Carbon intensity research and data

US CO2 and Methane Intensity by Basin

The CO2 intensity of oil and gas production is tabulated for 425 distinct company positions across 12 distinct US onshore basins in this data-file. Using the data, we can break down the upstream CO2 intensity (in kg/boe), methane leakage rates (%) and flaring intensity (mcf/boe), by company, by basin and across the US Lower 48.

In this database, we have aggregated and cleaned up 957 MB of data, disclosed by the operators of 425 large upstream oil and gas acreage positions. The data are reported every year to the US EPA, and made publicly available via the EPA FLIGHT tool.

The database covers 70% of the US oil and gas industry from 2021, including 8.8Mbpd of oil, 80bcfd of gas, 22Mboed of total production, 430,000 producing wells, 800,000 pneumatic devices and 60,000 flares. All of this is disaggregated by acreage positions, by operator and by basin. It is a treasure trove for energy and ESG analysts.

CO2 intensity. The mean average upstream oil and gas operation in 2021 emitted 10kg/boe of CO2e. Across the entire data-set, the lower quartile is below 3kg/boe. The upper quartile is above 13kg/boe. The upper decile is above 20kg/boe. And the upper percentile is above 70kg/boe. There is very heavy skew here (chart below).

The main reasons are methane leaks and flaring. The mean average asset in our sample has a methane leakage rate of 0.21%, and a flaring intensity of 0.03 mcf/bbl. There is a growing controversy over methane slip in flaring, which also means these emissions may be higher than reported. Flaring intensity by basin is charted below.

US CO2 intensity has been improving since 2018. CO2 intensity per basin has fallen by 17% over the past three years, while methane leakage rates have fallen by 22%. Activity has clearly stepped up to mitigate methane leaks.

(You can also see in the data-file who has the most work still to do in reducing future methane leaks. For example, one large E&P surprised us, as it has been vocal over its industry-leading CO2 credentials, yet it still has over 1,000 high bleed pneumatic devices across its Permian portfolio, which is about 10% of all the high-bleed pneumatics left in the Lower 48, and each device leaks 4 tons of methane per year!).

Most interesting is to rank the best companies in each basin, using the granular data, to identify leaders and laggards (chart below). A general observation is that larger, listed producers tend to have lower CO2 intensity, fewer methane leaks and lower flaring intensity than small private companies. Half-a-dozen large listed companies stand out, with exceptionally low CO2 intensities. Please consult the data-file for cost curves (like the one below).

Methane leaks and flaring intensity can also be disaggregated by company within each basin. For example, the chart below shows some large Permian producers effectively reporting zero flaring, while others are flaring off over 0.1 mcf/bbl.

All of the underlying data is also aggregated in a useful summary format, across the 425 different acreage positions reporting in to EPA FLIGHT, in case you want to compare different operators on a particularly granular basis.

Refrigerants: leading chemicals for the rise of heat pumps?

What chemicals are used as refrigerants? This data-file is a breakdown of the c1MTpa market for refrigerants, across refrigerators, air conditioners, in vehicles, industrial chillers, and increasingly, heat pumps. The market is shifting rapidly towards lower-carbon chemicals, including HFOs, propane, iso-butane and even CO2 itself. We still see fluorinated chemicals markets tightening.

Refrigerants are used for cooling. The thermodynamic principle is that these chemicals have low boiling points (averaging around -30ºC). They absorb heat from their surroundings as they evaporate. Then later these vapors are re-liquefied using a compressor.

The global market includes over 1MTpa of refrigerants, for use in refrigerators (around 100 grams per fridge), passenger cars (1 kg per vehicle) and home AC systems (4 kg per home). There is also an industrial heating-cooling industry, including MW-scale chillers that might contain 400kg of refrigerants, to large global LNG plants.

The market is growing. Structurally, heat pumps could add another 4kg of refrigerant demand per household, especially in markets such as Europe with traditionally low penetration of AC. Rapid rises are also occurring in global AC demand.

From the 1930s onwards, CFCs were used as refrigerants. But CFCs are inert enough to reach the middle of the stratosphere, where they are broken down by UV radiation, releasing chlorine radicals. These chlorine radicals break down ozone (O3 into O2). Hence by the 1980s, abnormally low ozone concentrations were observed over the South Pole. Ozone depletion elevates the amount of UV-B radiation reaching Earth, increasing skin cancer and impacting agriculture. And hence CFCs were phased out under the Montreal Protocol of 1989.

CFCs were largely replaced with fluorocarbons, which do not deplete the ozone layer, but do have very high global warming potentials. For example, R-134a, which is tetrafluoroethane, is a 1,430x more potent greenhouse gas than CO2.

