Bellringer:

I. Alternative energy:

A. Still in development

B. Energy that does not come from fossil fuels

C. Alternative energy must be:1. Cost efficient

2. Have minimal effects on the environment

II. Tidal Power

A. Similar to a hydroelectric dam

B. Tidal Drawbacks:

1. Expensive to implement2. Few suitable locations

Sihwa Lake Tidal Power Station – S. Korea

Built: 1994Peak output: 254 MW (10 25.4 MW turbines)Cost: $288 MillionSize: About 12 mi2

Google maps Link

III. HydrogenA. Characteristic

s:1. Abundan

t2. No carbon – no pollutants associated with fossil fuels

3. Produces water vapor when burned

B. Problems:

1. Takes a lot of energy to produce hydrogen

2. Energy used to make hydrogen comes from burning fossil fuels or other currently available energy sources

C. Challenges/Storage:

1. Using solar cells to split water molecules in to H2 and O2

2. Storage in pressurized pipelines

3. Could be stored in fuel cells

A device that produces electricity by combining hydrogen with oxygen

IV. Efficiency

A. % of energy put into a system that does useful work

1. Efficiency = x 100

B. Most devices not efficient

2. Increasing efficiency may involve sacrifices or investments in new technologies

energy in energy out

V. Efficient TransportationA. Internal combustion engines are very

inefficientB. Hybrids:

1. Use electricity and gas2. Cost more but are more efficient3. Converts brake energy into electrical energy used to charge battery

4. Gas engine turns off at low speeds and stops

VI. Energy ConservationA. Process of saving energy

by:1. Reducing energy and

wasteB. On average US households spend

$1,200.00/year on energy bills

1. Energy is wasted through: