IT MUST BE GREEN

Because they produce no exhaust gases in operation electric vehicles (EVs) are seen as the eco-friendly alternative to conventional gas-fueled cars. While zero-local emissions is clearly a big plus, other factors contributing to the overall environmental impact of EVs are often overlooked – namely the manufacture, usage and disposal of the batteries used to store the electrical energy and the sources of power used to charge them. Now, for the first time, a team of scientists from the Swiss Federal Laboratories for Materials Testing and Research (or EMPA) have made a detailed life cycle assessment or ecobalance of the type of lithium-ion batteries most frequently used in EVs, to see if they really are as environmentally friendly as their manufacturers would have us believe.

Fuel source is the key

The investigation shows that, if the power used to charge the battery is not derived from purely hydroelectric sources, then it is primarily the operation of the EV that has an environmental impact, exactly as is the case with conventionally fueled vehicles. In other words, the size of the environmental footprint depends on which sources of power are used to “fuel” the EV. Contrary to initial expectations that the manufacture of the batteries could negate the advantages of electric drive vehicles, the Li-ion battery itself was actually found to have a limited effect.

The team calculated the ecological footprints of electric cars fitted with Li-ion batteries, taking into account factors such as those associated with the production of individual parts, the operation of the vehicle during its lifetime, all the way through to the scrapping of the vehicles and the disposal of the remains. The electric vehicles evaluated were equivalent in size and performance to a VW Golf, and the power used to charge the batteries was assumed to be derived from sources representing an average European electricity mix – that is, a mixture of atomic, coal-fired and hydroelectric power stations.

For comparison the team used a new petrol-engined car, meeting the Euro 5 emission regulations. It consumes on average 5.2 liters (1.37 U.S. gallons) per 100km (62 miles) when put through the new European Driving Cycle (NEDC), a value significantly lower than the European average. In this respect, therefore, the conventional vehicle belongs to the best of its class on the market.

Results

The study shows that the electric car’s Li-ion battery drive is in fact only a moderate environmental burden. At most only 15 per cent of the total burden can be ascribed to the battery (including its manufacture, maintenance and disposal). Half of this figure, that is about 7.5 per cent of the total environmental burden, occurs during the refining and manufacture of the battery’s raw materials, copper and aluminum. The production of the lithium, in the other hand, is responsible for only 2.3 per cent of the total.

“Lithium-ion rechargeable batteries are not as bad as previously assumed,” according to Dominic Notter, coauthor of the study which has just been published in the scientific journal Environmental Science & Technology.

The outlook is not as rosy when one looks at the operation of an electric vehicle over an expected lifetime of 150,000 kilometers (93,205 miles). The greatest ecological impact is caused by the regular recharging of the battery, that is, the “fuel” of the e-car. Topping-up with electricity sourced from a mixture of atomic, coal-fired and hydroelectric power stations, as is usual in Europe, results in three times as much pollution as from the Li-ion battery alone. If the electricity is generated exclusively by coal-fired power stations, the ecobalance worsens by another 13 per cent. If, on the other hand, the power is purely hydroelectric, then this figure improves by no less than 40 per cent.

The EMPA team concluded that a petrol-engined car must consume between three and four liters per 100km (or about 70mpg) in order to be as environmentally friendly as the electric car studied, powered with Li-ion batteries and charged with a typical European electricity mix.

If someone asks you to describe a solar power plant you’d likely look to convey an image of row upon row of sun-soaking panels pointing skyward. It’s doubtful that the first thought to pop into your head would be of someone’s home, unless of course you’ve already witnessed the likes of the Heliotrope. Sited at the foot of the Black Forest in Germany, this magnificent cylindrical power house is the creation of solar architect Rolf Disch and is the world’s first home to produce more energy than it consumes. As the architect announces plans to take his PlusEnergy vision to a global audience, we take a closer look at his first creation.

