Celebrating 12 years of good tunes and maintaining its position as the leader of environmentally conscious concert events, the Bonnaroo Music and Arts Festival has once again raised the green bar. This week, Bonnaroo and it's partners announced the installation of its first permanent solar array. Although the use of PV panels and solar-powered stages is not new to the festival circuit, Bonnaroo is treading on new ground with a permanent installation. Generating more than 61,000 kWh per year, this system will mark the first of it’s kind for any US musical festival.

To read more details about Bonnaroo's environmental programs and the new solar array please visit our sister site, Green Up Music.

Tired of being tethered to the outlet? Set yourself free with an off-grid charger.

Editor's Note: This is a guest post by Rebecca Keller of AndGeeks.com.

As a writer, I depend on my 14 inch laptop and take it with me everywhere I go. However, lately I've become interested in greener alternatives when it comes to my electronics usage. That’s why I decided to invest in a solar charger to charge my laptop—as well as my other small electronics, like my digital camera and my cell phone.

Solar chargers work by drawing electric energy from the sun via a small solar panel—kind of like the solar panels that folks isntall on their roof to provide energy, except this one is much smaller. The solar charger I chose is specifically for small, portable electronic devices so I just tuck this one in my overnight bag or laptop bag and take it with me wherever I go.

The great thing about a solar charger is that it doesn't need an outlet, just add sun and power up. Not only does it save me money on my utility bill, it’s also really handy in areas where electricity isn’t available—for instance, when I’m camping, travelling by car or train, etc., or in countries where my plug isn’t compatible. I took my solar charger with me to France this past year and was able to use it wherever I could get access to direct sunlight. I even bring it with me on hikes when I’m camping so I can access the sun’s rays and juice up my cell phone and camera when I get back to my campsite.

How handy is that?

Now that you’re familiar with the way that they work, here are some simple tips for choosing a quality solar charger to power your portable electronics…

1. Do your research

Of course, a little research can go a long way when choosing a solar charger that’s compatible with your electronic device(s). For instance, there are 3 important factors you’ll need to consider before purchase:

1. Solar panels—which come in two types—crystal silicon solar cells, which will give you an electrical current but are limited in low light and amorphous silicon solar cells, which can conduct an electric current over a larger range, but tend to be more expensive.
2. Battery conversion rate—or where solar energy is collected in the charger to power your electronics efficiency. Obviously the higher power the solar charger’s battery conversion rate—the more efficiently it charges.

2. Ensure the charger is compatible with your device(s)

My portable solar charger is a universal style model. It simply connects to my electronic devices directly via a collection of cords to transfer power over. Most universal models come with a series of power transfer cords so you just choose the one to fit your specific electronic inputs so they’re compatible with the majority of electronic devices. However, it’s important that you check the packaging to make sure or talk to a salesperson to ensure the charger will work with whatever portable electronics you wish to power. A universal solar charger, like the one I purchased, can be used to power a variety of devices.

3. Test the charger before you throw out the packaging and receipt

I would recommend testing the solar charger to make sure it works to power your portable electronics. That means, keep the packaging as well as your sales receipt and test the charger to make sure it works before making a firm commitment. For example, a high-quality solar charger should be able to charge a laptop or digital camera many hours beyond their original battery limitations. If it doesn’t cut it, return the charger for a full refund. I recommend looking for a solar power charger that has at least 0.75 watts or more otherwise the charge current will be too small to charge even a small calculator efficiently.

About the author: Rebecca Keller is a graduate of the Arts and Technology program at the University of Texas. An admitted tech-junkie, freelance writing about Android devices for AndGeeks.com offers the perfect outlet for a tech geek like Rebecca. When she's offline, which isn't very often, Rebecca enjoys volunteering for her local animal shelter and off road mountain biking.

Top image via cogdog/Flickr

Researchers at Tufts University School of Engineering have discovered that silkworm cocoons possess incredible refrigeration properties.

Tufts biomedical engineers, led by David L. Kaplan (pictured below), are seeking a solution to a serious obstacle: how to keep life-saving pharmaceuticals cold. Most vaccines, enzymes and antibodies and many antibiotics and other drugs require constant refrigeration from manufacture to delivery to maintain their effectiveness.

“Silk protein has a unique structure and chemistry that makes it strong, resistant to moisture, stable at extreme temperatures and biocompatible, all of which make it very useful for stabilizing antibiotics, vaccines and other drugs.” says Kaplan, who has been studying silk for two decades.

Measles is one of the leading killers of children worldwide. Without refrigeration, the MMR vaccine rapidly loses potency. But after six months of storage in freeze-dried silk films at body temperature (37 degrees C) and at 113 F (45 degrees C), all components of the vaccine retained approximately 85 percent of their initial potency. found that silk stabilization preserved the efficacy of the measles, mumps and rubella (MMR) vaccine, as well as penicillin and tetracycline, at a wide range of temperatures (at least up to 140 degrees Fahrenheit).

Researchers have not only found a solution to "the cold chain", but also uncovered a way to provide refrigeration for months and possibly years at temperatures above 110 degrees Fahrenheit. by stabilizing them in a silk protein made from silkworm cocoons.

According to co-author and research assistant professor Bruce Panilaitis, the research team hasn’t found any pharmaceutical that they have been unable to stabilize. Panilaitis says the use of silk protein as an insulator could be a “universal storage and handling system.”

