Steamboat Hills Geothermal Power Plant

On November 19, 2002, we, the ChE 101 class, visited the Steamboat Hills geothermal power plant.  Steamboat Hills is a 10 MegaWatt plant situated on the south side of Reno.  The plant is powered by steam that is created due to high temperatures deep within the earth, which is used to turn a steam turbine, which in turn spins a generator, creating electricity.

The tour started in the office area.  The engineers introduced themselves and explained a bit about the operations of the plant.  They explained that a major engineering obstacle for them was scaling within the pipes of the plant, since the water in the plant was rich in minerals.  When the water there cools, it tends to leave deposits.  They then produced what appeared to be rocks, but were thick deposits of mostly silica removed from the pipes.

We then exited the office area and saw two large cooling towers that were used to cool the water/steam so that it could be injected into a well some distance from the plant.

Then, we walked to the other side of the building and saw a confusing network of pipes that conveyed the water/steam out of the well and into the side of the building.  The well was around 2000-3000 ft deep, and the water around 445o F.  There was a giant compressor that was used to start the flow of the well, should that ever be necessary.

Next, we went inside the plant to see the turbine itself.  Large pipes conveyed the water/steam into the turbine, which was a 1950’s model GE turbine originally used to power a ship.  They said that they had two other identical turbines on hand in case it broke.  The turbine was bolted to a gearbox that reduced the rotational velocity to the necessary 900 rpm needed to operate the generator.  The generator, surprisingly small, sat there producing 10 MegaWatts of electricity.  The plant was surprisingly simple.

The last thing we were shown was the injection well where all of the water was placed so that it could return to where it came from, heat up again, and continue the process perpetually.  A pipe ran from the plant several hundred feet to a location where it connected to a valve and entered the ground.  Not too interesting really, but the pipes did make an eerie hissing sound and were visibly hot.  One of the engineers opened the valve briefly to demonstrate the pressure contained in the pipes.  It shot a jet of steam into the air of about 25 feet or so, a nice way to end the tour.

Throughout the tour, I was impressed mostly by the simplicity of the plant.  I expected something magical or highly confusing, but it was really straightforward and logical, and quite interesting.
 

Heath Workman, Class of 2005
December 4, 2002