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Renewables and Natural Gas are Partners Not Opponents

Natural Gas and Renewables Compete

Renewable energy sources and natural gas should be considered as complements and not rivals.  A hybrid gas-electric clean energy provides a workable engineering solution while 100% Renewables models based heavily on wind, solar and efficiency fall short of the meeting the functional needs of a modern technology intensive society.

Natural gas and renewables are already functional partners on the grid.  Because wind and solar are intermittent sources of electricity, some form of backup power is required to fill the down times.  By and large this backup power has been provided by natural gas because gas is the most flexible in its deployment.  Gas turbines can be turned on and off quickly to meet fluctuating power demands.  Large boiler based systems such as coal and nuclear are not so flexible in their operations, they can take hours to turn up and efficiency is lost.  Big boilers work best when they are operating consistently which makes it more challenging to integrate with the intermittent wind and solar power sources.

Secondly, natural gas is primarily methane and methane is itself renewable.  Methane can be manufactured in vast quantities and is indistinguishable from fossil sources.   Renewable methane can be made from biomass, garbage, sewage, farm waste and is given a variety of names; biomethane, renewable natural gas, substitute natural gas, biogas and others.  Many of the best resources for biomethane are waste products today and are treated as liabilities but could be converted into assets.  Biomethane can be produced in greater quantities than other biofuels such as ethanol or biodiesel.

Third, power-to-gas offers the potential to convert excess electricity into methane and store it in the pipeline infrastructure.  Electrolysis uses electricity to separate water (H2O) molecules into hydrogen and oxygen.  This hydrogen can be used directly for a variety of industrial purposes and powering fuel cells, but can also be used in the manufacture of biomethane which is CH4.  In Germany experiments are being run to determine how much methane can be injected directly into the natural gas pipelines.  While power-to-gas is not being implemented in commercial scales today, the technology is all completely proven.  As solar and wind deployments ramp up the need for storage becomes more pronounced and gas production has advantages over batteries because gas can be stored indefinitely while batteries lose their power over time.  Gas can also be easily transported in pipelines and tankers and converted into other products.

The natural gas infrastructure enables the use of fuel cells to produce emissions free electricity.  Proton Exchange Membrane (PEM) fuel cells use pure hydrogen as fuel and are being developed for vehicles.  Solid Oxide fuel cells can use methane as fuel but are best for stationary power production.  There is great promise in hydrogen fuel cell vehicles but there is a fundamental challenge in distributing and storing pure hydrogen.  Hydrogen is tiny and extremely volatile, it both leaks out of conventional steel pipes and reacts with steel making it brittle.  Hydrogen distribution requires the use of stainless steel (or other specialty material) pipes with high test welds at all joints and special valves.  This is a very expensive and complex engineering proposition compared to the existing natural gas infrastructure that uses common galvanized steel pipe.  The practical and economic answer is to connect hydrogen fueling stations to natural gas distribution and steam reform and pressurize the hydrogen on site where it is sold.  Industry generally produces hydrogen from natural gas as it is far cheaper than producing hydrogen from electrolysis.  In this way natural gas enables the widespread use of hydrogen and fuel cells.

As the cleanest burning of all hydrocarbons methane is naturally a friend to the environment when used to replace coal and petroleum.  Renewable electricity solutions can replace many uses of coal for power but are challenged at replacing petroleum for vehicles, big ships and high horsepower machines such as mining equipment, freight trains and airplanes.  Natural gas is a direct replacement for diesel, gasoline and bunker fuel and can be converted into high quality liquid fuels such as jet fuel.  Dirty fuels such as coal and diesel are loaded with particulates, heavy metals, sulfur and other contaminants that cause toxic pollution and kill hundreds of thousands of people every year globally.  Methane is clean enough to burn indoors and cook food on, its widespread adoption to replace dirty fossil fuels would create significant air quality improvements and save many lives.  Methane also has the lowest carbon content of any hydrocarbon so when used to replace coal and petroleum it reduces carbon pollution.

