Showing posts with label natural gas. Show all posts
Showing posts with label natural gas. Show all posts

Monday, March 31, 2014

President Obama to Reduce Methane Emissions

On Friday the Whitehouse announced that the President, will continue to fight against climate change using executive fiat. The next step for the White House climate plan, originally introduced in a speech at Georgetown University in June 2013, is an “interagency methane strategy.” Towards this goal, the Whitehouse is directing federal agencies to clamp down on emissions of methane, a greenhouse gas, though U.S. methane emissions have fallen 11% since 1990.
data from US EPA
According to the Intergovernmental Panel on Climate Change (IPCC), methane is more than 20 times as effective as CO2 at trapping heat in the atmosphere. If you recall it is the greenhouse effect that is expected to increase the sensitivity of the climate to carbon dioxide, methane and the other greenhouse gases. Though in its September 2013 report the IPCC eliminated attempts to estimate the “most likely” sensitivity of the climate to the expected manmade doubling of the carbon dioxide concentrations in the atmosphere because according to British climate scientist Nic Lewis “the best observational evidence indicates our climate is considerably less sensitive to greenhouse gases than climate scientists had previously thought.” All the climate models had failed to predict that for the last 15 years there has been essentially no net warming. Global Warming has been having what the IPCC calls a hiatus.

Over the last two hundred and fifty years, the concentration of methane in our atmosphere has increased by 151% to 1.8 parts per million. Methane is the primary component in natural gas, methane is emitted to the atmosphere during the production, processing, storage, transmission, and distribution of natural gas and because gas is often found alongside petroleum which is much more valuable, methane is sometimes vented to the atmosphere rather than captured during oil production. Methane is also produced from the decomposition of human and animal waste as well as garbage and is the major component of landfill gas. Methane is also released from the natural biological process of enteric fermentation which is fermentation that takes place in the digestive systems of animals. In particular, ruminant animals that have two stomachs and eat grasses (cattle, buffalo, sheep, goats, and camels) produce and release methane from the microbial fermentation that breaks down the grass and hay into soluble products that can be utilized by the animal. Also, when natural gas and other petroleum products are used as a fuel incomplete combustion releases traces of methane.


Methane emissions come from diverse sources and sectors of the economy, unevenly dispersed across the landscape and not well tracked. These uncertainties have resulted in estimates of current and projected methane emissions by simplified models and rules of thumb for the source of methane emissions. Nonetheless, the estimates below are the best available and the Administration has launched a methane mitigation plan.

The President’s Strategy to Reduce Methane Emissions targets reductions in methane emissions from landfills, coal mining, and agriculture, and oil and gas systems that include action on four fronts:

  1. Landfills: This summer, the EPA will propose regulation to reduce methane from new landfills and begin the process to tighten the methane standards for existing landfills.
  2. Coal Mines: In April 2014, the Department of the Interior, Bureau of Land Management will begin the process of developing a program for the capture and disposal of waste mine methane on lands leased by the Federal government. 
  3. Agriculture: In June 2014, in partnership with the dairy industry, the U. S. Department of Agriculture, the EPA and U.S. Department of Energy will jointly release a “Biogas Roadmap” outlining voluntary strategies to reduce U.S. dairy sector greenhouse gas emissions by 25 % by 2020. Maybe the administration will reduce the U.S. consumption of dairy products, beef, buffalo, sheep and goats and thus reduce the herds of rumens. 
  4. Oil and Gas: This spring EPA will assess potential sources of methane and other greenhouse gas emissions from the oil and gas industry and in the fall of 2014, EPA will determine how best to pursue further methane reductions from these sources. EPA is expected to develop additional regulations if necessary by the end of 2016. Later this year, the Bureau of Land Management will update the rules to reduce venting and flaring from oil and gas production on public lands. In addition the Administration will identify “downstream” methane reduction opportunities. Through the Natural Gas STAR program, EPA will work with the industry to expand voluntary efforts to reduce methane emissions.

One downstream area for reduction of methane is our natural gas distribution systems. In 2012 and 2013 two scientists mapped the gas leaks under Boston and Washington DC using a new, high-precision methane analyzer provided by Picarro installed in a GPS-equipped car. They found that there were approximately 4.3 leaks per mile of street in both cities. Levels of methane in the surface air on some streets exceeded 15 times the normal atmospheric background value.

