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#1 2019-04-20 05:02:50

louis
Member
From: UK
Registered: 2008-03-24
Posts: 4,565

Power to gas is the way forward for storage

This article reflects my own thinking:

https://www.carboncommentary.com/blog/2 … hxegtd41n0

"As wind and solar electricity grows in importance, the cost of power will inevitably drift towards zero. (First year economics tells us that prices always edge towards the marginal cost of production). Electricity will become cheaper than gas. On a windy weekend night in the North Sea offshore turbines will produce more electricity than northern Europe needs at some date in the not-to-distant future. Negative wholesale electricity prices will become increasingly prevalent."

So as the marginal cost of electricity production via wind and solar is close to zero and the market price is close to zero, or negative, during periods of excess production, that is the time whe you use your electricity to make gas, methane being the most obvious choice, that you can subsequently use to produce electricity through gas generators.

If you have wind and solar producing electricity at say 2 cents per KwH for an average 11 months per year but you have to cover the equivalent of one month using your stored gas at let's say 20 cents per KwH, then the average cost is 3.5 cents per KwH. The crucial factor here is going to be how cheaply we can produce the stored gas.  If it costs 40 cents per KwH then the average cost across the year  goes up to 5.2 cents per KwH.

But at least in terms of technology we know wind + solar + artificial gas (supplemented by other technologies like hydro and waste to energy which can also be stored) is all proven and we know there are no carbon emissions associated with this technology. Throw in a continental grid and I think it's "case closed".

Last edited by louis (2019-04-20 05:03:52)


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#2 2019-04-20 07:02:32

tahanson43206
Member
Registered: 2018-04-27
Posts: 567

Re: Power to gas is the way forward for storage

For Louis re #1 of your new topic ...

SearchTerm:SolarMethane
SearchTerm:GreenMethane

As I thought about your post, a number of advantages came to mind .... Natural gas is already well established as infrastructure for heating in the United States and other nations around the world.  It serves as well for production of electrical power and even transportation to some extent.

It is certainly a technology with risks.  Failures of pipe lines or fittings lead to occasional fires and even explosions on occasion.

That said, it would surely not cause anyone to blink an eye if a new supplier of "natural gas" were to appear on the scene.

If that supply were to come from a location where solar energy is abundant, or wind is abundant, then the same ships that carry the product from underground sources could carry the new supply.

In another topic kbd512 just reminded me (and hopefully other forum readers) of the value of capitalism as a mechanism for providing goods and services for a population.  Here is an example of how capitalism could shine once again, by working out a profitable way of creating methane from renewable energy sources.

It is possible someone with great wealth will chance upon your post, and decide to investigate the cost of building a plant to produce methane to compete with supplies drawn from underground reservoirs today. 

I'd like to remind you of another source of methane that is available on Earth right now.  I understand there is some concern that methane stored under the oceans may be freed from the constraints of pressure at depth, and able to enter the atmosphere.

First, I'd like to post a quote provided by Mr. Google:

87%
Wikipedia notes “Methane is the major component of natural gas, about 87% by volume” though other sources typically give a range of around 70% to 90%. Most of the rest of nat gas is ethane, propane and/0r butane. The stuff that gets to your home “is almost pure methane.”Apr 13, 2011
Natural gas is mostly methane – ThinkProgress
https://thinkprogress.org/natural-gas-i … 17027a978/

Next, I'll try to post a citation (or so) regarding methane hydrates:

Source of world's biggest pool of underwater greenhouse gas ...
https://www.independent.co.uk/.../under … n-hawaii-s...

Feb 28, 2017 - There is concern that as the world warms stores of methane frozen in the Arctic tundra and at the bottom of the sea bed could be released, ...
Ocean waters prevent release of ancient methane - Phys.org
https://phys.org › Earth › Environment

Jan 17, 2018 - Trapped in ocean sediments near continents lie ancient reservoirs of ... methane from the ancient atmosphere that was preserved in the ice of ...
Massive Underwater Domes of Methane Look Set to Blow at Any ...
https://www.sciencealert.com/massive-un … set-to-blo...

Jun 6, 2017 - Massive Underwater Domes of Methane Look Set to Blow at Any Moment ... massive frozen domes of methane in the Arctic Ocean say there are signs ... (1.2-mile) layers of ice kept huge amounts of methane hydrates - an icy ...
Researchers establish long-sought source of ocean methane: An ...
https://www.sciencedaily.com/releases/2 … 141635.htm

Dec 7, 2017 - An abundant enzyme in marine microbes may be responsible for production of ... Some of this naturally released methane comes from the ocean, .... 31, 2016 — Methane is stored under the sea floor, concentrated in form of ...

The concern about release of methane from under oceans does not (in my opinion) detract from the value of the proposition you have advanced.

