Environmental Engineering Reference
In-Depth Information
Solar
Advantages
Disadvantages
Solar energy is most efficient where sunlight is most consist-
ent.
There is an infinite, free supply of solar energy.
Solar energy is clean, renewable, and sustain-
able.
Initial costs for installation and building are high.
The energy collected can be stored in batteries. Solar panels require a large area for efficiency.
There is limited or no maintenance.
Sunlight can be blocked by trees and buildings.
Some people consider the solar panels to be unsightly.
Hydrogen Fuel Cells
The basic concept of a hydrogen fuel cell is to use hydrogen and oxygen in a chemical reaction to produce en-
ergy and water. Like a typical battery, a hydrogen fuel cell uses an anode and a cathode that are separated by an
electrolyte. Hydrogen reacts with a catalyst on the anode electrode, splitting into negatively charged electrons
and positively charged hydrogen ions. The electrons flow out of the cell and are used as electrical energy. The
positively charged hydrogen ions move through the membrane to the cathode, where they combine with oxy-
gen to produce water. Unlike in a typical battery, as long as the fuel cell is fed with hydrogen and oxygen, it
will never run down or run out. Hydrogen fuel cell technology is being developed for cars and other forms of
transportation. These fuel cells are being used to generate small amounts of electricity to supplement larger
power systems. They are also being used in isolated areas where running transmission lines may be difficult or
expensive.
Basic Fuel Cell Reaction
2 H
2
+ O
2
→ 2 H
2
O + energy