Towering above the homes and vineyards that surround it stands the Heliotrope home of solar architect Rolf Disch. Whilst a few of the other buildings in the southern German city of Freiburg sport the odd rooftop solar panel to offset some of the spiraling energy costs, using freely available energy from the sun is central to the very design of the Heliotrope. And just like the flora that inspired its name, this solar tower actually follows the path of the sun as it makes its way across the sky. The main structure of the house is built onto a central load-bearing wooden column that’s 47.5 feet (14.5m) high and has a diameter of 9.5 feet (2.9m). The house is designed to rotate around the column at a rate of about 15 degrees per hour, following the path of the sun. It regulates heat entering the home by facing its triple-glazed windows in the sun’s direction in winter and pointing its insulated rear sunward during the warmer summer months. Inspection balconies outside also incorporate sunshades to help prevent seasonal overheating.

Snaking around the balconies are special railings that double up as solar thermal tube collectors and provide hot water for the building’s domestic needs and supply storage tanks for space heating. As heat from the sun pours through the Heliotrope’s windows, it is stored and used by the floor heating system and a geo-thermal heat exchange system makes the most of controlled ventilated air. There’s also a low-temperature ceiling radiation system that helps keep rooms nice and toasty when needed.

On the building’s roof sits the impressive solar sail. It’s made up of highly-efficient monocrystalline silicon solar cells and is able to independently rotate on a two-axis system, allowing for both horizontal and vertical adjustment for optimum tracking. This design is said to achieve an energy gain of between 30 and 40 percent over conventional fixed-panel units.

Access to the 590+ square feet (180m²) of living space in the upper structure is via a spiral staircase that winds its way up the central column. And there’s even more space on offer to the occupants in the base structure. Other pro-environment features of the design include a dry compost toilet and a grey-water well, where the home’s waste water is combined with rain water for re-use.

Unless you’re already aware of the Heliotrope, it may surprise you to learn that Disch’s home was completed in 1994, at a time when green architecture was still in its infancy. It was the world’s first home to produce more energy than it consumes and in spite of its age, continues to lead the field in energy efficiency and solar architecture technology. In fact it is said to produce up to five times more energy than it requires to meet its annual power consumption of 20 kWh, with the surplus fed into the public power grid.

Of course, there’s a bit of give and take in operation here – the Heliotrope supplies surplus power to the grid but draws from the grid when solar power is not sufficient to operate the power plant. This is considered a more efficient and green method than using batteries to store and draw, which may contain varying degrees of nasty heavy metals.

The Heliotrope template has been used to build an energy-producing showroom at Hansgrohe’s plant in Offenburg, the solar architect has also produced plans for a large hotel and even a special exhibition hall for the Shanghai EXPO 2010.

About five minutes away from Disch’s home is a solar settlement that uses many of the technologies found in the Heliotrope but incorporated into a less futuristic-looking and more familiar form. Hidden from view behind a 410 ft (125m) long, five story high commercial building are 59 two and three story townhouses. All of the buildings in the settlement have large photovoltaic roofs and produce more energy than they consume. And now the solar architect is looking to expand his PlusEnergy vision beyond Germany.

Disch believes that U.S. states like Hawaii, Florida and California – which already have systems in place to financially encourage the use of renewable energy – would benefit from the roll-out of homes based on his proven vision. Announcing an international push outwards, Disch’s company said: “PlusEnergy is a dual solution which exceeds the highest ecological standards and puts money back in the pockets of owners. Rolf Disch has proved that ecology and economy, function and form can be happily combined to bring double profits: for investors and the environment.” By Paul Ridden 20:11 August 29, 2010

