Electricity 101
Photo Source: Peter from Wellington
As we may remember from high-school science class, the electricity supplied to our homes and businesses comes from large generators. These pieces of equipment are almost always powered from steam that is forced through turbine blades. This steam is mostly produced by the burning of fuels such as fossil fuels (coal, oil, propane, etc), naturally occurring gasses (natural gas, hydrogen), landfill waste (organic yard waste, methane gas), nuclear reaction or fuel produced from starches (ethanol). Steam also can come from other means such as solar energy being directed by mirrors to heat water and geothermal steam. The production of steam to produce electricity constitutes over 90% of electricity production in the U.S. (Source: U.S. Dept. of Energy)
This process has efficiency flaws. Any process that does not directly produce electricity is inherently wasteful because the ratio of energy put in, to usable energy derived, is never unity. In the three step process that is producing electricity from coal, the coal burns to heat water, the steam derived expands rapidly and forces itself through a turbine and then the magnets in the generator are rotated by the turbine to move electrons. In all of these processes there is significant energy loss.
This energy does not contribute to the end goal. If the efficiency of energy put in to energy produced in each step where 1.5:1 then that would be multiplied by the three steps. This gives us a ratio of 4.5:1! These figures are not accurate because each facility is different but remember is that as mentioned before, the ratio is never unity. Also – a short physics lesson, matter cannot be destroyed or created. What does that mean? It means that if you burn 10 tons of coal, you will have ten tons of waste. Just because it was burned it doesn’t mean it has disappeared.
On the flip side we have electricity produced by means that do not include burning fuels. Most of these processes are a much more direct way of producing electricity such as wind turbines. The wind blows past the blades, turning them; they are connected directly to the generator which produces power. How is this more efficient, since not all the wind is turned into usable energy? The wind that is not turned into usable energy is still wind. It has not been burned and turned into a waste; it will continue on (hopefully to the next wind turbine) and will not be tainted in any way by the process.