However, in the context of your topic, I think it is worth keeping in mind that when it comes to methane, there can be "too much of a good thing".

In any case, please try to develop your idea into a competitive industry.  It won't cost anything to think through what would be involved, and your initiative may inspire others to contribute to the discussion.

Edit: This PowerPoint on production of various gases at Mars should help anyone thinking about producing methane on Earth:
https://www.slideserve.com/suzuki/bulk- … ad-project


(th)

Last edited by tahanson43206 (2019-04-20 09:01:22)

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#3 2019-04-20 09:18:36

SpaceNut
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From: New Hampshire
Registered: 2004-07-22
Posts: 15,037

Re: Power to gas is the way forward for storage

The earthly issue is capitalism which means business are in it for huge profits even when they can make it cheaply they do not lower there prices to the consumer. Business care nothing about the consumer.

As a self done program you have all the regulation for your own use there in of any storage or energy and with the moment to which you provide that to anyone else you fall under the business rules governing sales.

So creation of a business that can provide the self owned access to the resources to provide for ones self will be faught heavily by those that provide power in any form. This is the current status quo for solar....

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#4 2019-04-20 09:48:54

tahanson43206
Member
Registered: 2018-04-27
Posts: 567

Re: Power to gas is the way forward for storage

For Louis with a nod to SpaceNut ...

Louis, if you are able to design a corporation able to compete in the US Marketplace, here are prices as reported by:
https://www.eia.gov/naturalgas/

Natural Gas    Electricity    Spark
Spread
Region    $/million Btu    % chg*    $/MWh    % chg*    $/MWh
New England    2.19    NA    23.63    NA    8.33
Mid-Atlantic     2.08    NA    24.47    NA    9.94
Midwest            2.33    NA    25.40    NA    9.10
Southwest          0.33    NA    19.13    NA    16.83
Northwest          1.44    NA    15.30    NA    5.21

It looks to me as though your best bet would be to sell into the New England market.  If you can beat $2.19 per million Btu, and if you have the delivery capability to serve enough of that market so you are taken seriously, you should be able to compete if all is is equal. 

Entrenched interests may look for ways to resist outside competition, of course.  It has certainly happened before.

(th)

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#5 2019-04-20 11:31:36

kbd512
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Registered: 2015-01-02
Posts: 2,717

Re: Power to gas is the way forward for storage

SpaceNut,

What you stated in Post #3 about businesses "not caring about the consumer" is just absurdly false.  If a business can't convince consumers that they should spend their money with that business instead of a competitor, then they go out of business.  Period.

A business is not mommy and daddy, if that's what you meant.  They don't exist to stroke your hair and tell you what a good little boy or girl you've been after you go out and do something stupid with one of their products.  If that's what you mean by "not caring", well then no, they don't care.  If you drive your car off a cliff because you won't obey the speed limit signs, for example, the automotive industry doesn't "care" that you were going 70 in a 30 with one of their products and literally flew off the side of a mountain.  It's not their job to prevent the customer from doing every imaginable stupid thing with their product, though somehow our "true believers" in government think it is.  Car makers don't need another government regulation that tries to negate the requirement for prudent behavior because the dumbest people on the planet are so stupid or reckless in their behavior that that same government foisting regulations on the car maker never should have granted a driver's license to that person to begin with.

Regarding "all the regulation for your own use", I see you have discovered why people like myself want the government out of every aspect of their personal lives.  Governments create regulations so they can tax and fine.  That consolidates more power within the government and creates more avenues of approach for corruption.  That's all that governments create.  They create nothing else.  Period.

I don't want a massive government with unlimited power.  Any government big enough to give you everything you think you want (you'll change your mind after you get it) is also big enough to take away everything you have for entirely capricious reasons.

People say President Trump is too thin-skinned.  I say that's a mile high pile of partisan political horse manure.  If you think for one second that anyone, press / media personality / Joe Blow off the street can say what they say every day about the leader of a communist country, I got news for ya.  You'll find yourself face down in a shallow ditch with a new hole in the back of your head, if you're lucky.  If you're unlucky, the carcasses of all your family members will be lined up next to your carcass.

People create small businesses all the time, even in the absurdly over-regulated environment we live in today.  Some are smashing successes, but most fail within about 5 years of starting operations and fewer still are around 10 years or more.

Nobody is stopping you from making a water electrolyzer.  You can do that with materials you find at the hardware store.  It may not be the most efficient design in the world, but it'll work nearly as well as the absurdly expensive varieties made in government labs.  Overall, the reason we don't use water electrolysis if we can help it is that it's not energy efficient compared to sucking gas out of the ground.

