U.S. Energy Information Administration - EIA - Independent Statistics and Analysis
Electricity Monthly Update
With Data for September 2014 | Release Date: Nov. 25, 2014 | Next Release Date: Dec. 23, 2014
Resource Use: September 2014
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 2014, net generation in the United States decreased 0.4% compared to the previous year. This decrease in electricity generation occurred because the country experienced slightly cooler temperatures in September 2014 compared to September 2013, due to lower demand for residential cooling, as evident in the 2.1% year-over-year decrease in U.S. population-weighted cooling degree days. At the region-level, the Northeast, MidAtlantic, Southeast, Florida, and West, all saw slight increases in electricity generation compared to September 2013, while the Central region and Texas saw a decrease in electricity generation.
Compared to the previous September, the only regions that saw an increase in electricity generation from coal were Florida and the West, with each seeing only small increases compared to last year. The MidAtlantic and Central saw considerable drops in coal generation compared to September 2013, while the Southeast and Texas only saw a slight decrease in electricity generation from coal. Texas and Central region saw decreases in natural gas generation. All other regions saw an increase in electricity generation from natural gas, with the MidAtlantic and Southeast regions seeing the largest percentage increases in natural gas generation compared to the previous year.
Total electricity generation from nuclear in the U.S. was up 2.6% compared to the previous September. For the fourth consecutive month, the Central region had the largest percentage increase in nuclear generation compared to the previous year. This occurred because the Fort Calhoun nuclear plant was offline in September 2013 (and Fort Calhoun nuclear plant had been offline since May 2011 due to damage caused by severe flooding). In September 2014, Fort Calhoun nuclear plant was operating at full capacity.
Fossil fuel consumption by region
The chart above shows that the change in total coal consumption mirrored the change in electricity generation from coal in each region.
The second tab compares natural gas consumption in September 2013 and September 2014 by region. This consumption pattern mirrored the change in electricity generation from natural gas, with the Central region having the largest percentage change in natural gas consumption for the third consecutive month.
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. The Central region was the only part of the country where coal showed a noticeable increase in the share of total fossil fuel consumption at the expense of natural gas. In the MidAtlantic and Southeast regions, natural gas increased its share of total fossil fuel consumption at the expense of coal, while in Florida, both coal and natural gas showed an increase in the share of total fossil fuel consumption at the expense of other fossil fuels.
The fourth tab presents the change in coal and natural gas consumption on an energy content basis between September 2013 and September 2014 by region. Once again, the changes in total coal and natural gas consumption were very similar to the changes 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 slightly from the previous month, going from $4.01 / MMBtu in August 2014 to $4.04 / MMBtu in September 2014. The natural gas price for New York City (Transco Zone 6 NY) decreased for the eight consecutive month, going from $2.50 / MMBtu in August 2014 to $2.30 / MMBtu in September 2014. Like many natural gas prices in the Northeast, the New York City natural gas price is now well below the price of natural gas at Henry Hub. This is mainly due to the growth of natural gas coming out of the Marcellus region and a slight increase in pipeline capacity to the Northeast.
For the second consecutive month, the New York Harbor residual oil price decreased from the previous month, going from $16.89 / MMBtu in August 2014 to $16.34 / MMBtu in September 2014. Regardless, oil used as a fuel for electricity generation is almost always priced out of the market.
A fuel price comparison based on equivalent energy content ($ / 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. The spread between the Henry Hub natural gas price and the price of Central Appalachian coal on a $ / MWh basis increased only slightly compared to last month. However, because of the continued decrease in the New York City natural gas price, the price of Central Appalachian coal on a $ / MWh basis continues to be higher than the New York City natural gas price.
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.