Biomass – 04
Hydrogen fuel and fuel cells
Hydrogen is universally accepted as a best preferred alternative to fossil fuels because of its cleaner nature with no greenhouse emissions and being projected as a potential energy carrier of the future. The richest source of hydrogen is water. The fossil fuels like petroleum, natural gas, coal and biomass are also used as major sources for hydrogen. It is renewable energy resource, environmentally safe, and can be directly utilized for different types of fuel cells, in portable electronics, power plants and in specially designed internal combustion engines. The hydrogen and oxygen are the main fuel and oxidant for most of the fuel cells.
Fuel cell – A fuel cell is an electrochemical energy conversion device which converts the hydrogen and oxygen into water with electricity production. The current that produced in a fuel cell is DC (direct current). Hydrogen based fuel cells are the most common.
Types of fuel cells
There are different types of fuel cells and their applications range from powering a laptop computer (few watts) to utility power plants (few megawatts). The different types of fuel cells based on their operating type and the type of electrolyte they use include
∙ Polymer Electrolyte Membrane Fuel Cell (PEMFC) is a low-temperature fuel cell being developed for transportation and other portable applications
∙ Phosphoric acid fuel cell (PAFC) – operates at 200 °C and is suited for stationary applications.
∙ Molten carbonate fuel cell (MCFC)
∙ Solid oxide fuel cell (SOFC)
∙ Alkaline fuel cell (AFC)
Microbial Fuel Cell (MFC) – The fuel cell that generates electricity with the help of microbes is known as microbial fuel cell or MFC. The biochemical energy produced during metabolism of organic substrates is converted to electric energy.
Benefits of fuel cells
- Direct energy conversion
- High electricity generation potential
- Less pollution
- Carbon sequestration
- Reduced dependence on imports of oil
Conclusion – The high efficiency and the lack of emissions
Make hydrogen as an alternate fuel and as a fuel in
Fuel cells. The emerging hydrogen production
Technologies may provide low cost clean hydrogen in
the future for automobiles and power generations and
provide a sustainable energy source for the future.
Energy Efficiency And Conservation
The demand on energy resources is continuously increasing over the years. There is a huge gap between supply and demand chains of energy. The energy efficiency along with renewable and other non-conventional energy sources is required for ensuring sustainable energy consumption in the world.
The energy conservation (EC) and energy efficiency (EE) are two terms involved in utilization of energy in efficient ways and measures for sustainable energy development. The conservation aimed at using less energy while the efficiency denotes the wise use of energy with minimum wastage.
Energy conservation: It is a behavioural change in reducing energy consumption. The examples of energy conservation are switching off the lights while leaving a room, unplugging of computers when not in use, etc.