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The Environmental Case for Natural Gas and Renewable Energy

Highlights

  • With the right policies, renewable energy and natural gas can lead to an energy system with low environmental impacts.
  • Compared to coal, natural gas has lower CO2 emissions, air quality, and water impacts while renewable energy has lower environmental impacts than either coal or natural gas.
  • In the short term, natural gas can reduce emissions while renewables scale up.
  • In the long term, renewables can limit natural gas consumption to only that necessary to balance renewable intermittency.

NG and RE are Environmental Complements as Well

Part 1 of this analysis described how renewable energy and natural gas make good allies from a financial perspective. In short, high capital cost, low marginal cost renewables balance well with low capital cost, high marginal cost natural gas. Renewables provide a key hedge against natural gas price volatility while natural gas’ ability to dispatch enables higher levels of renewable energy.

In this second part of the analysis, I focus on how natural gas and renewable energy work well together from an environmental perspective.

Very simply, renewable energy and natural gas have better environmental profiles when compared to coal. Although renewable energy is better than natural gas environmentally, both lead to significant reductions in air emissions and power plant water withdrawals.

From a systemic perspective, the combined environmental attributes of a joint renewable energy and natural gas system are much higher than systems that are dominated by either type of energy individually.

Renewables Have No Significant Air Emissions

From an environmental perspective, wind and solar are probably the lowest impact energy sources available.

They do not emit any toxic air pollutants or greenhouse gasses during operation.

The absence of traditional air pollutants (SO2, NOx, mercury) is especially notable. By reducing these air pollutants, renewables from RPS policies provided $2.6-9.9 billion in health and environmental benefits in 2013 alone.

When accounting for upstream manufacturing, the median lifecycle greenhouse gas emissions of renewables are also minuscule compared to fossil fuel sources:

Renewables also have smaller variations in their lifecycle greenhouse gas profiles compared to natural gas, coal, or oil. Different plant efficiencies and upstream emissions for fossil fuels can lead to significant variations in lifecycle carbon intensity, posing distinct plant-level and upstream greenhouse gas management challenges for different countries.

Solar and Wind have Minimal Water Needs

Solar photovoltaics and wind are also great resources from a water perspective.

Traditional thermal power plants (coal, natural gas, and nuclear) with once-through cooling withdraw 20,000-60,000 gallons of water per MWh. In total, thermal power plant water withdrawals accounted for 161 billion gallons per day in 2010, 45% of total water withdrawals in the U.S.

Comparably, once built, solar PV and wind do not withdraw or consume water.

This has two major implications. First, thermal plants and hydro facilities can be heavily impacted by drought, which can reduce their output significantly and impact grid reliability. Second, thermal plants and hydro facilities can impact surrounding watersheds, aggravating the impacts of drought on both human and natural systems.

With climate change potentially worsening droughts worldwide, the drought resilience of solar and wind are valuable environmental attributes. State RPS policies, primary drivers of renewable energy growth to date, reduced power sector water withdrawals and consumption by 2% in 2013. Critically, the largest reductions occurred in California and Texas, especially water stressed regions.

Land Use Concerns Could Delay Renewable Growth

While very good on the air and water front, solar and wind do have distinct land use issues. Both energy sources require large amounts of land to produce electricity and their resources have regional constraints.

Wind projects frequently run into local opposition worried about the impact of the turbines on view sheds and property values. At its most extreme, this NIMBYism was responsible for more than a decade of challenges to the flagship offshore Cape Wind Project.

Utility-scale solar projects also face notable land use challenges. A recent study in the Proceedings of the National Academy of Science found that the majority of solar power plants in California were sited in natural environments and were close to protected areas.

Opponents of renewable energy often play up these land use issues while proponents often dismiss them. In reality, the situation is pretty straightforward – land use issues do not make renewable energy an unattractive energy source but they are legitimate concerns.

Better planning and community outreach  can address many land use challenges. Nevertheless, land issues can delay projects, increase project risk, and could become larger impediments to renewable energy growth if wind and solar continue to scale up rapidly.

Natural Gas Enables Greater Renewable Buildouts

Although land issues can delay renewables, they are not the main challenge with using wind and solar to green the power sector. Rather, the primary environmental challenge for solar and wind is the time it will take to build enough renewable energy to replace dirtier fuels.

As discussed in Part 1, the capital intensive nature of solar and wind make them less scalable than natural gas in the short term. Even in best case deployment scenarios, solar and wind will take years to fully replace coal.

In this context, there are three primary ways that natural gas can enhance the environmental benefits of using renewable energy: reducing coal generation in the short term as renewables are built out, balancing intermittency to allow more renewables to be used in the mid-term and beyond, and by pairing renewables with natural gas employing carbon capture in the long-term.

During the last several years, increased natural gas generation brought significant environmental benefits by reducing coal generation. Since the shale revolution began in the late-2000’s, coal generation has fallen as natural gas generation rose. This has brought significant environmental benefits, as discussed further below.

As the chart above indicates, natural gas is now passing coal as the primary electricity source in the U.S. Despite the recent rapid gains in wind and solar, their overall generation share remains low. Natural gas can quickly reduce air pollution and water impacts from coal during the next 10 years, buying time for renewables to grow to their full potential.

Natural gas can also play a critical role in balancing out the intermittency poised by wind and solar generation. While this balancing is a key factor behind the financial synergies of renewables and natural gas, it is also beneficial for their environmental synergies. Natural gas power plant dispatch is more flexible than coal or nuclear, so it can support higher levels of renewables than other types of grid configurations.

Finally, carbon capture can make natural gas a very low carbon power source. An electric system balanced between nuclear, hydro, solar, wind, and natural gas with carbon capture can provide an optimal low-cost, reliable system with very limited climate or environmental impacts.

Natural Gas has Moderate Environmental Impacts

Although renewable energy is better, natural gas still has an attractive environmental profile compared to coal.

Perhaps the most heralded environmental characteristic of natural gas is its lower carbon emissions compared to coal. On an energy basis (per MMBtu), natural gas is 43% less carbon intensive than coal.

Moreover, most natural gas is burned in power plants that use efficient combined cycle technology. On an electricity generation basis (per MWh), natural gas combined cycle power plants can thus be around 57% less carbon intensive compared to existing coal plants. This lower carbon intensity explains the major role natural gas has played in the U.S. reducing power sector carbon emissions more than 15% since 2005.

While the carbon benefits of natural gas get the most attention, the air pollution benefits compared to coal are potentially more important. Natural gas facilities emit negligible amounts of SO2, particulate matter, and mercury. Although natural gas power plants do still emit NOx, they emit significantly less than coal plants.

Coal plants face increasingly stringent environmental regulations due to their air pollution. Low natural gas prices have led to coal plants retiring instead of retrofitting with pollution controls (which still have notable emission levels).

The U.S. is now reaching decade lows in NOx and SO2 emissions. Low natural gas prices played a critical role in achieving power sector reductions since 2008. One estimate found that natural gas alone was responsible for reducing SO2 and NOx emissions in the power sector by 40-44% in the last decade.

Water Impacts Better than other Thermal Power Plants

At the power plant, natural gas is also good on the water front.

When using similar cooling technologies, natural gas withdraws and consumes less water than coal or nuclear. However, the timing of the natural gas build out in the United States has led to very different cooling technology properties for the natural gas fleet.

Almost all nuclear and coal power plants in the U.S. were built decades ago, meaning they primarily use water withdrawal-intensive once-through cooling. Most existing natural gas combined cycle capacity has been built since the 1990’s when recirculating cooling technology became more widely used. As a result, most natural gas power plants withdraw a fraction of the amount of water that nuclear or coal units do, with similar consumption levels.

More importantly, natural gas power plants are still being built in the U.S. – these new builds are able to take advantage of dry or hybrid cooling technologies which virtually eliminate water withdrawals and consumption. These systems do bring efficiency penalties, but are ideal in drought-prone areas like Texas.

Upstream Impacts are Major Environmental Question for Natural Gas

While the air quality and water impacts at the power plant level are limited, the upstream environmental impacts of natural gas are potentially troubling.

Hydraulic fracturing, now responsible for the majority of U.S. natural gas production, is a water intensive process. It has caused competition for water resources in water-stressed regions. In Oklahoma, the use of waste water injection wells has also caused a significant increase in earthquakes.

