September 5, 2011 | 2
Electricity is used for many purposes – for example, illuminating a space, cooking food, cooling a store, or running a production line. In Wyoming, more than half of the electricity sold in the state is used for industrial applications. In the District of Columbia, more than 60% is sold to the commercial sector. When searching for the most efficient ways to investment in the nation’s power infrastructure, it is important to understand our electricity use patterns. Specifically, knowing how and where we use electricity can help us to make better engineering and investment decisions.
Last week, on Culture of Science, Sheril Kirshenbaum presented an overview of U.S. energy consumption by state. Out of the 94.4 quadrillion Btus of energy used in 2009, more than one-fifth (20.5%) was used by just two states – Texas and California. But, as Kirshenbaum mentioned in her blog post, these numbers do not take into account the state’s populations or the sectors – residential, commercial, industrial, or transportation – that consume this energy.
California, with its more than 37 million people, is home to about 12% of the nation’s total population. Combining this with Texas’s 25 million residents, we find that these two states account for about one-fifth of the country’s population (which tops 308 million).
In other words, one-fifth of the U.S. population is responsible for about one-fifth of the nation’s energy consumption. But, Texas (with its 25 million residents) consumes more energy than California (with its 37 million residents).
Taking a look at the electricity consumption part of the energy equation, I will generally focus on four states – Texas, California, Ohio and Wyoming – for several reasons, including the following:
Historically, these states have significantly different electricity sales profiles and growth rates. The graph below displays electricity sales by year from 1960 to 2008 for each of these four states.
The industrial sector electricity sales provide a very different picture, with Ohio surpassing California in total industrial sales from 1960-2008 (with the exception of a couple of years in the early 1980’s).
Now, lets factor in populations. In the graph below, you can see the per capita electricity sales by state for 2008. Noted here is that I have included the District of Columbia in the graphs below (and in the discussion), though this is not technically a state.
California tops the chart, meaning that it has the lowest total electricity sales on a per person basis in this year with about 7 Megawatt-hours (MWh) of sales. On the other extreme is Wyoming, with more than 30 MWh per person in sales in 2008.
So, why are Wyoming’s numbers so much higher than California?
For the purpose of this discussion, the energy policies and unique geographic characteristics (i.e. the weather) for each state is ignored. Instead, the primary focus on what the electricity is used for and how many people are using it.
Below, I have broken down per capita electricity sales into three sectors – residential, commercial and industrial – for each state and the District of Columbia. I then sorted the states according to their industrial electricity use (from lowest to highest, on a MWh per-person basis). Noted here is that electricity for transportation is included under commercial sales.
Wyoming, with just over 500,000 residents, is the least populous state in the nation. It has just 5.8 people per square mile of land, compared to the U.S. average of 87.3, making it the least-densely populated state in the continental U.S. (Alaska has just 1.2 people per square mile). But, Wyoming is also the nation’s second largest energy producer, and is home to sizable agriculture and mining industries. So, when looking at their industrial energy use per person, they become the most energy intensive for industry of the 50 states.
Washington, DC on the other hand is by far the most densely populated geographic area, when compared to other states in the U.S. with 9,800 people per square mile. Combining this with the district’s relatively low amount of industrial activity, results in an almost nonexistent industrial electricity use per person. Its commercial electricity intensity, however, is by far the highest compared to the 50 states.
In her post, Kirshenbaum briefly mentioned how Texas is home to a significant amount of the nation’s energy production – including petroleum refining. Looking at the data, we see that the state’s total electricity consumption for industrial activities is the highest in the nation, with more than 96 million MWh in industrial electricity sales in 2008. But, in terms of industrial electricity sales on a per person basis (as shown in the previous graph), Texas is less intensive than 20 other states. Noted here is that Texas could have significantly higher electricity use, but a large part of its industry utilizes combined heat and power (CHP) technology to produce electricity on-site. This electricity is not included in the 2008 value used in the previous graph.
In absolute terms, the state of Ohio – with its 58 million MWh in industrial electricity sales in 2008 – ranks second among the 50 states. However, due to its relatively large population of 11.5 million people, it is not the highest in terms of industrial electricity sales on a per person basis. Though is it interesting to note that per capita electricity sales for industrial purposes in Ohio are significantly higher than in Texas.
When searching for the most efficient ways to investment in the nation’s power infrastructure, it is important to understand our electricity use patterns. By knowing how and where we use electricity, we can optimize how we spend the nation’s limited funds in order to improve the strength of our power systems. Knowledge, as they say, is power.
Reference: All of the data used to produce the graphs above can be directly referenced to EIA and the U.S. Census Bureau.