I.

Physical Sciences
• Constituents and Structure:
Universe, Galaxy, Light Year, Solar System, Sun, Earth,
Astronomical System of Units.
• Process of Nature:-
Solar and Lunar Eclipses, Rotation and Revolution, Weather
Variables (Global Temperature, Pressure, Circulation, Precipitation
, Humidity) and Weather Variations.
• Natural Hazards and Disasters:-
Earth Quake, Volcanic Eruption, Tsunami,
Floods, Avalanche, Travelling Cyclone (Tropical Cyclone, Middle
Latitude Cyclone and Tornadoes), Drought, Wildfire, Urban Fire.
Disaster Risk Management.
• Energy Resources:-
Sources of Energy (Renewable i.e. LED Energy, Solar Energy,
Wind Energy and Non-Renewable Energy
conservation and its sustainable use.
• Atomic Structure, Chemical Bonding, Electromagnetic Radiations.
• Modern Materials/Chemicals:-
Ceramics, Plastics, Semiconductors, Antibiotics, Vaccines,
Fertilizers, Pesticides.
Prepared by Engr. Mahwish Saleem 2
CONTENTS

• Why we need renewable energy?

• Wind
• Solar
• Hydroelectric
• Geothermal
• Biofuels
 • CO2 is at 407ppm (Oct
2018) increased by 90ppm
in the last 70 years
• Global warming ~1.1°C in
the past 200 years
• Ocean acidification
• Rising sea level ~3.2mm
each year
• Decreasing ice sheet mass
• Retreating glaciers
• Decreasing Arctic ice at a
rate of 13% each decade

Renewable energy is crucial for mitigating climate change

 Propeller Wind farm
Blade • Strong winds
• Clear hilltop
• Turbines in prevailing wind
direction
Nacelle
containing
generator

Tower

Wind turbine
The amount of power, and therefore electricity, a
wind turbine can produce is largely based on wind
velocity using this equation:
Higher wind speed =
lots more power

Power = ½ ρAV3
Larger wind turbine =
more power

ρ = air density; ~1 kg/m3

A = area (π r2 )
Power is measured
V = velocity (m s-1) in Watts
How much power can be generated in this situation?
Power = ½ ρAV3

ρ = air density; ~1 kg/m3

A = area (π r2 )
V = velocity (m s-1)

Power is measured
in Watts
• UK has 9,220 wind
turbines (Oct 2018) with
a capacity for 20.1
gigawatts – 6th largest
producer of wind power
in the world.

• In 2017 17% of UK
electricity was generated
from wind power (29% by
renewables in total). © 2014 Syon Geographical Ltd.
• Thermal solar panels
are used to generate
heat energy.
• Photovoltaic (PV) cells
made from silicon turn
sunlight directly into
electricity.
• 3.4% of total electricity
was generated by Solar
PV in the UK in 2017
(29% by renewables in
total).
• Geothermal energy = heat
energy from the Earth.
• Decay of radioactive
elements and residual heat
from planetary formation
4.5 billion years ago.
• Water is pumped down into
hot rock where it is heated.
• Steam can then be used to
heat buildings directly or to
generate electricity by Nesjavellir Geothermal Power Station, Iceland
spinning a turbine.
 Electricity pylon
Generator
Cooling tower Turbine
Homes and
buildings

Injection Steam
well

Hot
Cold water
water

Water is heated
 • Hydroelectric power harnesses the kinetic energy of running
water. Hydroelectric
• Water flows downwards with dam
gravity to spin a turbine.
• More reliable than solar and Reservoir of
wind power. water
• Hydroelectric dams are very
expensive and can harm
Generator
wildlife.
Turbine
• 1.5% electricity from
hydroelectric schemes in the
UK (29% total).
Cruachan Power Station, Argyll and Bute, Scotland
• Biofuel - either directly from plants
or from waste.
• Main UK sources are wheat and
cooking oil.
• Bioethanol – used as fuel and as a
petrol additive to increase octane
and lower carbon emissions.
• Biodiesel – used as fuel and used
to reduce levels of particulates and
carbon monoxide in diesel powered
vehicles.
• Natural resources and energy resources
• Non-renewable & renewable energy
• Oil and gas
• Coal
• Nuclear power
Natural resources – natural substances required
by humans for different needs.

