of kit called solar trackers, which tilt an array of mirrors so as to direct large amounts of sunlight onto small, high-performance cells.

An alternative now being tested is called the luminescent solar concentrator (LSC). Instead of focusing the sun’s rays on a cell, as a solar tracker does, an LSC first traps them, wherever they have come from, and then delivers them to the cell using what is known as a waveguide. No moving parts are involved. A group of MIT researchers using this technology believe it could boost a solar panel’s efficiency by up to 50 percent and formed a company, Covalent Solar, to develop the technology.

The team has spent two years identifying organic dyes, painted onto glass or plastic that can effectively concentrate the sun’s light onto solar cells, enabling them to produce more electricity from fewer cells. The dyes basically reflect the light (technically, it’s actually absorbed and then sent back out), so that some of it is trapped inside the plane of glass. With the help of a scientific principal called “internal refraction”, which is the same principal that keeps light trapped in optical fibers, the light bounces to the edges of the glass, which have been equipped with strips of solar cells that convert it into electricity.

Integrated into solar panels available today, the technology could potentially boost the amount of light the panels convert into electricity by as much as 50 percent so consumers would get more electricity for their money.

The company hopes the technology could be used for both rooftop systems and for large solar farms and even one day could be integrated into windows, where a greyish tint would let in 20 percent to 30 percent of the outside light, while simultaneously directing the light toward solar cells around the window’s edges. Covalent Solar expects to bring its first product to market in three years.

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Google pushes for enhanced geothermal

In August 2008 Google.org, the philanthropic arm of Google, announced more than $10 million in investments in enhanced geothermal systems and put out the call for a big increase in federal funding for geothermal in the U.S.

Their investments are the latest rounds of funding under Google.org’s Renewable Energy Cheaper than Coal initiative, launched in 2007. But Google.org is going beyond cash investments and plans to push for a boost in funding for federal research and development, the streamlining of the siting, leasing and permitting process, the extension of tax credits, and the formation of a national renewable portfolio standard.

Enhanced geothermal doesn’t need the naturally occurring pockets of steam and hot water used in traditional geothermal. Instead, it replicates those conditions by fracturing hot rock and injecting water.

According to a 2007 report from the Massachusetts Institute of Technology on enhanced geothermal, just 2 percent of the heat below the continental U.S. at between 3 and 10 kilometers — depths within the range of current drilling technology — would be enough to supply more than 2,500 times the country’s total annual energy use.

In September 2008 Tata Power bought 10% in the Australian enhanced geothermal systems firm Geodynamics Geodynamics has geothermal exploration interests in three Australian states including a license for exploring 2,000 square kilometers in the Cooper Basin in South Australia. Tata Power said the Cooper Basin contains the hottest granites on earth, estimated to provide a thermal resource equivalent of 50 billion barrels of oil.

Original article: David Ehrlich. Cleantech Group. 19 August 19 2008. Read more…