Post on 21-Jan-2016
transcript
Conservation of Energy
What types of energy can you think of?
Solar
Kinetic
Electric
Chemical
Sound
Plus many others
Energy Resources
What is it?
A recourse that provides energy to bring about movement or change
How is it classified?
Renewable: ones that can be reused in one human lifetime
Non-renewable – one that can only be used once in a human lifetime
Some History
1500000 BCE– only food and sun were energy
1000000 – 500000 BCE – fire is added for heat and light
5000 BCE – animals used to help farming
4000 – 2500 BCE – wind energy harnessed for sailing
200BCE – 200CE – wood used on large scale for heat and metal work
500 – 900 CE – wind used for windmills to grind grain and pump water
1698 – 1900 CE – coal burned for steam power
1859 – first gas powered engine
1945 – ZEEP nuclear reactor in Canada built
Non-renewable
What do they have in common
Oil
Coal
Natural Gas
We Call TheseFossil Fuels
Coal
Made from peat buried below sediments and large pressure
ON, BC, SK, NB, and AB all have coal deposits
2 types of mining
Underground
Strip mining
Oil
We burn lots of this…..duh
How is it made?
Microscopic organisms from ancient oceans
Process is similar to coal
Takes millions of years
Found in sedimentary rock
In AB we have the tar sands
Are there dangers???
Natural Gas
Formed with both oil and coal deposits
It is trapped above the oil pockets underground
Large deposits under the Arctic Permafrost and deep ocean
Canada is a large producer of Natural Gas
Uses and dangers?
Heard of hydraulic fracturing? Good/Bad
How is power created?
In all 3 previous examples the energy source is burned
The fires are placed under water vessels which create steam
The steam is pushed through turbines that spin
The spinning drives a shaft with magnets through a large tube of wire
Uranium/Nuclear Energy
Consists mainly of uranium-238 (an isotope) and about 0.7% uranium-235 (the actual fuel)
The U-235 is split in the reactor and under goes fission to create huge amounts of power
When one atom splits it causes others to split following that
Canada’s nuclear reactor (CANDU) – 18 in Canada and 20 in other countries
Pros and Cons???
Pros
Low pollution and GHG produced
Small amount of source leads to large amount of energy
We have the expertise in reactor technology
Cons
Disposal of waste rods is not solved
Plant accidents can release radioactive materials
Public concerns about safety
Costly to build and maintain
Renewable Energy
Solar Energy
Passive Collection
Transforms solar into thermal with no special devices
Windows let the heat in bit not back out
Materials absorb heat and radiate it out as thermal
Active Collection
Concentrates solar energy
Collectors placed on roof or ground for heating
Mainly used for water heaters, pools, and homes
Photovoltaic Cells
Use solar energy to generate current in a circuit
Made of silicon crystals that convert 10 – 20% of the solar energy into electrical energy
Low efficiency and high cost in the past, but its getting better
Starting to see PV powerplants
Solar Pros and Cons
Renewable and abundant
Minimal environmental impact
Availability limited to season, climate and altitude
Requires energy storage or use of other sources when there is no sun
Making them uses lots of energy and polluting chemicals
Wind
Fastest growing source of alternative energy in the world
2012 – Ontario generated more electricity using wind than coal for the first time
Where do you think wind is the most successful?
Pros and Cons
It is renewable
Environmental impact is low
Wind farms located in areas to not disturb people
Land used can be used for other reasons
Wind is intermittent and variable in speed
Kill birds and bats
Opposition due to appearance, reduced property values, and noise
Hydro
Geothermal
Energy from the Earth’s interior
US is a large producer of geothermal
Canada is creating its first geothermal power plant in BC
Its environmentally friendly, reliable, and unlimited
Releases dangerous gases and radioactive radon
Biomass Energy
The burning of non-fossil fuels
Wood, vegetation, plant oils and organic wastes from landfills
Change chemical energy to thermal
Used in great quantities in poorer countries
Economical and renewable fuel
Example – ethanol, biodiesel
Tidal Energy
Uses the ocean’s waves to turn a turbine
Only used in 40 places around the world
Bay of Fundy
Requires the tides vary by at least 5m to be cost effective
Renewable and reliable, generates little pollution
Limited in locations, ecosystem disturbance is a problem