This water usage intensity leads to water quality concerns. A major study by EPA on the water impacts of hydraulic fracturing recently found no evidence “widespread, systemic impacts on drinking water resources in the United States.” However, its Science Advisory Board has since questioned that conclusion, noting contradictions between high level findings and the body of the report, as well as challenges from a distinct lack of data.

These are major issues that need more scientific study to fully understand their severity and, importantly, how policy can be used to mitigate their impact.

Methane Leakage is a Key Uncertainty

Perhaps no area is more contentious in the debate about the sustainable use of natural gas than methane leakage.

As methane is a stronger greenhouse gas that carbon dioxide, relatively small leaks in natural gas infrastructure hurt the lifecycle carbon benefits of natural gas over coal. The best meta-analysis of these numbers to date, however, indicate that leakage is not high enough to completely eliminate the climate benefits of natural gas compared to coal, particularly over long time scales.

Indeed, the relative youth of the U.S. natural gas fleet compared to the coal fleet impacts the equation. Inefficient coal units are being replaced by very efficient natural gas combined cycles. This reduces the negative impacts of methane leakage on natural gas lifecycle emissions greatly.

Nevertheless, methane leakage is an environmental issue that needs to be addressed. Well-designed regulations can reduce leakage while minimizing impact to industry.

Longer term, carbon capture for natural gas can reduce lifecycle emissions of natural gas significantly, minimizing the importance of leakage. At leakage rates of 1-3% (likely levels following leakage regulation), carbon capture can reduce lifecycle greenhouse gas emissions of natural gas by 56-70%.

Renewables Limit Natural Gas Consumption

In conclusion, key environmental characteristics make grid systems with a mix of renewable energy and natural gas ideal. In the short term, natural gas generation can quickly ramp up to replace coal use, driving reductions in CO2 emissions, plant-level water impacts, and toxic air pollution.

Long term, solar and wind can grow into roles as dominant energy sources, virtually eliminating many environmental impacts in the process.

The long term replacement pattern that this puts forth likely means that the environmental negatives for natural gas should have increasingly lower effects over time, as consumption decreases.

For more information:

  1. The following publications from NREL and JISEA have a more in-depth look at many of the issues present here: http://www.nrel.gov/docs/fy13osti/56324.pdfhttp://www.nrel.gov/docs/fy15osti/63904.pdf
  2. An in-depth report focusing on water consumption at power plants: http://www.ucsusa.org/sites/default/files/attach/2014/08/ew3-freshwater-use-by-us-power-plants.pdf
  3. An overview of how to address renewable intermittency issues: http://www.nrel.gov/docs/fy13osti/60451.pdf
Alex Gilbert's picture

Thank Alex for the Post!

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Discussions

Bruce McFarling's picture
Bruce McFarling on February 19, 2016

So “in the long term” we can commit suicide more slowly, rather than more rapidly.

Unless the natural gas has effective CCS, it does not qualify as a long term solution.

 

Bob Meinetz's picture
Bob Meinetz on February 20, 2016

Alex, the idea that fossil fuel interests will close up shop when renewables meet some arbitrary, imagined level of market penetration is so simple-minded it defies comprehension.

What’s playing out in 2016 is exactly the opposite: renewables are the smiley-faced ‘bridge fuel” permitting gasoline to be replaced by natural-gas electricity to power electric cars; permitting nuclear electricity to be replaced with natural gas electricity to light homes and soccer stadiums; permitting natural gas to continue to be burned for just about everything else.

That arrangement might be profitable for Exxon-Mobil in 2016. Because it will result in changes to the earth’s climate through 102,016, however, it’s not really an option.

Clayton Handleman's picture
Clayton Handleman on February 20, 2016

Alex, your posts are a great addition to TEC community.  You are bringing fresh, current and highly visual data.  This can only serve to enrich the conversation.

Clayton Handleman's picture
Clayton Handleman on February 20, 2016

Is there no level of carbon emissions that natural systems can absorb? 

With 140m turbines bringing higher CF, decorrelated wind, HVDC offering a way to efficientily aggregate solar with the wind and over multiple timezones and likely massive deployment of EVs offering flexibility in load shifting it appears that a primarily renewable grid could be developed that used small amounts of NG to address intermittency in the relatively rare circumstances when other sources are not available. 

Do you feel that there are no reasonable scenarios that anthropogenic natural gas could be used to cover remaining intermittency while rendering emissions sufficiently small to avoid climate catastrophe?   

 

Engineer- Poet's picture
Engineer- Poet on February 20, 2016

Is there no level of carbon emissions that natural systems can absorb?

In the short term, no.  Bill McKibben is almost certainly correct that we need to cut atmospheric CO2 levels to 350 ppm, possibly lower.  This requires negative emissions for some time.

With 140m turbines bringing higher CF, decorrelated wind, HVDC offering a way to efficientily aggregate solar with the wind and over multiple timezones and likely massive deployment of EVs offering flexibility in load shifting

There’s the “Gish gallop” again, throwing out a host of different things as “fixes” without a single fact in evidence to prove that they’d actually work.  One of them, EV batteries, would require a massive build-out which would itself be resource (and CO2) intensive until the completed system at last de-carbonized the energy system as a whole… assuming it could actually do so.

Know what EV batteries would be really good for?  Buffering the minute-by-minute grid fluctuations that current nuclear plants don’t track well.  But to make enough batteries to handle demand for just one day would take more than 200 Gigafactory-years of output.

Do you feel that there are no reasonable scenarios that anthropogenic natural gas could be used to cover remaining intermittency

Anthropogenic “natural” gas (an oxymoron) typically comes from biomass, and the biomass resource is far too small to deal with a problem of this size.

Engineer- Poet's picture
Engineer- Poet on February 20, 2016

Once again, we get a piece demonstrating that Green is a front for the natural-gas industry.  The actual zero-emission option doing the heavy lifting gets short shrift in this “analysis”:

Traditional thermal power plants (coal, natural gas, and nuclear) with once-through cooling withdraw 20,000-60,000 gallons of water per MWh.

Here’s a propaganda scare tactic.  The water is withdrawn, and then put back… the omission making a mountain out of a molehill.

Natural gas power plant dispatch is more flexible than coal or nuclear, so it can support higher levels of renewables

Whereas an all-nuclear baseload scheme with some combination of storage, renewables and combustion for the remainder would have far lower CO2 emissions.  Mr. Gilbert seems to think that renewables are an end rather than a means.  Who benefits from this confusion?  Natural gas interests do.

Who provides the financing for the Spark Library, Mr. Gilbert?  Who provides your grants, who buys your reports?  What strings are attached to this money, if any?

Bob Meinetz's picture
Bob Meinetz on February 20, 2016

EP, EBW Analytics, Alex’s former employer, coined the term “Shale Revolution” and boasts:

The depth of EBW’s knowledge regarding each facet of the natural gas and power markets is invaluable and unrivaled.

Not a word about emissions anywhere on their site. The “Spark Library” is no doubt devoted to increasing its clients’ spark spread – the gross margin available to a gas utility to sell a unit of energy after buying the gas required to generate that energy.

Meh. Any perceived “green” in Alex’s report is a charade.

Alex Gilbert's picture
Alex Gilbert on February 20, 2016

Engineer-Poet, you raise several important substantive points.

When it comes to measuring power plant water’s usage there are two major metrics: water withdrawals and water consumption. Both have different implications. Thermal power plants do withdraw a lot more water than they actually consume. They need significant volumes of water to operate and when there are water shortages, the need for water withdrawals can limit a plant’s output. This is particularly worrisome in drought-prone regions, such as the western United States.

It also matters where the water is withdrawn from – the data is sketchy but power plants can and do withdraw water from groundwater resources, which can contribute aquifer depletion. The process of withdrawing water and the higher temperatures that the water has after the plant releases it can have major local environmental impacts on aquatic ecosystems. Reducing these withdrawals through using renewables or power plants with less water intensive cooling technologies is one of the key ways to mitigate impacts from the electricity-water nexus.

We also did not address nuclear power in detail in this piece – our focus was on specifically examining how renewable energy and natural gas can work together to achieve environmental goals. Unlike nuclear energy, at least in the United States, renewable energy and natural gas are poised to significantly increase their generation shares. Nuclear certainly does have valuable environmental attributes. However, it is not as good as natural gas in balancing renewable intermittency. Storage is promising but unproven at scale. In the short term, natural gas can allow quicker integration of wind and solar.

I would agreee that renewables are not an end in and of themselves – just like any energy resource, it should be judged on the basis of the economic, social, and environmental pros and cons. Having established the major environmental benefits of renewables in the article, it follows that actions that maximize renewables minimizes the environmental impacts of energy systems.

