Electrolysis of Water Peter Lindner Ridgewood High School December 1, 2010
Energy can neither be created or destroyed, it can only be changed from one form to another – Albert Einstein
ConventionalAlternate
How do we store electricity? Through Chemistry Fossil Fuels Batteries Hydrogen
Why is Hydrogen such a big deal? Energy Density (Mega Joules per kilogram) Li-ion Battery0.54 Gasoline46.9 Hydrogen120.0 ~ 220 times more energy than batteries ~ 2.6 times more energy than gasoline NO AVAILABLE SOURCE OF HYDROGEN
Electrolysis of Water Electrolysis: Using electricity to drive a non-spontaneous chemical reaction H 2 and O 2
What do we need? Water Electrolyte (PEM, salt water, citric acid) Metal electrodes (Anode +, Cathode -) Electricity
Chemical what Happens Anode (positive): Cathode (negative): OVERALL: 2H 2 O O 2 +4H + +4e - 4H + +4e - 2H 2 2H 2 O O 2 +2H 2
What is a PEM PEM – Proton Exchange Membrane Used as fuel cells to produce electricity Must use deionized water Can be run backwards as an electrolyzer
Proton Exchange Membrane
DEMO 4H + +4e - 2H 2 2H 2 O O 2 +4H + +4e -
How do we use the Hydrogen? Fuel Cells (electrolyzer in reverse) Run on H 2 and O 2 to form clean water. Water can then be recycled to electrolyzer.
What are we going to do? Setup PEM electrolyzer(s). Produce efficiency curves of PEM using simple circuitry. Determine Hydrogen Generation Rate vs. Power input. Build our own electrolyzer powered by our Solar Cells
Electrolyte Solar Cell
Design a Power Plant
What Industry Wants to Make Solar Cells
Electrolysis of Water 349qvMhttp:// 349qvM
Questions???
Take Aways Solar cells can make electricity That electricity can be used to produce hydrogen from water Hydrogen can be used to store energy Electricity can then be produced by running hydrogen through Fuel cells. PEM – Proton Exchange Membrane Anode – Positive Electrode Cathode – Negative Electrode