For some time we have failed to maintain our unseen infrastructure systems as a way to cut costs. We have failed to maintain and upgrade the oil and gas distribution system. Gas distribution companies are well aware of the leaks in the system. The companies calculate the difference between the gas pumped into the distribution system and what is metered at the end user. This is referred to as "lost and unaccounted-for" gas is often a surcharge on customer bills. These leaks are wasteful, dangerous and a significant source of greenhouse gas released into the environment.

Distribution companies try to prioritize finding and fixing leaks likely to be explosion hazards, where gas is collecting and concentrating and ignore the small losses from deteriorating iron pipe and the deteriorating distribution system in our cities. Natural gas distribution leaks and explosions cause an average of 17 fatalities, 68 injuries, and $133 million in property damage each year, according to the U.S. Pipeline and Hazardous Materials Safety Administration. In 2010 a natural gas pipeline exploded in San Bruno, CA, just south of San Francisco. There was no warning and eight people were killed, 58 were injured and 38 homes, the entire section of a neighborhood, destroyed. In 2011, a leak from an 83-year-old cast-iron main in Allentown, Pa., caused an explosion that killed five people. And just last month a gas explosion killed eight people in East Harlem.

Detecting and reducing gas leaks are critical for reducing greenhouse gas emissions, improving air quality in cities and consumer safety, and ultimately saving future generations of consumers from loss of life, property and wasted money. Right now, repairing our infrastructure will be very expensive, but as the pipes that distribute gas (and the other essential utilities of water, sewer, and electricity) continue to age failure will become more frequent. Infrastructure is the foundation of our economy, connecting businesses, communities, and people, making us a first world country-we need to repair and maintain it.

Thursday, February 14, 2013

2011 U.S. Electrical Power Generation by Fuel


Last week when the Environmental Protection Agency, EPA released the second year of reported greenhouse gas emissions data from large sources they stated in their press release that “Power plants remain the largest stationary source of GHG emissions, with 2,221 million metric tons carbon dioxide equivalent (mmtCO2e), roughly one-third of total U.S. emissions. In 2011 emissions from this source were approximately 4.6 % below 2010 emissions, reflecting an ongoing increase in power generation from natural gas and renewable sources.”

 Many news sources published the press release verbatim. If the increase in renewables was due to the recent surge in construction of wind and solar power generation installations this could be just the beginning in the shrinking of the CO2e footprint of the U.S. electrical grid. A fuel change from coal to natural gas would also significantly reduce the CO2e footprint of electrical power.  I decide to take a hard look at the Electrical Generation Data available from theU.S. Energy Information Administration. The major uses of energy in the United States are heating of residential and commercial buildings (11%), industry (20%), transportation including cars, trucks, trains, planes and ships (27.4%), and electric power generation (40%). Clearly, changes in the makeup of the generating sectors would have a profound effect on the CO2e generation of the nation.
From the U.S. EIA Data

 Overall from 2010 to 2011 electrical power generated in the U.S. fell fractionally less than half a percentage point- 19.40 billion Kilowatt hours to 4,105.7 billion Kilowatt hours of power generated in 2011. Power generated from coal fell 113 billion Kilowatt hours to 1,743.3 billion Kilowatt hours. Power generated from natural gas rose 28.9 billion Kilowatt hours to 1016.6 billion Kilowatt hours. Nuclear power generation fell 16.8 billion Kilowatt hours to 790 billion Kilowatt hours. Hydroelectric power generation rose 64.9 billion Kilowatt hours. Wind generation rose 25 billion Kilowatt hours and solar generation rose 0.6 billion Kilowatt hours.

The big reduction in greenhouse gas emissions appears to be from the overall reduction in fossil fuel based power generation of 93.4 billion Kilowatt hours which also included a reduction in coal generation and an increase in natural gas generation that generates only 56% of the CO2e per Kilowatt hour of power as coal and the significant increase in hydroelectric power. Power generated from renewable sources increased 92.7 billion Kilowatt hours in 2011 over 2010 the largest portion of which is attributed to an increase in hydroelectric power generation.

