Showing posts with label methane. Show all posts
Showing posts with label methane. Show all posts

Wednesday, April 20, 2016

Out of Reach Without Nuclear and Shale

  • US emissions reduction goals for 2025 could not be achieved without nuclear power and the fracking technology necessary to extract shale gas. 
  • Recent revisions by the EPA in its estimates of methane leaks from natural gas production and use do not negate the benefits of gas in reducing emissions.
In its lead editorial yesterday, the Washington Post took presidential candidate Bernie Sanders to task for his attacks on nuclear power and natural gas. The Post focused its critique on greenhouse gas emissions and the emissions trade-offs involved in substituting one form of energy for another. That speaks directly to one of the main reasons that Mr. Sanders' argument resonates with his supporters, but it ignores an even more basic problem. The energy contribution from shale and nuclear power is so large that if our goal is a reliable, low-emission energy mix that meets the future energy needs of the US economy, we simply cannot get there without them, at least not in any reasonable timeframe.

The pie chart below shows the current sources of US electricity in terms of the energy they generate, rather than their rated capacity. This is an important distinction, because the renewable electricity technologies that have been growing so rapidly--wind and solar--are variable and/or cyclical, generating only a fraction of their rated output over the course of any week, month, or year.


For example, replacing the output of a 2,000 megawatt (MW) nuclear power plant such as the Indian Point facility just north of New York City would require, not 2,000 MW of wind and solar power, but between 7,600 MW and 9,400 MW, based on the applicable capacity factors for such installations. Now scale that up to the whole country. With 99 nuclear reactors in operation, rated at a combined 98,700 MW, it would take at least 375,000 MW of new wind and solar power to displace them. As the Post's editorial points out, money spent replacing already zero-emission energy is money not spent replacing high-emitting sources.

At the rates at which wind and solar capacity were added last year, that build-out would require 24 years. That's in addition to the 36 years it would take to replace the current contribution of coal-fired power generation. It also ignores the fact that intermittent renewables require either expensive energy storage or fast-reacting backup generation to provide 24/7 reliability.

That brings us to natural gas, the main provider of back-up power for renewables, and the "fracking" (hydraulic fracturing) technology that accounts for half of US natural gas production. Fracking has transformed the US energy industry so dramatically that it is very hard to gauge the consequences of a national ban on it, even if such a policy could be enacted. Would natural gas production fall by a third to its level in 2005, when shale gas made up only around 5% of US supply, and would imports of LNG and pipeline gas from Canada ramp back up, correspondingly?

Or would production fall even farther? After all, one of the main factors behind the rapid growth of shale gas in the previous decade is that US conventional gas opportunities in places like the Gulf of Mexico were becoming scarcer and more expensive to develop than shale, which was higher-cost then than today. Either way, the constrained supply of affordable natural gas under a fracking ban would not support generating a third of US electricity from gas, vs. 20% in 2006. So we would either need even more renewables and storage--in addition to those displacing nuclear power--or, as Germany has found in pursuit of its phase-out of nuclear power, a substantial contribution from coal.

One of the primary reasons cited by Mr. Sanders and others for their opposition to shale gas, aside from overstated claims about water impacts, is the risk to the climate from associated methane leaks. Here he would seem to have some support from the US Environmental Protection Agency, which recently raised its estimates of methane leakage from natural gas systems.

Methane is a much more powerful greenhouse gas than carbon dioxide (CO2), so this is a source of serious concern. However, a detailed look at the updated EPA data does not support the contention of shale's critics that natural gas is ultimately as bad or worse for the climate than coal, a notion that has been strongly refuted by other studies.

The oil and gas industry has questioned the basis of the EPA's revisions, but for purposes of discussion let's assume that their new figures are more accurate than last year's EPA estimate, which showed US methane emissions from natural gas systems having fallen by 11% since 2005. On the new basis, the EPA estimates that in 2014 gas-related methane emissions were 20 million CO2-equivalent metric tons higher than their 2013 level on the old basis, for a year-on-year increase of more than 12%. This upward revision is nearly offset by the 15 million ton drop in methane emissions from coal mining since 2009, which was largely attributable to gas displacing coal in power generation.

