Wednesday, August 22, 2007

Using Sewage In Power Plants


The Washington Post reports that, once implemented, an innovative new system will use sewage instead of precious groundwater in the operations of several power plants in Maryland.

The system will pipe in treated sewage from processing plants and use it as the basis of the power generation process, whereby water is heated to steam and used to spin turbines to produce electricity. It will also be used in cooling towers, to return the heated water to a functional temperature.

This design provides several benefits. First, it avoids effluent discharge into bodies of water. A bad thing for obvious reasons, the graphic to the right mentions this. Second, the system avoids the use of groundwater in plant operations, which would otherwise be copious. Third, the "closed-loop" system avoids so-called "thermal pollution," which often occurs when river or lake water is used to cool plant water and then is discharged back into a natural body of water. The subsequent temperature change alters the ecosystem in question.

Florida is in a drought situation right now, with our aquifers extremely low. Something like this could be a huge boon if a traditional power plant were to be built here in the future (although of course alternative sources of energy would be ideal). Or maybe existing plants could be fitted with this system... Very cool stuff!















System Would Use Effluent to Produce Power (Washington Post.com via Grist)

[Image from here; "SOURCE: Charles County Governement | GRAPHIC: The Washington Post - August 19, 2007"]