Methane is the most abundant and versatile of all hydrocarbons.  It can be used to produce heat, power and transportation.  Methane can be converted into ultra clean diesel and jet fuel through Fischer-Tropsch processes.  Methane is also a critical raw material for the production of plastics, chemicals and fertilizers.  Recycling plastics back into methane can help facilitate zero-waste goals.  Natural gas resources are broad and deep and found all over the world.  The shale gas revolution has already overturned global energy markets and there appears to be vast resources to be tapped.  If the methane hydrate resources in the ocean can be brought to market that would further tilt the energy landscape towards natural gas as those reserves are massive and dwarf all coal and petroleum known to exist.

Natural gas has an excellent safety record, though it is often thought of as very dangerous.  LNG in transport is very safe.  LNG has been shipped in huge quantities by ship for decades and there has never been a disaster (knock on wood).  When used for a vehicle fuel it has distinct safety advantages over gasoline, diesel and propane because methane is the only one that is lighter than air and dissipates quickly if released while the others pool on the ground awaiting ignition.  Methane has a very narrow range for ignition making harder to combust accidently.  Also the tanks used for CNG and LNG are very robust by nature, whereas liquid fuels are often carried in thin walled tanks.  

Methane combustion does produce carbon emissions but far fewer than other fossil fuels, and methane is itself a greenhouse gas, so its use does need to optimized to mitigate any global warming effects.  Capturing leaking methane is important, and has the benefit of increasing fuel supplies.  Natural gas is easily deployed as fuel for power production and can be deployed nearer to where the electricity is used minimizing line losses and improving efficiency.  Combined heat and power is part of this efficiency playbook that natural gas enables.

In conclusion methane, aka natural gas, is a clean, high performance and versatile fuel that complements the roll out of renewable electricity technologies.  In practice, intermittent power sources such as wind and solar require stored fuel to be available at all times to keep the grid online.  Electrical sources are also not proven to power high horsepower vehicles while gas can.  Natural gas is the most abundant, clean and safe of all hydrocarbons and fulfills a critical role in our energy infrastructure.  Renewables advocates should recognize this fundamental harmony between these energy sources.

Photo Credit: Renewables and Gas/shutterstock

Ed Dodge's picture

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Bob Meinetz's picture
Bob Meinetz on Nov 26, 2013 4:00 pm GMT

Ed, while

a hybrid gas-electric clean energy provides a workable engineering solution

it doesn’t provide a workable environmental solution. WIth climate change tipping points looming ever nearer, the time has come to leave carbon in the ground (actually it came several decades ago, but what’s done is done). Gas generates half as much carbon as coal, and that’s simply not good enough.

Could we use power-to-gas as a temporary band-aid to wean us from fossil fuels? That power would have to come from nuclear, as it’s the only carbon-free source which is robust enough to overcome the efficiency losses of the conversion. If we’re going the hydrocarbon route (as opposed to ammonia) we need an above-ground carbon source, and while crop waste and excess are frequently put forth as feedstocks for power-to-gas, in truth available waste is a tiny fraction of what would be required to make a dent in coal or oil production. In practice, forests are clearcut or food supplies are raided to feed a hungry biofuel production infrastructure. Sidestepping destruction of natural resources, this is an extremely inefficent use of land, and when all the nunbers are added up it’s doubtful whether there are any savings in fossil fuel use at all.

Too often, idealized micro-technologies are put forth as being representative of entire industries, and both renewables and gas are guilty of this game. The little pilot biofuel plant on the news is a front for flaring thousands of tons of methane into the air, fracking, drilling, spilling, polluting. We should be devoting resources toward ammonia as a liquid fuel, toward battery tech, building out nuclear, and sealing up all those holes in the ground.


Nathan Wilson's picture
Nathan Wilson on Nov 26, 2013 6:44 am GMT

Perhaps it’s a partnership in which the fossil gas provides most of the energy output and the renewables provide a green veneer to help sell the deal to environmentalists?

If you want renewables, then pay extra and get the energy storage to go with it.  If you can’t afford renewables and energy storage, buy nuclear instead (it is much cheaper, especially for fleet average cost, which averages old and new plants).

As for using sustainable electricity to make synthetic methane fuel, this requires a carbon source, which is not easily done sustainably.  Yes our very limited biomass resources can fulfill this role, but our first priority for hydrocarbon fuel is aviation.  For applications like electrical peaking plants, industrial heat, building space heat, combined heat and power, and fuel for trucks, trains, stationary diesel motors, solid oxide fuel cells, and perhaps personal cars, ammonia (which contains no carbon, it’s NH3) is adequate.  Due to the low cost materials, ammonia will probably always be the cheapest practical fuel that can be made from solar, wind, or nuclear energy.  

The other problem with synthetic or biomethane is that it will create a very strong temptation to continue using fossil methane, in other words, it’s a trap that will likely block attempts to make deep reductions in CO2 emissions.

Jessee McBroom's picture
Jessee McBroom on Nov 26, 2013 5:06 pm GMT

Thanks for the post Ed. Natural gas and Renewables can be perfect partners when the hydrogen produced from excess electrical production in off peak hours exceeds the stored electrical needed to meet peak demand; when this excess is converted into hydrogen via electrolysis and blended into the natural gas to produce a much cleaner natural gas emissions profile; or used as hydrogen fuel for FCEVs. This approach allows for peak demand loads as well as  electric and gas and hydrogen fueled vehicles to be more easily met. The obvious additional methane produced from Bio Digesters and landfill methane production are inclusive and productive compliments to the natural gas and renewables partnership; as natural gas is for the most part methane as sold and delivered anyway.

James Hopf's picture
James Hopf on Nov 28, 2013 12:03 am GMT

It’s been known (or should have been known) for some time that renewables and natural gas are complimentary.  The are, in fact, necessary components of a plausible, viable overall power generation system option.  The real generation mix option that is being proposed (by serious people) is not a renewables only system but a gas + renewables system (with gas probably providing at least 2/3 of the overall electricity, due to renewables’ intermittentcy limitations, not to mention land use and cost).

Since only gas plants can throttle up and down rapidly, as necessary to backup intermittent renewables, large amounts of renewable capacity essentially requires most of the remaining generation to be gas.  Many of us have come to understand that the primary impact of renewables is to force market share from coal and nuclear to natural gas (a bigger impact than the renewable generation itself).

Furthermore, many of us believe that the (very rich, powerful and influential) gas industry is probably (and secretly?) the main political driving force behind the large push for renewables (large subsidies, outright mandate policies, etc…).  Renewables will warp the playing field in a way that will allow gas to take large amounts of market share from its main competitors.  How else can one explain that the only policies that go forward are things like renewable portfolio standards instead of far more rational, effective and fair policies such as a CO2 tax or cap-and-trade?  (That would actually give nuclear a chance, instead of that non-emitting option actually being harmed by policy, and the rigged market it creates.)

I’ve all but resigned myself to the fact that the gas + renewables approach (vs. nuclear or any other option) is the one that will win out.  The entities behind it are too powerful and influential.  We’re talking about the gas (and oil) industry in addition to the “environmentalists”; both pushing in the same direction.

As for the author’s dream of using renewable (non-fossil) gas, won’t ever happen.  Fracked gas is far to cheap for any renewable gas options to make any significant market contribution, for the forseeable future.  Unless the govt. mandates it……

Ron Wagner's picture
Ron Wagner on Nov 28, 2013 8:28 pm GMT

Natural gas is the best answer to the clean energy needs of the world. It will give abundant, reasonably priced energy to people around the world. It can support wind and solar as needed. Nothing can come close  to competing with it in areas that have it. LNG can supply areas that do not have pipelines. Biogas is a huge potential source of energy that also minimizes waste, Landfills are large sources of methane also. See References for the Natural Gas Revolution: https://docs.google.com/document/d/19Yf0MWpo91vrlu-mmJtjB1ERukjJo5W41oi4RZVQBug/edit

Thanks for the excellent article. The opposition is increasingly being educated. 

Clifford Goudey's picture
Clifford Goudey on Dec 1, 2013 12:36 am GMT

Val, you are clearly clueless on how wind power works, yet you profess to be an expert.  A 34% capacity factor does not mean wind is not producing 76% of the time.  It simply means it’s MWH output is 34% of what it would be if it was running continuously at its rated capacity.  Most wind turbined are generating >90% of the time.  Every MWh from wind is a MWh not from fossil fuels and that is good for everyone.

Electricity in Germany and Denmark is expensive because of the way it’s taxed.  Their wind and solar is working and they are building more.

You are welcome to your opinions about wind power, but cease the baloney.

 

 

Bob Meinetz's picture
Bob Meinetz on Dec 2, 2013 4:25 am GMT

Clifford, your definition of capacity factor is less ambiguous than Val’s, but you’re wrong on another point:

Every MWh from wind is a MWh not from fossil fuels and that is good for everyone.

That would be correct if all other generation was fossil-based, and it’s clearly not. I might add that 34% capacity factor is about double what Germany’s turbines are yielding:

“…the German nation-wide average wind power capacity factor over all of 2012 was just under 17.5%”

http://en.wikipedia.org/wiki/Wind_power#Capacity_factor


Clifford Goudey's picture
Clifford Goudey on Dec 2, 2013 12:38 pm GMT

Bob, ambiguous?  Val’s comment on capacity factor was simply wrong.

Regarding the role of wind in reducing GHG emissions, please read: http://cleantechnica.com/2013/10/28/wind-power-dramatically-cut-global-w...

I appreciate your concern over the capacity factor of onshore wind in Germany.  But what are they to do in order to meet their renewable goals?  Maybe the emerging class of low-wind turbines will help onshore.  It should comfort you to know that both of Germany’s offshore wind farms have capacity factors in excess or 40%.

Bob Meinetz's picture
Bob Meinetz on Dec 2, 2013 5:46 pm GMT

Clifford, cleantechnica.com is a renewables industry echo chamber which attempts to take on the veneer of authority by providing links which lead to other articles on its own website, or are unrelated, or  completely contradict it (they apparently assume readers will be too lazy to click on them). I will here for your edification; for any other purpose it’s a waste of time. From the page you reference, a link leads here:

The 2012 data show that in the two years since reporting began, emissions from power plants have decreased 10 percent. This is due to a switch from coal to natural gas for electricity generation and a slight decrease in electricity production. Fossil-fuel fired power plants remain the largest source of U.S. greenhouse gas emissions. With just under 1,600 facilities emitting over 2 billion metric tons of carbon dioxide in 2012, these plants account for roughly 40 percent of total U.S. carbon pollution.

http://yosemite.epa.gov/opa/admpress.nsf/bd4379a92ceceeac8525735900400c2...

However, the other main contributor to the cut in global warming pollution was clearly renewable energy generation, especially generation from wind energy.
Read more at http://cleantechnica.com/2013/10/28/wind-power-dramatically-cut-global-warming-pollution-u-s/#R1T8X2gRk0aXh0iI.99

Cleantechnica.com quickly assigns credit for these reduced emissions to renewables, concluding without basis that

…the other main contributor to the cut in global warming pollution was clearly renewable energy generation…

In fact, there’s nothing in the EIA release which does so. Making up only 4% of U.S. generation, it’s fairly evident in a headline like “Wind Energy Has Dramatically Cut Global Warming Pollution in the U.S.” the drama is generated by the imagination of the author and not by the meager, variable output of America’s wind farms.

