Sources of Thermal Energy Topic 7

Sources of Thermal Energy Energy is often converted before we can use it Many sources come with environmental concerns

Sources of Thermal Energy Mechanical Chemical – burning fuel Electrical – generators Nuclear Wind Geothermal Solar Fossil Fuels (*)

Mechanical Energy

Generation of Electric Energy Fuel is burned to produce heat Heat is transferred to water to produce steam Steam is channeled Steam used to turn turbine which in turn cranks the generator

Generation of Electric Energy

Chemical Energy Chemical energy can be transformed into thermal energy when wood or coal is burned Impact: Pollution is caused by the release of greenhouse gases when fossil fuels are burned Coal

Sheerness Thermal Generating Station – Hanna

Hydro-Electric Energy Gravity is used to pull water over dams to turn turbines, attached to generators Mechanical energy of the generators creates electricity

Hydro-Electric Energy Impact: Habitats are affected, heated waste water is produced and ecosystems are reshaped

Itapú Dam

Nuclear Energy

Pickering Nuclear Power Plant

Wind Energy Wind turbines spin from the force of the wind, powering a generator

Wind Energy Impact: the spinning turbines create areas of low pressure, when bats enter the pocket, the low pressure causes their lungs to explode

Bill Nye  Finite = limited Harnessing = using Joe Barton = not a scientist :P

Wind Energy

Wind Energy - Canada

Geothermal Energy Geo – to do with the earth Thermal – related to heat Volcanoes, hot springs and geysers are sources of geothermal energy This heat creates steam which is harnessed in power plants on the surface Geothermal vs. other sources

Geothermal Energy HDR (Hot, dry rock) is another technique – water is pumped down, heated and resurfaces as steam, which is used to generate power

Geothermal Energy This is a clean and environmentally friendly technique It could reduce the threat of oils spills, pollution from fossil fuels and their wastes The initial cost of installing geothermal is still quite high.

Solar Energy

Solar Energy Solar energy is clean and unlimited There are two ways to use solar power: Passive Solar Heating – uses the materials in the structure to absorb, store and release solar energy Active Solar Heating – uses mechanical devices to collect and distribute the thermal energy

Solar Energy – Passive

Solar Energy – Active

Solar Energy

Fossil Fuels

Fossil Fuels Big Problems: Non-renewable Greenhouse gases contributing to global warming

Fossil Fuels – Cogeneration This uses about 2/3 fossil fuel, and released thermal energy is put to use as well

Other Energy Sources Organisms burn food to generate body heat Composts are a source of thermal energy – Decomposers break down food and release thermal energy, speeding up decomposition (waste management) Turkey power! Internal Combustion Engine

Think About it! What else could be used as an energy source?

Conserving Our Fossil Fuel Resources Topic 8

Introduction We still use many fossil fuels: Coal is burned Oil and gas are used How can we reduce our use? Technology gives us ways to use energy more responsibly.

Programmable Thermostats

Hot Water on Demand p.252

Thermal Energy Movers Thermal energy movers transfer thermal energy from one location to another at a different temperature Fridges and air conditioners The operation of these devices requires refrigerants to remove thermal energy from food.

Thermal Energy Movers As the refrigerant evaporates, it absorbs the thermal energy from the food so it cools down. This warmed gas is then compressed and releases the thermal energy into the room. Deconstructed: Fridge

Thermal Energy Risks Some harmful effects of thermal energy are: burning ourselves on a hot utensil (us) forest fires (our environment) burning houses (our belongings) What are some other negative effects of thermal energy use?

Thermal Energy By-products Not all the dangers of using thermal energy are as obvious as the ones already discussed. Sulfur-dioxide is released when coal and natural gas are burned. This gas is an irritant to the eyes, nose and throat. It contributes to the production of Acid Rain

Thermal Energy By-products Carbon monoxide is produced when a fire burns without enough oxygen. It is colorless and odorless. Hinders brain reasoning and is lethal Smoke detectors and CO detectors should be installed in every building to protect the people from being overcome by these lethal gases.

Thermal Energy By-products Carbon dioxide that is released from the burning of fossil fuels is a greenhouse gas, which traps heat energy in our atmosphere and leads to global warming

THE END! Go through the homework questions and study guide to make sure you understand everything Study from your quizzes and notes Remember you will need to convert temperatures Go online and use your text for review