Providing Alternative Energy by Alternative Means
Underwater line transmission on the Trans Bay Cable project in the San Francisco Bay Area.
Alternative energy is all the rage these days with everything from salt water desalination to cellulose being suggested as potential sources of energy. But when it comes to ways to deliver that energy to consumers, power utilities have been mostly on land transmission lines carried over transmission towers.
These towers have been controversial not only for their aesthetic effect but more important, their health effects. The high voltage carried by the lines cause them to emit EMF waves which have been known to cause adverse health effects.
As a result, power companies are re-thinking their modes of transmission in this New York Times article.
One such company is Transmission Developers (based in Toronto, Canada), which is focusing on underwater transmission line projects that can eliminate the need for transmission towers on land.
Underwater installation even has the cautious support of environmental groups, which have vehemently protested against transmission via land. The biggest environmental impact so far seems to be potential industrial pollutants being disturbed into the water during installation.
The cost of underwater transmission is comparable to land transmission (approx. $10M/mile vs. $1-4M/mile, respectively). Some of the additional cost is used to convert the energy to DC current (which is easier to transport in underwater cables), and may be offset when the line help open up new markets traditionally served only by land transmission lines.
Locally here in the Bay Area, the Trans Bay Cable project laid 33 miles of underwater transmission line to connect the power grid.
In conclusion, it looks like power companies are getting serious about not only greening their energy sources but transmission as well.
