Alternative Energy. 90% of the energy used today is in the form of fossil fuels. Forms of energy...

Alternative Energy

• 90% of the energy used today is in the form of fossil fuels.• Forms of energy OTHER than fossil fuels are termed “alternative” energy sources

Alternative energy sources can bedivided into two main categories.

1)Non-renewable• Nuclear

2)Renewable• Solar• Wind• Hydro/Water • Ocean currents/Tidal• Geothermal • Biomass

Solar EnergySolar Energy• The amount of incoming solar energy is immense. • Distribution is variable, due to climate, location, etc…

Active solar collection requires energy to run pumps for circulation of water/oil/air, and to move collectors’ orientation to follow the sun.

The Luz Solar Electricity Generation System

Wind PowerWind Power: • Generation of electricity using wind to turn turbines. • Free energy, but needs to be in an area that has constant winds with enough velocity to warrant placingwindmills. • Best used in particular sites with a good steady supply of wind.

Outlook: Wind power will continue togrow, but in limited areas. Some disadvantages and concerns exist.

• Windmills kill birds, and interfere withmigratory patterns. • Large windmill farms take up large areas of land.

• Windmills also produce noise, which may be objectionable.

Hydro/Water PowerHydro/Water Power: • Hydro-power is a good alternative energy source, because it is essentially unlimited.

• Use the power of water to turn an electric generator

Hydroelectric Power Generation

• Power is generated by harnessing the energy of falling water.

• The greater the difference in waterlevel, the more energy

Outlook for Hydropower: generally good, although there are a few drawbacks.

• Dams prevent the migration of fish,and also prevent the natural flows ofrivers, causing sedimentation behindthe dam.

Tidal/Current PowerTidal/Current Power: Generation of electricity from movement of ocean tides/currents.

• Rising tides are trapped behind a dam, then released to turn a generator.

• Also some work on ocean buoys that harness the movement of water to generate electricity.

Outlook: Generally good, but can only be used in areas where tides are of sufficient height to warrant an electrical station.

• High costs may be associated.

• Offshore buoys would need electrical transmission lines along the ocean floor.

Geothermal EnergyGeothermal Energy: heat energy from the Earth• Conversion of natural heat from the Earth’s interior to heat buildings and generate electricity.

• Steam generated within volcanic areas is used to turn turbines, which generate electricity.

Outlook: Limited, because areas with enough volcanic activity are not widespread.

• Great success in areas where geothermal activity is high, e.g., Iceland, New Zealand

Biomass EnergyBiomass Energy: energy from organic matter

• Probably the first source of energy for man, this energy is renewable and abundant.

• Already in use in many places, such as sugar plantations and saw mills.• Also includes the burning of urban waste, in “trash to steam” plants.

Outlook: Biomass fuel will continueto be a large part of the alternativeenergy picture. However:

• Environmental degradation can and will occur if the biomass is not harvested in a renewable manner.

• Burning biomass causes pollution, especially air pollution, and leaves ash behind. The ash can be very toxic.

Will the energy future include fossil fuels?

- There are a few “new” sources of fossil fuels which may play a role in the future.

- They are still NON-RENEWABLE.

- They still cause pollution (in varying amounts)

Methane Hydrates (Burning Methane Hydrates (Burning Ice)Ice)• White, ice-like compound consisting of

Methane (CH4) and water.

• A potential source of energy, as large as twice the known reserves of gas, oil, and coal COMBINED.

• Found in very deep ocean sediments (over 300m in depth)

Outlook:

• Drilling technology has not caught up, and until it does, it is not possible to drill.• Methods to capture and transport the gas will be necessary.• Higher prices will be needed to support the large expense of exploration and drilling

Hydrogen PowerHydrogen Power

• Hydrogen has the potential to be the largest energy source of all.• Clean Burning (only water as exhaust!)

• Inexhaustible supply, which is recycled

Ways to create Hydrogen Gas

1)Electrolysis: breaking water into Hydrogen and Oxygen using electricity.- uses lots of power to accomplish- if harnessed to renewable power, the hydrogen could be free

2) Stripping Methane of Hydrogen: using steam to remove the 4 hydrogen atoms from CH4.

- still uses a fossil fuel, and releases Carbon Dioxide gas in the process.

The Future of Alternative EnergyThe Future of Alternative Energy

• Alternative energy sources will play larger roles in the future, but each needs to be utilized in a manner which damages the environment as little as possible.

• Energy sources will need to be mixed, to use them to their maximum potential.

World’s Alternative Energy Use

(by region), 2009