U.S. Energy Information Administration - EIA - Independent Statistics and Analysis
Electricity Monthly Update
With Data for December 2013 | Release Date: Feb. 21, 2014 | Next Release Date: Mar. 21, 2014
Resource Use: December 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
Net generation in the United States increased 5.3 percent in December 2013 compared to the previous year. This year-over-year increase in electricity generation occurred because the U.S. experienced below normal temperatures in December 2013 and significantly above normal temperatures the previous December. This lead to an increase in residential heating compared to last year which caused increased demand for electricity generation during December 2013. The only region that experienced a decrease in electricity generation in December 2013 was Florida, where the overall average temperature for the month was close to the record high temperature for December. This caused Florida to have a 1.6 percent decrease in electricity generation compared to last December.
In December 2013, electricity generation from coal increased in all regions of the country except for the West. The change in natural gas generation was much more varied, with the Mid-Atlantic, Central, West, and Texas experiencing increases in natural gas generation. This increase in generation was likely a result of the below normal temperatures experienced in December 2013 compared to the warm December experienced the previous year. The Northeast, Southeast, and Florida all experienced decreases in natural gas generation compared to last December.
Electricity generation from nuclear plants increased in almost all parts of the country, except for in the Northeast and West where nuclear generation was down slightly from the previous year. Other fossil generators, mainly used for peaking purposes during times of increased electricity demand, increased electricity generation in all regions of the country, except for Florida, compared to the previous year.
Fossil Fuel Consumption by Region
The chart above shows that the change in coal consumption mirrored the change in electricity generation from coal.
The second tab compares natural gas consumption in December 2012 and December 2013 by region. This consumption pattern is consistent with changes in natural gas generation, with the Mid-Atlantic, Central, West, and Texas experiencing increases in natural gas consumption and the Northeast, Southeast, and Florida experiencing 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. Coal increased its share of total fossil fuel consumption in the Northeast, Southeast, Florida, and Texas at the expense of natural gas. The West, Central, and Mid-Atlantic regions all saw natural gas increase its share of total fossil fuel consumption at the expense of coal. Also of note, other fossil fuels in the Northeast cut into natural gas's share of total fossil fuels.
The fourth tab presents the change in coal and natural gas consumption on an energy content basis between December 2012 and December 2013 by region. Once again, the change in total coal and natural gas consumption was very similar to the change seen in total coal and natural gas net generation in each region.
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. The price of natural gas at Henry Hub increased significantly from the previous month, going from $3.75 / MMBtu in November 2013 to $4.38 / MMBtu in December 2013. The natural gas price for New York City (Transco Zone 6 NY) also experienced a significant increase from the previous month, going from $3.91 / MMBtu in November 2013 to $6.12 / MMBtu in December 2013. Increases of this magnitude in New York City's natural gas price are often observed during this time of year when there is an increased demand for natural gas used for heating in an area of the country where the natural gas pipeline infrastructure is subject to significant congestion. The price of Central Appalachian decreased slightly from the previous month, going from $2.73 / MMBtu in November 2013 to $2.72 / MMBtu in December 2013.
For the fifth consecutive month, the average price of residual oil priced at New York Harbor increased from the previous month, rising from $19.76 / MMBtu in November 2013 to $20.02 / MMBtu in December 2013.
A fuel price comparison based on equivalent energy content ($ / 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. Due to the significant increase in the price for natural gas, the spread between the Henry Hub and New York City natural gas prices climbed well above the price of Central Appalachian coal on a $ / MWh basis in December 2013.
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.