In any case, the new data shows gas-related emissions essentially unchanged since 2005, despite the 44% increase in US natural gas production over that period. The key comparison is that the EPA's entire, updated estimate of methane emissions from natural gas in 2014, on a CO2-equivalent basis, is just 2.5% of total US greenhouse gas emission that year. In particular, it equates to less than half of the 360 million ton per year reduction in emissions from fossil fuel combustion in electric power generation since 2005--a reduction well over half of which the US Energy Information Administration attributed to the shift from gas to coal.

In other words, from the perspective of the greenhouse gas emissions of the entire US economy, our increased reliance on natural gas for power generation cannot be making matters worse, rather than better. That's a good thing, because as I've shown above, we simply can't install enough renewables, fast enough, to replace coal, nuclear power and shale gas at the same time.

What does all this tell us? Fundamentally, Mr. Sanders and others advocating that the US abandon both nuclear power and shale gas are mistaken or misinformed. We are many years away from being able to rely entirely on renewable energy sources and energy efficiency to run our economy. In the meantime, nuclear and shale are essential for the continuing decarbonization of US electricity, which is the linchpin of the plans behind the administration's pledge at last December's Paris Climate Conference to reduce US greenhouse gas emissions by 26-28% by 2025. That goal would be out of reach without them.

Thursday, November 13, 2014

How Good Is The New Emissions Deal with China?

  • President Obama's emissions deal with China sets an ambitious target for US CO2 cuts while leaving substantial headroom for emissions growth in China. 
  • It will likely compound his problems, domestically, but could have significant influence on upcoming international climate negotiations.
Only an event like Tuesday's agreement between President Obama and his Chinese counterpart to limit greenhouse gas emissions (GHG) from the two countries could top the unexpected scramble in the US Senate to pass a Keystone XL pipeline bill as the big energy story of the week. The significance of the climate deal is open to interpretation, from both international and US political perspectives. Before exploring those, we should examine its consequences.

The White House announced that in exchange for the US agreeing to reduce "net greenhouse gas emissions 26-28 percent below 2005 levels by 2025", China would undertake to cap its GHG emissions by "around 2030." It also announced plans to step up a number of cooperative efforts with China in this area, including joint R&D and a jointly funded public/private carbon capture and sequestration (CCS) project in China. What does all this mean in terms of US emissions?

We need to start with the 2012 baseline in which net US emissions were already nearly 11% below 2005 levels. The current Annual Energy Outlook of the US Energy Information Administration (EIA), assuming the laws and regulations in force at the time it was produced, projects that US energy-related CO2 emissions will increase by 236 million metric tons (MT) by 2025, compared to 2012, leaving us at roughly 7% under 2005. Emissions from transportation would shrink, while those from industry would rise as the US economy grows by an expected 2.4% per year.

As I understand it that EIA forecast doesn't include the emissions that the EPA's "Clean Power Plan" for existing power plants would be expected to save if fully implemented. EPA targets reducing CO2 emissions from the US electricity sector--accounting for 39% of net emissions in 2005--by 25% by 2020 and 30% by 2030, compared to 2005. That would shave around 460 million MT from the EIA figure for 2025, getting us to nearly 15% below 2005. The additional savings to reach 26% below 2005 are thus in the neighborhood of 700 million MT per year by 2025. To put that in perspective, it's equivalent to the 2012 CO2 emissions from combustion in the entire US industrial sector, and exceeds total emissions of methane from all sectors, including agriculture, oil & gas, and landfills.

So unless I've done my sums wrong, or misinterpreted the government's data, the US/China deal commits to reducing US emissions by as much again as we've cut since 2005--largely as a result of a weaker economy and the shale gas revolution--after banking the expected savings from the 2011 fuel economy regulations, energy efficiency programs and renewable energy incentives, and an EPA plan for the power sector that is certain to run into strong opposition in the new Congress. That seems pretty ambitious to me, although it falls short of the 40% reduction recently agreed by the EU for 2030.

It's harder to assess what China's side of the deal means in practical terms. Its 2012 emissions were estimated at nearly 10 billion MT/yr, having grown by 8%/yr since 2004 and by 6%/yr since 2009. At that rate, even if its emissions peaked in 2030, they could double before starting to decline. If China's emissions growth declined to just 2% per year, consistent with the lower rates of growth in coal consumption observed recently, by 2030 it could still add nearly 4 billion MT/yr--equivalent to the current emissions of the entire EU, and 5 times the incremental US cuts to which President Obama just agreed. The most recent projection of China's emissions from the EIA had them growing by 5 billion MT by 2030 but essentially plateauing thereafter.

