Electricity Carbon Intensity Viewed in Terms of Export and Import.

[NNadir]

The paper I will discuss in this brief post comes from the most recent issue of Environmental Science and Technology, a scientific journal that is a publication of the American Chemical Society.

The paper is here:

Virtual CO2 Emission Flows in the Global Electricity Trade Network (Xu et al, Environ. Sci. Technol., 2018, 52 (11), pp 6666–6675)

Some introductory text:

Electric power generation contributes significantly to global greenhouse gas (GHG) emissions. In 2014, over 40% of the global carbon dioxide (CO2) emissions were from the electric power sector.1 Mitigation initiatives, strategies, and policies related to the power sector have taken place at various scales, including the national, regional, organizational, and even individual scales. Underpinning such effects is the accurate and fair accounting for GHG emissions, for emissions from both electricity generation and consumption. Consumptionbased accounting is particularly relevant to initiatives and policies at regional, organizational, and individual levels. Converting grid electricity consumption (or purchased electricity) into emissions from power generation requires the measurement and use of the emission factor, which is defined as the emission generated due to unitary electricity consumption.

Current practices mostly use production-based emission factors for estimating emissions driven by electricity consumption...

...However, as electricity is purchased and consumed from interconnected grids, production-based emission factors lead to inaccurate measurements of emissions due to electricity consumption. In particular, power grids are connected and interdependent at the regional and even the global level. Indeed, global electricity trade has been steadily increasing in past decades. For example, electricity exports and imports of OECD countries have been growing by 4.5% and 4.3% annually from 1974, and reached 511 TWh and 510 TWh in 2015, respectively.5 Electricity trade brings about economic benefit, since it opens the opportunities to exploit region variations in natural resources, climate and load timing, reducing the surplus generation capacity needed.5,6 However, similar to the fact that globalized supply chains distance production and consumption and render environmental responsibilities more “invisible”,7,8 cross-border electricity trade furthers the separation between electricity generation and consumption...

In other words, if you live in a prominent middle European nation that makes a big deal about its Hoary Bat and Raptor grinding wind turbines, but import lots of electricity when the wind isn't blowing from the neighboring country of Poland - where almost all power is generated by burning coal - that counts.

One would think that would be obvious, but somehow it's not.

The graphics in this paper can be a little challenging to look at, but here are two that are straight forward:

Figure 1. Global electricity trade network in 2014. Curves represent direct electricity transfers, which flow clockwise from origins to destinations. Curve widths indicate the amount electricity transfers, some of which are labeled in TWh. Node size represents electricity generation of countries/ regions. Countries/regions are labeled with their ISO codes. The insets of (A) and (B) zoom in the African community and the European part of the Eurasian community, respectively. Map images are from the GADM database of Global Administrative Areas.30

The caption:

Figure 2. (A) Emission factors of electricity consumption of countries/regions. Shades of color represent the values of emission factors (efi C,network for country/region i), while sizes of circles represent total electricity consumption. White areas are where data are incomplete. (B) Differences between various accounting methods for country/region-level emission factors of electricity consumption. Blue area indicates that emission factors for electricity consumption (efi C,network) is smaller than those for generation (efi G); red area indicates the opposite. For hashed/meshed areas, enlarging the system boundary of accounting for electricity trade significantly changes estimates of emission factors, either downward (in hashed areas, where efi C,network/efi C,direct adjust < 95%) or upward (in meshed areas, where efi C,network/efi C,direct adjust > 105%). Map images are from the GADM database of Global Administrative Areas.3

Some more text:

When a country/region is a net virtual CO2 importer (or exporter) in the electricity trade network, the CO2 emission responsibility for its electricity consumption is greater (or less) than that for its electricity generation. In Europe, countries with the largest amounts of net virtual CO2 imports through electricity trade are Italy (11 Mt), Austria (7.7 Mt), Switzerland (5.5 Mt), and Hungary (5.1 Mt); and the most important net virtual CO2 exporters are Germany (32.4 Mt), Czech Republic (8.5 Mt) and Ukraine (5.4 Mt). In Africa, Mozambique, and Botswana have the largest net virtual CO2 imports (5.5 Mt and 4.9 Mt, respectively), and South Africa is the most important net CO2 exporter (12.4 Mt).

While the paper itself is not open sourced, the supplementary information is open sourced. It is here: Supporting Info Environ. Sci. Technol., 2018, 52 (11), pp 6666–6675

One may refer to table S4 in the supporting info to see the carbon intensity of almost every country in the world, based on production and then adjusted for consumption of imported electricity.

