U.S. Energy Information Administration - EIA - Independent Statistics and Analysis
Electricity Monthly Update
With Data for June 2015 | Release Date: Aug. 26, 2015 | Next Release Date: Sep. 24, 2015
Resource Use: June 2015
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 0.9% compared to June 2014. At the regional level, the Southeast, Florida, and Texas saw net generation increase by 3.7%, 5.5%, and 2.0%, respectively. The Northeast and Mid-Atlantic regions both saw a decrease in net generation compared to last June, as most States in the Northeast experienced temperatures that were cooler than June 2014. Some Mid-Atlantic region states are warmers while others are cooler than last year. The net result is slightly lower demand for electricity. The Central and West regions both saw net generation stay relatively unchanged compared to last year, with the Central region only experiencing a 0.3% increase and the West region seeing a 0.1% decrease from the previous year.
Electricity generation from coal decreased in all regions of the country, except for the West, where coal generation increased by 4.1% compared to June 2014. Electricity generation from natural gas increased in all parts of the country, except for the Northeast, where cooler temperatures compared to the previous year decreased the demand for electricity.
Total electricity generation from nuclear in the U.S. was up 0.6% compared to the previous June. The only region that experienced a significant decrease in nuclear generation was the West, as the Columbia nuclear plant was offline for a refueling outage during June 2015. The Western region also experienced a significant decrease in hydroelectric generation compared to the previous year, with electricity generation from conventional hydroelectric generators decreasing by 32.5% due to well below average rainfall experienced during June 2015.
Fossil fuel consumption by region
The chart above compares coal consumption in June 2014 and June 2015 by region and shows that changes in coal consumption for electricity generation were similar to changes seen in electricity generation from coal.
The second tab compares natural gas consumption by region and shows that all regions of the country, except for the Northeast, saw an increase 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. In June 2015, the share of natural gas consumption increased in all regions of the country at the expense of coal consumption compared to the previous year.
The fourth tab presents the change in coal and natural gas consumption on an energy content basis by region. 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 average price of natural gas at Henry Hub decreased from the previous month, going from $2.91/MMBtu in May 2015 to $2.85/MMBtu in June 2015. The natural gas price for New York City (Transco Zone 6 NY) also saw a decrease from the previous month, going from $2.67/MMBtu in May 2015 to $2.38/MMBtu in June 2015.
The New York Harbor residual oil price decreased from the previous month, going from $10.18/MMBtu in May 2015 to $9.81/MMBtu in June 2015. Regardless, oil used as a fuel for electricity generation is almost always priced out of the market.
A fuel price comparison based on equivalent energy content ($/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. For the sixth consecutive month, the price of natural gas at Henry Hub was below the price of Central Appalachian coal on a $/MWh basis, and the spread between the two prices widened slightly due to the month-to-month decrease in the price of natural gas at Henry Hub. Likewise, the spread between the New York City gas price and the price of Central Appalachian coal also decreased compared to the previous month, also a result of a decrease in the natural gas price of New York City.
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.