Water, a little bleach and a plastic bottle are all Filipino entrepreneur Illac Diaz needs to light up the world. He's out to make lighting free and safe, one slum at a time.

Until now, nearly three million people in the Philippines have gone without electricity, according to philstar.com. Those with access often use unsafe or illegal technology, creating disastrous effects. For example, 2,520 electricity-related fires were reported in 2009. In the Philippines, through the My Shelter Foundation, Diaz is implementing Solar Bottle Bulbs to diminish these problems. A used plastic bottle filled with water and a touch of bleach is placed in a hole of a tin roof. For up to five years, 50 watts of light fill up the once-gloomy windowless shack any time the sun is out, Diaz told Reuters in the video above.

Although WattWatt.com reports that the idea originally started with mechanic Alfredo Moser of Brazil, who used the creation locally, Diaz attempts to spread it worldwide. With an MIT student design, Diaz has brought the appropriate technology farther, with his two-hour seminar about the simple product. The invention is something that is so simple, cheap and sustainable that anyone can create it and maintain it themselves. As Diaz says, the three rules of appropriate technology are that people can find it, they can replicate it, and most importantly, they can make a business of it. Not only does the Solar Bottle Bulb bring free, sustainable lighting to places that haven't had it before, they also create a new market for people to install the bulb at small costs.

The only downfall of the Solar Bottle Bulb is that the idea only works during the day. But that hasn't stopped nearly 300 households, small businesses and schools in San Pedro, Philippines, from installing the Solar Bottle Bulbs.

These squares represent how much land would be needed to power the world, Europe or Germany with solar-thermal power. Photo: Treehugger

A single solar farm in the Sahara desert could provide clean electricity for all of Europe.

Scientists are investigating solar farms in the Sahara, as part of a $62 billion plan to provide all green power for a new, carbon-neutral European super-grid.

Because the sunlight in northern Africa is more intense, solar panels in the Sahara can capture up to three times more energy then panels located in northern Europe.

Arnulf Jaeger-Walden of the European commission’s Institute for Energy said today at the Euroscience Open Forum in Barcelona that a mere 0.3 percent of the light falling on the Sahara and Middle Eastern deserts would supply all the energy Europe needed.

The proposed solar farms will utilize advanced solar technology created by the California-based firm Ausra. These solar power plants use movable reflectors to concentrate sun light on pipes. The water in these pipes is solar-heated to produce high-pressure steam, which then goes through a turbine to generate electricity.

These innovative solar plants store enough hot water to make electricity even at night, and to increase production during peak demand periods. The plants are much more effective than traditional solar panel designs, allowing the plants to generate electricity at a mere 10 cents per kilowatt hour, much less than what the average consumer is paying now.

Ausra’s technology has been made cost-efficient by advances in transportation. Jaeger-Walden explained today that transporting the solar electricity would be relatively easy using new high-voltage direct current transmission (DC) lines instead of the alternating lines currently used. Energy loss using DC lines is very low, making the usual issue of transportation over long distances less of a problem.

Sixty-two million dollars for a project of this kind seems expensive — until you compare it with the more than $45 trillion in green-energy systems the world needs over the next 30 years to avoid global catastrophe, according to the International Energy Agency.

Doug Parr, Greenpeace UK's chief scientist, welcomed the project, saying:

"A large scale renewable energy grid is just the kind of innovation we need if we're going to beat climate change. Europe needs to become a zero-carbon society as soon as possible, and that will only happen with bold new ideas like this one. Tinkering with 20th-century technologies like coal and nuclear simply isn't going to get us there."