Metals and
Rainforests
minerals Crops

Water Coal, oil and Forests

gas
 Solar
Biofuel Coal
Wind
Natural gas
Biomass
Nuclear

Hydroelectric
Geothermal

Energy mix - the specific combination of different energy sources a

country uses to meet its energy consumption needs.
 Depends
Renewable Non-renewable
 Depends
Renewable Non-renewable
 *renewables includes
wind, solar,
geothermal, biomass
and biofuels

Billion toe =
billion tonnes
of oil
equivalent
• Oil
• Natural gas
• Coal
• Nuclear
 • Organic rich
sediments are
buried by layers
and layers of
sediment.
• Increased and
sustained heat and
pressure ‘cooks’
the organic matter
in the source rock
into petroleum.
• Temperature and
Organic rich sediments burial depth
determine which
hydrocarbons are
produced.
Temperature and
burial depth
determine
whether you get
oil or gas and how
much is formed.
 • Oil and gas migrate
upwards form the
Oil rig
source rock into
reservoir rocks
capped by
Drill Sea impermeable
seals.
Impermeable seal rock • Can sometimes
Reservoir rock migrate all the way
Oil
to the surface.
• Trapped deposits
are drilled to
release oil and gas.
Oil rich • Hydraulic fracking
source rock can also be used to
extract gas.
 Oil & gas burned to heat steam propels Electricity
water turbine
• Crude oil is refined by fractional distillation into kerosene, petrol,
diesel etc. before it is used as a fuel.
• Relatively inexpensive to extract.
• Reliable and dependable source of energy and income for local
community.
• Natural gas can be converted into liquid form.
• When oil and gas are burnt they release gas into the atmosphere,
carbon dioxide.
• Oil spills are environmental disasters – e.g., BP Mexico oil spill 2010.
 • Most of the coal
we have on Earth
today was formed
in the
Carboniferous
Swamp period 360 – 299
million years ago.
• Tropical, swampy
climate.
• Plants die and
over time form
Older rock layers layers of squashed
plant material.
 • Squashed plant
material
accumulates
over thousands
Peat of years.
• Plant material
turns into peat.
• Peat is used for
fuel.
 • Peat is buried by
layers of sediment
and subjected to
increased heat and
Younger rock layers pressure.
• ‘Cooked’ into coal.
• The type of coal you
Coal seam get depends on
how long it was
buried, how deep
and how hot it got.
Older rock layers
 Peat The hotter the
temperature, the
deeper the coal is
buried, and the
Lignite
longer the amount of
time the coal is
Bituminous buried, the more
coal efficient coal you get.

Anthracite
 Coal burned to steam propels Electricity
heat water turbine

• Coal is cheap and there is lots of it!

• When coal is burnt it releases carbon dioxide,
sulphur dioxide and nitrogen dioxide into the
atmosphere contributing to global warming
burned for heat and acid rain.
• Coal mining is harmful to the environment and
mine workers – toxic dust, cave-ins and
explosions.
 steam propels
Nuclear reactions Heat Electricity
turbine
• Uranium and plutonium are nuclear fuels – fission reactions.
• Nuclear fuels do not produce harmful greenhouse gases.
• Nuclear power is very efficient.
• Produces radioactive waste which is dangerous and has to be
sealed in containers and buried for thousands of years.
• Nuclear cores can melt down releasing harmful radiation.
• Safety is expensive.
• Nuclear power currently
generates 21% total UK
electricity (2018 Department
of Business, Energy & Industrial
Strategy).
• 15 operational reactors
across the UK (2018).
• Scotland have banned
any future nuclear
plants.