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Soylent Green is people; what's Soylent Fuel made of?
From: David Farber <dave () farber net>
Date: Fri, 7 Apr 2006 17:43:28 -0400
Begin forwarded message:
From: Randall <rvh40 () insightbb com>
Date: April 7, 2006 5:19:37 PM EDT
To: Dave <dave () farber net>, Dewayne Hendricks <dewayne () warpspeed com>
Subject: Soylent Green is people; what's Soylent Fuel made of?
Friday, April 07, 2006 at 5:17 PM EDT
Oslo's sewage heats its homes
By Alister Doyle, Environment CorrespondentFri Apr 7, 10:01 AM ET
In an extreme energy project tapping heat from raw sewage, Oslo's
citizens are helping to warm their homes and offices simply by flushing
Large blue machines at the end of a 300-meter long tunnel in a hillside
in central Oslo use fridge technology to suck heat from the sewer and
transfer it to a network of hot water pipes feeding thousands of
radiators and taps around the city.
"We believe this is the biggest heating system in the world using raw
sewage," Lars-Anders Loervik, managing director of Oslo energy company
Viken Fjernvarme which runs the plant, told Reuters. The plant opened
The heat pump, a system of compressors and condensers, cost 90 million
Norwegian crowns ($13.95 million) and has an effect of 18 megawatts
(MW), enough to heat 9,000 flats or save burning 6,000 tonnes (5,900
tons) of oil a year.
And experts say sewers could be exploited elsewhere.
"The technology is there, so if the infrastructure is also there, this
is a feasible solution in many cities worldwide," said Monica Axell,
head of the International Energy Agency's heat pump center. The agency
advises 26 industrialized nations.
She said a bigger heat pump in Sweden, with a 160 MW capacity, exploited
heat from treated sewage. And in Finland, a 90 MW plant ran on waste
In Oslo, untreated sewer flows -- from toilets, bathtubs, sinks and
rainwater from the streets -- runs into the system past a filter that
keeps out big objects such as dead rats.
Sewage was flowing into the system at 9.6 Celsius (49.28 Fahrenheit) on
Friday and coming out at 5.7 Celsius after heat is extracted with a
The energy in turn goes to warming the water in the 400 km (250 mile)
pipe system, fed to offices and homes, to about 90 C from a temperature
of 52 C when it reaches the sewerage plant. Other plants, burning
industrial waste, also heat the water.
Similar heat pumps can be run on any stable source of water -- in Paris
the Seine River is tapped to run air-conditioning systems. Sea water can
also be exploited.
Sewer power is less polluting than burning fossil fuels but more than
renewable energy like wind power. About a third of the heat energy comes
from electricity to drive the system and the other two-thirds is the
heat from the sewer.
"Oil prices have an impact on investment willingness, but more important
is the ratio of fuel price and electricity price," Axell said. "A high
fuel price and a low electricity price is a strong driver to invest in
heat pump technology."
Among other sewage energy projects worldwide, U.S. scientists are
looking to exploit sewage-eating bacteria to generate electricity.
"The microbial fuel cell work is going well, but we still are not out of
the lab on this technology," said Bruce Logan of Pennsylvania State
In Oslo, a problem is that the flow in the sewers is irregular -- Monday
mornings between 4-6 a.m. are especially dry because people go to bed
early on Sunday. But at weekends, the flow is good.
"When people have been out to parties there's a lot of beer going into
the sewer," said Oyvind Nilsen, the project manager for the Oslo plant.
At the opening ceremony for the plant, Oslo mayor Per Ditlev-Simonsen
was given a new toilet seat for his office. "It will be an inspiration,"
[I got it in an email, so I don't know the source URL]
"The people who still support George Bush are the same people who
believe Adam and Eve rode to church on the backs of dinosaurs". - SNL
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- Soylent Green is people; what's Soylent Fuel made of? David Farber (Apr 07)