renewable energy -- alternative energy sources

transition to renewable enrgy

environmental benefits:
saves lives by reducing air pollution
help keep climate change from spiraling out of control and creating ecological and economic chaos
slow the increase in ocean acidity


economic benefits
save money
create jobs and business opportunities

energy priorities

  1. improving energy efficiency, reducing energy waste
  2. decreasing our dependence on nonrenewable fossil fuels
  3. relying more on a mix of renewable energy

energy efficiency and energy conservation are the biggest sources of renewable energy

energy efficiency is a measure of how much useful work we can get from each unit of energy we use

energy conservation means reducing or eliminating the unnecessary wasting of energy

energy efficiency generally concerns unavoidable loss that happens as a result of inefficient technology and systems

energy conservation generally concerns avoidable loss that happens as a result of carelessness or ignorance

  • energy-inefficient technologies:
  • internal combustion engine
  • nuclear, coal, and natural gas power plants
  • data centers
  • ways to improve our energy-efficiency
  • power plants and industry:
  • variable-speed electric motors
  • reduce, reuse, recycle
  • cogeneration
  • upgrade the electrical grid to an energy-efficient smart grid
    - transportation
  • CAFE vehicle fuel efficiency targets
  • electric and hybrid vehicles
  • mass transit systems -- discourage car use
    - buildings
  • insulate building for more efficient heating and cooling
  • use energy-efficient appliances, devices and lights
  • switch off unused energy-consumers, especially computers and servers
  • industries and power plants

fuel economy (mpl, kilometers per liter)

  • utilities: power plants
  • industries: all facilities and equipment used to produce, process, or assemble goods

transportation

  • ways for industry to save money and fuel:
  • variable-speed electric motors
  • recycling materials
  • energy-efficient in offices
  • cogeneration
  • cogeneration is to produce two useful forms of energy (electricity and heat) from the same fuel source

corporate average fuel economy (CAFE)

energy-efficient vehicles
gasoline-electric hybrid cars
plug-in hybrid electric vehicle
all-electric vehicle

reducing weight of vehicle

  • consumers and their car usage
  • tax breaks
  • fuel-efficient vehicles
  • raise taxes on gasoline
  • importe mass transit systems
    -bicycle-only routes and areas

buildings

biggest energy costs at home heating, cooling, electronics and appliances

home insulation

green architecture

energy star US Environmental Protection Agency (EPA)

solar energy

passive solar heating system - absorbs and stores heat from the sun directly

cooling buildings naturally (wind)

solar cookers

solar thermal systems / concentrated solar power
parabolic mirrors
moving mirrors

solar cells for electricity

photovoltaic cells/solar cells


advantages:
no greenhouse gases or pollutants
no toxic materials
easy-to-use, low maintenance


disadvantages:
low energy efficiency
cannot produce electricity at night

wind power

wind turbines and wind farms

  • wind power has the potential to produce 40 times the world's current for electricity
  • advantages of wind power
  • wind is abundant, widely distributed, and inexhaustible
  • carbon-free and pollution-free
  • fast and relatively cheap
  • increasing energy efficiency and reducing costs
  • disadvantages
  • wind turbines kill birds and bats 😢

geothermal

  • geothermal energy geothermal heat pump system is the most energy-efficient, reliable, environmentally clean, and cost-effective way to heat or cool a space

hydrothermal reservoirs

  • advantages:
  • medium net energy

  • low CO2 emissions


  • disadvantages:

  • drilling geothermal wells is expensive and risky
  • not many hydrothermal sites with concentrations of heat high enough to make it affordable
  • can be non-renewable if heat is extracted faster can be restored

deep heat

biomass

  • energy can be produced by bringing the soil biomass or organic matter or converting it to gaseous or liquid biofuels
  • liquid biofuels:
  • ethanol
  • biodiesel
  • advantages:
  • can be grown throughout much of the world
  • no net increase in CO2 emissions
  • easy to store and transport
  • bad idea tho
  • 20% more greenhouse gases
  • uses huge amount of water
  • ecosystems destroyed
  • algae
  • advantages:
  • can grow year-round

  • 10 times more energy


  • disadvantages:

  • too costly

biodigesters -- biogas

fed with organic material, which is broken down by bacteria to produce biogas, can be used as fertilizer

advantages: reduces amount of waste
helps get rid of and make use of food and plant waste
reduces amount of livestock and human waste entering water ecosystems

disadvantages:
too low net energy for mass scale
impurities can damage

hydropower

uses flowing rivers, tidal flow, waves

dams - least expensive

tidal energy and wave energy

hydrogen

advantages
no CO2 emissions or air pollutants
more efficient
little maintenance

renewable energy and the economy

shift could be accelerated by
full-cost pricing to include health and environmental costs
tax carbon emissions
subsidize renewable energy
eliminate subsidies for fossil fuel industries
feed-in-tariff system
mandate that a certain percentage of the electricity generated by utility companies