France for example, a country largely dependent on nuclear energy although there is an idiotic quest to destroy that happy circumstance along with the entire avian ecosystem, as my son, who is spending the summer in France, reports, has a carbon intensity based on production of 41.0 grams CO2/kwh, adjusted for trade and consumption to 44.2 grams CO2/kwh. The offshore oil and gas drilling hellhole of Denmark, internationally worshiped for its hatred of hoary bats and seabirds, has a carbon intensity for production that is 620% times that of France, at 255.1 grams CO2/kwh based on in country production but only 522% times that of France, at 227.2 grams CO2/kwh when adjusted for exports, compared, again, to France's 44.2.

The raptor and bat hating country of Germany, which can't grind up its avian ecosystem fast enough to satisfy world cheering, has an electricity carbon intensity based on production of 474.0 grams CO2/kwh, in "percent talk" so favored by people who love grinding up hoary bats and raptors, 1156% greater than that of France, but when adjusted for exports is "only" 1026% greater than that of France, at 453.6 grams CO2/kwh. This figure is very close to the standard figure for a dangerous natural gas fueled power plant, although Germany still produces lots of coal based electricity along with its bird and bat grinding based electricity.

This year the dangerous fossil fuel waste carbon dioxide concentrations peaked in the planetary atmosphere at close to 412 ppm. No one now living will ever see concentrations below 400 ppm again. Twenty years ago they were around 370 ppm, and 20 years before that they were at 338 ppm.

We're doing great. We really know what we're doing. Even if we hate bats and raptors and every other damned creature that flies, we're practically breaking our arms patting ourselves on our backs for being "green."

Have a great weekend.

[StevieM]

1. I have a couple more questions for you.

First, what do you think of Generation IV Molten Salt Reactors. I have heard that they may produce electricity at a cheaper price than current nuclear power plants.

Second, do you think that nuclear power plants could also produce hydrogen that could in some way be beneficial to our energy economy?

[NNadir]

2. I was once very enthusiastic about molten salt reactors of the Oak Ridge MSRE type.

I'm less so now.

I think it's not necessarily a bad concept, but it has some chemical risks - while very few nuclear risks - that I think ought to be avoided.

Beryllium is a toxic metal.

Thorium is present to a larger extent in terrestrial ores than uranium is, but it is not as sustainable as uranium is, since uranium has enough solubility in seawater to be economically extracted from it.

Also thorium breeding is considerably slower than uranium/plutonium breeding.

Now, lots of thorium has been mined and dumped to get the lanthanides that are commonly used in the ridiculous wind turbine industry (as well as certain types of electric and hybrid cars) and semiconductor devices.

My environmental vision calls for the elimination of all energy mining (coal, gas, oil, and uranium) for the next several centuries in the hopes that humanity will become an intelligent life form concerned with its own survival.

In order to do this, we must utilize depleted uranium. Depleted uranium is only useful with high breeding ratio reactors. The fuel with the highest breeding ratio is liquid plutonium in its molten state. This was last investigated in the late 1950's and early 1960's in the wonderful LAMPRE experiment. In its time, it had a profound materials science problem that I believe should have a solution today with modern materials science development.

In the meantime, we have several versions of "breed and burn" reactors in late stage development. These in my view are next best nuclear thing. I hope that in the near future we will be building these things like crazy. They are designed to run for decades without refueling. They're nice reactors, albeit, regrettably, in many cases cooled with liquid sodium. (Other metals are better.)

As for the question of nuclear hydrogen, this is a well reviewed concept, and many very interesting thermochemical hydrogen cycles are known. There are also thermochemical cycles that spit carbon dioxide into carbon monoxide and oxygen. If one has carbon monoxide, one effectively has hydrogen. In fact 99% of the hydrogen currently produced on this planet, most of which is consumed to make ammonia is made using the water gas shift reaction with carbon monoxide as a reactant. It's old chemistry, effectively practiced for a century on an industrial scale.

Thermochemical cycles are not industrialized, but could be. Unfortunately most of the effort in modern times has been devoted to idiotic solar thermal schemes, all of which have been commercial and technical disasters. But this is one area of solar research that will not be as useless as most of it has been.

Nuclear hydrogen is a technically feasible and in fact, highly desirable idea, particularly if future generations undertake the extremely difficult engineering task of removing our waste carbon dioxide from the place we dumped it, the atmosphere.

Thanks for asking.

[StevieM]

3. Thank you for that information. I have long thought of how hydrogen could benefit us.

Obviously, it could also be used to produce electricity.

Perhaps it could be used for heating homes and water.

But I think we have to find another way of fueling transportation. I know you hate what you call "car culture" but realistically it is not going away. There are no imaginable circumstances under which people will stop driving cars to get places. Which means we need to find a new way of fueling them. If it is not going to be electric, then it needs to be something else.

