Being the most abundant element on earth, hydrogen has been identified as one of the most viable and long term renewable alternatives to fossil fuel after solar. A fuel cell is an electrochemical cell which captures the electrical energy of a chemical reaction between fuels, through chemical reactions from hydrogen and air (oxygen), without the production of greenhouse gasses. In principle, although a fuel cell operates like a normal battery, it does not run out nor requires charging as long as fuel is supplied to it.
Fuel cells are not commercially available yet, and remain very expensive. They are used as power sources in remote areas. Fuel cells cannot store energy like batteries. Even if the energy delivered from fuel cells is stored, their electrical efficiency is not nearly as high as a battery's efficiency which also happens to be a much cheaper option.
At the moment, research and development is being carried out to harness hydrogen to be used in fuel cells for transportation purposes. Hydrogen and fuel cells are identified as priority research by the Ministry of Science, Technology and Innovation (MOSTI) after solar, as applications of fuel cells are viewed as one of the more important energy conversion devices in the future.
A fuel cell is a device that converts the chemical energy from a fuel into electricity through a chemical reaction with oxygen or another oxidizing agent. Hydrogen is the most common fuel, in the form of hydrocarbons such as natural gas and alcohols like methanol. Fuel cells are different from batteries in that they require a constant source of fuel and oxygen to run, but they can produce electricity continually for as long as these inputs are supplied.
Fuel cells are consists of an anode (negative side), a cathode (positive side) and an electrolyte (in this case, Hydrogen) that allows charges to move between the two sides of the fuel cell. Electrons are drawn from the anode to the cathode through an external circuit, producing direct current (DC) electricity. Individual fuel cells produce very small amounts of electricity, about 0.7 volts, so cells are "stacked", or placed in series or parallel circuits, to increase the voltage and current output to meet an application’s power generation requirements.
In addition to electricity, hydrogen fuel cells produce water and heat. The energy efficiency of a fuel cell is generally between 40-60%, or up to 85% efficient if waste heat is captured for use. Although fuel cell is technically not a renewable energy source but fuel cells can play an important role in the design of hybrid renewable energy system. Renewable energy sources, like the sun and wind, can't produce energy all the time, like at night. Fuel cells can be used as the primary power source during that period. The renewable energy system can produce electric energy and hydrogen for the fuel cell, which can be stored until it's needed.
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