Since it has been two generations since the U.S. has built large damns, it seems most likely that the increase in hydroelectric generation was due to the heavy rains in that year increasing hydroelectric generation. Unfortunately in the drought year of 2012 the amount of power generated by hydroelectric will fall and fossil fuel generation will have to make up the difference. There has been a permanent  increase in wind power generation capacity as newly built wind farms have been tied into the power grid. This is likely to continue to increase in the short run as long as building the wind farms are subsidized by the government and the expense of connecting the wind generation to the power grid is carried by the rate payers. 

  
The drop in fossil fuel generation from 2010 to 2011 is almost exactly equal to the increase in renewable power generation- primarily hydroelectric and wind. The U.S. use of electricity is fairly stable at this time. The overall reduction in fossil fuel generation accounts for half the reduction in CO2e the other half of the reduction of CO2e appears to be coming from the migration to natural gas.  A slight reduction in overall generation would account for the difference. While this is exciting news, I was surprised how big hydroelectric generation was overall. Also, we have not built any damns in over two generations so that the hydroelectric capacity is very dependent on how wet a year it is. In the past40 years hydroelectric power generation has fluctuated from a high of around 325-350 billion Kilowatt hours a year during the wet years of the mid 1980’s and 1990’s to the lows of 220-250 billion Kilowatt hours during the early 2000’s. Since, 2012 was a drought year, the CO2e of electrical generation in the U.S. will increase despite the growing importance of wind power generation from 1.34% of power generated in 2008 to 2.92% of power generated in 2011. 
Hydroelectric Generation vs total Electrical Generation 1949-2011

Thursday, April 19, 2012

EPA Regulates Air Releases from Fracked Wells

When natural gas is produced, some of the gas and other volatile substances present in the wells escapes. EPA released the first federal air rules for natural gaswells that are hydraulically fractured, specifically requiring operators of newfractured natural gas wells to use “green completion,” which is a series of technologies and practices to capture natural gas and other volatile substance that might otherwise escape the well during the completion period when the well transitioned from drilling through the completion string and fractured.

Much of the air pollution from fracked gas wells is vented when the well transitions from drilling to actual production, a multi-day process that involves running a pipe casing or a liner down the well to the production zone, and cementing it in place leaving perforations for flow. Once the completion string is in place, the final step is to fracture the well. Drilling requires large amounts of water to create a circulating mud that cools the bit and carries the rock cuttings out of the borehole. After drilling, the shale formation is then stimulated by hydro fracking, using 2-5 million gallons of water. For gas to flow out of the shale, all of the water not absorbed by the formation during fracking must be recovered and disposed of. Though less than 0.5% by volume, the proprietary chemicals represent 15,000 gallons in the waste water recovered from the typical hydro fracking job. The chemicals serve to increases the viscosity of the water to a gel-like consistency so that it can carry the propping agent (typically sand) into the fractures to hold them open so that the gas can flow.

The flowback fluid carries residual drilling muds, fracking fluid and gas. In many instances it is allowed to flow our of an open well and the fluid is placed in open ponds. The new rules will require this fluid to be captured by 2015, and flared before that. Open ponding of fracking fluids is eliminated. An earlier version of the rule limiting air pollution from gas wells would have required companies to install pollution-reducing equipment immediately after the rule was finalized, but in the final version there is a phase in period. Besides the new air pollution standards for oil and gas wells, the EPA also updated existing rules for natural gas processing plants, storage tanks and transmission lines.

According to the EPA , these new rules have received inter-agency feedback and provide industry flexibility as required under the recently signed Executive Order on Natural Gas Development. Agencies involved include the departments of Defense, Interior, Agriculture, Commerce, Health and Human Services, Transportation, Energy and Homeland Security, as well as the EPA, Council on Environmental Quality, Office of Science and Technology Policy, Office of Management and Budget, and National Economic Council.

Monday, January 23, 2012

Energy Consumption in the US 2010


According to the US Energy Information Administration, the statistics branch of the Department of Energy, the US used 98 quadrillion BTU last year. Energy sources are measured in different physical units depending on the type of energy source: barrels of oil, cubic feet of natural gas, tons of coal, kilowatt hours of electricity. In the United States, British thermal units (Btu), a measure of heat energy, is a commonly used unit for comparing different types of energy. In 2010, U.S. primary energy use equaled 98 quadrillion (=E15, or one thousand trillion) Btu. If it helps to visualize this any better, that is equivalent to about 2,471 Mtoe (million tons of oil equivalent) the energy measurement standard used by the International Energy Agency, IEA, the keeper of world statistics. In a world with seven billion people the United States is estimated to have 310 million people, about 4% of the world’s population, 7% of the land mass and use about 14% of the energy (depending on how fast China and India are growing since the world energy data is about two years old).

