Power and How It Is Generated in the US

I started diving into the EIA data I had collected from 2008 to 2015, in an effort to learn about the facts on power generation in the US.

Before drilling down into any detailed vertical analysis, I decided to take a look at power generation at a higher level. I set out to answer the following questions:

  • how much power is generated by each state?
  • how much fuel is used to generate all the power each year?
  • how much power (megawatt-hour) does each type of fuel produce each year?

Here is what the data reveals.

How Much Power is Generated by Each State

Annual Total Power Generation by State 2008–2015

The graph above confirmed my projection that Texas, the energy giant, produces the most power among all 50 states, by A LARGE MARGIN. There is also a second tier of states with a comfortable lead above all other states: California, Floria, Illinois and Pennsylvania. It’s not surprising to see these five states taking the top spots on the chart because they are five of the top six most populous states in the country. This finding may reveal a positive correlation between power generation and the size of the population.

Annual Total Power Generation in FL, PA, CA, IL and NY 2008–2015

But the state of New York, with the fourth largest population, falls outside of this correlation. It’s unclear if the state receives power from neighboring states to fulfill its own demand or this is a statistical exception.

Are power plants’ production level evenly distributed throughout the year?

Monthly Total Power Generation by State 2008–2015

If we break down the power generation by months, we can see a clear nature of seasonality of power generation. The summer months see the most power generated, whereas second peaks occur in the winter months.

What about all the power generated by all the power plants in the United States?

Annual Total Power Generated in the US 2008–2015

It looks like there is a dip in 2009, but the production level bounced right back in 2010, even higher than that in 2008 before the drop. The power generation data in these three years (2008–2010) seems to correlate with the GDP growth rate of the US in the same period. This may tell us the importance of consumption of power to economic activities.

US GDP Growth 2008–2015. Data and graph credits: World Bank.

A digressing voice in my head is now asking, does power generation correlate to the size of the population more tightly or economic activities more directly? Looks like I need to collect more data to answer this question.

How Much Fuel is Used for Power Generation

Power plants around the US use a variety of means to generate power, this includes electricity and heat. This data is only meaningful for fossil fuel based power plants since nuclear and most renewable sources do not consume any fuel.

The EIA has defined a list of codes that represent all the types of sources from which a power plant can use in order to generate power. I have learned a ton on what can be used as energy sources, e.g. there are eight different types of fuel sources that are either coal or coal-derived.

EIA Fuel Type Code and Description

We can see the list is rather long and it has a very detailed classification of all types of fuel. It is not very straight forward to help anyone understand a simple question like “how many of these codes collectively represent coal?”. Luckily the EIA also has another set of codes at a higher level, aimed at simplifying the classification and for the AER (Annual Energy Review).

AER Fule Type Codes and Description

How have the usages of broad categories of fuels been trending? Are we using more fossil fuels or are renewables catching up? We can’t answer these questions from fuel consumption data alone since hydroelectric means, wind, solar, geothermal and nuclear don’t consume any fuel. But we can examine the trend of consumption for all remaining fuel types.

This is a very interesting graph that shows the change in the percentage of consumption of these 13 types of fuel since 2008. Consumptions of most types of fuel are fairly steady except two with staggering growth and two others with a significant decline.

Top 2 in growth

The turquoise line with the most growth is petroleum coke, also known as petcoke. The use of petcoke JUMPED by 478% in 2011 compared to 2010. The overall growth trajectory of petcoke usage is something any tech startup would hope to achieve. Oxbow, one of the major companies that deal petcoke, sold about 11 million tons of it in 2013 alone. The company is owned by William I. Koch, a member of the Koch Family. Could this level of growth be achieved by superior sales teams or marketing strategies? Maybe, but these facts might tell a different story.

The line in hot pink represents another big growth: Other Renewables. This is a broad AER fuel type that entails a few types of biomass and waste based liquids and solids. It’s interesting that these fuel sources are called “renewables”. I guess municipal waste (garbage) will be renewed since we produce it every day. This type of power plants is called waste-to-energy plants. They are apparently a big part of power generation and it’s an important way to tackle landfill problems. Burning waste also comes with its own baggage as toxins will be released from the process. Proper handling of the toxic byproduct is essential in these plants.

Top 2 in decline

The dark olive green line at the very bottom of the graph represents the biggest decline in fuel usage on Other. This is another broad category that includes several fuel types, but the most important one and most welcoming one is Tire-derived Fuel. It’s basically burning old tires swapped out of automobiles!!! A 2004 study (paywall) pointed out the environmental impact of burning TDF clearly:

… atmospheric contamination dramatically increases when tire rubber is used as the fuel. Other different combustion variables compared to the ones used for coal combustion should be used to avoid atmospheric contamination by toxic, mutagenic, and carcinogenic pollutants, as well as hot-gas cleaning systems and COx capture systems.

The bright green line just above the dark olive line represents Residual Petroleum. Power generation using residual oils has been declining since the 1970’s and the trends seem to hold even in recent years. In the United States, these types of power plants are primarily located on the east coast, Florida and Hawaii. The decline is certainly better for the environment since the negative effects of burning petroleum are well known.

How Much Power is Generated per Type of Fuel Annually

With all these types of fuel and consumption data, we still haven’t answered one of the most burning questions: which type of fuel does America use to generate the most power nationwide? This data will give us insights on the most heavily depended on source of energy. We could also then in turn to assess the environmental impact and our carbon footprint (in later writings). Let’s see what the data tells us:

Annual Power Generation by Fuel Type

Coal is the king of power in the United States. Even in 2015, the year with the tiniest margin, 200 million more megawatt hours of power was generated by coal than the runner-up natural gas. The gap is shrinking FAST though, natural gas may dethrone coal very soon. Nuclear is sitting at 3rd place pretty steadily at about 800 million Mwh or so annually throughout the 7-year period.

The king of renewable is hydro. The yellow line sways between 250 and 320 Mwh. It’s great to see a renewable energy source ranked highly. Next up we have wind (purple), gradually making its way into the 200 million Mwh range.

All other sources of power generation haven’t separated themselves from the pack. Solar power has seen its share of popularity in recent years. Some of the well-known names in the industry are Solar City and Sunrun. Solar is one of the most residential-friendly means of power generation, the rooftop panels make an excellent independent, off-the-grid alternative. Solar power has grown from 864,000 Mwh in 2008 to 24.7 million Mwh in 2015, but clearly it has a long way to go before becoming a dominant force.

These high-level analyses provide a lot of answers for me, but it also creates even more questions. In the next writing, I will be diving into a geographical analysis in the United States on power generation.