In regards to Germany, your appreciation for my concern is misplaced. I’m less concerned about the CF of onshore wind than about enthusiasts finding comfort in 40% CFs for offshore wind, while apparently failing to understand this is included in Germany’s average. Take away offshore, and what is onshore CF for wind in Germany? 8%? 6%? Probably low enough to justify the growing resistance to erecting 60,000 wind turbines with associated transmission lines across the German landscape, and awareness of its environmental impact.

Wind Power Has Dramatically Cut Global Warming Pollution In The U.S.
Read more at http://cleantechnica.com/2013/10/28/wind-power-dramatically-cut-global-warming-pollution-u-s/#R1T8X2gRk0aXh0iI.99
Clifford Goudey's picture
Clifford Goudey on Dec 2, 2013 7:23 pm GMT

Bob, I honestly thopught we were talking about Germany.  Indeed, it was your comment about CF of German wind that prompted my response.  Now you want to discuss power plants in the US and how fossil-fuel interests have stymied the needed growth of renewables in this country.

Since you seem preoccupied by plant utilization rates, you must be fuming over the fact that gas-turbine plants in the US run at capacity factors from <4% to 19%.  And when they do run, they operate at embarrassingly low efficiencies.  Most unfortunate, wouldn’t you agree?

 

Bob Meinetz's picture
Bob Meinetz on Dec 2, 2013 8:04 pm GMT

Clifford, are you possibly getting your information from a circular reference at cleantechnica.com? Here’s some accurate info:

http://www.eia.gov/todayinenergy/detail.cfm?id=13191

You’ll notice that 2012 capacity factor for CCGT varied from 0% to 28%, depending on the time of day. In Texas – the land of supposedly-abundant wind – CCGTs were fired up more often than anywhere else in the country, illustrating not only the inadequacy of wind for addressing peak demand but wind’s reliance on gas for backup.

Why would anyone support an industry which guarantees fossil fuels a place in America’s energy portfolio for decades to come?

Clifford Goudey's picture
Clifford Goudey on Dec 2, 2013 8:58 pm GMT

Bob, what that Texas statistic illustrates is the fundamental inadequacy of conventional power plants at responding to demand variation.  They do not run efficiently at partial power and that is why there is all that starting and stopping.  I hope someone is working on that problem. 

Most spinning reserves are sitting there wasting fuel and gushing CO2 to be ready for demand spikes and to be prepared for a large thermal plant tripping off.  The gradual variation of wind power is a minor concern to grid managers.

Bob Meinetz's picture
Bob Meinetz on Dec 2, 2013 9:22 pm GMT

Clifford, to accept that explanation I’d have to believe that demand varies more rapidly in Texas than other parts of the country.

Are Texans as a race more impetuous, or could it be more gas is required to balance a variable and unpredictable source like wind?

Clifford Goudey's picture
Clifford Goudey on Dec 2, 2013 10:50 pm GMT

They simply have low NG prices.

Ed Dodge's picture
Ed Dodge on Dec 5, 2013 4:40 pm GMT

Siemens demonstrates this model in Germany.  Proof of Concept of what I described here.

http://www.siemens.com/innovation/en/news/2013/e_inno_1332_1.htm

Clifford Goudey's picture
Clifford Goudey on Dec 5, 2013 5:06 pm GMT

Val, if you were the expert you claim to be, you’d know that the cut-in speed of a wind turbine varies with the design.

You wrote, “Turbines use 20,000 mwh of grid power per 1,000 mw installed capacity of wind.”  Which would mean that in a couple days of operation that energy debt would be paid back.  In fact it’s much longer than that, yet its a faster return on energy invested that any power source.

Honestly, I am baffled about where you come up with this baloney.  Most anti-wind activists through in a few facts just to earn credibility.  Not you.  You simply hate wind turbines, so anything goes.  Enjoy your lunacy.

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