Please enable JavaScript.
Coggle requires JavaScript to display documents.
7.3 and 7.4 (energy properties: improve energy efficiency and reducing…
7.3 and 7.4
energy properties: improve energy efficiency and reducing energy waste, decreasing our dependence on nonrenewable fossil fuels, relying more on a mix of renewable energy.
energy conservation means reducing or eliminating the unnecessary wasting of energy. avoidable loss that happens as a result of carelessness or ignorance.
Energy efficiency is a mesure of how much useful work we can get from each unit of energy we use. unavoidable loss that happens as a result of inefficient technology and systems
benefits of transitioning to a renewable energy: save lives by sharply reducing air pollution, slow the increase in ocean acidity, saves money, creates jobs and business opportunities.
reasons for energy waste: internal combustion engine/ nuclear, coal, and natural gas power plants/ huge data centers.
ways to improve energy efficiency: power plants and industry, transportation changes, insulate buildings for more efficient heating and coolings
-
hydropower is any technology that uses the kinetic energy of flowing and falling water to produce electricity
dams store up water and allow it to flow through a turbine to generate electricity
advantages: not expensive renewable resource.
disadvantage: reservoirs fill with silt and become useless, flood and destroy terrestrial habitats, floods vegetation and produces methane
-
-
-hydropower is the worlds leading renewable energy resource and produces about 16% of the worlds electricity
Homes require insulation to isolate the inside from the outside and prevent heat escaping, and heat entering.
to save energy and money: use insulated windows, seal gasps around the window frame, insulate the building roof and walls.
saving energy and money in buildings: heat interior spaces/ heat water/ use energy efficient appliances/ use energy efficient computers/ use energy efficient lightning/ stop using standby mode
Design new buildings that save energy and money. Green roofs can reduce the costs of cooling and heating.
passive solar system heating: such system that absorbs and stores heat from the sun directly within insulated structures.
solar thermal systems also known as concentrated solar power use different methods to collect and concentrate solar energy to boil water and produce steam for generating electricity.
-
advantages of photovoltaic cells: no greenhouse gases or pollutants, no toxic materials and easy to use with a low maintenance / disadvantages of photovoltaic cells: low energy efficiency, cannot produce electricity at night and storing energy is expensive.
biomass
energy can be produced by burning the solid biomass or organic matter found in plants or by converting it to gaseous or liquid biofuels.
using liquid biofuels to power vehicles, the two most common liquid biofuels are ethanol and biodiesel.
advantages: help countries reduce their dependence on imported oil, no net increase in CO2 emissions, easy to store and transport.
disadvantages: 20% more greenhouse gases in the atmosphere, requires huge amounts of water and large volumes of water waster, tropical rainforests and grasslands are being destroyed.
-
wind power
advantages of wind power use: wind is abundant and inexhaustible/ carbon free and pollution free/ fast and relatively cheap/ occupy small portions of land/ increasing energy efficiency and reducing costs.
disadvantages: turbines kill more than 234,000 birds each year/ low level noise bothers some people/ needs backup or storage when wind dies down.
-
hydrogen power
advantages: no CO2 emissions or air pollution, more efficient and requires little maintenance.
disadvantages: negative net energy, very little hydrogen gas in the earths atmosphere, very expensive and dangerous to store and transport
biodigestion
how does it work? organic material----microorganisms break in an oxygen free environment----used as biogas stream or waste stream
advantages of biogas: reduces the amount of waste going into landfills, helps get rid of and make use of food waste and plant waste, creates less CO2 than fossil fuels, creates jobs.
disadvantages: too low net energy for mass scale and impurities may damage if used in combustion engines.