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#6 2019-04-20 11:51:56

kbd512
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Registered: 2015-01-02
Posts: 2,717

Re: Power to gas is the way forward for storage

Louis,

Somebody wrote all that to come to the conclusion that we need to burn more gas to solve the CO2 emissions problem.

Why didn't we think of that?  Oh, wait...  Yeah.

If we make the gas ourselves it's somehow more efficient or green or renewable or some other meaningless buzzword than if we simply suck it out of the ground like we're already doing.  We make things from scratch when there's no other choice, not to try to sell an idea as "new".

We keep rolling a donut on CO2 emissions reduction because our brilliant technologists keep proposing schemes to emit more CO2 than we already are, such as manufacture of batteries at unprecedented scale or making our own CH4 when we can simply suck it out of the ground using far less energy.

Case closed?  For emitting even more CO2?  Sure.  That case is closed.  I've never seen so much creativity directed towards "not solving the problem" as it pertains to the CO2 emissions problem.  Imagine what could be accomplished if people like Chris Goodall were actually interested in solving the problem.

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#7 2019-04-20 17:23:11

louis
Member
From: UK
Registered: 2008-03-24
Posts: 4,565

Re: Power to gas is the way forward for storage

You do realise that you take the carbon from the atmosphere so it's carbon neutral?

If the power to manufacture artificial methane comes from solar and wind, it's a carbon neutral technology.

Surely that much is obvious?

The key here is that when solar and wind are overproducing (ie the grid doesn't want their energy) that is the ideal time to manufacture artificial methane.

kbd512 wrote:

Louis,

Somebody wrote all that to come to the conclusion that we need to burn more gas to solve the CO2 emissions problem.

Why didn't we think of that?  Oh, wait...  Yeah.

If we make the gas ourselves it's somehow more efficient or green or renewable or some other meaningless buzzword than if we simply suck it out of the ground like we're already doing.  We make things from scratch when there's no other choice, not to try to sell an idea as "new".

We keep rolling a donut on CO2 emissions reduction because our brilliant technologists keep proposing schemes to emit more CO2 than we already are, such as manufacture of batteries at unprecedented scale or making our own CH4 when we can simply suck it out of the ground using far less energy.

Case closed?  For emitting even more CO2?  Sure.  That case is closed.  I've never seen so much creativity directed towards "not solving the problem" as it pertains to the CO2 emissions problem.  Imagine what could be accomplished if people like Chris Goodall were actually interested in solving the problem.


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#8 2019-04-20 18:10:30

SpaceNut
Administrator
From: New Hampshire
Registered: 2004-07-22
Posts: 15,037

Re: Power to gas is the way forward for storage

Here is information as it relates to the ammonia fuel cell topic as well but also to this one as its Ammonia as a Grid-Supporting Energy Storage Solution

As for the carbon neutral we talked about Swiss company Climeworks, that uses waste heat to create methane for a supply to sell.

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#9 2019-04-21 13:20:29

tahanson43206
Member
Registered: 2018-04-27
Posts: 567

Re: Power to gas is the way forward for storage

For Louis #7 ...

A modern (built in 2018) LNG tanker is "Megara".  You can find details about this vessel using:

www.marinetraffic.com

Just Google: find vessel megara

I do not understand the nautical measurements listed in the display for Megara, but report them here as a first step in what I hope will lead to clarification.

Dead weight is given as 85000 tons (this appears to be weight the vessel can carry, but it includes everything not cargo)

Gross tonnage appears to not be weight at all, but a measure of volume.  There is probably an historical reason for this oddity in nomenclature.

In any case, assuming you are interested in pursuing your "free" methane idea, the volume of LNG carried by this vessel is an example of the levels of performance you (and your corporation) are going to need to produce to compete in the LNG market.

Since this vessel exists, it is clear there are investors with the resources to build and certify such a vessel, and to cover all the startup expenses necessary to handle all operational expenses, including insurance to cover a wide variety of risks, until the payload is delivered to a customer and all those risks are retired.

Your concept for producing methane from solar energy needs investors able and willing to build the systems, complete the certifications, train and contract with staff to operate the facility, and patiently wait until the first load is safely delivered to a customer who actually pays the bill.

(th)

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#10 2019-04-21 13:47:15

kbd512
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Registered: 2015-01-02
Posts: 2,717

Re: Power to gas is the way forward for storage

Louis,

Why is it that we must continually come up with impossible tasks that require impossible solutions?

I mean that in the mathematical sense.  It's not a pejorative.  It's not hyperbole.  It's just the very frightening truth- to me, anyway.  It means people can't or won't use basic math to determine how feasible these schemes are when run at an industrial scale.  Nothing more complicated than addition, subtraction, multiplication, and division is required.  All other required data is at your fingertips with a quick Google search and tools like the Engineer's Toolbox website and US EIA's website.

