SUMMARY ENERGY TECHNOLOGY
1. INTRODUCTION
1.1. E NERGY CONSUMPTION
The consumption of energy by mankind is large and increasing and is mainly driven by fossil fuels.
There is a strong correlation between the Social Progress Index and the energy consumption per
capita.
The tonne of oil equivalent (toe) is the amount of energy released by burning one tonne of oil.
When considering coal there is an equilibrium between mining and consumption, when considering
oil there is not.
1.2. E NERGY AND POWER
Work (W) is delivered to a body when a body moves over a distance (s) by applying a force (F) to
it, and W = F * s, and thus the unit 1J = 1N * 1m
o Work, energy, heat (quantity) is expressed in Joule (unit)
W
Power (P) is the amount of work delivered in one unit of time, and P = and thus the unit =
∆t
1J
1W =
1s
Quantity Force (F) Distance (s) Work (W) Power (P)
Unit Newton (N) Meter (m) Joule (J) Watt (W)
Consider an electrical voltage U (Volt) loaded by a resistor R (Ohm), then a current I (Ampere) is
U
flowing and I =
R
The voltage source then generates a power (or the resistor consumes a power), and P = U * I and
thus the unit 1W = 1V * 1A
o When considering a time interval t, the voltage source sends an amount of energy:
W = P * t = U * I * t
o The energy or work is expressed in 1J = 1W * 1s
1 kWh = 3 600 000 W * s = 3 600 000 J
1.3. E LECTRICAL ENERGY CONSUMPTION
The electrical energy consumption is also increasing.
1
, 1.4. F INITE ENERGY RESOURCES
The steady increase of the worldwide energy consumption implies several challenges:
o Ensuring a security of supply
o Keeping the energy affordable
o Facing environmental problems and climate change
Since mankind consumes fossil fuels much faster than nature can produce them the depletion of
the energy resources arises.
o An indication is obtained by calculating the ratio between the reserves R and the current
production P.
The Hubbert curve approximates the production rate of a resource over time.
o Has three components: A rise from 0 production, A quick increase till
the Hubbert peak has been reached, A drop from the peak.
Estimated Ultimate Recovery = EUR = the total amount of oil which is potentially recoverable or has
already been recovered from the reserve.
1.5. R EAL LIFE IMPACT OF ENERGY SUPPLY
Security of supply: very often, energy is imported from foreign countries. This gives power to the
exporting countries.
Keeping the energy affordable: in general energy prices are fluctuating and increasing.
Environmental problems and climate changes
1.6. T HE FUTURE
Many opinions and scenarios exist.
2. THERMODYNAMICS: INTRODUCTION & FIRST LAW
2.1. T HERMODYNAMICS : I NTRODUCTION
Thermodynamics is the branch of physical science that deals with the relations between heat and
other forms of energy, and by extension, of the relationships between all forms of energy.
Notice the central importance of heat.
2.2. T HERMODYNAMICS : B ASIC CONCEPTS 1
System = a quantity of matter or a region in space chosen for study.
Surroundings = the mass or region outside the system.
Boundary = the real or imaginary surface that separates the system from its surroundings.
Isolated system = neither mass nor energy can cross the selected boundary.
Closed system = only energy can cross the selected boundary.
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