This falls substantially short of what would be required to keep global emissions within the range that climate models predict would limit average global temperature increases to 2°C, compared to pre-industrial levels. However, it goes well beyond China's previous commitment on emissions intensity at Copenhagen in 2009.

Now consider how this deal looks from the standpoint of US politics. Voters just resoundingly handed undivided control of the legislative branch of government to the President's opposition. Republican office-holders and those who just voted for them are likely to regard it as an unwelcome commitment of the US by a lame-duck President to a promise that only his successors could fulfill. In the process, it hands China and other countries a point with which to prod future US administrations should they fall short of its goals. In exchange, he got President Xi Jinping to admit that China can't emit CO2 limitlessly, but can still do more or less what it may have been planning, anyway. It's hard to see this making things easier in Congress for the President's existing environmental agenda.

The deal looks better from the perspective of international environmental and climate policy circles in the lead-up to the Paris climate conference, "COP21", at the end of 2015. One lesson from the Kyoto Protocol is that to be meaningful a global climate agreement must have a strong commitment from the world's largest emitters of CO2 and other GHGs. China and the US are the two biggest emitters, and the EU at #3 is effectively pre-committed. Together these three blocs account for over half of all emissions today. Having them on-side at the start raises the chances of reaching a  big agreement.

As others have observed, this deal makes it harder to argue against a global CO2 agreement based on China's relative inaction, while increasing pressure on other developing countries to agree to limit their own emissions. It also signals that despite political weakness at home, the White House will likely push for aggressive targets at COP21, setting up further conflict with Congress in the next election year. Finally, its timing is early enough to influence the negotiations but not so early as to permit close scrutiny of Chinese or US follow-through on its goals before the Paris talks begin.

Thursday, October 17, 2013

Study Sheds Light on the Environmental Impact of Shale Gas

  • The view that methane leaks render shale gas "worse than coal" has been further undermined by the release of a new study based on actual measurements at hundreds of gas wells.
  • Previous estimates of methane leakage relied on modeling or extrapolation from remote measurements. The University of Texas study addresses these shortcomings.
Since the late 1990s natural gas has been identified by both energy experts and environmentalists as a likely "bridge fuel" to facilitate the transition to cleaner energy sources. This view has recently been challenged by suggestions that methane leakage from natural gas systems--particularly from shale gas development--might be significant enough to negate the downstream climate benefits of switching to natural gas. The results of a new study from the University of Texas, sponsored by the Environmental Defense Fund (EDF) and nine energy companies, should alleviate many of those concerns.

In order to understand why indications of potential natural gas leakage rates well above the previously assumed level of around 1% would cast doubt on the environmental benefits of gas, a brief primer on greenhouse gases (GHGs) is necessary. When present in the atmosphere, these gases contribute to global warming by trapping infrared radiation that would otherwise be emitted to space. Carbon dioxide is the primary GHG implicated in climate change. It currently makes up roughly 400 parts per million (ppm)--equivalent to 0.04%--of earth's atmosphere and is increasing by around 2 ppm per year.

The main constituent of natural gas is methane. Although atmospheric concentrations of methane are much lower than that of CO2, totaling less than 2 ppm, pound for pound it is a much stronger GHG. Its "global warming potential" is 25 times higher than CO2's over a 100-year time horizon, and even higher on a shorter time span. While most atmospheric methane has been traced to natural or agricultural sources, a large increase in atmospheric methane from natural gas production could overwhelm the undisputed downstream emissions benefits of gas in  electricity generation, compared to coal.

Several academic studies raised precisely this concern with regard to natural gas produced from shale by hydraulic fracturing, or "fracking", starting with a widely-publicized paper from a professor at Cornell University in 2010. This work relied on estimates and limited data from early shale production to arrive at a conclusion that shale gas wells leak 3.6-7.9% of their cumulative output. A more recent series of studies from the National Oceanic and Atmospheric Administration (NOAA) and the University of Colorado Boulder used airborne remote sensing techniques to calculate leakage rates similar to Professor Howarth's.

Other studies from groups as diverse as IHS CERA, Carnegie Mellon University, and Worldwatch Institute and Deutsche Bank addressed the same question but arrived at much lower leakage rates and impacts. And earlier this year the US Environmental Protection Agency reduced its previous estimate of overall natural gas leakage to a figure equivalent to 1.7%.

