EIA's Electric Power Monthly - October 2018 Edition With Data For August

by: Ron Patterson

By Islandboy

The EIA released the latest edition of their Electric Power Monthly on October 24th, with data for August 2018. The table above shows the percentage contribution of the main fuel sources to two decimal places for the last two months.

This report is usually prepared by adding the data for the latest month to spreadsheets that have been populated carrying out this process each month. This month, however, this produced effects in the graphs that appeared somewhat unusual. On further investigation, a comparison of the data in Table 1.1 Energy Source: Total - All Sectors with the result of adding the data for each month to the existing spreadsheet as it becomes available showed that for most sources the data for every month was different. In total, some 88% of the cells in the range under consideration were different, including data that had not been added by appending monthly data to the existing spreadsheet. I have reached out by email to the folks at the EIA for an explanation but have not yet received a response as at the time of this post.

According to the adjusted data, the total amount of electricity generated for the month of July 2018 was the highest amount generated for any single month since January 2013 at 412,383 GWh. Again, according to the new data, the month of August 2018, at 410485 GWh, ranks third, behind July 2016 but ahead of August 2016. In the previous edition of this report, based on the old data, it was stated that July 2018 had the second largest amount of total generation behind July 2016, but the adjusted data has July 2018 up and July 2016 down.

Coal and Natural Gas fueled just over 68.25% of US electricity generation in August, with the contributions from most major sources in both absolute and percentage terms being very similar (within 0.1%) to the previous month. The percentage contribution from Wind was up almost 1%, and Hydro was down a little more than 0.5%.

The graph below helps to illustrate how the changes in absolute production affect the percentage contribution from the various sources.

The chart below shows the total monthly generation at utility scale facilities by year versus the contribution from Solar. The left-hand side scale is for the total generation, while the right-hand side scale is for Solar output and has been deliberately set to exaggerate the Solar output as a means of assessing its potential to make a meaningful contribution to the midsummer peak. In August 2018, the output from solar at 10,000 GWh was 3.51 times what it was four years ago in August 2014. It is now safe to say this year Solar energy peaked in June, the month of the summer solstice, and the peak monthly output for 2018 was 10,869 GWh, according to the adjusted data.


The chart below shows the monthly capacity additions for 2018. In August, Natural Gas contributed 86.87 percent of new capacity. With 7.22 percent of new capacity coming from Wind and Solar contributing 5.69 percent, Natural Gas, Solar and Wind made up almost 99.78 percent of new capacity in August. The only capacity added that was not fueled by Natural Gas, Wind or Solar was a 2.5 MW battery installation by Advanced Microgrid Solutions in Irvine, California. In August 2018, the total added capacity reported was 1,135.8 MW, compared to the 505.5 MW added in August 2017.

The adjustments to the data this month were not restricted to the tables used to create the charts at the top of this post. There were significant amendments to the capacity retirements for the month of March. Up until last month, there were only 14.4 MW of capacity retirements listed for March, but this month, the retirement of 741 MW of coal capacity at a plant named Allen in Tennessee, owned by the Tennessee Valley Authority, was listed. In addition, the retirement of a 107 MW Natural Gas-fired steam turbine at a plant called Jack Watson in Mississippi was also added for March.

The chart below shows the resulting monthly capacity retirements so far for 2018. The scale on the Y axis has been adjusted to start at 60%, since there is no month when the largest single fuel source retired was less than that figure and between January and June; the minor contributors were so small that they would barely be visible if the scale started at zero. In August, the only retirements noted were four 300 kW Natural Gas-fired units at the California State University, Northridge.

Following the report on the edition of the EPM with data for March, there was some discussion about coal consumption for the production of electricity. At the request of peakoilbarrel.com member Shyam, I am including a table of the top ten states in order of coal consumption for electricity production for August.