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Could free energy be only one flush away?


Benkatina: Power in a Pipe
The Benkatina turbine is enclosed in a pipe so it can fit into existing piped-water systems.
The Benkatina turbine is enclosed in a pipe so it can fit into existing piped-water systems.
Courtesy of Leviathan Energy

­One­ of the latest developments in water power takes the hydro-turbine to a whole new level. A much smaller level.

The Benkatina turbine isn't built to tap into the energy potential of Niagara Falls. It's built to tap into the potential of the sewage lines running through your neighborhood, your city's wastewater treatment plant and really any piped system with water running through it. Yes, in theory, this could mean your toilet.

An Israeli company named Leviathan created a water turbine that could open the field for potential energy sources. The "low-cost" Benkatina turbine has several traits that distinguish it from traditional water turbines [source: Kloosterman]:

  • It's smaller, and it can work in lower-flow situations. The Benkatina can adjust to various water pressures and pull electricity from water moving through any downhill pipes -- it doesn't have to be the kind of rushing water you see at, say, the Hoover Dam.
  • The turbine is enclosed in a pipe, so it can be fit into existing piped-water systems. There are water pipes running underground for all sorts of purposes, like carrying wastewater away from factories and carrying clean water into your home. One or more of these turbines can be inserted into the piping to capture energy from this water.
  • The Benkatina can be made into a sealed system so the water running through the turbine is completely sealed off from the gears the turbine is spinning. This makes it feasible for clean-water systems, since the clean water is isolated from mechanical parts coated in lubricants or other chemicals.

Another interesting application has to do with the way water loses some of its pressure when it transfers its energy to the turbine. Pressure reduction can fix leaks in a pipe system. Companies or municipalities that have been dragging their feet on fixing leaks would have an economic inducement to reduce water waste: Fix leaks and lower the electricity bill at the same time.

Can individuals do the same thing by slipping a Benkatina into a toilet's outgoing pipe? Theoretically, yes -- you can put one in there if you want. It's not going to generate much power, though, unless you flush your toilet constantly, all day every day [source: Leviathan]. And in that case, the cost/benefit analysis has to go against you.

But it looks like the Benkatina might be implemented in slightly larger water systems soon. Leviathan plans to start selling the turbines in the United States as early as late 2008.

For more information on Benkatina and other new new-energy technologies, look over the links on the next page.