However, until now all scientific studies of this issue--on both sides--were based on limited data, or on indirect measurements obtained at a significant distance from actual production sites. They relied heavily on assumptions about what was happening at large numbers of gas wells, in the absence of direct observations at these sites.

That's what makes the UT study so significant; it is based on a wealth of data from actual, on-site measurements at "190 production sites throughout the US, with access provide by nine participating energy companies." That translates to roughly 500 shale gas wells in different stages of development and production. 

Overall, for the segment of the gas lifecycle they investigated, the UT team found methane emissions that were lower than EPA's latest estimates.  Emissions from "completion flowbacks" were  98% lower, partially offset by somewhat higher observed leaks from valves and other equipment. Although this study did not measure emissions from the entire gas lifecycle, including pipelines, it would be very hard to reconcile their observed average leakage rate of 0.4% of gross gas production with leakage estimates as high as those embraced by many of shale's critics.

Immediate criticisms of this study also missed several crucial points. First, without the industry involvement that they characterized as a "fatal flaw", access on this scale for direct measurements at production sites--surely the gold standard for emissions studies compared to estimates based on assumption-laden models--would have been difficult or impossible to obtain. More importantly, they also ignored the fact that the principal sources of methane emissions found by the UT team involved valves and equipment by no means unique to shale development, many of which should be amenable to hardware improvements or different technology choices.

While the UT team and their sponsors at EDF stated clearly that more work needs to be done to measure methane emissions from other parts of the gas value chain, the current paper convincingly dispels the notion that the emissions from shale gas development are inherently much higher than those for gas produced from vertical wells in conventional oil and gas reservoirs. Since shale gas already accounts for over a third of US natural gas production and is widely expected to dominate future production, that result has large implications for the environmental benefits of further fuel switching and other applications for natural gas.

A different version of this posting was previously published on the website of Pacific Energy Development Corporation.

Tuesday, July 30, 2013

A First-Hand View of Fracking in Pennsylvania's Marcellus Shale

  • Producing shale gas requires drilling numerous wells, often in regions that have seen little or no oil & gas activity for decades. Addressing environmental and other community concerns is crucial to acceptance.
  • On a recent visit to a shale operation in Lycoming County, PA, I was impressed by the rigorous attention I saw to safety, spill prevention, soil conservation, and other impacts. 
It’s easy to talk about the shale gas revolution in the abstract and forget that it is the cumulative result of thousands of operations in locations across the country. It combines the technological marvel of precisely planned and executed drilling more than a mile below ground with the efforts of teams of skilled workers on the surface, and affects the surrounding community in many ways. Last month I had my first opportunity to visit one of these sites, near Williamsport in north-central Pennsylvania. I also saw several nearby sites in different stages of development. Although I was consistently impressed, I also tried to observe with the concerns of shale gas critics in mind.

Anadarko Williamsport 001Anadarko Williamsport 004

The Anadarko Petroleum well site, or “pad” that I toured is located in Cogan House Township in rural Lycoming County, atop the Marcellus shale formation. API arranged this site visit for bloggers and other media and paid for accommodations in Williamsport. Anadarko provided experts from its local engineering and public affairs staffs and hosted a dinner with members of the community the evening before the site tour. No one paid me to write about the visit, nor was there any expectation that I would report anything other than my candid, objective opinion of what I saw.

I’m no stranger to industrial sites or oil fields. I’ve also invested countless hours researching and discussing shale drilling and hydraulic fracturing. When it comes to complex technical subjects like this, however, no amount of reading or Youtube videos can substitute for seeing the real thing and being able to talk to the people actually doing the job about how it all works.

One example of that is safety. Safety plans, targets and slogans are important, but it carries more weight when the site engineer looks you in the eye and says emphatically in his own words, “The most important thing is that everyone goes home at night,” and then proceeds to explain the stop-work rules, the “red zones” that have to be clear of workers when the fracking pumps are running, and other aspects of onsite safety. We were constantly reminded to watch where we stepped and to make sure we had multiple points of contact with the ground whenever we looked at something or photographed it.

