Electricity Production

Electricity Production continues to grow around the world, from a variety of sources. In terms of world electricity production, the US Department of Energy predicts advances strongly from 2004 to 2030. Global electricity production increases by 2.4 percent per year over the projection period, from 16,424 billion kilowatthours in 2004 to 30,364 billion kilowatthours in 2030. Much of the growth in electric power demand is projected for nations outside the OECD. Although the non-OECD nations consumed 26 percent less electricity than the OECD nations in 2004, total electricity production in the non-OECD region in 2030 is projected to exceed generation in the OECD by 30 per cent.

Total electricity demand in the non-OECD nations is expected to grow from 2004 to 2030 at an annual rate that is nearly triple the rate of growth for electricity demand in the OECD. The difference reflects the relative maturity of electricity infrastructure in the more developed OECD region, as well as the expectation that populations in the OECD countries generally will grow slowly or decline over the next 25 years. In addition, fast-paced growth in the developing non-OECD economies translates to rising standards of living and robust growth in consumer demand for lighting and appliances. Total electricity production in the non-OECD region increases by an average of 3.5 percent per year in the IEO2007 reference case, as compared with a projected annual growth rate for OECD electricity production that averages 1.3 per cent per year from 2004 to 2030. Among the energy end-use sectors, the most rapid growth in total world demand for electricity is projected for the buildings (residential and commercial) sectors.

Electricity Production involves the generation or creation of electric power, using rotating turbines attached to electrical generators. This mechanical manufacturing of electricity produces most commercially available electricity. Turbines are driven by a fluid which acts as an intermediate energy carrier. The fluids typically used are:

• steam - Water is boiled by nuclear fission or the burning of fossil fuels (coal, natural gas, or petroleum). Some newer plants use the sun as the heat source: solar parabolic troughs and solar power towers concentrate sunlight to heat a heat transfer fluid, which is then used to produce steam. Another renewable source of heat used to drive a turbine is Geothermal power. Either steam under pressure emerges from the ground and drives a turbine or hot water evaporates a low boiling liquid to create vapour to drive a turbine.
• water - Turbine blades are acted upon by flowing water, produced by hydroelectric dams or tidal forces,
• wind - Most wind turbines generate electricity from naturally occurring wind. Solar updraft towers use wind that is artificially produced inside the chimney by heating it with sunlight.
• hot gases - Turbines are driven directly by gases produced by the combustion of natural gas or oil. Combined cycle gas turbine plants are driven by both steam and gas. They generate power by burning natural gas in a gas turbine and use residual heat to generate additional electricity production from steam. These plants offer efficiencies of up to 60%.

Various other technologies have been studied and developed for electricity production. Solid-state generation (without moving parts) is of particular interest in portable applications. This area is largely dominated by thermoelectric (TE) devices, though thermionic (TI) and thermophotovoltaic (TPV) systems have been developed as well. Typically, TE devices are used at lower temperatures than TI and TPV systems. Piezoelectric devices are used for power generation from mechanical strain, particularly in power harvesting. Betavoltaics are another type of solid-state power generator which produces electricity from radioactive decay.

Fluid-based magnetohydrodynamic (MHD) electricity production has been studied as a method for extracting electrical power from nuclear reactors and also from more conventional fuel combustion systems.

Electrochemical electricity production is also important in portable and mobile applications. Currently, most electrochemical power comes from closed electrochemical cells ("batteries"), which are arguably utilized more as storage systems than generation systems, but open electrochemical systems, known as fuel cells, have been undergoing a great deal of research and development in the last few years. Fuel cells can be used to extract power either from natural fuels or from synthesized fuels (mainly electrolytic hydrogen) and so can be viewed as either generation systems or storage systems depending on their use.