As for your concerns about potential bias: Spark Library is our self-funded startup. We are developing software to make it easier and quicker to conduct high quality energy research and analysis. Our market is very broad and is not focused on any one industry. We do not answer to anyone and stridently believe in being objective, transparent, and thorough when writing articles like these.

Alex Gilbert's picture
Alex Gilbert on February 20, 2016

Clayton, thanks for the feedback and the welcome to the community! We are very excited to continue providing this type of analysis and are glad that you find it helpful. If there are any specific issues you think we are well suited to assess, please let us know.

Alex Gilbert's picture
Alex Gilbert on February 20, 2016

Thanks for the comments Bob.

This piece was focused on how the conceptual environmental profiles of renewables and natural gas complement eachother, as opposed to focusing on how policies can work to maximize these benefits. Transitioning our energy system to a low cost, low carbon system will be a policy and technical challenge, particularly as there are many stakeholders will be effected. Both renewables and natural gas can play major roles in reaching this system – the challenge is figuring out how to create the right policy and regulatory systems to achieve these outcomes.

Alex Gilbert's picture
Alex Gilbert on February 20, 2016

Good point about CCS, Bruce. We need to reduce carbon emissions as much as possible as quickly as possible. In the short term, natural gas can achieve massive CO2 reductions as renewables begin to scale. Longer term, CCS is probably the only way to be able to use large amounts of natural gas.

Joe Deely's picture
Joe Deely on February 20, 2016

Alex,

As Clayton said – your writings add a solid new voice to this forum. Love the background data and links that you provide. Keep up the good work and hope to see many more of your SparkLibrary articles here in the future.

Natural Gas and Renewables as a combination are currently the only viable choice to help move coal to 10% of total electricity generation by 2030 and continue to substantially lower CO2 emission from electricity generation. 

Would love to see you explore some of these issues on a regional market basis. (Western US, PJM, Southeast, ERCOT etc…)

Robert Hargraves's picture
Robert Hargraves on February 21, 2016

You nicely point out the CO2 emissions of natural gas

and write about NGCC turbines, but are not most gas turbines built for renewables support the high-emission NGCT turbines? EPA’s original draft regulations (now replaced by the vague clean power plan) limited emissions to 454 g CO2e/kWh. Was it the “greens” who realized this would kill natural gas backup foo solar and wind?

Why not include nuclear power in the analysis? This article follows the “Crest” marketing philosophy. The customer tries to decide whether to buy Crest Mint or Crest Whitening (ignoring Colgate) toothpaste. 

Why, indeed, is there no CCS for natural gas? It’s certainly easier than CCS for coal. Is it impractical at any price?

Bob Meinetz's picture
Bob Meinetz on February 21, 2016

Alex, I have to admit I have no idea what a “conceptual environmental profile” is, and with my Substance Detector still reading “0” (I just replaced the batteries) my best guess is it’s the latest flavor of fossil fuel marketing gobbledy-gook.

The smartest minds on the environment have weighed in, and the verdict is that any “low carbon system” which still relies on emitting carbon which last graced our ecosphere during the the time of the dinosaurs, when the world was 21F hotter than it is today, is not remotely good enough. That all of it must be left underground or we risk changes to climate lasting 100,000 years, and a mass extinction rivaling the Permian-Triassic Event which laid waste to 70% of all species alive 65 million years ago.

With that prediction firmly based in available science, you can understand why any scenario which prolongs reliance on fossil fuels – any at all – might come across as grossly ignorant, grossly irresponsible, or both. Can’t you?

Bob Meinetz's picture
Bob Meinetz on February 21, 2016

Alex, I live roughly 20 miles from Sempra Energy’s Aliso Canyon methane leak in California, which in five months negated the benefits of an entire year’s worth of our state’s renewables generation.

If Sempra can’t even keep valuable methane stored underground, how does the conceptual environmental profile of CCS fit with an environmentally-responsible one?

Bob Meinetz's picture
Bob Meinetz on February 21, 2016

Joe, the conceptual environmental profile you’re exploring with Alex might have regional market issues applicable to Clean Coal as well, as solar/wind entrpreneurs go seeking venture capital with their stock prices in the toilet.

Many warm/fuzzy potentialities available.

Engineer- Poet's picture
Engineer- Poet on February 21, 2016

When it comes to measuring power plant water’s usage there are two major metrics: water withdrawals and water consumption.

But of course, only the former receives a mention in your analysis, and the fact that the oceans will never run out of water is also omitted.  I guess the fact that this is a convenient scary-sounding club with which to beat thermal power plants is just a coincidence.

About your open-cycle gas turbine plants which are required to track the variations of renewables.  At 670 gCO2(e)/kWh, how many hours of operation before the heat trapped by their emitted CO2 causes more net evaporation from lakes, rivers and aquifers than the water consumed by an otherwise non-emitting thermal powerplant?

The leak in the Porter Ranch gas-storage field was estimated at up to 50 metric tons per hour.  At a 20-year equivalent of 72 times the strength of CO2, this was equivalent to emitting 3600 tons of CO2 per hour.  That’s roughly the emissions from 3.6-4 GW of coal-fired powerplants.  How can natural gas be enviro-friendly when such leaks are inevitable, if not on such a large scale?

The process of withdrawing water and the higher temperatures that the water has after the plant releases it can have major local environmental impacts on aquatic ecosystems.

Apparently, fish love the warmer water during winter weather and their growth is accelerated.

Reducing these withdrawals through using renewables or power plants with less water intensive cooling technologies is one of the key ways to mitigate impacts

You assume that this is actually desirable.  The warmer water on lakes Erie, Michigan and Huron from NPPs is likely to have beneficial effects on fish during cold weather.

our focus was on specifically examining how renewable energy and natural gas can work together to achieve environmental goals.

Those goals are not specified.  At 670 gCO2(e)/kWh, how much natural gas consumption can you allow and still meet those goals?  How much expense and embodied energy (with the associated CO2 emissions) is required to match the performance of other non-emitting base load technologies?

I’ve recently seen an estimate of the social cost of CO2 at $220/metric ton.  That’s 22¢/kg, or 14.7¢/kWh at the 670 gram figure.  How much can you even afford if that cost must be internalized?

Having established the major environmental benefits of renewables in the article

No, you assumed them.

it follows that actions that maximize renewables minimizes the environmental impacts of energy systems.

I’m afraid it does not follow.  It is an article of faith among Greens that nuclear power must go to make room for the unreliable sources dubbed “renewables”.  But those unreliable sources require backup from GHG-emitting sources, and mining and drilling to feed them.  Neither the production nor use of fossil fuels are low-impact activities.

Suppose for the sake of argument that you can manage 50% of electric generation from wind and solar.  This leaves 50% to come from your OCGTs at 670 gCO2/kWh, or 335 gCO2/kWh average.  This is multiples of the per-kWh emissions in France or Sweden and substantially greater than the average for Canada.  Canada’s most populous province gets a large majority of its electric power from nuclear and hydro, both non-emitting sources.  Exactly what “environmental benefits” would you gain from replacing nuclear power in these areas with wind, solar and natural gas?  That is something I’d really like to know.

Clayton Handleman's picture
Clayton Handleman on February 21, 2016

“Suppose for the sake of argument that you can manage 50% of electric generation from wind and solar. 

Your strawman 50% renewable energy is a good one “for the sake of argument” but not much else. 

Great Plains Wind (GPW) alone offers 65% CF wind using 140m towers (already deployed in Europe) and >50% with current US technology.  But of course, any high penetration scenario would also utilize solar (20 – 25% CF) which is highly decorrellated with GPW as well as geographically diversified wind power which also is highly decorrelated.  The US gets about 10% of its power from hydro which is dispatchable, 20% from nuclear which provides baseload.  EVs are highly symbiotic with GPW and can therefore smooth the night generation peak if EVs reach high penetrations (appearing far more probable than massive deployment of nuclear).  That doesn’t leave a lot for the Natural Gas if its primary job is to manage intermittency.  Further the ability to predict renewable generation 24 hours ahead is getting quite good so dispatching the natural gas power is quite managable.

 

 

Alex Gilbert's picture
Alex Gilbert on February 21, 2016

Hi Joe,

Thanks for the additional feedback and happy to hear the links are helpful.

We were just thinking about doing several pieces with a more regional focus. We’ll go ahead and put this on our editorial calendar and should have something ready in a few weeks.