In 2017 my home state of Texas produced 204,511,996MWh of electricity using natural gas.  That generated 99,579,127 metric tons of CO2.  That means an average of 0.4869t of CO2 were produced per MWh of electricity generated.  Capturing the CO2 from that process after it's already airborne requires 3 times as much energy input as compared to what was originally generated as output from combustion.

ClimeWorks' CO2 capture solution has the following power requirements for each metric ton of CO2 they pull out of the air:
2.5MWh (thermal)
0.5MWh (electric)

Here's your source for those numbers:
The Swiss company hoping to capture 1% of global CO2 emissions by 2025

Generating 3MWh of power to make this process work at an industrial scale would dictate a complete conversion to solar and wind (clearly not even possible if we're even discussing using power-to-gas) or the emission of 1.4607t of CO2 to capture 1t of CO2 if we burn hydrocarbon fuels to generate that energy.  Unless the power required comes almost entirely from renewable sources (solar, wind, geothermal, nuclear), then Carbon capture schemes like this are only adding to the problem.  We're emitting 40,000,000,000 (forty billion) metric tons of CO2 per year.  That's how much we'd have to stop emitting or pull out of the atmosphere every year just to keep our atmospheric bathtub's CO2 level where it already is.

We're looking at 120 billion MWh of electricity to remove that much CO2.

40,000,000,000t of CO2 * 3,000,000Wh (3MWh) = 120,000,000,000,000,000Wh

120,000,000,000,000,000Wh = 120,000,000GWh

120,000,000GWh = 12,000TWh (TeraWatt-hours)

12,000TWh = 120PWh (PetaWatt-hours)

Total US electricity production in 2018 was 4,178TWh according to the US EIA:
4,178 TWh (billion kWh) net
1,468 TWh (35%) gas
1,146 TWh (27%) coal
807 TWh (19%) nuclear
292 TWh hydro
275 TWh (6.6%) wind
67 TWh (1.6%) solar
63 TWh biomass
60 TWh geothermal or other sources

All nuclear reactors in the world generated 2,506TWh worth of power in 2017.  So far as I know, total wind and solar output didn't come close to that.  About 3 times as much energy as the entire US of A consumes in a year would be required to be "carbon neutral"- meaning we stop filling up the bathtub.  When you're in a hole that you can't get out of, the best first course of action is to STOP DIGGING!

Edit:

After reading about this nonsense, something very important skipped my mind entirely.  The 3MWh is the power required to remove the CO2 from the air and store it.  We haven't factored in a single kWh to actually produce Methane unless we have a single step process for doing that.  If we're going to electrolyze water to obtain H2, then we need to add that to the energy cost.  Thereafter, we need to either liquefy, pump via pipe, or burn the CH4 created on the spot (to avoid pumping or liquefaction losses due to the power required to do that).

Last edited by kbd512 (2019-04-21 14:00:14)

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#11 2019-04-21 15:05:56

Terraformer
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From: Lancashire
Registered: 2007-08-27
Posts: 3,012
Website

Re: Power to gas is the way forward for storage

Converting solar energy to electricity to produce methane probably doesn't make sense. If you have vast expanses of desert with clear skies, you can use concentrated solar power to produce CO from CO2, then use part of that CO to produce H2 with the water gas shift reaction, feeding the CO2 produced back into the furnace to produce more CO and using the H2 and CO to produce hydrocarbons.


"I guarantee you that at some point, everything's going to go south on you, and you're going to say, 'This is it, this is how I end.' Now you can either accept that, or you can get to work." - Mark Watney

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#12 2019-04-21 16:28:16

louis
Member
From: UK
Registered: 2008-03-24
Posts: 4,565

Re: Power to gas is the way forward for storage

I see you've taken the outlier figure for a thoroughly inefficient process. The theoretical minimum is 138 KwH per tonne.

I'm suggesting that you probably only need to store something like 10% of your annual energy output to provide sufficient storage for electricity.  I can only go on the UK experience but the number of days when we have very little wind and very little solar energy being produced are fairly rare. I once had a look at the figures and it looked like probably 2-3 days per month. There's never a period when we go a whole month in that "rut". You use the intervening periods to build up your energy store.

In the UK some of the stored energy can be in the form of energy from waste, hydro and biofuels - and some can come in from other countries via the continental grid.  There will be increasing chemical battery storage (including via the increased number of EVs on the road, which can feed energy back into the grid).  Maybe when you get down to the detail you might need only something like 5% of the annual energy ouput to be stored as artificial methane.

