Electrical power is an incredibly convenient part of modern life. However, for most consumers, the way that it is produced is relatively disconnected from how it is consumed. Most people are not sure where their power comes from, and where the power to most of the electrical grid is coming from at any given time.
First, when it comes to power production, it is best to produce it close to where it will be used. Transporting electrical power long distances will mean that some of the power is lost along the way. You can think about this by imagining a truck full of gasoline. If you want to drive 100 miles, more gasoline will get there than if you drive 1000 miles, because the truck will need to burn more of the gasoline in order to get there. When it comes to electrical power, this loss of power is largely due to the resistance of the electrical power line. So, power production is always a balancing act between the larger cost involved with a large number of smaller power stations, with the power loss over distance you would see if there was only one large centralized power station for the entire grid.
Another factor which helps to encourage the building of multiple dispersed smaller power stations is that all power stations turn some type of natural resource into power. This resource is essentially their fuel. As energy is not created or destroyed, these power stations are reliant on being relatively close to their fuel source, as transporting this fuel source could be expensive, both financially and in terms of total energy cost. For example, a coal burning plant might be near rivers, major shipping centers, or near domestic coal production centers. Hydroelectric plants are some of the most geographically constrained types of power production centers available, as they must be built in very specific locations.
So, these are the factors which help inform the ideal distribution for power plants, but what does the actual distribution look like? The U.S. government has an organization called the Energy Information Agency, or EIA, which is responsible for the collection and dissemination of information about the nation’s energy production and distribution. Currently they list over 8000 power plants nationwide with an annual energy production of greater than 1 megawatt. All information in this article is sourced from the EIA website.
National Power Production
So what kind of breakdown do we see in our national energy production? Overall, the five major domestic energy sources are (as of 2016), in descending order, petroleum (37%), Natural Gas (29%), Coal(15%), Renewables (10.2%), and Nuclear power (9%). However, this is not the breakdown of how much of this power is used for electrical power production. Much of this power is used for other things, such as transportation, heating, and is not part of the electrical grid. For example, while petroleum accounts for 37% of the nations energy consumption, it is only about 1% of the national electricity production. Most of this petroleum is used as vehicle fuel. Conversely, 100% of the nuclear power generated in the country is converted directly to electricity and becomes part of the electrical grid. Let’s look at this breakdown a little more closely.
National Power Consumption
We looked at production of power, but how is this energy consumed? The 4 major sectors for power consumption are, in descending order, Electrical Power (39%), Transportation (29%), Industrial Consumption (22%), and residential/commercial consumption (11%). Each of these take some of the power produced by the power sources listed above, but not at even rates. For example, 72% of all petroleum fuel is used for transportation, with 23% going to industrial needs, and the rest being split elsewhere. This 72% of petroleum power is enough to make up 92% of the transportation sectors need’s, with the transportation sector pulling small amounts of power from natural gas and renewable energies. Industrial power consumption is more split, using power roughly evenly produced by both petroleum (38%) and natural gas (45%). Residential and commercial uses of power rely heavily on natural gas, filling 74% of their power consumption with this resource. Finally, electrical power, the one we are particularly interested in, pulls from a variety of sources. 27% of electrical power is produced from natural gas, 34% from coal, 22% from nuclear power, and 15% from renewable energy sources. The only sector which barely affects electrical power is petroleum, being used for only 1% of the nation’s transportation needs.
We can see something interesting here. Currently, transportation is mostly based around the consumption of petroleum. The use and production of petroleum resources is a hugely important political debate in this country. However, it is not currently very commercially viable to use petroleum as an energy source for electrical power. It is possible that the adoption of electric vehicles could lead to an increased reliance on the electrical grid, which largely gains power from non petroleum based energy sources.