The Kigali Amendment was signed by UN Member States in 1989, and commits to phase down high-GWP HFCs by 85% by 2036. This has been supplemented by F-gas regulation in the EU and the AIM Act in the US. High GWP fluorocarbons are effectively banned in new vehicles and stationary applications in the developed world.

In addition, there has long been a market for non-fluorinated chemicals as refrigerants, but the challenge with these alternatives is that they tend to be flammable. Over half of domestic refrigerators use iso-butane as their refrigerant, which is permissible under building codes because each unit only contains about 100 grams of refrigerant (e.g., in Europe, a safety limit has historically been set at around 150 grams of flammable materials in residential properties, and is being revised upwards).

So what outlook for the fluorinated chemicals industry? Overall, we think demand will grow mildly. It is true that regulation is tightening, and phasing out fluorocarbons.

However, some of the leading refrigerants that are being “phased in” as replacement actually use more fluorinated chemicals than the refrigerants they are replacing…

Hydrofluoroolefins (HFOs) have no ozone depleting potential and GWPs <10. As an example, R-1234yf is now used in over 100M vehicles, and comprises 67% fluorine by mass. This is an increase from the 44% fluorine content in R-22, which was the previous incumbent for vehicle AC systems.

Impacts of electric vehicles? You could also argue that EVs will have increasing total refrigerant demand, as there are in-built cooling systems for many fast-chargers.

Using CO2 as a refrigerant could also be an interesting niche. It is clearly helpful for our energy transition ambition to increase the value in capturing and using CO2. But the challenging is that even if 215M annual refrigerator sales all used 100% CO2 as their refrigerant, this would only “utilize” around 25kTpa of CO2, whereas our Roadmap to Net Zero is looking for multi-GTpa scale CCUS.

For heat pumps, we think manufacturers are going to use propane, CO2, HFOs and a small class of low-GWP fluoro-carbons. So there is a small pull on the fluorinated chemicals value chain from the ramp-up of heat pumps. But the main pull on the fluorinated chemicals chain is going to be coming from batteries and solar, as explored in our recent fluorinated polymers research.

Leading Western companies making refrigerants in the data-file include Honeywell, DuPont, Chemours, Arkema, Linde, and others in our fluorinated chemicals screen.

Solar: energy payback and embedded energy?

What is the energy payback and embedded energy of solar? We have aggregated the consumption of 10 different materials (in kg/kW) and around 10 other line-items across manufacturing and transportation (in kWh/kW). Our base case estimate is 2.5 MWH/kWe of solar. The average energy payback of solar is 1.5-years. Numbers and sensitivities can be stress-tested in the data-file.

Our base case estimate covers a standard 560W solar panel, as is being manufactured in 2022-23, weighing 30kg, and having an efficiency of 22%.

By mass, this solar panel is about 65% glass, 15% aluminium, c10% polymers (mainly EVA encapsulants and PVF back-sheet), c3% copper. Photovoltaic silicon is only 5% of the panel by mass, but about 40% by embedded energy.

Another 10kg of material is contained in the balance of project, across inverters, wiring, structural supports, other electronics. Thus the energy embedded in manufacturing the panel is likely only around 60% of the total energy embedded in a finished solar project.

Our base case is that it will take around 2.5 MWH of up-front energy and release almost 3 tons of CO2 per kW of installed solar capacity. In turn, this suggests an energy payback of around 1.5-years and a CO2 payback of around 1.8-years.

The complexity of the solar value chain is enormous. Often it is also opaque. Thus the numbers can vary widely. We think there will be solar projects installed with an energy payback around 1-year at best and around 4-years at worst.

Our numbers do not include energy costs of power grid infrastructure or battery back-ups. This is simply a build-up for a vanilla project, trying to be as granular and objective as possible.

Inputs for the embedded energy and CO2 of different materials are drawn from our other CO2 screening work and economic models.

The other great benefit of constructing a detailed bill of materials for a solar installation is that we can use it to inform our solar cost estimates. Our best guess is that materials will comprise around half of the total installed cost of a solar installation in 2021-22 (chart below). There is going to be a truly remarkable pull on some of these materials from scaling up solar capacity additions.

We absolutely want to scale solar in the energy transition. This will be easiest from a position of energy surplus.

Please download the data-file to stress test our numbers around the embedded energy needed to construct a solar project, and the energy payback of solar.

Crop production: how much does nitrogen fertilizer increase yields?

How much does fertilizer increase crop yields? To answer this question, we tabulated data from technical papers. Aggregating all of the global data, a good rule of thumb is that up to 200kg of nitrogen can be applied per acre, increasing corn crop yields from 60 bushels per acre (with no fertilizer) to 160 bushels per acre (at 200 kg/acre).