That is part of the reason I am curious about hydrogen and DME. If nothing else maybe hydrogen can power buses and DME can replace diesel. I just feel like there has to be a plan to reduce carbon emissions from cars that recognizes that they are not going to disappear from our society.

[NNadir]

4. Hydrogen is a poor fuel for consumer use.

It's critical temperature is far too low; as is it's viscosity, which gives it a high propensity for leaking.

It is extremely useful captive intermediate, and of all the very many hydrogen carriers investigated and hyped, everything from aluminum to zinc to halogen acids to...well what have you... dimethyl ether is the best.

This is because of its high critical temperature, around 150C, which makes it an alternative fuel for internal combustion engines that is easy and safe to transport, in particular diesel engines; its lack of a carbon carbon bond, which makes it largely free from particulates outside of the Boudouard equilibrium; it's short atmospheric half-life; and it's ready use, with minor adjustments, for most existing LPG, propane, and dangerous natural gas infrastructure.

There is other features of DME about which I haven't written much but have become aware, which is as an excellent heat transfer agent as well as interesting solvent properties in both its liquid and supercritical state.

I often rail against energy storage and in fact, did so today in another thread. However capturing and storing energy that would otherwise be dumped or wasted is a good idea, and DME offers interesting properties along these lines as well.

We'll have to agree to disagree on whether or not the car CULTure will go away or not. I personally believe it will go away simply because it is not sustainable. I say this as something of a hypocrite since I am a participant in the car culture and what's worse, I know it's wrong, which were I more interesting than I actually am, might make me a good literary figure, say like Jean-Baptiste Clamence or Lord Jim.

But I'm not that interesting except that I have certain insights into what is possible that might make a better world than the one in which I live.

Thanks for your comments.

Have a nice evening.

[StevieM]

5. Have you read this article?

I was wondering what you thought of it.

https://ac.els-cdn.com/S187661021100292X/1-s2.0-S187661021100292X-main.pdf?_tid=7055f7f0-f977-4fd5-bcb9-8ff633901484&acdnat=1528815770_68f2cb12b4b63a89ae6f865fc10c5bc1

[NNadir]

6. Not this particular one, but many, many like it.

From my perspective I believe that carbon dioxide capture only makes sense if there is a use for it.

I probably have hundreds if not thousands of such files in my computer.

Making commercial organic molecular commodities from carbon oxides is well known chemistry which has been industrialized many different times.

The question is one of energy.

I personally believe that high temperature nuclear reactors of a type not yet common or well known would be ideal for this purpose.

[StevieM]

7. Here is a much better version of that article. It is more easily readable and I think it adds

some material.

https://ac.els-cdn.com/S187661021100292X/1-s2.0-S187661021100292X-main.pdf?_tid=5b4421ac-b481-4d7d-9883-51ca9549dccd&acdnat=1528822188_651fc50a117b0c2c9198e08a2443410f

I had meant to post this version above. I am not sure how I posted to the other link.

ON EDIT: Actually it seems to be coming out the same. Maybe I was wrong. It seems like if you click on it more than once it doesn't get presented the same way on the screen.

[NNadir]

9. I opened the paper up, downloaded it, and briefly scanned it.

It's an electrolysis paper, designed to utilize excess power by avoiding boration of the core water.

It's an OK idea for existing reactor type and has certain merits. However electrolysis is thermodynamically inefficient and there are far more efficient ways to convert nuclear heat to hydrogen, but none that address the problem of existing reactor types.

I'm not all that familiar with French reactor standard operating procedure, but it does make sense to run any device at near capacity and balance utilization.

In the Pacific Northwest this used to be the practice for aluminum manufacture running off hydroelectric plants. They'd make power during periods of peak demand and aluminum during periods of low demand.

In the type of system I envision, I have a similar thought, although I would divert heat rather than electricity. This allows for much higher thermodynamic efficiency.

Thanks for the reference.

[hunter]

8. That link is a redirect to...

CO2 to fuel using nuclear power: The French case

Abstract

In France, the majority of the electricity generated is derived from nuclear energy which has a low CO2 footprint.

A preliminary analysis showed us that, in the French specific context, without any new nuclear power plant construction, the emission of several millions tons of CO2 could be avoided by using a CO2 to fuel technology to adjust the electricity produced by nuclear energy to the electricity grid demand. This will not only mitigate CO2 emissions but could also increase nuclear economic competitiveness.

Possibilities of direct using nuclear heat are also under investigation, to improve the efficiency of the global system of conversion.

https://www.sciencedirect.com/science/article/pii/S187661021100292X

The only way we can make this and other similar projects happen is to ban fossil fuels.

I think many affluent anti-nuclear activists would warm to nuclear power if they couldn't otherwise drive or fly to their favorite vacation playgrounds.