Dam it

We’ve come a long way from the first water-powered mills that were located along rushing streams; today’s hydroelectric plants have been carved out of landscapes that are dramatically changed as a result.

Damming a river and creating a reservoir results in the loss of land and habitats upstream of the dam, and changes the dynamics of the entire river system. Dams and reservoirs have a finite lifespan, on the order of 20 -200 years, and maintaining them can be costly.

But dams bring life to the desert and reservoirs provide recreational opportunities not otherwise possible in arid regions. As with all decisions regarding potential energy sources, there are trade-offs and consequences.

Photo credit: View of Hoover Dam, http://geochange.er.usgs.gov/sw/changes/natural/codrought/

Alternative Energy: Water

This week: Alternative energy

Fossil fuels are relative newcomers as energy sources. For as long as water has been running downhill, there has been a cheap, renewable, readily available energy source.

The energy created by water flowing downhill under the influence of gravity has been harnessed for hundreds of years. Factories in the 19th century were built at waterfalls or along rivers where the energy of flowing water could directly turn the waterwheel that drove their machinery.

In modern times, this energy is used to turn turbines that create electricity for distribution over power lines to large areas. Hydroelectric power is relatively inexpensive, clean, it produces no greenhouse gasses or smog, and it is renewable for as long as water can be made to run downhill.

Tomorrow: is there a downside to hydroelectric power?

Photo credit: http://www.top-alternative-energy-sources.com/images/water-wheel.jpg