Alex Gilbert's picture
Alex Gilbert on February 21, 2016

Robert, thanks for your questions and the opportunity to explore a few things.

The difference in emissions between NGCCs and NGCTs is definitely important to keep in mind. I would disagre that most gas turbines are built to balance renewables. In a transmission constrained region for small utilities, this indeed could be the case. However, most of the country now has competitive wholesale markets. In these markets, renewables intermittency is expressed through wholesale prices – more renewables lowers the price, while higher renewables increase the price. Forecasting has made it easier to predict these price impacts, and natural gas facilities are well suited to changing output to capture price changes. There may be differences depending on the specific plant and year, but CTs and CCs can both be dispatched more quickly than other resources on the grid. So a lot of renewable intermittency is being balanced by CCs, with lower environmental impacts. Carbon pricing can further incentivize the use of CCs over CTs.

The capacity changes in the country indicate how CCs are becoming the dominant technology. Since 2010, around 35 GW of new natural gas CCs have been built while only 12 GW of new natural gas CTs/STs have been built. However, when you include retirements, the capacity of NG CTs/STs has actually been decreasing – one of the less told stories of the last several years are the large retirements of the least efficient CTs/STs.

It is true that we did not include nuclear in this analysis – nor did we include biomass, hydro, geothermal, coal, or oil. The environmental attributes of every technology are important considerations in developing a low environmental impact system. Our goal with this set of articles was to examine how the financial and environmental profiles of solar, wind, and natural gas interact. These three resources have grown significantly in recent years, unlike nuclear or hydro which have been flat. Understanding their characteristics, and how they interact, is critical to developing policies to guide our future energy development. In the future, we plan on examining nuclear’s critical role in the grid, its difficulties in getting new facilities built, and the potential for innovation to unlock a larger role for nuclear, so stay tuned.

The reason that very few companies have tried to develop carbon capture for natural gas is that it did not make sense until recently. Even five years ago, before the shale revolution, natural gas prices were very high – at $10/MMBtu or more, a natural gas CCS facility would be much more expensive than coal CCS. The low prices resulting from the shale revolution have changed the equation significantly. Even with its significant price volatility, a natural gas CCS facility at current prices would be cost competitive with many power sources. New research, development, and demonstration take time – luckily, there are signs that the federal government is beginning to focus on natural gas CCS as opposed to just coal CCS and that some companies are exploring new technologies. As with any technological development, its future is uncertain but the potential emissions reductions are significant.

Clayton Handleman's picture
Clayton Handleman on February 22, 2016

“But to make enough batteries to handle demand for just one day would take more than 200 Gigafactory-years of output.”

Anonymous commenter Engineer Poet, your strawman is pretty weak. 

“One day”, that appears pretty arbitrary which, I assume, is why you didn’t include references to support it.  It is quite a reach to assume that, for an entire day, the sun will stop shining, wind will be stilled across the nation and out at sea, no nuclear power plants will be built and the existing ones will be shut down and all the lakes will dry up so there is no hydro.  I.e. the whole generation system shuts down for a day.  Further it would appear that you are assuming that all NG peaking plants, diesel backup generators and the like have been taken offline.  All pumped storage is gone, no additional has been built.  And, further you appear to be assuming that under the bizaar circumstances that created this scenario, people would still be showing up to work and using the same amount of electricity that they always do. 

This outlier strawman appears designed to show the implausibility of EV traction batteries playing a dominant or even significant role in grid storage. 

1 Giga Factory Year (GFY) = 50GWhr of storage and is the planned output of the Giga Factory currently under construction.  Is 200 GFY an unattainable or implausible number?

1 GF produces enough batteries for 500,000 cars at 100kwhr each.  The US population buys about 17,000,000 cars and light trucks.  So at high penetrations lets say we see 10,000,000 / year fleet electrification.  20 GFs are needed to produce the batteries for those cars.  So in 10 years we would hit cumulative production of 200 GFY.  That is of a scale well within the capability of todays society. 

Now of course you will argue, the batteries degrade.  That is true but in non traction settings they don’t need to hold full charge to be valuable.  There likely will be a large aftermarket in using degraded EV batteries for grid storage.  Most of the time these would be used for short term management which is pretty easy on the batteries.  So they would have a long second life in this application.   

You have pointed to a great deal of urgency as per McKibbon.  If this is taken to heart we would need to eleminate all carbon from driving passenger vehcles.  That would nearly double the production of batteries getting us to high levels of storage even faster. 

This myth appears to be Busted

 

 

 

 

 

Alex Gilbert's picture
Alex Gilbert on February 21, 2016

Respectfully, we actually did discuss water consumption during several points in our article.

  • Comparably, once built, solar PV and wind do not withdraw or consume water.”
  •  State RPS policies, primary drivers of renewable energy growth to date, reduced power sector water withdrawals and consumption by 2% in 2013.”
  • “When using similar cooling technologies, natural gas withdraws and consumes less water than coal or nuclear.”
  • As a result, most natural gas power plants withdraw a fraction of the amount of water that nuclear or coal units do, with similar consumption levels.”
  • “More importantly, natural gas power plants are still being built in the U.S. – these new builds are able to take advantage of dry or hybrid cooling technologies which virtually eliminate water withdrawals and consumption.”

I would disagree with your comments that warmer waters are actually desirable, as I believe would most ecologists. If you would like to find out more about thermal power plants and how both water withdrawals and consumption are important, I would suggest the following publications, one by DOE and one by UCS:

The Porter ranch leak is an environmental catastrophe that highlights the importance of increased regulations on the industry. However, the negative climate impacts from this leak, which is now sealed, pale in comparison to the 35 GW of coal fired power plants that have permanently closed in the last five years, with natural gas playing a key role in making them uneconomic.

Nowhere in this article did we contend that nuclear must make room for renewables or natural gas. In fact, our discussion of natural gas primarily focused on its environmental benefits compared to coal, the primary energy source that it is replacing. Nuclear has played a central role in the grid and will continue to do so. However, some existing plants are not economic while new plants are very difficult to build due to their near guarantee of cost overruns. These are very complex issues that we did not focus on in this piece, because it would be impossible to fully do them justice in anything less than a similar length analysis.

Alex Gilbert's picture
Alex Gilbert on February 21, 2016

Its apparent that we agree that we need to reduce emissions as quickly as possible. Ideally, we would have a zero carbon system tomorrow, but thats just not possible. We need time to transition things, including:

  • Building solar
  • Building wind
  • Taking advantage of hydro where still possible
  • Researching enhanced geothermal systems, tidal power, biomass, fusion, and other new fuels.
  • Improving storage technology through research and deployment.
  • Figuring out whether its possible to build a nuclear plant cheaply.
  • Developing carbon capture technologies for not just the power sector but the industrial sector as well.

All of these could be fantastic long term solutions that can achieve a zero carbon system, but many have significant uncertainties. We can reduce emissions massively right now, and indeed we are, by replacing coal with natural gas. It does not make sense to have a zero carbon system in 50-100 years but continue to emit massively now. As an aside, it is also wrong to continue to use coal, which is causing significant air pollution deaths, if we could replace it with natural gas now.

There is also confusion between fossil fuels and CO2 emissions. The two are closely related but not identical. Carbon intensity of fuel sources matter, which is why natural gas is favorable compared to coal or oil. So does the fact that carbon capture technologies, some of which have existed for decades, could negate almost all emissions from using fossil fuels at a power plant or factory.

Alex Gilbert's picture
Alex Gilbert on February 21, 2016

The Aliso Canyon leak is an absolute environmental disaster. The only potential bright side (if it can be even called that) is that it can hopefully increase the urgency to address methane leakage from natural gas infrastructure both at the state and federal levels.

Leakage of stored CO2 is an interesting question that needs to be more fully explored. So far, initial research shows that stored CO2 in the North Sea has stayed put, while a significant amount if it in other locations has been shown to turn to rock within several years of being stored. A lot more research is needed to better understand the potential leakage and the risks of geological sequestration. Measurement and verification methods are certainly needed. While leaks would absolutely need to be minimized, CO2 is a much less potent greenhouse gas than CH4 – relatively small 1-3% leaks of CO2 would have limited climate impacts compared to the emissions avoided by CCS.

Joe Deely's picture
Joe Deely on February 21, 2016

Bob,

Not really that conceptual – gas and renewables have cut coal usage dramatically and will continue to do so over the next fifteen years. The numbers show this.