This is definitely a research team to keep your eye on. If a material derived from silkworm protein can effectively keep vaccines cool in sweltering temperatures, imagine what other everyday objects it can refrigerate. This material could conserve a lot of energy - in a natural way! It could be used in food or beverage packaging, athletic apparel, home insulation, the possibilities are endless...

Of course, if the technology is scaled up, careful consideration of the silkworm population will have to be taken.

What do you think, readers?

Sources:  Tufts University , PopTech

Designer Joey Roth introduces a clever planter made out of terracotta that naturally irrigates plants.

Roth was inspired by the "olla" an ancient irrigation tool that farmers still use to conserve water in arid climates. A user simply pours water in the center chamber and the planter’s porous earthenware material allows water to gradually seep into the surrounding soil. It is an efficient system because virtually no water is lost to evaporation or run-off.

The planter is 8 inches in diameter and 6 inches tall and is designed to hold three herbs or six succulents. The vessel can hold up to 2.5 liters of soil and 0.4 liters of water and it is suitable for indoor or outdoor use. For indoor gardeners, this self irrigating planter means you won't need to worry about a puddle of water accumulating on your floor if you over water.

Roth's design philosophy is to combine simple functionality with honest, unfinished materials. His planter isn't available for sale yet, but you an pre-order it at JoeyRoth.com for $45.

Sources: Joey Roth & Core77

Most greenhouse gasses come from combustion engines used for transportation. Cars and trucks usually take most of the heat for this pollution, but did you know marine vessels are also major emitters?

In fact, marine gasoline and diesel engines are among the greatest contributors of hydrocarbons (HC) and oxides of nitrogen (NOx) pollution in the United States. So while cruising around the lake may feel better than sitting in traffic, it's actually having a similar negative impact on the planet.

Traditional boat owners can take steps to minimize their vessel's polluting ways, like eliminating unnecessary idling and avoiding carburetor equipped engines. Or they can simply buy a boat that doesn't have a pollution-emitting engine, like this sweet all-electric motorboat from Hammacher Schlemmer.

Forget about costly gas and dangerous tail-pipe emissions--this 5-foot craft is perfect for lounging on the water in eco-friendly style. Outfitted with a 12-volt electric motor that drives a two-bladed propeller, it's true that this compact watercraft isn't going to break boating speed records anytime soon, but its perfect for taking 4 mph cruises around the pond or small lake without disturbing everyone in a five-mile radius (including the fish!). On a full charge, the batteries will provide up to 6 hours of continuous use.

Featuring advanced fiberglass construction technology, the Hammacher Schlemmer limited edition is trimmed with mahogany, chromed moldings, and stainless steel drink holders, cradling riders in twin foam-padded recumbent seats upholstered in marine-grand vinyl. It also includes a waterproof 120-watt audio system with two 5" speakers that play music from a connected iPod and a built-in cooler that holds up to 24 bottles or cans...of soda, right? No drinking and boating allowed.

Best of all, it's made in the USA, and unlike many all-electric alternatives, is pretty cost-competitive. Sail away with it for only $4,000.

One of the many creations of Kate Hartman, Botanicalls provides a digital pathway of communication from plants to humans.

Just a few months ago we brought you a story about a little device that helps those with less than a green thumb keep their plants happy, healthy and well watered. Botanicalls is the creation of Kate Hartman, Kati London and Rob Faludi. This past week I had the chance to see Kate Hartman speak about the project at the second annual Eyeo festival in Minneapolis. A designer with a diverse set of talents spanning electronics and wearable tech, Kate's projects are whimsical and about connecting with others, your plants and sometimes your own thoughts.

A DIY kit that is simple to construct, Botanicalls was originally designed to call you when your plant needed watering but over time was upgraded to tweeting. Your plant essentially has its own Twitter account and status updates let you know when it's in need of watering. Although I think I might prefer a call or text as it would feel like a more direct connection to me, giving plants the ability to tweet is an interesting way of providing them with a voice within the human world.

The Botanicalls kit is available through Sparkfun here.

Image source: MOMA

Summer is just around the corner, and for those who live in big cities, that means spring warmth will soon give way to searing heat. Green roofs can help regulate city temperatures, giving people, and the electrical grid, a much needed break.

Toronto is the first city in North America with a bylaw that requires roofs to be green. And we're not talking about paint. A green roof, also known as a living roof, uses various hardy plants to create a barrier between the sun's rays and the tiles or shingles of the roof. The plants love the sun, and the building (and its inhabitants) enjoy more comfortable indoor temperatures as a result.

Toronto's new legislation will require all residential, commercial and institutional buildings over 2,000 square meters to have between 20 and 60 percent living roofs. Although it's been in place since early 2010, the bylaw will apply to new industrial development as of April 30, 2012. While this is the first city-wide mandate involving green roofs, Toronto's decision follow's in the footsteps of other cities, like Chicago and New York.

Under the direction of Mayor Richard Daley the city of Chicago put a 38,800 square foot green roof on a 12 story skyscraper in 2000. Twelve years later, that building now saves $5000 annually on utility bills, and Chicago boasts 7 million square feet of green roof space. New York has followed suit, and since planting a green roof on the Con Edison Learning Centre in Queens, the buildings managers have seen a 34 percent reduction of heat loss in winter, and reduced summer heat gain by 84 percent.

But lower utility bills aren't the only benefit of planting a living roof. In addition to cooling down the city, green roofs create cleaner air, cleaner water, and provide a peaceful oasis for people, birds and insects in an otherwise polluted, concrete and asphalt-covered environment.

Image via Flickr/pnwra