5% would be about 210 TwHs for the USA. 23 Gws averaged over the year.  Very large amount but even if you had to use 100 Gws of renewables to produce it, it would be doable. As the article I cited noted if the marginal cost of energy is close to zero (or even negative depending on how you price up your energy) - because you are doing the storing at times of overproduction -  then the energy use is really rather unimportant. The cost of the processing machinery to create artificial methane is really where the costs lie.   

The other cost reduction factor is that in a country like the UK we already have the gas storage, pipeline and gas turbines that can be used with artificial methane.

Obviously electricity production is only part of the picture.

There's still a lot of scope for wind energy expansion but I think solar energy will be the really big area of expansion because I think we'll the costs of installation come down as well.


kbd512 wrote:

ClimeWorks' CO2 capture solution has the following power requirements for each metric ton of CO2 they pull out of the air:
2.5MWh (thermal)
0.5MWh (electric)

Here's your source for those numbers:
The Swiss company hoping to capture 1% of global CO2 emissions by 2025

Generating 3MWh of power to make this process work at an industrial scale would dictate a complete conversion to solar and wind (clearly not even possible if we're even discussing using power-to-gas) or the emission of 1.4607t of CO2 to capture 1t of CO2 if we burn hydrocarbon fuels to generate that energy.  Unless the power required comes almost entirely from renewable sources (solar, wind, geothermal, nuclear), then Carbon capture schemes like this are only adding to the problem.  We're emitting 40,000,000,000 (forty billion) metric tons of CO2 per year.  That's how much we'd have to stop emitting or pull out of the atmosphere every year just to keep our atmospheric bathtub's CO2 level where it already is.

We're looking at 120 billion MWh of electricity to remove that much CO2.

40,000,000,000t of CO2 * 3,000,000Wh (3MWh) = 120,000,000,000,000,000Wh

120,000,000,000,000,000Wh = 120,000,000GWh

120,000,000GWh = 12,000TWh (TeraWatt-hours)

12,000TWh = 120PWh (PetaWatt-hours)

Total US electricity production in 2018 was 4,178TWh according to the US EIA:
4,178 TWh (billion kWh) net
1,468 TWh (35%) gas
1,146 TWh (27%) coal
807 TWh (19%) nuclear
292 TWh hydro
275 TWh (6.6%) wind
67 TWh (1.6%) solar
63 TWh biomass
60 TWh geothermal or other sources

All nuclear reactors in the world generated 2,506TWh worth of power in 2017.  So far as I know, total wind and solar output didn't come close to that.  About 3 times as much energy as the entire US of A consumes in a year would be required to be "carbon neutral"- meaning we stop filling up the bathtub.  When you're in a hole that you can't get out of, the best first course of action is to STOP DIGGING!

Edit:

After reading about this nonsense, something very important skipped my mind entirely.  The 3MWh is the power required to remove the CO2 from the air and store it.  We haven't factored in a single kWh to actually produce Methane unless we have a single step process for doing that.  If we're going to electrolyze water to obtain H2, then we need to add that to the energy cost.  Thereafter, we need to either liquefy, pump via pipe, or burn the CH4 created on the spot (to avoid pumping or liquefaction losses due to the power required to do that).

Last edited by louis (2019-04-21 16:30:19)


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#13 2019-04-21 16:31:14

SpaceNut
Administrator
From: New Hampshire
Registered: 2004-07-22
Posts: 15,037

Re: Power to gas is the way forward for storage

Energy is a supply it and we demand it more and more so its cost even when considering free energy sources will not make it go down as the demand will always out weigh the source. We use it even when we do not need to...The current grid supply monitors the draw and need and will compensate for excess by powering down facilities and as well by powering them up when demand rises.

The sources of solar and water do not have the natural ability to power down they only have on and off due to condition of water flowing and sun shining.

Nuclear and things that burn can all be throttled back down or to off.

So rather than fight the independant individual for solar or wind it goes out of its way to make the cost rise and deploy there own fields to keep there profit margins up.

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#14 2019-04-21 16:41:41

louis
Member
From: UK
Registered: 2008-03-24
Posts: 4,565

Re: Power to gas is the way forward for storage

Just to add:

As you can see from the link below photovoltaics are growing at a phenomenal rate with doubling of capacity about every 2-3 years.

https://en.wikipedia.org/wiki/Growth_of_photovoltaics

Grid parity has now been achieved in some 30 countries. More will follow of course.

There is nothing really to stop PV power being scaled up globally.

It might take 20, 30 or maybe 50 years but I can't see anything stopping solar eventually becoming our key energy source (because it will be so cheap).

As we go forward the storage issue will be resolved.