The relationship is almost logarithmic. The first 40 kg/acre of nitrogen application doubles crop yields, from 60 bushels per acre to around 130 kg/bushel. The next 20 kg/acre adds another 5% to crop yields. The next 20kg/acre adds 4%. The next 20kg/acre adds 3%. And so on. Ever greater fertilizer applications have diminishing returns.

In 2022-23, many decision-makers and ESG investors are asking whether energy shortages will translate into fertilizer shortages, which in turn translate into food shortages. The answer depends. A 10kg/acre cut in nitrogen fertilizer may have a negligible 0-2% impact on yields in the most intensive developed world farming. Whereas it may have a disastrous, >10% impact in the developed world, on the “left hand side” of our logarithmic curves.

The scatter is broad, and shows that corn yields are a complex function of climate, weather, crop rotations, soil types, irrigation, other soil nutrients; and the nuances of how/when fertilizers are applied in the growing cycle. Nitrogen that is applied in the form of ammonia, ammonium nitrate, urea or NPK is always prone to denitrification, leaching, volatilization, and being uptaken by non-crop plants.

Moreover, while this data-file evaluates corn, the world’s most important crop by energy output, the relationship may be different for other crops. Corn is particularly demanding of nitrogen in its reproductive stages of growth. This ridiculously prolific crop will have 55% of its entire biomass invested in its ‘ears’ by the time of maturity. These ears contain so much nitrogen than around 70% is sourced by remobilizing nitrogen out of leaves and stems.

How much does fertilizer increase crop yields? For economic reasons. And to minimize the CO2 intensity of crop production. As a rule of thumb, the CO2 intensity of corn crop production is 75kg/boe, of which 50kg/boe is due to nitrogen fertilizer.

A constructive conclusion is that the first c40-80 kg/acre of nitrogen application does not increase CO2 intensity, or may even decrease it due to much greater yields. Best-fit formulae are derived in this data-file, using the data. So are our notes from technical papers, of which our favorite and most helpful was this paper from PennState.

We still see upside in conservation agriculture, and question marks over excessive reliance upon some biofuels as part of the energy transition.

Coal grades: what CO2 intensity?

What is the CO2 intensity of coal? To answer this question, we have aggregated data on twenty five coal samples, across different countries, grades and technical papers. Sampled countries include China, Indonesia, Mongolia, Germany, Poland, the US, Canada, Australia, Japan and Korea.

The coal grades in the data file span across petcoke, anthracite, bituminous coal, sub-bituminous coal and lignite. All of these are classified as “coal”. Although their chemical and physical properties vary vastly.

The average coal grade in our data-file consists of 63% carbon, 30% volatile components that will gas out when coal is heated, 12% moisture (i.e., water) and 12% ash. (Note that the numbers do not add to 100% because some of the volatile components include hydrocarbons, including methane, which in turn contain carbon). Again these properties vary widely, from anthracites with >5% moisture to lignites and peats with over 50%.

The average energy content is 6,250 kWh/ton, within a range of 3,000 kWh/ton to 9,000 kWh/ton. This is mostly determined by the amount of carbon in the coal grade, which in turn will determine its CO2 emissions. CO2 intensity can then be calculated by dividing CO2 emissions (in kg) by energy content (in kWh).

The typical CO2 intensity of burning coal is estimated at 0.37 kg/kWh, looking across these twenty-five examples, with a straight line average. The range is approximately 0.3 – 0.5 kg/kWh. This is consistent with the CO2 intensity range given by the IPCC, which comes out around 0.35 kg/kWh.

The CO2 intensity of coal depends mostly upon the mineral composition of the coal sample, and appears to vary, sample by sample, with little underlying pattern. Strictly, for a full-cycle CO2 intensity calculation, we should also add in the CO2 intensity of producing, processing and distributing coal, i.e., Scope 1-2 CO2 intensity. And then we must also adjust for different fuel’s efficiency factors.

The data support the conclusion that coal is approximately 2x more CO2 intensive per unit of thermal energy than natural gas, where CO2 intensity is around 0.19kg/kWh. This is consistent with our analysis of bond enthalpies and energy units and conversions.

Crop production: what CO2 intensity?

The CO2 intensity of crop production is broken down in this datafile. We have focused our numbers on corn production, as it is the world’s largest crop, with production of around 1.2 GTpa, or c5,500 TWH of primary energy. (Amazingly, corn thus comprises about 25% of all human food-energy production; and 3% of all total human energy production, 2x more than all wind and solar energy in 2021 combined).

