380 likes | 721 Views
RENEWABLE ENERGY. What it is & What it isn’t. Vocab Buzz. Sustainable Renewable NonRenewable Organic Green Clean . Energy Waste & Inefficiency What’s the moral of this story?. Conservation vs. Efficiency 84% of commercial energy in US is wasted 41% due to entropy
E N D
RENEWABLE ENERGY What it is & What it isn’t
Vocab Buzz • Sustainable • Renewable • NonRenewable • Organic • Green • Clean
Energy Waste & InefficiencyWhat’s the moral of this story? • Conservation vs. Efficiency • 84% of commercial energy in US is wasted • 41% due to entropy • 43% unnecessary; inefficiency • $570,000/min
Where are we now? Coal Gasification Where might we go? Hydrogen Fuel Cells What’s the bridge to get there? Photovoltaic Cells
How does energy get wasted? • Net Energy Yield • Net Energy Efficiency • Combine efficiencies of all steps in energy conversion for the entire system
Why do we waste so much? • Fossil fuels cheap • Few gov’t incentives • Inaccurate pricing • Inequitable subsidies • What are the benefits to reducing?
What is Energy? • “The Ability to do Work” The world is made up of MATTER & ENERGY. • Which one cycles and which one flows? • The 2 classes are Potential & Kinetic • The 6 types are: • Chemical, Mechanical, Nuclear, Light (EM), Heat, Electrical
What IS a Battery? • Energy Storage System! • As easy as a clock spring or a log • Is that potential or kinetic?
What IS a Battery? -aka cell • Changes chemical energy to electrical • Voltaic cells (cells that can transfer voltage) • Electrons collect on the negative terminal of the battery • Flows between the positive and negative terminals if a conductor (or wire) is present
http://www.howstuffworks.com/battery.htm Battery video
Hydrogen Fuel Cells • How it Works: • Combines H with O to produce energy • Can be fueled by anything with H in it • Natural gas, alcohol, gas • Gives off water http://www.pbs.org/wgbh/nova/sciencenow/3210/01.html
ADVANTAGES H is abundant Non polluting DISADVANTAGES Not very efficient to produce Takes electricity to split water and produce H Expensive Needs to be stored at high pressure Hydrogen Fuel Cells
Photovoltaic Cells • Sunlight strikes semi-conductor • Electrons move • Energy can be stored in battery • Life is carbon-based for a reason • Silicon atoms have the same capabilities http://www.youtube.com/watch?v=K76r41jaGJg
ADVANTAGES No pollutants Safe DISADVANTAGES Expen$ive! Need large surface area Unattractive Is there enough available sunlight in all areas? Requires a backup electricity source Solar Cells
Passive Solar Heating http://www.livingonsolar.com/passive-solar-video.html
Passive Solar Heating SOUTH FACING Venting in summer Thick walls & insulation on north side.
ADVANTAGES HIGH net energy yield Free energy No pollutants Moderate cost DISADVANTAGES Is there enough available sunlight in all areas? Need 60% of the time Needs correct orientation Need heat storage or backup Passive Solar Heating
Solar Cooling • Super-insulation • Block summer sun trees, awning, etc. • Good ventilation • Earth Tubes • Soil ~5-13ºC • Moves cool, dry air in • Inexpensive • Light colored roof • Reflective foil in attic • Earth sheltered building
Active Solar Heating • Solar collectors on roof • Heat stored in insulated tanks of water, rocks, heat-absorbing chemical • Used for heating and hot water
Solar Water Heaters • Should governments require measures, such as solar water heating in new buildings, as part of an energy efficiency plan?
ADVANTAGES No pollutants Moderate net energy Free after initial installation DISADVANTAGES Unattractive Is there enough available sunlight in all areas? Needs correct orientation Requires a backup hot water source Pump requires energy, maintenance Active Solar
Energy Types:Can you match and discuss the +/- ? • Chemical • Electrical • Mechanical • Light (EM) • Nuclear • Heat • Clean • Renewable • Sustainable • Wind • Hydrothermal • Active Solar • Biomass • Passive Solar • Coal, Oil, Natural Gas • Hydrogen Fuel Cells • Hydroelectric • Tidal
Use renewable energy! • Benefits of shifting to local, renewable energy sources • More reliable source • Improve national security • Reduce trade deficits due to importing oil • Reduce greenhouse gases and other air pollution • Creates jobs • Saves $ in the long run
Hybrid, Fuel Cell, Electric • Hybrid Car Flash Animation • Prius Hybrid Synergy Drive • Fuel Cell Flash Animation • Bill Nye video • The EV-1 • http://ev1-club.power.net/ • GM Volt (2010) • http://gm-volt.com/about/ • http://www.chevrolet.com/electriccar/ • The Tesla • http://www.teslamotors.com/ • http://www.fueleconomy.gov/feg/ • http://www.nrel.gov/vehiclesandfuels/hev/
More on Batteries • Carbon-Zinc – 1st Duracell • Lead-Acid – Car batteries • Nickel Cadmium – consumer electronics • Nickel-Metal Hydride • Lithium Ion – notebook computers • Lithium polymer – newest development
TRADE-OFFS Passive or Active Solar Heating Advantages Disadvantages Need access to sun 60% of time Energy is free Net energy is moderate (active) to high (passive) Sun can be blocked by trees and other structures Environmental costs not included in market price Quick installation No CO2 emissions Very low air and water pollution Need heat storage system Very low land disturbance (built into roof or windows) High cost (active) Active system needs maintenance and repair Moderate cost (passive) Active collectors unattractive