PDS AP Environmental Science 8th Period 2010-11

Hydrogen Energy

Hydrogen energy uses hydrogen ions and a process called electrolysis to create electrical energy. Heres a diagram and  two short videos describing this process:

How Electrolysis Works

What this video doesn’t show you is that the energy needed to break apart these molecules must come from another source (e.g. coal, natural gas, or renewables like solar and wind.) To be a truly “clean” process this energy must come first from other “clean” sources (like wind and solar).

How Electrical Energy is Produced

http://biodiesel.environmentalactiongroup.org/hydrogen.html

Hydrogen energy is a very efficient source of electrical energy:

• It uses up to 75% of the energy produced by the process (it can use up to 90% if the heat energy it creates is also harnessed.)
• its byproducts, if using water as a fuel source, are only heat and H2O.

However, as perfect as it may seem, Hydrogen is a very volatile and dangerous substance (as illustrated by the Hindenburg disaster.) and is dangerous to transport long distances. Not only this, but scientists fear that releasing more hydrogen gas into the atmosphere will deplete the ozone layer by binding with ozone molecules.

As of right now, there are very few people using hydrogen power in todays world. One of them is Iceland. In 1998, Iceland signed an agreement to proclaim it’s wish to change into a “hydrogen powered society”.  It attempted to do this by introducing hydrogen fueled buses in Reykjavik. These buses used only hydrogen fuel and electrolysis to create all the energy needed to run. From an ecological standpoint, these buses were a success. However, Icelands recent economic troubles have put these buses out of commission, but have not put a stop to their research. Recently they have created a few private car prototypes that run completely on this process, and can go over 350 miles without refueling. In the future, with the help of solar and wind energies, this process could help rid us of the need for fossil fuels.

http://geographyfieldwork.com/g427.gif

Today in class we talked about the Demographic transition. We used this model to discuss how countries change over time to fit our four stages.

The four stages were:

1. Pre-Industrial: Countries without industry. Usually don’t have a centralized gov’t system (usually tribal). We didn’t find many (if any) countries that fit this stage.
2. Transitional: These countries are in the transition stage between Pre and Industrialized nations. They are characterized by high birth rates, and high death rates that decrease over time. These death rates decrease over time because the country starts to gain the ability to defeat death through medical advancement (anti-biotics and vaccinations) as well as sanitation and readily accessible food resources.  Countries like Rwanda and Ethiopia fit this model.
3. Industrial: This stage describes nations who have low death rates and birth rates that are lowering towards 0% population growth, but aren’t quite their yet. Countries like China and India fit this stage.
4. Post-Industrial: This stage describes countries that have low death rates, high life expectancy, and an AGR of zero or even negative %. Germany and Japan fit this model.

our class Stages

I think that one of the most important environmental problem is our overconsumption of fossil fuels. We are depending on this non-renewable resource to fuel almost all of modern technology, and are just recently seriously looking at alternative renewable energy solutions. Also, the use of fossil fuels increases the amount of CO2, a greenhouse gas, in the atmosphere. In addition, accidents in the production, and shipment of these fuels have caused many environmental problems (eg. Exxon and BP oil spills).