Let's Go to Mars...Google on: Fast Track to Mars blogspot.com

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#15 2019-04-21 17:41:55

kbd512
Moderator
Registered: 2015-01-02
Posts: 2,717

Re: Power to gas is the way forward for storage

Louis,

I've taken the actual power requirement figures that are actually required to power the actual ClimeWorks CO2 capture plant at the actual scale it's being run at in Zurich, an actual city in Switzerland.  In this case, as in all other cases, or so I hope, the word "actual" means the opposite of fictional, notional, aspirational, or anything other than objective reality.  The figures I presented were thus "actual" power requirements for CO2 capture, as opposed to fictional, notional, aspirational, or any other form of fantasy that ignores objective reality.

From the article:

Driving the Climeworks process uses 2.5 megawatt hours (MWh) of heat, at around 100C, for each tonne of CO2, along with 0.5MWh of power. This energy requirement is roughly equivalent to the 12GJ/tCO2 estimates set out above, though the firm hopes to shave 40% off this figure, bringing it down to around 7GJ/tCO2. Gebald says an increase in energy resources – he points to wind and solar – would be needed to scale up direct capture.

1t of crude oil contains approximately 41.868GJ of energy.  ClimeWorks' process requires 12GJ of energy just to capture the CO2.  Assuming we could somehow use 66% of that intrinsic energy content in this process, we're left with just over half of the energy that we get from simply sucking CH4 out of the ground.

So yeah, let's shave off 40% of that 120PWh figure.  Now we're at 72PWh.  We still need more power than the entire United States generates in a year to actually halt the increase in CO2 emissions.  You can't decrease emissions by burning more gas, especially if you're "making" the gas instead of simply sucking it out of the ground.  Why is that so hard to accept?

Here's a thought.  We could just burn the CH4 we suck out of the ground and capture the emissions from that instead of dumping it into the atmosphere.  That way we don't need to expend 50% of the energy we received from the combustion process to recapture the CO2 we created through combustion.  RamGen's supersonic CO2 compressor requires about 10% of the plant's output to capture and liquefy the CO2 in the exhaust and can recover some of that waste heat to lower the total power consumption requirement even further.

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#16 2019-04-21 17:56:18

louis
Member
From: UK
Registered: 2008-03-24
Posts: 4,565

Re: Power to gas is the way forward for storage

Is it the energy or the cost that's the concern?

If the energy cost is close to zero, as it is with overproduced wind and solar energy (stuff that would otherwise just get earthed), then it matter very little how much energy is required. We are NOT looking at replacing the whole of energy output with artificial methane, we are looking to replace  maybe 5% of output with artificial methane. It might actually be lower. A lot depends on the efficacy of continental grids.


kbd512 wrote:

Louis,

I've taken the actual power requirement figures that are actually required to power the actual ClimeWorks CO2 capture plant at the actual scale it's being run at in Zurich, an actual city in Switzerland.  In this case, as in all other cases, or so I hope, the word "actual" means the opposite of fictional, notional, aspirational, or anything other than objective reality.  The figures I presented were thus "actual" power requirements for CO2 capture, as opposed to fictional, notional, aspirational, or any other form of fantasy that ignores objective reality.

From the article:

Driving the Climeworks process uses 2.5 megawatt hours (MWh) of heat, at around 100C, for each tonne of CO2, along with 0.5MWh of power. This energy requirement is roughly equivalent to the 12GJ/tCO2 estimates set out above, though the firm hopes to shave 40% off this figure, bringing it down to around 7GJ/tCO2. Gebald says an increase in energy resources – he points to wind and solar – would be needed to scale up direct capture.

1t of crude oil contains approximately 41.868GJ of energy.  ClimeWorks' process requires 12GJ of energy just to capture the CO2.  Assuming we could somehow use 66% of that intrinsic energy content in this process, we're left with just over half of the energy that we get from simply sucking CH4 out of the ground.

So yeah, let's shave off 40% of that 120PWh figure.  Now we're at 72PWh.  We still need more power than the entire United States generates in a year to actually halt the increase in CO2 emissions.  You can't decrease emissions by burning more gas, especially if you're "making" the gas instead of simply sucking it out of the ground.  Why is that so hard to accept?

Here's a thought.  We could just burn the CH4 we suck out of the ground and capture the emissions from that instead of dumping it into the atmosphere.  That way we don't need to expend 50% of the energy we received from the combustion process to recapture the CO2 we created through combustion.  RamGen's supersonic CO2 compressor requires about 10% of the plant's output to capture and liquefy the CO2 in the exhaust and can recover some of that waste heat to lower the total power consumption requirement even further.


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#17 2019-04-21 18:55:25

kbd512
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Registered: 2015-01-02
Posts: 2,717

Re: Power to gas is the way forward for storage

Louis,

This is nuts.  It does the opposite of solving the problem.  It makes the problem worse.  It requires more energy input than we get as output from the processes we already use.  The simple physics of ClimeWorks' process is grossly infeasible at current efficiencies and at aspirational efficiencies.  There are no free lunches to be had here.  Sorry.