In the United States the US Energy Information Administration collects and reports the energy statistics in quadrillion BTUs and has recently reported the summary data for 2010. These statistics paint a picture of who we are today. The major energy sources in the United States are petroleum-gas and oil (37%), natural gas (25%), coal (21%), nuclear (9%), and renewable energy primarily biomass and hydro power generation (8%). The United States only produces about 75% of the energy we consume, the shortfall is imported petroleum. The major users are heating of residential and commercial buildings (11%), industry (20%), transportation including cars, trucks, trains, planes and ships (27.4%), and electric power generation (40%).

The slightly complicated chart above shows the types of fuel and the sector that consumes it. Looking at petroleum, you can see that it supplies 37% of our energy needs. Transportation, cars, trucks, trains, planes and ships, uses 71% of petroleum and that petroleum provides 94% of the total energy used in transportation. Industry uses 22% of the total petroleum consumed by the United States to supply 40% of the energy used by industry. Studying all the details of the chart tells you a lot about the United States in 2010. It will also allow you to understand the impact that policies, regulation and scientific advances might have on the country.

For example, 92% of coal mined in the United States is used to generate electricity, regulations like the EPA’s Mercury and Air Toxics Standards and the Cross-State Air Pollution Rule affecting electricity generation are likely to impact coal use, cost of electricity, mining and mining regions. In 2010, of the 1,085.3 million short tons of coal produced in the United States, about 7.5% was exported, so if the number of coal fired electrical plants is decreased, the demand for coal to produce electricity is reduced, the amount of coal mined in the United States will decrease, the number of coal miners and employees of coal companies will decrease, the trains transporting coal and their employees will not be necessary, and the cost of electricity will increase as the electrical power industry builds new generation plants burning other fuels.
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Some primary energy sources, such as nuclear and coal, are entirely used in one sector, electrical generation. Others, like natural gas and renewables, are more evenly distributed across sectors. Similarly, while transportation is almost entirely dependent on petroleum, electric power uses a variety of fuels. Because the United States is the world’s largest oil importer, it may seem surprising that it also exports about 2 million barrels a day of refined petroleum products. It seems were are also an excellent oil refiner on the easily accessed Gulf Coast. Petroleum is used primarily for gasoline for cars (55%), diesel for trucks and heating oil (23%), propane and liquefied petroleum gases used in homes and farms for cooking, heating, and jet fuel (9%). The five biggest sources of net crude oil imported to the United States in 2010 were: Canada (25%), Saudi Arabia (12%), Nigeria (11%), Venezuela (10%), Mexico (9%). Policy decisions about a future Keystone pipeline may change that in the future. U.S. crude oil imports grew rapidly from mid-20th century until the late 1970s, but fell sharply from 1979 to 1985 because of restructuring the economy (manufacturing as a component of the economy was reduced), conservation, and improved efficiency. After 1985, the upward trend resumed, peaking at 10.1 million barrels per day in 2005, and falling to 9.2 million barrels per day in 2010.

Natural gas is the source of 25% of the energy consumed in the United States and in 2010 was used almost equally for industry, electrical generations and residential and commercial heating. Most, but not all, of the natural gas consumed in the United States is produced in the United States. Some natural gas is imported to the United States in the older Keystone pipelines. Natural gas is also being shipped to the United States as liquefied natural gas (LNG). U.S. natural gas production and consumption were nearly in balance through 1986 though U.S. production of natural gas peaked in 1973. From 1986 to 2006 consumption of natural gas outpaced production, and imports rose. Then in 2006 U.S. production of natural gas began to increase as a result of the development of more efficient and cost effective hydraulic fracturing techniques. In 2010 natural gas production in the United States reached the highest recorded annual total since 1973. Regulation and control of hydraulic fracturing will impact the cost of natural gas production in the United States, the availability of gas and the environmental impact to our natural resources.

In truth I am an old time engineer who learned to look at the world with a slide rule (calculators were just coming in and thought to be cheating). Through numbers I understand the world, policies and see relationships.