How Southern Company generates electricity
Southern Company has a number of different plants in its fleet. The diversity of fuels used in these plants enables us to provide a reliable, environmentally conscious power supply for our commercial, industrial and residential customers. Learn more about the different types of plants and fuels, the technologies behind them and the controls we use to minimize gaseous emissions while recovering electricity from lost-waste heat.
Southern Company has a number of different plants in its fleet. The diversity of fuels used in these plants enables us to provide a reliable power supply for our customers.
In this segment, we will investigate the different types of plants and fuels, and the technologies behind them. We will also explore the importance of reliability and customer satisfaction.
Traditional fuel sources, such as coal, natural gas, hydro, and nuclear are used on a consistent basis to generate the massive amounts of energy demand for our industrial, commercial, and residential customers.
We are also exploring less traditional energy generating sources like solar, wind, and biomass. First, let's look at the traditional sources, gas and coal, both of which make electricity through combustion.
When coal is used, it is pulverized into a fine powder, or gasified state. The fuel burns in a large furnace that superheats water into pressurized steam. The steam carries tremendous force, which is used to turn turbine blades that spin electric generators. The steam is then condensed back into water, and returned to the cycle for re-use. The byproducts of combustion leaving the plant are in the form of gas emissions, or solids residue called particulates. Close to 99% of particulates are removed by equipment called electrostatic precipitators. Many coal plants are also fitted with additional emission control technologies that help minimize the quantities and impacts of gaseous emissions.
When gas is used, it is typically in gas turbine plants, or combined-cycle plants. Gas turbines don't use steam to turn the turbine, but instead use high-temperature pressurized air, combined with gas or oil to create the force that moves the turbine blades.
In combined-cycle plants, electricity is produced from otherwise-lost waste heat exiting from one or more gas combustion turbines. The exiting heat is routed to a heat recovery steam generator for use by a steam turbine to produce electricity.
Another type of combined-cycle plant is called integrated gasification combined cycle, or IGCC. In IGCC plants, coal, water, and oxygen are fed into a gasifier which produces a gas called Syngas, which is then cleaned, particulates and sulfur compounds removed, and is fed to the combined cycle generating unit. This technology is making its debut at Southern Company with Mississippi's Plant Ratcliffe in 2014.
Combined cycle plants have fewer emissions than traditional coal-fired plants. In addition, 65% of the carbon dioxide produced by the process at Plant Ratcliffe will be captured and marketed to oil companies for enhanced oil recovery. This process pumps CO2 into aging oil wells to help pump out otherwise unrecoverable oil, and in the process stores, or sequesters, CO2.
Our hydro plants use water and gravity as fuel to create electricity. The water is stored in a reservoir behind a dam. When power is needed, gates are opened and gravity takes the water in the reservoir through the dam, moving the turbine blades of the generator. Hydro power removes no water from the river, and produces no solid waste or air emissions.
Nuclear plants make electricity by heating water into pressurized steam that spins turbine blades and turns generators. The heat comes from the nuclear fission process. Nuclear plants vary in design, but are based on the same scientific process of fission. Nuclear plants do not produce greenhouse gas emissions, and have the advantage of being easily able to isolate their waste, in the form of spent fuel, from the environment.
Our traditional fuel sources are the mainstay of our generation mix, but we are continuing to explore and experiment with less-traditional technologies. Our future focus allows Southern Company to plan for a more diverse energy portfolio, and includes what roles renewable resources like biomass, wind, and solar might play in how we generate power in the future.
Biomass utilizes materials like wood pulp, or switch grass, which are burned in a boiler furnace to turn water into steam which then turns the blades of a turbine. These waste materials become a useful source of fuel, and have emissions lower than, or equal to, coal.
Wind technology utilizes the power of the wind to turn turbine blades. Potentially favorable conditions exist for wind power in select areas of the Southeast. However, cost and regulatory issues need further exploration.
Southern Company, and its partners Ted Turner and First Solar, have one of the nation's largest solar photovoltaic plants located in New Mexico. Sunlight is converted into electricity through solar cells that absorb the sun's energy. The Cimarron Solar Facility is a 30-megawatt facility, capable of powering 9,000 homes.
As one of the largest energy providers in the nation, Southern Company will continue to be challenged to meet the ever-increasing energy demands of our customers. We are dedicated to providing reliable and environmentally conscious energy for many years to come.