designo
April 27th, 2004, 02:01 AM
Power from the bottom line
April 26, 2004 - 12:38PM
Human waste could be turned into a new renewable energy source, scientists believe.
Scientists have developed a device that generates electricity from human waste.
The Microbial Fuel Cell devised by American researchers at Pennsylvania State University uses bacteria to break down waste, liberating electrons in the process.
Normally the electrons would power respiratory reactions in the bacterial cells and be combined with oxygen molecules.
But the MFC wrestles the electrons away from the bacteria and uses them to power a circuit.
"There are extraordinary benefits if this technology can be made to work," Bruce Rittmann, an environmental engineer at Northwestern University in Illinois, told New Scientist magazine.
The device consists of a sealed can, 15 cm long, containing a special arrangement of electrodes.
Organic waste is pumped in and broken down by clusters of bacteria. By depriving the bacteria of oxygen, electrons are freed to set up a voltage between the electrodes.
Previous attempts to produce electricity in this way have only run on glucose solutions.
The current design produces only a 10th of what the researchers calculate the potential power output of the system could be, said New Scientist.
Even so, if scaled up, the device would produce 51 kilowatts of power from the waste produced by 100,000 people.
Microbiologist Derek Lovley, from the University of Massachusetts at Amherst, USA, believes generating power from waste on a large scale is a long way off.
"One way to think of this technology is that it is currently at the state of development that solar power was 20 to 30 years ago," he said.
"The principle has been shown, but there is a lot of work to do before this is widely used."
April 26, 2004 - 12:38PM
Human waste could be turned into a new renewable energy source, scientists believe.
Scientists have developed a device that generates electricity from human waste.
The Microbial Fuel Cell devised by American researchers at Pennsylvania State University uses bacteria to break down waste, liberating electrons in the process.
Normally the electrons would power respiratory reactions in the bacterial cells and be combined with oxygen molecules.
But the MFC wrestles the electrons away from the bacteria and uses them to power a circuit.
"There are extraordinary benefits if this technology can be made to work," Bruce Rittmann, an environmental engineer at Northwestern University in Illinois, told New Scientist magazine.
The device consists of a sealed can, 15 cm long, containing a special arrangement of electrodes.
Organic waste is pumped in and broken down by clusters of bacteria. By depriving the bacteria of oxygen, electrons are freed to set up a voltage between the electrodes.
Previous attempts to produce electricity in this way have only run on glucose solutions.
The current design produces only a 10th of what the researchers calculate the potential power output of the system could be, said New Scientist.
Even so, if scaled up, the device would produce 51 kilowatts of power from the waste produced by 100,000 people.
Microbiologist Derek Lovley, from the University of Massachusetts at Amherst, USA, believes generating power from waste on a large scale is a long way off.
"One way to think of this technology is that it is currently at the state of development that solar power was 20 to 30 years ago," he said.
"The principle has been shown, but there is a lot of work to do before this is widely used."