Renewable
Energy
The Real
Alternative?
Module Overview
Principles
Research
Assessment
Lesson 1,
Lesson 2,
Lesson 3,
The REal
alternative
Which
alternative?
The
Crunch!
Why, how much,
when and what
Your chance to
research the
options
Worksheet
At home
Present your case
and use your vote
Why Bother?
• Because energy resources are limited
– Oil and gas will run out, probably in your
lifetime
• Because burning fossil fuels release
greenhouse gases and pollutants
– Affecting your environment and health
• Because you can do something about it
– Using your energy and vote
Lesson 1:
Does it all add up?
Sun
How much
power?
Wind
Waves
How much
power?
Rivers
Plants
Part 1:
How much energy do we use?
In our world
In our country
Starting in YOUR Household
• How much energy do you use?
Calculating power and energy
100W
50W
4 hours
Thinking
Chilling
Brain
thinking hard
20 hours
Brain
chilling
Daily energy = Power x time = (100 x 4) + (50 x 20) = 1400 watts hours
Average power = {Daily energy}/{Daily hours} = 58 watts (W)
How much power per household?
Equipment
Group
Lights
1
TV
Computers
2
3
Cooking
4
Washing
5
Cars
6
Food
7
Heating
8
Total average power per household
Ave. power
????
Experiments
• Split into seven groups
• Use equipment supplied to estimate the average
power consumed in a typical household
• Report back to the class when complete
• Use the information to estimate the total average
power used by a typical family
• Consider the error involved in this estimation
How much power per person?
Four per household?
2kW/household
÷
=
500W
per person
but…..that’s not all
Power
source
Transport and conversion 33%
100%
500W
1500W
This is the
power you
actually use
66%
1000W losses
This is the
power you
measure
How much power per person?
but…..that’s still not all
Industrial/commercial
Power consumed
Domestic
Power consumed
1500W
¼
¾
4500W
You!!
You are responsible for about 6000W of power consumption!!!!
How much energy in world?
=
6000W X
per person
38 TW
World power use
6,400 million people
(www.esa.un.org.gov)
but, most of the world don’t burn energy like us…yet!
Actual total is 15 TW now
(www.rcep.org.uk)
Predicted to rise to 20 TW
by 2020
?
Big numbers
1 watt = standard unit of power = 1 joule per second = 1 W
1,000 watts = 1 thousand watts = 1 kilo-watt = 1 kW
1,000 kilo-watts = 1 million watts = 1 mega-watt = 1 MW
1,000 mega-watts = 1 billion watts = 1 giga-watt = 1 GW
1,000 giga-watts = 1 trillion watts = 1 tera-watt = 1 TW
?m
Grain of sand
Less than 1mm3
?m
?m
?mm
?mm
?mm
Part 2:
Where does the energy
come from?
The sun provides more than
99.9% of our primary energy
It is a nuclear reactor 200,000 trillion times
more powerful than nuclear power stations
Solar energy
Power arriving at the earth is 200,000 TW (2x1017 watts)
Checking the balance
Sun
6,000
Watts
200,000 tera watts
15 tera
watts
Stored as fossil fuels
Atmosphere
Wind
Waves
Rivers
Plants
Where does
the solar
energy go?
Radiated
back into
space
Renewable Energy
- Overview
Solar energy
Wave energy
Sun
Wind energy
Hydro energy
?
Biomass energy
Solar Energy - Heating
Sun
Solar Energy
Photovoltaics
Direct current
devices
Charger
Batteries
Inverter
Alternating
current
devices
Energy from Rivers (Hydro)
Large schemes with reservoirs and dams
Supply town and cities
Small schemes without reservoirs
or dams
Supply villages
Demonstration
• Several demonstrations of energy processes
around classroom
–
–
–
–
Evaporation-condensation cycle
Solar-powered “wind turbines”
Wind-up radios
Tap water powered hydro-turbines
• Make a note of the energy conversions and
estimate the power involved
Energy from Rivers (Hydro)
Dam
Energy from Rivers (Hydro)
Energy from
Wind
Energy from Wind
Wind Turbine Generators
Your
house
Electrical energy
Wind energy
Energy from Waves
Energy from Waves
Other Wave Devices
Energy from Biomass
Energy from Biomass
Summary
Atmosphere
Solar
Wind
Waves
Rivers
Plants
Fossil fuels
Coming next………Your turn!
Group 7: Energy transport
Group 1: Solar energy
Group 2: Wind energy
Group 3: Hydro energy
Group 6: Wave energy
Group 5: Nuclear energy
Group 4: Biomass energy
The End