Don’t really understand your clean coal reference. There is no venture capital needed. Big pipelines extending out  into the future for both wind and solar and prices continue to drop. Plenty of funding available.

One thing that Alex did not explore in this article is the prospect of renewables substituting for natural gas. This is already happening in California and will shortly be doing the same in other high% Nat Gas/Low Coal states.

Hopefully at some point we will see viable nuclear projects (possibly the UAMPS project that Rod wrote about). These can then also be used to help supplant Nat Gas.

Willem Post's picture
Willem Post on February 21, 2016

Alex,

If we assume there will be 25% wind energy on the US grid, which consists of 3-island grids that are weakly interconnected, then the efficiency of reducing CO2 will be significantly decreased. The combination of wind and natural gas is not nearly as good regarding fuel and CO2 reduction as claimed. See below examples.

Here is an example of Ireland, an island grid.

Ireland’s Power System: Ireland had an island grid with a minor connection with the UK grid until October 2012. Eirgrid, the operator of the grid, publishes ¼-hour data regarding CO2 emissions, wind energy production, fuel consumption and energy generation. Drs. Udo and Wheatley made several analyses, based on 2012 and earlier Irish grid operations data, that show clear evidence of the effectiveness of CO2 emission reduction decreasing with increasing annual wind energy percentages.

The Wheatley study of the Irish grid shows: Wind energy CO2 reduction effectiveness = (CO2 intensity, metric ton/MWh, with wind)/(CO2 intensity with no wind) = (0.279, @ 17% wind)/(0.53, @ no wind) = 0.526, based on ¼-hour, operating data of each generator on the Irish grid, as collected by SEMO.

If 17% wind energy, ideal world wind energy promoters typically claim a 17% reduction in CO2, i.e., 83% is left over.

If 17% wind energy, real world performance data of the Irish grid shows a 0.526 x 17% = 8.94% reduction, i.e., 91.06% is left over.

What applied to the Irish grid would apply to the New England grid as well, unless the balancing is done with hydro, a la Denmark.

Europe is facing the same problem, but it is stuck with mostly gas turbine balancing, as it does not have nearly enough hydro capacity for balancing.

Fuel and CO2 Reductions Less Than Claimed: If we assume, at zero wind energy, the gas turbines produce 100 kWh of electricity requiring 100 x 3413/0.5 = 682,600 Btu of gas (at an average efficiency of 0.50), then 682600 x 117/1000000 = 79.864 lb CO2 are emitted.

According to wind proponents, at 17% wind energy, 83 kWh is produced requiring 83 x 3413/0.50 = 566,558 Btu of gas, which emits 566558 x 117/1000000 = 66.287 lb CO2, for an ideal world emission reduction of 13.577 lb CO2.

In the real world, the CO2 reduction is 13.577 x 0.526 = 7.144 lb CO2, for a remaining emission of 79.864 – 7.144 = 72.723 lb CO2, which would be emitted by 621,560 Btu of gas; 621560 x (117/1000000) = 72.723 lb CO2.

To produce 83 kWh with 621,560 Btu of gas, the turbine efficiency would need to be 83 x 3413/621560 = 0.4558, for a turbine efficiency reduction of 100 x (1 – 0.4558/0.50) = 8.85%.

Below is a summary:

Ideal World…………………………..Btu…………CO2, lb…….Turbine Efficiency

No Wind gas generation………..682,600………79.864……………0.5000

17% Wind gas generation……..566,558……….66.287…………..0.5000

Reduction…………………………..116,042……….13.577

Real World

17% Wind gas generation……..621,560……….72.723…………..0.4558

Reduction…………………………….61,040………..7.141

Actually, Ireland’s turbines produce much more than 100 kWh in a year, but whatever they produce is at a reduced efficiency, courtesy of integrating variable wind energy.

For example, in 2013, natural gas was 2098 ktoe/4382 ktoe = 48% of the energy for electricity generation; see SEIA report. This likely included 2098 – 2098/1.0855 = 171 ktoe for balancing wind energy, which had a CO2 emission of about 171 x 39653 million x 117/million = 791.4 million lb. This was at least 791.4 million lb of CO2 emission reduction that did not take place, because of less efficient operation of the balancing gas turbines.

The cost of the gas, at $10/million Btu, was about 171 x 39653 million x $10/million = $67.6 million; it is likely there were other costs, such as increased wear and tear. This was at least $67.6 million of gas cost reduction that did not take place, because of less efficient operation of the balancing gas turbines.

In 2013, the fuel cost of wind energy balancing was 5,872,100,000 kWh of wind energy/$67.6 million = 1.152 c/kWh, which would become greater as more wind turbine systems are added.

It must be a real downer for the Irish people, after making the investments to build out wind turbine systems and despoiling the visuals of much of their country, to find out the reductions of CO2 emissions and of imported gas costs, at 17% wind energy, are about 52.6% of what was promised*, and, as more wind turbine systems are added, that percentage would decrease even more!!

*Not included are the embedded CO2 emissions for build-outs of flexible generation adequacy, grid system adequacy, and storage system adequacy to accommodate the variable wind (and solar) energy, plus all or part of their O&M CO2 emissions during their operating lives; in case of storage adequacy, all of O&M CO2 emissions, because high wind and solar energy percentages on the grid could not exist without storage adequacy.

NOTE:  Gas turbine plant efficiencies are less at part load outputs. If gas turbines plants have to perform peaking, filling-in and balancing, due to variable, intermittent wind and solar energy on the grid, they generally operate at varying and lower outputs and with more start/stops. Such operation is less efficient than at steady and higher outputs and with fewer start/stops, just as with a car. Operation is unstable below 40%, hence the practical limit is about 50%, which limits the ramping range from 50% to 100%. Here is an example:

…………………………………..Output……Efficiency……….Output………Efficiency

Simple Cycle………………….100%……….38%……………..40%………….26%

Combined Cycle……………..100%……….55%……………..40%………….47%

http://www.wartsila.com/energy/learning-center/technical-comparisons/combustion-engine-vs-gas-turbine-part-load-efficiency-and-flexibility

http://docs.wind-watch.org/Wheatley-Ireland-CO2.pdf

http://theenergycollective.com/willem-post/89476/wind-energy-co2-emissions-are-overstated

http://www.seai.ie/Publications/Statistics_Publications/Energy_in_Ireland/Energy_in_Ireland_Key_Statistics/Energy-in-Ireland-Key-Statistics-2014.pdf

http://www.clepair.net/Udo20150831-e.html

http://fredudo.home.xs4all.nl/Zwaaipalen/17E_Wind_in_the_Irish_grid_SEAI_report_2015.html

Australia’s Power System: The Wheatley report states, with 4.5% wind energy on the grid, CO2 reductions were about 3.5%, which means the effectiveness was about 3.5/4.5 = 78% in 2014. The Wheatley report states, if wind energy were 9%, it would be about 70%. By extrapolation, if wind energy were 13.5%, it would be about 62%, and at 18%, it would be about 54%, i.e., the more wind energy, the less its effectiveness reducing CO2 emissions and fuel consumption. This would be similar to the effectiveness of 52.6% at 17% wind energy of Ireland’s power system. The laws of physics apply to Ireland, Australia, etc.

http://joewheatley.net/wp-content/uploads/2015/05/sub348_Wheatley.pdf

http://joewheatley.net/wp-content/uploads/2015/05/report.pdf

 

Clayton Handleman's picture
Clayton Handleman on February 21, 2016

You sidestep the fact that Ireland is small geographically so that the wind resource is highly correlated.  In serious climate change mitigation proposals for the US, aggregating across much larger geographic areas would be achieved.  These sources are highly decorrelated.  Ireland offers a good cautionary tale but that is the extent of it.  Ireland is not a good proxy for either Europe as a whole or the US if climate change mitigation is raised in priority.

Joe Deely's picture
Joe Deely on February 21, 2016

Back with Wheatley and Ireland…crap analysis by a guy who is funded by an Australian rancher who doesn’t like the way windmills look.  Note the bold comment in CO2 section… doesn’t seem to match up with Wheatley’s effectiveness conclusion. What would effectiveness be in 2015 now that wind is 24%?  What about next year when it is closer to 30%?

