 |
 |
 |
|
|
|
Lombardy - How is Energy Produced? |
|
In Lombardy, there are four types
of power plants: hydroelectric, thermoelectric, fuel
cell-powered and waste incinerators. |
|
 |
|
|
Hydroelectric power plants were the first type of power plants
used in Lombardy, as well as in many other areas that possess
watercourses. These types of power plants have a high rate
of productivity (approximately 85-86%). Hydroelectric power
was one of the first forms of energy to be harnessed by humans
. Today, hydroelectric power still accounts for nearly a
quarter of the power produced worldwide. Until the 1960s,
Italian hydroelectric plants produced 50 Md of kWh/year,
which was equal to 82% of all of the country’s electrical
power needs. Since 1980, however, hydroelectric energy production
has been reduced in favor of thermoelectric power, and its
usage has decreased by approximately 19%.
|
|
From
the top: Penstocks and Basin details |
|
|
Generally, a hydroelectric power plant uses a dam to block a
watercourse and create a reservoir where a near-constant
level of water can be maintained. The water from the reservoir
is piped through penstocks into the power plant’s turbines
and passes through the inlet valves and regulating system.
|
|
From
the top: Dam with fillways shot |
|
|
The water activates the turbines, and then flows out of the plant,
through the drainage channel, and back into the watercourse.
An electrical device known as an alternator is connected
to the turbine and transforms the mechanical energy produced
by the turbine into electrical power. Before the power generated
by the plant can be distributed to transmission lines, it
passes through a transformer that lowers the intensity of
the electrical power and increases its voltage (up to thousands
of Volts). The system is designed to minimize power dissipation,
which, according to Joule’s Law, is equal to the amount
of heat lost by the system. Once the electrical power arrives
at its intended destination, it is passed through another
transformer, which raises the intensity of the current and
lowers its voltage to make it suitable for domestic use (220
Volts is the standard voltage in Italy).
A hydroelectric power plant has the following components :
- Reservoir
- Dam
- Turbine
- Penstock
- Valve
- Tailrace
- Transformer
- Alternator
|
| |
|
|
What does Joule’s Law state about
the heat produced by an electrical current passing
through a conductor?
The dissipation of thermal energy (heat) in a conductor is directly
proportional to voltage, the intensity of the current, and the
electrical resistance: E dissipated = V.I.R (measured
in Joules).
How do you convert Joules into calories?
Since one Joule is equivalent to 0.24 calories, you can convert
Joules into calories by multiplying the number of Joules by 0.24.
|
|
|
At night, when electricity demand is lowest, hydroelectric power
plants divert a portion of the power they produce to pump
water into the upper-levels of the reservoir. This helps
conserve power.
|
|
|
|
| |
|
 |
   |
|
|
Taccani
hydroelectric power station, named Moretti .
Trezzo
d’Adda. Milan.
ENEL Power Plant
Designed by the architect Moretti on the basin
of Adda at dawn of XIX century, i s operative from
1906 with 10 generators for a total of 10.000 kW.
Nowadays
renewed, it is composed of 6 alternators and supplies
the overall capacity of 10.500 kW. |
Taccani power station of Trezzo on Adda
is one of the finest examples of the industrial architecture.
At the beginning of XIX century, an important event opens
a new chapter in the Lombard economy. The cotton manufacturer
Cristoforo Benigno Crespi (1833-1920), progenitor of the
Crespi's dynasty (pioneers of the Italian cotton industry)
and founder of the homonymous village, acquired in 1894 the
whole river headland from Adda to Trezzo, where stood the
rests of an antique castle.
The manufacturer’s interest
was not so much turned to the old manor as to the construction
of a hydroelectric power station necessary for the Crespi ’s
cotton-mill of Adda. After have projected the plant and made
the request of concession of aquifer exploitation (1900),
Crespi founded the “Benigno Crespi joint-stock company
for the Hydraulic Forces of Trezzo on Adda". Subsequently,
he increased the capacity of aquifer exploitation acquiring
the 7 February 1903 the concession with which Rolla brothers
through a "natural
turn of water» had been producing power for their neighboring
weaving factory from 1892.
The engineer Peter Brunati, the
designer who worked for Crespi throughout the construction
of industrial village, executed in 1897 some preliminary
studies on the positioning of the new power station, of smaller
dimensions compared with the plant then realized. Nevertheless
the architect Gaetano Moretti (1860-1938), illustrious exponent
of the current inspired from the monumental modernism, carried
out t he definitive plan of the station. The technical director
Adolfo Covi assisted by Alexander Taccani and Oreste Simonatti
collaborated with Moretti. The first stone of the engine’s
building was laid the 11 July 1904 with a great participation
of people and authorities. The local workmen were involved
in the construction of the hydroelectric power station Benigno
Crespi; but some years later, as the works continued, the
consignors recruited skilled workers from other regions as
well.
"The house of the force", as the whole complex
was named, represented an important stage for the zone’s
development, like testifies the newspaper of those years: "From
there the light is got rid and from here it descends, flow
the light, a lot of power on the riversides and by Brianza’s
delightful countryside and all around, by the flourishing
land of Lombardy . Benigno Crespi’s power station entered
into function in 1906.
The derivation dam bars the Adda river
by the cove named cove of the castle of Trezzo and raises
its minimum flow up to nearly 7 meters. The turbines’ net
useful leap is approximately 8 meters. Short water pipes
equipped with an interception floodgate pour the water into
the turbines. Every turbine drags in rotation its own alternator
producing an electric power sent through the affixed conductors
to the transformers able to boost the voltage from 6 kV of
production level up to 15 kV. This power is then moved to
the primary room where is raised up to 132 kV before being
put o nto the national network.
Main components:
Weir
Long nearly 98 meters with floodgates
running under the oil-pressure. The derivable maximum capacity
is 180 cubic meters /s.
Turbine alternator’s groups
Are
operative 6 groups composed of: 4 turbines at screw and
2 Kaplan’s
turbines able to raise flows until 30 cubic meters. The
6 alternators have the speed of 187,5 turns per minute.
The set up power is equal to nearly 10.500 kW and the
producible power is in average 65 million kWh equivalent
to an average annual consumption of 24.000 families.
Transformers
The power is produced
by the generators at 6 kV voltage and sent through two
transformers of 6/15 kV to the medium voltage bars in
the primary room
Tailrace
Drawn from
the turbines the water flows down into a wide tank long
80 meters and large approximately 20 meters. From the
tank two galleries excavated in the rock and long 90
meters discharge the water into the river.
|
|
|
 |
 |
Verify your scientific erudition
with two strategy games: NRG and Station of Future. |
|
Bibliography
Study in depth any subject thanks to
the bibliographies suggested by lecturers and professors
who wrote the website's texts. |
|
|
Credits
Who carried out the website? |
|
Map
of contents
The website at a
glance
|
|
Questions
and answers
In any section you
can evaluate your learning with
thematic quiz. |
Glossary
Click on highlighted terms to learn
their meaning. |
|
|
