May 04 2010
Today we talked about hydrogen and how it can be used to power vehicles. Of the forty-four free response questions on previous A.P. exams, none have addressed hydrogen power, so Mr. Willard said this would be “good knowledge to have in our pockets.”
First we reviewed what we already knew about hydrogen. Hydrogen is the most abundant element in the universe. Despite this fact, there is almost none in the troposphere, and this is because hydrogen has a very low density and so it rises. Additionally, hydrogen is very unstable, so it likes to bond with things (i.e. with oxygen, thus water).
In a hydrogen-powered car, the traditional internal combustion engine is replaced with a fuel cell. Here is a link to a video we watched in class about how a fuel cell works: How A Fuel Cell Works: Inside A Hydrogen-Powered Car (http://auto.howstuffworks.com/fuel-efficiency/alternative-fuels/dangerous-hydrogen-fuel1.htm)
As with every energy source, there are pros and cons. The pros to a hydrogen-powered car is that water is its only emission, it is a strategy for reducing fossil fuel use, and hydrogen is the most abundant element in the universe. On the flip side, the cons to a hydrogen-powered car are that we have to harvest the hydrogen or “make it” (which requires energy input), since this source of energy is new, the infrastructure for hydrogen power is not there, and that we can’t simply convert petro-gas stations to hydrogen gas stations. Perhaps we can add on to our petro-gas stations, and if we harvest the hydrogen or “make” the hydrogen by generating energy from renewable resources such as wind or solar power, technically the energy is still clean. But if we generate the energy for hydrogen from a coal-based power plant, then we’re just moving the source, but the impact is still the same.
Hydrogen can be “harvested” or “made” from electrolysis (splitting water), from biomass, and from fuel.
The U.S. Government is currently funding research on hydrogen power in the state of California. Hydrogen power is still very much in the research and development stage. Hope this helped!
Below is a picture of a typical hydrogen fuel cell: