Biofuels •  Uses plant material and

animal waste to convert to a biofuel

•  Types of Biomass/fuels Wood logs, Animal dung, Kelp, and Paper/cardboard Pros •  Tree farms can restore degraded

lands •  Large potential supply Cons •  CO2 emissions if harvested and

not planted back •  Soil erosion, water pollution, and

loss of habitat

ECU 35 – Biodiesel / Hybrid

ECU 51 – BRT Clean Diesel Hybrid

Geothermal Energy

•  Energy is harnessed by tapping natural underground reservoirs of steam and hot water

•  hot water pulled from the earth is used directly for heating and to turn turbines to generate electric power

PROS •  Available 24/7 •  Little emissions of CO2 and

natural gas. CONS

•  Only available near geological activity

•  Habitat destruction when building it

www.eren.doe.gov/power/consumer/ rebasics_geothermal.html

The Geysers

Hydroelectric Water is stored behind a dam and released periodically by gravity. The falling water turns turbines which produce electricity. Pros •  Long life span •  No CO2 emissions •  Flood control method •  Provides water for year round

irrigation Cons •  Expensive •  Converts land to water habitat •  Danger of it collapsing •  Decreases fish spawning

Hydrogen Fuel Cells

•  A device that converts chemical energy into electrical energy.

•  Splitting water atoms to extract the hydrogen for energy use.

PROS •  No CO2 emissions •  Safe •  Low environmental impact CONS

•  High cost •  Doesn’t last long when made •  New energy – not readily

available

A typical hydrogen fuel cell

Solar Energy •  Uses energy from the Sun to produce energy

Pros •  Free •  No CO2 emissions •  Low air and water pollution

Cons •  Need access to sun 60% of

time •  Need a heat storage system •  Expensive system

Types of Solar Energy Passive system: Absorbs & stores heat from the sun directly within a structure

Active system: Collectors absorb solar energy, a pump supplies part of a buildings heating or water heating needs.

Tidal Power

www.bio.miami.edu/beck/esc101/Chapter14&15.ppt

Uses the force of water during a high tide to turn a turbine to create energy. East coast: two high tides

Pros •  Know when daily high

tides on the east coast •  No CO2 emissions Cons •  Unreliable on west coast •  Expensive equipment

Tidal Dam

Why is a large tidal range need to produce power?

Wave energy The motion of wind-driven waves at the ocean’s surface is converted into electricity. Pros •  No CO2 emissions •  Works during day and

night Cons •  Expensive •  Machines break down

and corrode in water

Wind Energy Uses wind power to turn a turbine which creates energy in the next 50 years, wind power could meet up to 10% of the country’s demand for electricity Pros •  Highly efficient •  Low environmental impact •  No CO2 emissions •  Quick construction Cons •  Need steady winds •  noise pollution •  Visual pollution •  damage/death to animals (birds)

www.bio.miami.edu/beck/esc101/Chapter14&15.ppt