You know, I’m pretty sure I remember a Far Side cartoon or something, where someone was selling powdered water – “Just add water!” Well, dry water isn’t quite the same thing. It’s 95 percent liquid water, but that water takes the form of tiny droplets each encased in a tiny globe of silica. The resultant substance is dry and granular. It first came to light in 1968, and was used in cosmetics. More recently, a University of Liverpool research team has been looking into other potential uses for the substance. They have found several, but most interesting is its ability to store gases such as carbon dioxide. In laboratory experiments, study leader Professor Andrew Cooper and his team found that dry water absorbed over three times as much CO2 as uncombined water and silica in the same amount of time. The gas combined with the water molecules to form a storable hydrate, which Cooper believes makes it ideal for reducing global warming. The Liverpool team also found that dry water could be used to store methane gas. As methane is a component of natural gas, they believe this discovery could make natural gas a more environmentally-viable energy source. They suggest that dry water could be used to absorb and transport the methane from stranded deposits of natural gas, or as a storage medium for methane fuel for cars. Another use that was discovered for dry water is as a catalyst to speed up reactions between hydrogen gas and maleic acid to produce succinic acid, a feedstock or raw material widely used to make drugs, food ingredients, and other consumer products. Hydrogen gas and maleic acid traditionally have to be stirred together to create a reaction, so by eliminating the need for mechanized stirring, maleic acid-infused dry water would allow for a more energy-efficient production process of the products. In yet another possible application, potentially harmful liquid emulsions could be transformed dry water-style into a dry powder, making them safer to store and transport. The team is now seeking commercial or academic collaborators to further develop the technology. “There’s nothing else quite like it,” said researcher Ben Carter. “Hopefully, we may see ‘dry water’ making waves in the future.” By Ben Coxworth 17:15 August 25, 2010

This 35cm by 25cm cheese board is one of 3 sizes that are made by the “Just Slate Company” in their factory in Scotland (the other 2 being 30cm round and 30cm square).

The Cheese Board came very well wrapped and came in a great looking black presentation box. When I finally did get all of the wrapping off the first thing I noticed was what a wonderful shimmer the slate had to it (more about that later). The slate has a very hand crafted feel to it, with interesting surfaces and edges.

You could use this board for anything – it doesn’t just have to be cheese. Other ideas that sprang to mind were sushi or hors dovres. Even better, this particular board from Just Slate had a “food safe lacquer” integrated onto the board, which not only brings out the detail of the slate (slightly more gloss than matt), but is ideal for hygienically placing food on it.

The best thing about this particular board though is a foam padding on the underside of the board. This allows you to place the board on, for instance, a wooden dining table without any risk at all of scratching the table. It also slightly ‘grips’ the board to whatever surface it is placed on – allowing you to cut the cheese on the board without it slipping.

Slate products should be wiped clean with a damp cloth and other models in the collection include:

• Slate Coasters
• Slate Placemats
• Slate Table Runner
• Slate Cheese Board
• Slate Serving Trays
• Slate Gift Packs
• Slate Memo Board
• Robert Burns Slate Collection

All are availble at It Must Be Green!

Review written by Dorian Hendrie

August 25, 2010

It would seem kind of strange if you were driving on a back road at night, far from any known source of electricity, when you suddenly came across a working streetlight. Such a thing is possible, however, and could even become a common occurrence. That’s because Lighting Science Group now manufactures solar powered LED streetlights, that can run entirely independent of local power grids. Even if the availability of electricity isn’t an issue, Lighting Science states they are also brighter, more efficient, and require less maintenance than regular HID streetlights. Those claims obviously impressed somebody, as the company’s PROLIFIC Series Roadway streetlights are now being installed on a 23-kilometer (14-mile) stretch of Mexico City’s elevated Viaducto Bicentenario superhighway. Lighting Science says their 100-watt, 5000K Roadways are at least 50 percent more efficient than HIDs. The lights are designed to run off a low-voltage direct current source of electricity, which could come from either solar or wind power. They are also said to give a more intense, uniform light distribution, and should save thousands of dollars in maintenance over the 60,000-hour lifetime of the fixture. This is because they don’t require relamping or reballasting, and direct line wiring is used instead of starters or capacitors. When maintenance is necessary, the electrical components can be accessed through a swinging door that requires no tools to open. The low maintenance requirements were one of the key reasons they were chosen by BHP Energy Mexico. Given that the lights have a listed operating temperature of -40 to 40C (-40 to 104F), it will be interesting to see how they hold up to the often-intense heat of Mexico City. By Ben Coxworth 19:27 August 20, 2010

Deserts are the obvious locations for solar power plants. The land is cheap and the sunshine is plentiful. Unfortunately so too is the dust, dirt and wind that leads to dirty solar panels that can take a big hit in efficiency. Sending a guy around with a squeegee in the sweltering heat doesn’t sound like the best job in the world and self-cleaning systems that rely on water aren’t always an option in areas where clean water is hard to come by. Another solution is self-dusting solar panels that are cleaned by an electric charge provided by the solar panels themselves. The self-dusting solar panels are based on technology developed for another dry and dusty environment – Mars.

