19-02-2013, 12:37 PM
Distributed Generation of Electricity by Solid Oxide Fuel Cell
Distributed Generation.docx (Size: 17.21 KB / Downloads: 28)
Abstract
Distributed generation of electricity allows us to generate electricity at the place of required and it will make us free from generation (at other place), transmission and distribution. This technology uses solid oxide fuel cells (SOFCs), for attaining high electrical efficiency. A single fuel cell has an anode, a cathode, and an electrolyte stuck between the two. These fuel cells are made up of sand that is baked into diskette-sized ceramic squares. Each fuel cell (of size 100mm × 100mm) is capable of producing about 25W that is enough to power a light bulb. For more power, the cells are sandwiched along with metal interconnect plates into a fuel cell called stack and few stacks are enough for powering of a house. These fuel cell stacks are housed in a refrigerator-sized box which is portable. In this oxygen is drawn into one side of the unit, and fuel (fossil-fuel, bio-fuel, coal gas) is fed into the other side. These two combine within the cell and undergo a chemical reaction that causes electrons to move into the fuel cell's circuit, producing electricity with no burning, no combustion, and no power lines.
CH4 + 2O2 CO2 + 2H2O + e- + ∆H
There are many different types of fuel cells. Some of the more popular ones include methanol fuel cells, hydrogen fuel cells, and zinc-air batteries but the solid oxide fuel cells, which are attractive because they can be made out of low-cost materials with high energy efficiencies. The cells can run on a variety of fuels, including traditional fuel, natural gas, biomass gas, landfill gas, and ethanol. SOFC can generate electricity at 50% to 55% conversion efficiency while our solar device can generate power only at the efficiency of 10% to 20%. Unlike solar panels, this method of generation produces CO2 as a byproduct. In this, when it is run on natural gas it produces CO2 below 0.8 pound/KWh, which is less than the national average for on-grid electricity that is around 1.3-1.5 lbs/kWh. If the box runs on landfill gas or biogas, it produces net zero carbon emissions.