Here are the actual Ireland results from 2014

  • Renewable electricity generation in 2014, consisting of wind, hydro, landfill gas, biomass and biogas, accounted for 22.7% of gross electricity consumption.
  • The use of renewables in electricity generation in 2014 reduced CO2 emissions by 2.6 million tonnes and avoided €250 million in fossil fuel imports.
  • In 2014, wind generation accounted for 18.2% of electricity generated and as such was the second largest source of electricity generation after natural gas. Without wind in 2014, power generation related CO2 emissions would have been 16.2% higher. (This includes accounting for the ramping and cycling of fossil fuels plants associated with supporting wind generation.)
  • The carbon intensity of electricity generation fell to a record low in 2014 of 457 grams of CO2 per kilowatt-hour of electrical output, half the level in 1990.

In 2015 Ireland produced 24% of its electricity from wind.

  • Ireland is set to move up the rankings into third place globally for our use of renewable wind energy following a record year in 2015 which saw 24 percent of Ireland’s entire electricity usage met by indigenous wind energy according to the Irish Wind Energy Association (IWEA).
  • December was a record setting month for wind energy in Ireland having met 39 percent of the full month’s overall electricity demand, compared to 30 percent for the same period in 2014, with production peaking at a record 2037MW on Saturday 19th December 2015, providing enough energy to power 1.3 million homes nationwide.
  • The significant increase in wind energy levels contributed to a 9.4 percent decrease in the price of wholesale electricity in 2015 compared to the previous year.

Still a huge number of wind projects in the pipeline. (Here and here) Work is also proceeding on an upgrade to interconnection with Northern Ireland. Wind will continue to grow in Ireland and CO2 will continue to fall.

As Clayton, says Ireland is a tiny island market(and a grid that is not that flexble yet)and therefore should not be used as a comparision for US. However, wind is performing well there and is reducing CO2 dramatically.

Willem Post's picture
Willem Post on February 21, 2016

Clayton,

Decorrelation starts to occur at distances of about 500 miles or more, depending on the size of the weather system.

If the US east were to have 25% wind, it would need to be fed into a nationwide HVDC system, so it could be distributed around the country. Similarly with the Great Plains having 25% wind.

Remember, in the future, the US economy will be electrified and consume about 3 times the electricity, i.e., 12000 TWh/y, will be produced. 25% of that would be an enormous balancing job. 

Any storage of energy, such as by batteries, involves at least a 20% energy loss.

http://theenergycollective.com/willem-post/2308156/economics-batteries-s...

Clayton Handleman's picture
Clayton Handleman on February 21, 2016

Decorrelation starts to occur at distances of about 500 miles or more

The JCSP came to a different conclusion.  Their data shows significant decorrelation on much smaller distance scales.  Still large comparied to Ireland but small compared to the continental US.

Bob Meinetz's picture
Bob Meinetz on February 22, 2016

Alex, compared to CCS cheaper nuclear is a no-brainer. It’s already here – or more correctly, there – in Russia, Japan, China, and twelve other countries around the world where it typically costs 1/2 the price of American nuclear (Mitsubishi Heavy Industries has entered an agreement with Turkey to build four new reactors for US $22 billion).

Why is nuclear so expensive in the U.S.? Because – it’s not. Even in the U.S., nuclear is generating clean electricity 24/7, day and night, in wind and calm, for $.065/kWh. Perfectly operational older plants are being closed not by the oft-cited “cheap gas”, but by energy holding companies like Sempra Energy, Edison International, Berkshire Hathaway Energy, and Pacific Gas & Electric Corp. exploiting century-old regulatory loopholes to sell themselves natural gas and bill the public for it. Getting rate increases – expanding the “spark spread” relative to the “quark spread” – using in-state influence peddling made possible by the 2005 repeal of FDR’s Public Utility Holding Company Act.

The solution is not a technological one, but one of reversing rampant deregulation at odds with the interests of the American public and environmental health. Like CCS, compared to cracking that nut, cheaper nuclear is a no-brainer.

Bob Meinetz's picture
Bob Meinetz on February 22, 2016

Alex, the only renewable intermittency being addressed by CCs is nighttime. Half of 2013 gas capacity additions in California were peakers built specifically to accomodate the minute-by-minute vagaries of solar/wind generation.

According to EIA, there is more peaker generation in the U.S. than ever before. What’s the source of your “untold story” that it’s decreasing?

http://www.eia.gov/todayinenergy/detail.cfm?id=15751

Bob Meinetz's picture
Bob Meinetz on February 22, 2016

Joe, not in California nor anywhere else in the world does renewable generation reduce consumption of natural gas. EIA consumption figures tell the story – not SEIA, NREL, AWEA, Greenpeace, or any of the other revenue mills whose existence is dependent on promoting renewables.

Is it, nonetheless, a prospect?

I had a bit of an epiphany while attending a rally last week in San Luis Obispo, CA for employees of California’s sole remaining nuclear plant, Diablo Canyon. Despite the fact the plant singlehandedly generates more clean power than any in-state renewable source – more than wind, almost twice as much as CA solar – forces within the corrupt CPUC and the plant’s owner, PG&E, are intent on closing it.

Breakthrough Institute founder Michael Shellenberger, who hosted the event, had an interesting take on interacting with renewables devotees – don’t attack anyone’s wind farm vision, their solar panel dreams, their unicorns, their rainbows. Right now – what do we do that works?

Joe Deely's picture
Joe Deely on February 22, 2016

Bob,

Leave it to you to cherry-pick a year where most of the Nat Gas capacity was added by one state – CA. Plus most of this capacity was added in a hurry by stupid SoCal utilities in order to replace a recently shutdown nuclear plant. I think you know this.

However, an easy measure to look at is the heat rate of Natural Gas over time in the US.

 The heat rate is the amount of energy used by an electrical generator or power plant to generate one kilowatthour (kWh) of electricity. The U.S. Energy Information Administration (EIA) expresses heat rates in British thermal units (Btu) per net kWh generated.

Here are the results for Natural Gas over the past ten years. (Btu per Kilowatthour)

Heat Rate    2004 2005 2006 2007 2008 2009 2010 2011 2012 2013 2014    8647  8551  8471  8403  8305  8160  8185  8152  8039  7948  7907

 

Seems to be continually improving. In fact an 8.5% improvement. Not bad.

More usage of efficient Combined Cycle plants and less peakers. And to think, this is happening with all those pesky intermittent renewable sources being added.

You are correct in saying that there are still many simple cycle peaker plants out there. Over time much of their output will diminish as new flexible combined cycle plants take their place. By the way, YTD on 2015 is an improvement over 2014.

Bob Meinetz's picture
Bob Meinetz on February 22, 2016

Alex, current nuclear plants are only “uneconomic” since 2005 due to repeal of FDR’s Public Utility Holding Company Act, which permits gigacorporations like Sempra Energy (Aliso Canyon owner, 2015 profits $17 billion) to bill captive ratepayers based on the amount of natural gas they’re able to burn. Gone is antitrust oversight from the SEC, the only agency with the resources and expertise to protect the public. They did so effectlvely for 70 years.

Why aren’t Sempra, PG&E, and other holding companies able to exploit nuclear generation the same way? Two reasons: 1) nuclear fuel assemblies only require replacement every 18 months, and 2) The federal government (NRC) keeps a tight leash on how much fuel is out there for security purposes. Unlike natural gas.

It’s not “renewables”, it’s not “nuclear”, not “coal”, “fossil fuels”, “oil”, nor “diesel fuel” – the #1 issue in American electricity is the repeal of PUHCA and the runaway exploitation of consumers by utility holding companies. Former FERC administrator Lynn Hargis in 2004:

In my thirty-odd years of electric utility regulatory practice, I have come to believe that PUHCA is the most important piece of federal legislation relating to electric and natural gas utilities…if PUHCA is repealed the consequences to electric and natural gas utility consumers and to our national economy may be catastrophic.

It was a 1994 exemption to PUHCA which permitted Enron Corporation to send California electricity markets into cardiac arrest, and ended up costing residents $billions.

Catastrophe unfolding.

Joe Deely's picture
Joe Deely on February 22, 2016

Bob,

Both state and national models show natural gas usage in CA declining.  Here is the state document.

“Staff estimates natural gas demand for power generation in California to decline by about 37 percent over the forecasted period in the mid demand case, due to the implementation of renewable generation and the penetration of energy efficiency. This trend differs from the rest of the United States, where staff estimates natural gas demand for power generation to increase by about 13 percent due to aggressive coal retirements. “

Note: this report was done before CA decided to up the Renewable standard to 50%. So these numbers are way low!

As for your comment –

“Despite the fact the plant singlehandedly generates more clean power than any in-state renewable source – more than wind, almost twice as much as CA solar” 

Let’s look at the EIA YTD for 2015 which goes through November.