The technology involves placing a transparent, electrically sensitive material deposited on glass or a transparent plastic sheet covering the panels. Sensors monitor dust levels on the surface of the panel and energize the material when dust concentration reaches a critical level. The electric charge sends a dust-repelling wave cascading over the surface of the material, lifting away the dust and transporting it off of the screen’s edges.

Within two minutes, the process removes about 90 percent of the dust deposited on the panels and requires only a small amount of electricity generated by the panel for cleaning purposes.

“We think our self-cleaning panels used in areas of high dust and particulate pollutant concentrations will highly benefit the systems’ solar energy output,” study leader Malay K. Mazumder, Ph.D. said. “A dust layer of one-seventh of an ounce per square yard decreases solar power conversion by 40 percent,” Mazumder explains. “In Arizona, dust is deposited each month at about 4 times that amount. Deposition rates are even higher in the Middle East, Australia, and India.”

Mazumder, who is with Boston University, said the need for that technology is growing with the popularity of solar energy. Use of solar, or photovoltaic, panels increased by 50 percent from 2003 to 2008, and forecasts suggest a growth rate of at least 25 percent annually into the future.

“Our technology can be used in both small- and large-scale photovoltaic systems. To our knowledge, this is the only technology for automatic dust cleaning that doesn’t require water or mechanical movement.”

Working with NASA, Mazumder and colleagues initially developed the self-cleaning solar panel technology for use in lunar and Mars missions. “Mars of course is a dusty and dry environment,” Mazumder said, “and solar panels powering rovers and future manned and robotic missions must not succumb to dust deposition. But neither should the solar panels here on Earth.”

The current market size for solar panels is about $24 billion, Mazumder said. “Less than 0.04 percent of global energy production is derived from solar panels, but if only four percent of the world’s deserts were dedicated to solar power harvesting, our energy needs could be completely met worldwide. This self-cleaning technology can play an important role.”

The team described the benefits of the self-cleaning coating in a report at the 240th National Meeting of the American Chemical Society (ACS).

By Darren Quick

19:39 August 22, 2010

Low-voltage halogen downlights are among the most commonly used globes in the world. Despite the low voltage moniker they aren’t very energy efficient, generally producing around the same amount of greenhouse gas as a 60-watt incandescent globe. While there are plenty of environmentally friendly alternatives to incandescent globes, finding a greener alternative for recessed lighting offers less options. Sharp is providing another, however, with its thin design LED ceiling lights.

Following on from its release of LED light bulbs that allow users to adjust the light color and brightness, Sharp is introducing six models of LED ceiling lights with similar features. Using the company’s proprietary light diffusion technology the new lights boast a thin design that is 43mm (1.7-inch) at the thickest part and 8mm (0.3-inch) at the thinnest.

Three of the new models, the DL-C501V, C301V and C302V, allow the use of a remote controller to change the color of the white light with the Adjustable Color function, and to adjust brightness with the Dimmer function. These functions combine to offer 110 different levels of color and brightness that match the mood or time of day.

These models also have three eco-functions that Sharp says reduce energy consumption up to 65 percent. For example, the Eco Light Rhythm function is a proprietary lighting program that automatically adjusts the color and brightness throughout the day; cool daylight white for waking up to in the morning, or a warm white in the evening for a more relaxed atmosphere.

The remaining three models, the DL-C501D, DL-C301D and DL-C201D, retain the Dimmer function but lose the Adjustable color function so are limited to producing a cool white light.

All six models also feature an Eco Dimmer function that reduces brightness gradually and an Eco Sensor function that detects the ambient light and reduces the light accordingly.

The lights range in brightness and power consumption from 2,350 lumens for the 46-watt DL-C201D, up to 5,100 lumens for the 86-watt DL-C501V.

Sharp will introduce the new LED ceiling lights into the Japanese market this September. No word on pricing or if/when they’ll get a release outside of Japan as yet.