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#18 2019-04-22 03:06:19

Terraformer
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From: Lancashire
Registered: 2007-08-27
Posts: 3,012
Website

Re: Power to gas is the way forward for storage

The more inefficient steps you add, the worse the Energy Return On Investment gets. If your round trip efficiency for storage is only 25%, then your EROI drops by a factor of four, and solar probably can't compete at that point. Solar panels *do* take energy to produce.


"I guarantee you that at some point, everything's going to go south on you, and you're going to say, 'This is it, this is how I end.' Now you can either accept that, or you can get to work." - Mark Watney

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#19 2019-04-22 05:10:24

louis
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From: UK
Registered: 2008-03-24
Posts: 4,565

Re: Power to gas is the way forward for storage

The key here - something neither you nor kbd seem to understand - is cost. If solar and wind are cheaper than coal, oil and gas then the EROI is irrelevant. In many contexts wind energy is already lower than competing hydrocarbons.  Cost (unsubidised) is all that matters.  You might get a better EROI from coal but you've still got to get it out of the ground and transport it thousands  of miles, and burn it - that involves a lot of human labour and that costs - and every tonne of coal requires that huge labour input.  When the wind is blowing nicely, a wind turbine needs hardly any human input at all.  That's why it can be so cheap (well on land at least for the moment - marine wind energy has yet to get costs down to competitive levels).

The marginal cost of wind energy produced on a windy day or solar on a sunny day is tiny .  The marginal price is effectively near zero because the grid doesn't need the overproduction. The energy just goes to waste if you don't use it. So that is the context: virtually free energy to undertake CO2 extraction and process artificial methane. The point here is that storage makes wind and solar able to increase their income because they can then provide baseload.

I am not saying all this will happen tomorrow. I am saying that when wind and solar consistently beat hydrocarbons on price the stage will be set to solve the storage problem so that wind and solar with storage can supply baseload. 

Terraformer wrote:

The more inefficient steps you add, the worse the Energy Return On Investment gets. If your round trip efficiency for storage is only 25%, then your EROI drops by a factor of four, and solar probably can't compete at that point. Solar panels *do* take energy to produce.


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#20 2019-04-22 17:36:44

kbd512
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Registered: 2015-01-02
Posts: 2,717

Re: Power to gas is the way forward for storage

Louis,

If you had a process that mandated burning more gas, or otherwise consuming more energy that had to come from somewhere, to get the same output that we already obtain from burning the gas that we suck out of the ground, please explain why you would do that?

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#21 2019-04-22 19:41:11

SpaceNut
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From: New Hampshire
Registered: 2004-07-22
Posts: 15,037

Re: Power to gas is the way forward for storage

Now that this Disney’s New 270-Acre Solar Farm Can Power Two Of Its Theme Parks has been built and producing power.

How does this impact my cost for power?
Did it change the cost per panel?

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#22 2019-04-22 19:53:13

louis
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From: UK
Registered: 2008-03-24
Posts: 4,565

Re: Power to gas is the way forward for storage

Because the overall unsubsidised cost across a year would be less.  Now you understand?

(I do have to add: do you understand what marginal cost and mariginal price theory is all about? If you don't I can understand your confusion.)

kbd512 wrote:

Louis,

If you had a process that mandated burning more gas, or otherwise consuming more energy that had to come from somewhere, to get the same output that we already obtain from burning the gas that we suck out of the ground, please explain why you would do that?

Last edited by louis (2019-04-22 19:54:44)


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#23 2019-04-22 20:16:10

kbd512
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Registered: 2015-01-02
Posts: 2,717

Re: Power to gas is the way forward for storage

Louis,

Could you show your math to illustrate to the rest of us how this scheme will work?

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#24 2019-04-23 04:10:30

louis
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From: UK
Registered: 2008-03-24
Posts: 4,565

Re: Power to gas is the way forward for storage

Well I can only do so in very general terms but this is based on how things already operate in large part in UK and European electricity markets.  It would not be entirely feasible at the moment since we don't yet have large scale artificial methane manufacture.

Baseload would be provided by a mix of wind, solar, hydro, energy from waste and other renewables with artificial methane being used where necessary.

The grid operators would control the methane gas turbines and the methane manufacture.

The grid operators would contract with wind and solar energy companies who would be paid a certain rate for their contribution to baseload and peak load.  Let's assume that's 2 cents per KwH*. The wind and solar companies would agree to sell their overproduction at 0 cents per KwH to the grid operator.  The grid operator would then use that energy to power the process of methane manufacture. Clearly that is still an expensive process because of the complexity and scale involved. Looking at the Climeworks figure we might be getting down to 20 cents per KwH at some point with free energy input...that would require a lot more research.  The stored gas would be used to drive gas turbines during period of low wind-solar energy output. But of course, the grid operator would also import electricity from elsewhere on the continental grid - in Germany they make a lot of use of Scandinavian hydro through the continental grid. You can also ramp up electricity produced from your own hydro, energy from waste and biofuel facilities.