  • Nuclear data YTD  – 16,922 GWh an increase of 9.5% over 2014. Good year for nuclear. (maybe more outages in 2014?)
  • Solar PV YTD – 16,719 GWh an increase of 46.7% vs. 2014.
  • Solar Thermal YTD – 2,219 GWh an increase of 45.2% vs. 2014

So let’s see. 18,938 GWh for Total Solar vs. 16,922 for Nuclear. Actually 12% more for Solar and not 2x for Nuclear. Wow. How did that happen? 

Going forward – I think we can easily add 5GWh yearly of Solar production in CA. That will be a drop in growth rate from 45% in 2015 to 20% in 2016.  So demand remains flat and we add 5GWh of solar. What goes down? Nat Gas production. Not really that hard to understand.

By the way – with that Nat Gas disaster in SoCal we may need to have that Nat Gas usage decline sooner rather than later.

Also for reference Nat Gas electricty production in CA for 2015 will be about 116,000 GWh. Should be below 50,000 GWh by 2030. 

Bob Meinetz's picture
Bob Meinetz on February 22, 2016

Joe, I missed specifying “PV” in solar, and you missed the weakest month in the solar year. You specify generation “in California”, I include the 30% of California electricity being outsourced to energy gigacorps like Pacificorp in Wyoming, 90%+ of which comes from burning coal. That’s how it happened.

An excursion into Unicorns and Rainbows La-La Land follows, where future conditional tense becomes present: “…according to no one, demand could remain remains flat and we could add 5GWh of solar. What could go goes down? Nat Gas production. Not really that hard to understand.”

I understand completely, but understanding is obviously not the point. Best wishes. My efforts are directed at things that work.

Engineer- Poet's picture
Engineer- Poet on February 22, 2016

Your strawman 50% renewable energy is a good one “for the sake of argument” but not much else.

So rather than postulating some other number and calculating emissions based on that instead, all you did is cast aspersions.  Thank you, Tar Baby, but no.

The US gets about 10% of its power from hydro which is dispatchable

Closer to 6.3%, and a fair amount of it is “must-consume” because reservoirs fill during the spring melt and spillways cannot be used without harming fish.  Needless to say, a source capable of meeting just 6.3% of demand cannot fill the deficits left by a source which has only 65% availability.

EVs are highly symbiotic with GPW and can therefore smooth the night generation peak if EVs reach high penetrations

Hand-waving, no evidence cited.

(appearing far more probable than massive deployment of nuclear).

And again, we have here a purported “alternative” to nuclear power.  An alternative that just happens to have no proof of feasibility, let alone affordability.  This would be a remarkable coincidence, if I thought it was a coincidence.

How is it that France and Sweden can de-carbonize their electricity with 78% and 50% nuclear power respectively, but the USA, which INVENTED it, cannot?  Obviously silly.

Clayton Handleman's picture
Clayton Handleman on February 22, 2016

Yawn.  Won’t spend a lot of effort debating an anonymous troll point by point but here is a piece on EVs playing nice with wind power.  Now do you actually disagree with it or are you simply wasting space and degrading the conversation on the board playing gotcha from behind the security of a pseudonym.

 

 

Bob Meinetz's picture
Bob Meinetz on February 22, 2016

Joe, apart from the gratuitous tap-dancing with heat rates, what’s “not bad”, and what “seems to be improving”: natural gas consumption in California, for the generation of electricity, is up 37% in the last decade – almost exactly the same as electricity rates (In 2015, San Diego rates were the highest in the nation).

Not coincidentally, it’s the 10th anniversary of the repeal of PUHCA, and when Californians started being suckered into the idea all those pesky renewables were environmentally beneficial.

What can I do to help you put the pieces together?

http://energyalmanac.ca.gov/electricity/electricity_generation.html

Joe Deely's picture
Joe Deely on February 22, 2016

Bob,

Here was your statement.

“Despite the fact the plant singlehandedly generates more clean power than any in-state renewable source – more than wind, almost twice as much as CA solar.”

Now it appears you want to count imported coal as in-state Nuclear generation. Huh? 

I include the 30% of California electricity being outsourced to energy gigacorps like Pacificorp in Wyoming, 90%+ of which comes from burning coal.”

I’ll update the numbers with the Dec data when EIA posts that. You are right – in that Nuclear produced more in Dec than solar. Not much more though. THe worst month for solar is no longer that bad. in fact, It looks like in February Solar will surpass nuclear – but I know you don’t like talking about the future. So, I’ll wait till EIA posts that at the end of April and update the numbers for you then.

One last thing – CA imports a lot of solar energy from other states. (Nevada & Arizona)  Do I get to count that?  CA also imports a lot of Hydro from the Pacific Northwest – If you get to count coal as nuclear can I count Hydro as solar?


Engineer- Poet's picture
Engineer- Poet on February 22, 2016

Respectfully, we actually did discuss water consumption during several points in our article.

But you didn’t establish that this actually provides an environmental benefit.  If water withdrawal or consumption has no impact, there is no benefit from avoiding it.  Further, that is the ONLY positive you’ve been able to raise.

Does this minimal benefit out-weigh 670 gCO2(e)/kWh emissions from open-cycle gas turbines?  I’ve read that emissions have to drop to no more than 50 gCO2(e)/kWh to stabilize the climate, and this needs to happen quite rapidly.  How do you square this with your promotion of natural gas?

“Renewables” (wind and solar) are simply not coming along fast enough to do the job.  France went from perhaps 600 kWh/capita/yr to over 6000 kWh/cp/yr from nuclear in 9 years; Sweden to about 4500, Belgium to around 3000.  From 2004 to 2013 , no country using “green” energy has gotten much above 1000 kWh/cp/yr… and that’s with substantially better technology available!  Worse, Germany’s per-kWh emissions rose substantially after the post-Fukushima nuclear panic, interrupting what had been steady if not spectacular downward progress.

You never addressed my main question:  how many hours/how much CO2 can you allow before the higher global temperatures and evaporation “consume” as much water as the thermal powerplant does?  California is experiencing worsening drought conditions due to climate change, so this is very obviously a factor today.  Continuing to add CO2 from natural gas (for ANY purpose) is only going to make this worse.  And how does this relate to plants cooled by seawater, which are at zero risk of depleting the resource?

Nowhere in this article did we contend that nuclear must make room for renewables or natural gas.

But every one of your metrics puts nuclear at the bottom, and the implication is that coal baseload will be replaced by wind, solar and natural gas.  The environmental impact of using even 35% NG backup compared to life-cycle emissions of 21 gCO2/kWh for nuclear ought to be at least given a nod.

Joe Deely's picture
Joe Deely on February 22, 2016

Bob,

Does your use of “tap dancing” mean that you feel using heat rates is not relevant for this discussion? or do you disagree with my source? 

Otherwise, I’ll take your lack of a substantative reply to the issue at hand as meaning that you now understand and agree with Alex’s comment.

Engineer- Poet's picture
Engineer- Poet on February 22, 2016

here is a piece on EVs playing nice with wind power.

Nothing quantitative.  No analysis of the per-capita generation or storage required.  No analysis of the impact of the variation of the resource between days (which is large and will be troublesome for anything relying on it), let alone seasons.  You don’t have anything on the size of the fleet required to provide an effective buffer.  You do mention the Ice Bear, but it’s only a mention; you don’t look to see how many kWh of demand can be moved forward to take advantage of availability.  Long-term, high-resolution data are available from ERCOT and BPA, to list two, but you didn’t use them to do any deeper analysis.

Industrial societies cannot be operated on handwavium; it has zero dispatchable capacity.

Now do you actually disagree with it or are you simply wasting space

Ah, projection!  Claims supported by little more than hot air don’t belong here.

Bob Meinetz's picture
Bob Meinetz on February 22, 2016

Joe, of course heat rates are not relevant in the context you’re using them. It’s the same hallucinogenic way renewables advocacy (RA) regards “efficiency”, as if it could magically spawn a quantitative something out of a subtractive nothing.

One is unlimited, the other is not.

When heat rate improvements hit a wall, what will you do then, Joe? Line the blades of your gas turbine with teflon? If only we could harness the energy you folks invest in your Gish Gallop of non-substantive distraction, we might be on to something (tip of hat to Engineer – Poet):

“Named for the debate tactic created by creationist shill Duane Gish, a Gish Gallop involves spewing so much bullshit in such a short span on that your opponent can’t address let alone counter all of it. To make matters worse a Gish Gallop will often have one or more ‘talking points’ that has a tiny core of truth to it, making the person rebutting it spend even more time debunking it in order to explain that, yes, it’s not totally false but the Galloper is distorting/misusing/misstating the actual situation. A true Gish Gallop generally has two traits.

