U.S. Energy Information Administration - EIA - Independent Statistics and Analysis
Electricity Monthly Update
With Data for September 2013 | Release Date: Nov. 22, 2013 | Next Release Date: Dec. 20, 2013
Resource Use: September 2013
Supply and Fuel Consumption
In this section, we look at the resources used to produce electricity. Generating units are chosen to run primarily on their operating costs, of which fuel costs account for the lion's share. Therefore, we present below, electricity generation output by fuel type and generator type. Since the generator/fuel mix of utilities varies significantly by region, we also present generation output by region.
Generation Output by Region
In September 2013, net generation in the United States increased 1.6 percent compared to the previous year. This increase in electricity generation occurred because September 2013 was warmer than September 2012. Only the Northeast and West regions saw a decrease in electricity generation compared to the previous year. This occurred because in both regions, temperatures were warmer in September 2012 compared to September 2013.
All regions of the country, except for Texas, saw a decrease in electricity generation from natural gas compared to the previous year. This decrease in electricity generation from natural gas was mainly a result of the rise in natural gas prices that occurred over the past year. Conversely, coal generation increased in all parts of the country except for in the West and Northeast regions, although there was very little electricity generation from coal in the Northeast in both September 2012 and September 2013.
Hydroelectric generation increased in all parts of the country, except for in the West, where it is a predominant resource used to produce electricity. Electricity generation from wind continues to see a year-over-year increase in most regions of the country, except for Texas and the Southeast, due to increased wind capacity compared to last year.
Fossil Fuel Consumption by Region
Consistent with the trends in coal generation, the chart above shows that the change in coal consumption mostly mirrored the change in electricity generation from coal.
The second tab compares natural gas consumption in September 2012 and September 2013 by region. This consumption pattern is consistent with changes in natural gas generation, with all regions of the country, except for Texas, seeing decreases in natural gas consumption.
The third tab presents the change in the relative share of fossil fuel consumption by fuel type on a percentage basis, calculated using equivalent energy content (Btu). This highlights changes in the relative market shares of coal, natural gas, and petroleum. Except for Texas and the West, coal increased its share of total fossil fuel consumption in all regions of the country at the expense of natural gas. For the sixth month in a row, other fossil fuels in Florida (mainly oil) also cut into natural gas's share of total fossil fuel consumption.
The fourth tab presents the change in coal and natural gas consumption on an energy content basis between September 2012 and September 2013 by region. Once again, the change in total fossil fuel use was very similar to the changes seen in total net generation in each region, with coal displacing natural gas in most regions of the country.
Fossil Fuel Prices
To gain some insight into the changing pattern of consumption of fossil fuels over the past year, we look at relative monthly average fuel prices. A common way to compare fuel prices is on an equivalent $ / MMBtu basis as shown in the chart above. For the first time in four months, the price of Henry Hub natural gas increased from the previous month, going from $3.54 / MMBtu in August 2013 to $3.72 / MMBtu in September 2013. The natural gas price for New York City (Transco Zone 6 NY) showed a similar increase from the previous month, going from $3.58 / MMBtu the previous month to $3.84 / MMBtu in September 2013. The price of Central Appalachian coal had its largest month-to-month change over the past year, decreasing $0.16 / MMBtu from $2.78 / MMBtu in August 2013 to $2.62 / MMBtu in September 2013.
For the second consecutive month, the average price of residual oil priced at New York Harbor increased from the previous month, going from $17.30 / MMBtu in August 2013 to $17.59 / MMBtu in September 2013. Regardless, it remains almost always priced out of the market in the continental United States.
A fuel price comparison based on equivalent energy content ($ / MMBtu) does not reflect differences in energy conversion efficiency (heat rate) among different types of generators. Gas-fired combined-cycle units tend to be more efficient than coal-fired steam units. The second tab shows coal and natural gas prices on an equivalent energy content and efficiency basis. On a $ / MWh basis, the price of natural gas at Henry Hub remained below the price of Central Appalachian coal in July and August 2013. However, due to the significant drop in the price of Central Appalachian coal from the previous month, the price of natural gas at Henry Hub climbed above the price of Central Appalachian coal in September 2013. Additionally, the price of natural gas for New York City (Transco Zone 6 NY) is now also higher than the price of Central Appalachian coal on a $ / MWh basis.
The conversion shown in this chart is done for illustrative purposes only. The competition between coal and natural gas to produce electricity is more complex. It involves delivered prices and emission costs, the terms of fuel supply contracts and the workings of fuel markets.