For somewhere like the UK, I estimate the amount of time (measured in relation to 100% of averaged electricity usage across the year) when wind + solar + other renewables + continental grid imports could not meet demand as something like 10%  or about 3 whole days a month.  (Of course there will never be a situation where you getting 0% from those sources. The shortfall is unlikely ever to be greater than 80%). Now, of course, you can ramp up electricity production from hydro, biofuels and energy from waste facilities when required. In the future I think it reasonable to assume as well we will have more chemical battery storage (but I haven't taken that on board in the figures below as a separate item it would probably be integrated into the grid operation). So the 10% figure can probably be reduced further. Let's say to 7% on this occasion.

So a likely scenario for a whole year might be:

Wind and solar - 80% at 2 cents per KwH for

Artificial methane - 7% at 20 cents per KwH

Other renewables - 9% at 8 cents per KwH

Continental grid - 4% at 6 cents per KwH

Average price would be 3.96 cents per KwH.

A more sophisticated model might also make use of the stored energy in EV batteries (giving drivers an incentive to sell the electricity back to the grid).

[* For future costing I am guided by  this:

"This month, Colorado utility company Xcel Energy received "shockingly low bids" for electricity from renewable sources. How shocking? Wind power bids had a median average price of 1.8 cents per kilowatt-hour, and solar’s median bid was 2.95 cents per kilowatt hour. Even with storage technology costs included — allowing renewables to generate 24/7 just like fossil fuels — the average wind price was 2.1 cents per kilowatt hour and the average solar price was 3.6 cents per kilowatt hour. According to the Denver Post, if wind bids come in at 2 cents per kilowatt hour, customers would save $175 million versus building new fossil fuel plants."

https://www.greenbiz.com/article/5-reas … nstoppable

I think we discussed those figures before and there may be some smallish subsidy effects permitting such low tenders but all the technology trends in wind and particular solar are driving down cost/price in that direction.]


louis wrote:

Because the overall unsubsidised cost across a year would be less.  Now you understand?

(I do have to add: do you understand what marginal cost and mariginal price theory is all about? If you don't I can understand your confusion.)

kbd512 wrote:

Louis,

If you had a process that mandated burning more gas, or otherwise consuming more energy that had to come from somewhere, to get the same output that we already obtain from burning the gas that we suck out of the ground, please explain why you would do that?


Let's Go to Mars...Google on: Fast Track to Mars blogspot.com

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#25 2019-04-23 19:21:42

kbd512
Moderator
Registered: 2015-01-02
Posts: 2,717

Re: Power to gas is the way forward for storage

Louis,

None of this was ever about cost, it was about simple energy expended to produce a specified amount of energy (edit: "specified amount of energy storage", not "specified amount of energy"), but you seem obsessed with cost (in practice the energy will come from more gas burned to achieve grid stability whenever the sun doesn't shine or the wind doesn't blow, which is exactly what's going on in Germany), so let's focus on cost since you're so fixated on that.

I'm not sure where your figures come from, but mine come from US EIA.  I seriously doubt they're trying to sell anything to anyone or spread propaganda, so we'll use their figures since they're ostensibly a bit more comprehensive than any single data point picked to support either side of this argument.

Earlier you accused me of cherry picking costs, but I merely reposted the current energy costs of ClimeWorks' CO2 capture solution- data that came from ClimeWorks.  That was the energy required before any of the captured CO2 was used to make anything, be it Methane or any other product.  That doesn't seem much like cherry picking to me, but I'll turn this argument around.  Cherry picking the cost of solar from some place where solar is heavily subsidized by the state government, for example, says nothing about what the actual cost is either there or elsewhere in the world.  When you add the cost of the tax credit (money taken from all tax payers to subsidize solar and wind that would otherwise never be used if cost was driving purchasing decisions) back into the LCOE for solar and wind, projected future solar and wind projects coming on line in 2020 are every bit as expensive as combined-cycle natural gas and then some.  The price is most definitely nowhere near zero.

Scroll to "Appendix A: LCOE tables for new generation resources entering service in 2020" (Page 12):

US EIA - Levelized Cost and Levelized Avoided Cost of New Generation Resources in the Annual Energy Outlook 2018

Please take note of the "Total system LCOE".  It's not less than gas, except for very expensive peaking plants, nor anywhere near zero.

Last edited by kbd512 (2019-04-23 19:22:36)

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