Transcript Ambiente & Energia - Instituto Politécnico de Tomar

Environment & Energy
Energy – Statistics
Valentim M B Nunes
Unidade Departamental de Engenharias
Instituto Politécnico de Tomar, March, 2015
Energy
Energy is a vital resource in any modern society: as the food the energy must
be stored and transported in time and place is available to where it will be
used.
Fossil and nuclear fuels, which store energy in the form of chemical or nuclear
are the most common way of storing and transporting energy.
Engine room:
boiler, turbine,
condenser
Refrigeration Towers
Transmission lines
(high voltage)
Thermoelectric Power Plant of Pego
Renewable Energy
Renewable energy sources are of various types: wind turbines, wave energy,
solar energy and hydro or mini hydro systems (dams) are some examples.
Stored water
Engine room
Transmission lines (high
voltage)
Castelo de Bode Dam
The Thermoelectric Power Plant of Ribatejo:
3 units or groups of production,
with nominal power of 392
MW.Combined cycle technology
allows to achieve an energy
conversion exceeding 57.5% of
yield, witch compares very
favorably with the 36% of a coal
fired power station at Sines or
Pego.
These modern units are quite complex, and are designed to achieve maximum
thermal efficiency. But combustion of fossil fuels gives rise to solid and gaseous
pollutants, such as COx, SOx, NOx, metal fumes, ashes, etc.. To remove these
pollutants are required expensive equipment as "scrubbers", electrostatic
precipitators, etc., which turns the price of electricity more expensive.
The Dam of Aguieira
Nuclear, Yes or not?
Nuclear power plants use a steam cycle to produce mechanical energy, but
the steam to power the turbine is generated by heat transfer from a hot fluid
that passes through the nuclear reactor, or contact directly with reactor fuel.
The main drawback of a nuclear power plant, which does not emit pollutants
into the air, is the difficulty in ensuring that the immense generated
radioactivity never escapes by accident.
Nuclear Power Plant of
Almaraz - Spain
Over time …
Agricultural societies: Solar Energy
1st Civilizations: hydropower
Growing of Europe: Canals/Dams/Mills
(wind energy)
Modernity: Chemical/Mechanical energy
Industrial Revolution: Coal/vapor
XX Century : electricity, oil, nuclear
XXI Century: Thermonuclear controlled fusion?
Global Sources of Energy
1 Q = 1x1015 Btu = 1.055x1018 J = 2.9307x1011 kWh
Global consumption of electricity
Electricity is a secondary form of energy generated from primary sources
(fossil, nuclear, hydroelectric, geothermal and other renewable sources).
Final Energy
Global supply of energy
World fossil reserves
Consumption
(Q/y) - 1995
Growing/ year
Lifetime/
years
Lifetime with
growing
Fuel
Reserves
(Q)
Coal
24000
93
0.8%
258
140
Oil
9280
141
1.1%
66
50
Gas
6966
78
2.5%
90
50
* By exploring are the immense reserves of methane hydrates in the bottom
of the ocean, but for which there is still no technology.
Energy consumption and production: overview
Final Energy Consumption
Energy Dependency
Production of electricity by renewable
Installed Power
International Comparison
Energy consumption in Portugal: transport, industry and domestic sector
Oil consumption
Natural Gas consumption
Electricity: Renewable vs non renewable
Evolution of prices
Price structure - 2014
Renewable
The total amount of electric power produced is corrected with the Producibility of
Hydro Index (HPI) for the purposes of comparison with target set in the directive
2001/77/CE
Renewable
Problem 1.
The coal reserves are estimated at 24000 Q. What the total value in kJ? What is the
lifetime of these reserves to the current consumption rate of 93 Q/year and if the
consumption increase r = 0.5%, 0.8% or 1%/ year? The lifetime can be calculated via
   QT
T  r ln  r 
   Q0
1
 
  1

 
where r is the rate of consumption growth, QT are the total reserves and Q0 is the
current consumption.
Problem 2.
The table below shows the situation of the production of electrical energy from
renewable sources by 2013. I) from the data estimate the production in 2020 from
various sources; II) calculate these production and sources for each year and trace the
scenario of evolution in Portugal.
Bibliographic references
Fay, J., Golomb, D.S., Energy and the Environment, Oxford University Press and Open
University, Oxford, UK, 2004
http://www.minerva.uevora.pt/odimeteosol/energias.htm
http://www.dgge.pt