Concern for environmental impacts was similarly thorough. I consider surface spills a much bigger potential risk to groundwater than fracturing a layer of shale thousands of feet below any aquifer. The first thing I noticed at the site, all five wells of which had already been drilled and prepared for fracturing, was the floor. The entire pad was covered with a three-layer mat of black felt, HDPE plastic and fabric, to isolate any spills from the ground. The pad was also surrounded by a berm to contain any spills, which would promptly be vacuumed up by a waiting truck. They even vacuum up rainwater. Yet the real key to spill control is prevention, which in Anadarko’s case is reinforced by its “Eyes On” program. This requires an extra observer any time a liquid other than fresh water is being handled or transferred. Soil conservation efforts looked similarly scrupulous.

Another issue I asked about was noise. I couldn’t gauge it for myself, because aside from trucks delivering supplies the site was shut down during our visit. It’s not prudent to have untrained people wandering around when 30,000 HP of truck-mounted pumps are running, injecting fluids down a well at nearly 10,000 psi. When I inquired, I was told that the pumps themselves were loud, requiring ear protection nearby but not at the perimeter of the site. How far the sound carries beyond the site is a function of terrain, foliage and weather conditions.

Then there were the fluids themselves. An Anadarko engineer described the company’s approach to the five wells at this site as minimal and “green”. The fracking fluid was a simple “slickwater frac”. The main ingredients consisted of around 4 million gallons of water per well--much of it filtered and recycled from nearby gas wells--and 4-6 million pounds of sand, to prop open the fractures created by high-pressure water. The formula also includes a little hydrochloric acid for downhole cleanup, and two other ingredients: a low dose of “biocide” to prevent corrosion from bacterial growth in the well, and a friction reducer, without which significantly higher fracking pressure would be required. The details of the chemicals used at the pad will be available on the public disclosure site www.FracFocus.org once the wells are complete.

I also inquired about methane emissions during well completion. Some critics claim--incorrectly, per independent analysis--that such emissions, along with other leakage, negate the climate benefits of shale gas. Although I was told Anadarko wasn’t specifically employing “green completion” techniques at this site, it was taking steps to minimize emissions, starting with having the gas gathering pipeline ready to go. As each well is completed, it’s hooked up to production so no methane escapes. That maximizes revenue. The site also had a temporary flare to burn off any excess gas from operations before the well could be connected to the pipeline. That sounds wasteful but is environmentally preferable to venting gas.

Of course for all the precautions and evident best practices there’s no disguising that while it is being prepared, drilled, fractured and completed, each drilling site is a compact industrial operation and hub of activity. Numerous trucks carry water, sand, chemicals and equipment back and forth. Anadarko has improved over 200 miles of country roads to handle this traffic, while minimizing freshwater haulage by the use of water pipelines connecting its sites.

The consolation for the neighbors is that the entire process runs its course like any construction project. A few weeks or months of intense activity are followed by years of unobtrusive operation, during which gas flows into pipelines and royalties into the community. The employment and other local economic benefits this creates are significant, especially for communities that have lost many of the industries that sustained their economies in the past.

Anadarko well

Several of the participants at the dinner the evening before drew comparisons to wind turbines, which are much taller than the drilling rigs used for gas wells, and remain on-site for decades. That got me thinking about relative energy contributions. At Anadarko's estimated lifetime gas production (EUR) of 8 billion cubic feet each well could generate more than 1.1 billion kilowatt-hours (kWh) of electricity in an efficient gas-fired power plant. By comparison, a 1.5 MW wind turbine would normally generate less than 80 million kWh over 20 years. So when brought online the five wells on the one pad I visited will together produce energy equivalent to a wind farm of more than 70 turbines.

Even if the ultimate recoveries from these wells turned out to be closer to the lower figures estimated by third parties from the limited data available to them, compared to those used in Anadarko's calculations, it would still represent a very substantial energy yield for such a small site.

I came away from the tour with a strong impression of a well-trained and experienced team, focused on doing the job right — safely and with minimal impacts, because this is where they and their families live; the landowners from whom they lease their sites are their neighbors. And for all the truly impressive technology deployed, what really counts is the people using it.I can understand skepticism about the balance of risks and benefits from shale gas development--this is a skeptical age--but nothing I observed in Williamsport would validate such concerns. Instead, I saw a well-tuned operation that is a microcosm of the biggest US energy revolution of the last 40 years.

A different version of this posting was previously published on Energy Trends Insider.