Green Energy: Fuel Cell? Solar? Wind? Our Future? Dr. Hayden So Department of Electrical and Electronic Engineering 3 Oct, 2008

What do we have today? Global Warming

Carbon Dioxide

… and running out of resources…

GeoThermal Finding Alternative Energy Sources Clean (Does not pollute) Renewable (Naturally Replenished) Wind Biodiesel Nuclear Hydrogen Fuel Cell Hydrogen Fuel Cell Ethanol Solar Fossil

Hydrogen Fuel Cell Hydrogen flows in Air/Oxygen flows in other side Catalyst forces H 2 to split into electrons and positive ions Polymer Electrolyte Membrane (PEM) only allows positive ions to flow through Negative charges flow externally to form electric current

H-RACER DEMO

Fuel Cell in Real World Honda FCX Clarity AC Transit (near Berkeley) BMW Hydrogen 7

Getting Hydrogen Honda Home Energy Station IV

Problems with Hydrogen Fuel Cell Cars  Bulky Large amount of hydrogen needed for long range  Energy efficiency of producing hydrogen Not all sources of hydrogen is renewable May use more energy to generate hydrogen that overcome its benefit  PEM depreciate fast  Not work at temp 100 degree C  Lack of infrastructure No existing infrastructure to deliver hydrogen economically

A Hybrid Solution

Hybrid Technology  Conventional combustion + Electric Engine  Gas: Power Electric: save gas  Combustion engine turns off automatically when not needed  Electric motor powered by on-board battery  Battery charged during brake/deceleration

Hybrid Vehicles Sale Hybrid Vehicle Sales

Solar Energy  Convert radiation from the Sun into electricity by photovoltaics and other means.  Pros: always available (during day time), renewable, free  Cons: doesn’t work at night, cloudy day, large area  Increase in efficiency recent years: 17% in 1980s, around 40% in 2007 Helios

Biofuel: Biodiesel and Ethanol  Generate electricity through Biomass Sugar cane, core, animal manure, etc…  Make biodiesel/ethanol to use in car  Pros: Net carbon neutral (hopefully)  Cons: Food for electricity? Pest?

Just Yesterday  Honda unveils new version of Insight The first commercially available hybrid vehicle Original Honda Insight, 1999

Summary  We NEED to find alternative Earth-friendly energy sources, NOW  Global warming + high oil price has motivated many innovations in the past 2-3 years  More innovations needed  Huge engineering effort  Do you best to save the world: Take care of Planet Earth. View of the Earth as seen by the Apollo 17