1) The factual and logical content of the Gish Gallop is pure bullshit and anybody knowledgeable and informed on the subject would recognize it as such almost instantly. That is, the Gish Gallop is designed to appeal to and deceive precisely those sorts of people who are most in need of honest factual education.

2) The points are all ones that the Galloper either knows, or damn well should know, are totally bullshit. With the slimier users of the Gish Gallop, like Gish himself, its a near certainty that the points are chosen not just because the Galloper knows that they’re bullshit, but because the Galloper is deliberately trying to shovel as much bullshit into as small a space as possible in order to overwhelm his opponent with sheer volume and bamboozle any audience members with a facade of scholarly acumen and factual knowledge.”

http://www.urbandictionary.com/define.php?term=Gish+Gallop

Joe Deely's picture
Joe Deely on February 22, 2016

Wow Bob, your rants are really starting to go off the deep end. Seriously.

I mentioned heat rates in relation to Alex’s comment below to take it a step further and show that CC usage as % of whole was actually increasing. Nothing else. 

“Moreover, most natural gas is burned in power plants that use efficient combined cycle technology.”

You disputed this comment with an irrelevant reference that showed that a bunch of peaker plants were installed in CA in 2013. You chastise others for not bringing facts to bear but have a problem when anyone pushes back. 

Gonna keep this one short – I don’t want to be the one that pushes you over the edge.

 

Bob Meinetz's picture
Bob Meinetz on February 22, 2016

Even shorter, Joe – “The ad hominem – last gasp of a bankrupt argument.”

Joris van Dorp's picture
Joris van Dorp on February 23, 2016

Clayton, which of the following is more expensive to build, maintain and operate:

 

A. The existing French-style electricity system, based on maxed nuclear, having by far the best co2 performance of any large inductrial country in the world.

B. Your 100% RE system, based on maxed wind and solar, a national HVDC grid, plus 200+ years of GF battery production.

 

For your information, the current cost of France’s electricity is about 7 ct/kWh. Your proposed 100% RE system will cost, how much?

 

 

Engineer- Poet's picture
Engineer- Poet on February 23, 2016

Anonymous commenter Engineer Poet

I am not anonymous, I am pseudonymous.  Further, there is a 12-year record of my opinions and analysis under this pen name.  If you think I’m wrong about something, you can pick it apart in detail.

I notice that details are something you’re awfully short on, which may be why you’re picking on names instead.

“One day”, that appears pretty arbitrary

Most off-grid systems have several days of battery storage, to avoid having to fall back to gasoline generators.  Of course, you were free to posit some other figure and run numbers on it… which you didn’t do.  Can you even do quantitative work, or are you innumerate?

It is quite a reach to assume that, for an entire day, the sun will stop shining, wind will be stilled across the nation and out at sea, no nuclear power plants will be built and the existing ones will be shut down and all the lakes will dry up so there is no hydro.

It is no reach at all to postulate an almost complete wind hiatus over a large area lasting two weeks; it’s historical fact over the entire BPA service area.  Any significant cloud cover shuts solar thermal down completely.  Heavy overcast cuts insolation by about 90%.  Hydro is a whole 6.3% of US generation, and that will be much smaller when more things are electrified.  And for any remote stuff to do you any good, it has to (a) be built out, (b) have enough EXCESS generation over local needs to share, and (c) have lines to get it to you.

Why do I even need to point out that killing the nuclear industry is the Greens’ #1 priority?

your strawman is pretty weak.

A strawman is a weak argument put up to avoid having to address a strong one.  I’m afraid that your Handwavium armor is closer to tissue paper.  Tissue paper is what sky lanterns are made from; they contain nothing but hot air.

Further it would appear that you are assuming that all NG peaking plants, diesel backup generators and the like have been taken offline.

To get down to the maximum of 50 gCO2/kWh consistent with stabilizing the climate, the fraction from those has to be well under 10%.  To get down to 350 ppm anytime soon, there would have to be net CO2 removal.

All pumped storage is gone

Pumped storage is minuscule.  Ludington is one of the biggest pumped hydro facilities in the world.  It can manage its rated output (2172 MW after the upgrade) for about 18 hours, or about 39 GWh.  This is less than 1 Gigafactory-year, from a facility which occupies 1000 acres of very particular geography.  You cannot scale this.

you appear to be assuming that under the bizaar circumstances that created this scenario, people would still be showing up to work and using the same amount of electricity that they always do.

Do yourself a favor.  Look up what hurricanes, snow emergencies and other natural disasters that keep people away from work cost the economy.  Now project what will happen when such events are regular consequences of vagaries of normal weather.

This outlier strawman appears designed to show the implausibility of EV traction batteries playing a dominant or even significant role in grid storage.

Handwavium Reality Shield, meet Numeric X-Acto Knife.  US electric generation in 2014 came to 4093.6 TWh, or about 467 GW average.  One Gigafactory-year of batteries (50 GWh) would power this average load for 6.42 minutes.  It would take 224 GF-years of batteries to power that load for one day.

Overcast, low-wind conditions are hardly rare; they may not take RE out completely, but unless the system was grossly (and expensively) overbuilt they’d bring it down well below demand.  You’d need several days worth of storage to make wind and solar sufficiently reliable.  3 days is 673 GF-years worth, and that’s assuming

  1. the batteries start fully charged, and
  2. they don’t have anything else to do, like running vehicles.

Now what are the odds of that?  And the cost!  At a future cost of $100/kWh, 467 million kW times 72 hours times $100/kWh comes to a whopping $3.36 TRILLION.  And it’s an on-going expense; you have to replace them every decade or so.  Are you prepared to spend $1000/capita/year just for battery upkeep?

There likely will be a large aftermarket in using degraded EV batteries for grid storage. Most of the time these would be used for short term management which is pretty easy on the batteries.

That assumes that the batteries aren’t worth more for recycled metals than as grid storage.  Plugged-in vehicles themselves are potentially manageable as schedulable demand, ideal for grid regulation (which AC Propulsion dug into back around the turn of the century); batteries don’t need to be on their second life to handle that job.  You’d most likely see battery banks used at fast-charge stations, but those are going to account for a relatively small fraction of net EV power demand.

Your problem with a mostly or wholly RE grid isn’t going to be minute-by-minute imbalances between supply and demand.  It’s going to be the feasts and famines lasting days, weeks and seasons.

You have pointed to a great deal of urgency as per McKibbon. If this is taken to heart we would need to eleminate all carbon from driving passenger vehcles. That would nearly double the production of batteries getting us to high levels of storage even faster.

It’s not storage you can use, because its primary purpose is to stay mostly charged to drive vehicles around.  Further, grid-level storage is much more cheaply served by very different means; IIRC, a tank-full of molten “solar salt” at 500°C can hold energy to make steam for electricity at much less than $1/kWh (insulated tank not included).  But if you’re going to eliminate the carbon emissions, you can’t use non-sequestered fossil fuels.  You can’t really use much biomass either, because trees take years to re-grow and many annual crops deplete soil carbon that needs to be built up.  Batteries and pumped storage are too small and costly.  You just can’t build a system around fickle sources like wind and sun.  Until fusion comes along or we go up into nightless, cloudless space, we have exactly one workhorse in the stable… and the Greens hate it like nothing else.

This myth appears to be Busted

Yes yours is, but you haven’t the wits to realize it.

Bob Meinetz's picture
Bob Meinetz on February 23, 2016

** TO ALL PARTICIPANTS IN THIS VIGOROUS DEBATE ** Tonight at 7:30 PM PST, UCLA’s Institute of the Environment and Sustainability will present a live simulcast:

POWERING EARTH 2050: Is California’s 100% Renewable Strategy Globally Viable?

http://www.environment.ucla.edu/oppenheim/

Panelists:
Dale Bryk, Director of Programs, National Resources Defense Council
Ken Caldeira, Climate Scientist, Stanford University
Mark Jacobson, Professor of Civil and Environmental Engineering, Stanford University
Michael Shellenberger, Founder, Breakthrough Institute

Names with which I know you’re all familiar. Try to ignore the tacit assumption that “California’s 100% Renewable Strategy” is locally viable, or that such a strategy even exists outside the mind of Mark Jacobson.

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