| ABOUT
GEM
Georgetown Energy
Museum is a fully functioning and operational
Hydroelectric generating plant in Georgetown, Colorado. The plant
is owned and operated by Xcel Energy. It has been in operation
since1900.
There are two generator-water wheel sets. Each set has
the maximum capacity of 720 kilowatts, bringing the total capacity
of the plant to around 1.5 megawatts of Alternating Current electrical
power. This is approximately enough power to support 700 to 1000
homes and businesses. Typically a modern home of today is rated
at 1500 watts usage.
The water wheels are of the Pelton design which claims
to have a 90% efficiency rating. The water used to drive the water
wheels comes from the Georgetown reservoir located approximately
.9 mile up the canyon towards Guanella Pass. That gives the water
a 700 foot vertical fall which produces 275 pounds per-square-inch
of water pressure at the water wheel. The water is delivered to
the wheel by a 30 penstock or supply pipe.
275 pounds is more pressure than the wheel needs to turn
the generator so a needle valve is used to control
the speed of the wheel at 360 RPM. The speed of the water wheel
has to be kept at 360 RPM so that the directly-coupled generators
speed is kept at 360 RPM. At that speed the generator will produce
60 hertz or 60 cycles-per-second of electricity. 60 Hertz is necessary
for the generators output to be synchronized with the distribution
grid.
The electricity that is generated here is added to the
substation located at the south end of the power plant, where
a transmission line from the Colorado distribution grid also feeds
the substation. This substation, in turn, feeds Georgetown, Silver
Plume and a transmission line that travels north to Empire and
the Henderson mining operation.
The fore mentioned needle valve position is
controlled by an electric motor at the right side of the water
wheel. The electric motor is controlled by way of a computer and
a communications link from the Cabin Creek hydroelectric plant.
Cabin Creek is a modern pumped storage hydroelectric plant located
approximately five miles up the canyon towards Guanella Pass.
All of the maintenance and monitoring of this plant is done remotely
from Cabin Creek. In 1976 the construction of Cabin Creek was
completed and it was added to the Colorado distribution grid.
When the plant was first built it did include an Alice
Chalmers Corliss steam
engine which drove one of the generators. Due to the cost of producing
steam from coal fired boilers the steam engine was only used when
the water level at the reservoir got too low to turn the water
wheels on.
There isn't any coal in the surrounding mountains so all
of the coal used had to be brought up from Denver. This was a
very expensive proposition. The economics of free water to expensive
steam retired the steam engine and boilers very early in the history
of the plant. To get away from steam generation the operators
of the plant moved the reservoir, also known as the forebay, from
the original location to the present location in 1902. They also
added pipe lines from Green Lake and Clear Lake to the forebay
capacity. This took care of the low water problems and the need
for steam generation. Although the steam generating machinery
was retired before the first world war, the boilers and the engine
were not removed until 1918.
In 1893 the Georgetown Electric Light and Power merged
with the Gas
Company and was named United Light and Power Company. In February
of 1906 Green and Clear Lake Company, Cascade Electric Company
and United Light and Power Company merged to form United Hydroelectric
Company. Then in July of 1916 the United Hydro Electric Company
was sold to Colorado Power Company. Colorado Power Company was
a conglomerate of several other Colorado power companies. In 1924
Colorado Power Company was renamed Public Service of Colorado.
In 1999 Xcel bought out Public Service of Colorado.
The same year, 1893, that the Gas Company and the Electricity
Company merged they built a two and a half mile transmission line
into Silver Plume. In 1900 a transmission line was built up to
Lamartine, a small mountain mining town high above and several
miles to the east of Georgetown. In 1901 this line was extended
down the mountain to the north and into Idaho Springs. By December
of 1902 the plant was contracted to supply electricity to Black
Hawk and Central City as well. So by 1903 the plant was supplying
electricity to Georgetown, Silver Plume, Idaho Springs, Black
Hawk, Central City, and any of the mines in the area that were
electrified.
|