The CO2 intensity of producing corn averages 0.23 tons/ton, or 75kg/boe. This is relatively low, compared to industrial commodities, that tend to range from 0.5 – 150 tons/ton CO2 intensity, across our economic models.

The largest component of crop’s CO2 intensity, at c50% of the total, is N2O emissions, as c0.3-3.0% of all nitrogen fertilizers break down into N2O (per the IPCC). N2O is a greenhouse gas with 298x higher global warming potential than CO2, which explains around 7% of total US greenhouse gas emissions (per the EPA).

Another 30% of the total emissions footprint for producing crops is from producing fertilizers themselves, such as ammonia and urea.

Another 10% is liquid fuels, mainly diesel, used in farm machinery, for tillage, sewing seeds, harvesting crops and transporting them to a processing/storage facility.

Our base case estimate of 75kg/boe of Scope 1+2 CO2 intensity for crop production is interesting, as it is actually higher than the Scope 1+2 CO2 intensity of producing oil and CO2 intensity of producing gas.

The energy return on energy invested for crop production is around 12x on this model. Or in other words, for each 1 kWh of energy in the corn crop, around 0.09 kWh must be supplied, of which c6pp is in the form of natural gas and 3pp is in the form of oil products, mainly diesel. It is sometimes said that the modern agricultural system can be described as the conversion of fossil energy into food energy. Or numbers would suggest this statement is about 9% true!

Implications for biofuels. Making 1 boe of bio-ethanol requires around 2 boe of corn, plus additional gas, electricity and the re-release of CO2 from fermentation. Thus we can compile a total look-through CO2 footprint for corn ethanol, including data from actual bio-ethanol plants and our corn ethanol economic model. We think the Scope 1-3 CO2 of corn ethanol is 240kg/boe, or around 50% below conventional oil products. Although this does not include opportunity costs of biofuels, for example, the potential to re-forest croplands growing corn for ethanol, which could abate over 5 tons of CO2 per acre per year.

All of our numbers can be stress-tested in the data-file. The numbers can vary markedly, from 0.1 – 0.4 tons CO2/ton of corn; or in other words, from 40kg/boe to 160kg/boe. Agricultural improvements remain an important part of the energy transition.

CO2 intensity: Scope 1, 2 & 3 and Scope 4 emissions?

This database aims to calculate the Scope 1, 2, 3 and Scope 4 emissions of different energy sources, fuels and decarbonization investments, on a bottom up basis. The numbers vary vastly, from -1.25 kg/kWh to +1.25 kg/kWh, and offer a more constructive view for funding decarbonization initiatives.

Specifically, we take examples in coal, oil, gas, biofuels, wind, solar, nuclear, hydrogen, CCUS, EVs, heat pumps and forestry. Next we calculate the Scope 1&2 CO2 emissions involved in producing the energy product. Then we calculate the Scope 3 CO2 emissions involved in using the product. Finally, we deduct the Scope 4 CO2 emissions that are avoided via using this energy product versus the most likely counterfactual.

For example, generating 1 MWH of power from coal emits 1.15 tons of CO2. Generating that same 1 MWH of power from natural gas emits 0.45 tons of CO2, resulting in a net saving of 0.7 tons of CO2. Thus $1bn invested in natural gas power plants, debatably, will save over 100MT of total CO2 over the lifetime of the plant. This is actually more than the 40MT of total lifetime CO2 that will be saved by investing $1bn into wind or solar.

Looking at the numbers in these terms is instructive, as it will promote an ‘all of the above’ approach to decarbonizing global energy.

Decision-makers may wish to use numbers in the data-file to illustrate the Scope 1-4 CO2 associated with investment decisions and production. In many cases, there is a good argument that energy investments will offer net CO2 reductions on a Scope 1-4 basis.

The file calculates full Scope 1 – Scope 4 emissions of different energy sources, in kg/boe, kg/kWh, tons/ton, tons/$bn and TWH/$bn metrics for all the different energy products. We are also happy to help TSE subscription clients explore bespoke cuts of the data. We have also published back-up research on the philosophy of CO2 accounting.

Palm oil: what CO2 intensity?

Global palm oil production is running at 80MTpa in 2022, for use in food products, HPC products and bio-fuels. CO2 intensity of palm oil is assessed in this short note and data-file.

Palm oil is controversial, as it is linked to destruction of virgin rainforests, c40% of recent production has been associated with deforestation and c20% has been associated with peatland degradation.

The purpose of this data-file is to estimate the CO2 intensity of palm oil production, in tons of CO2e per ton of crude palm oil. We have aggregated data from 12 technical papers, and also constructed our own bottom up estimates.

Excluding land use impacts, we think palm oil production most likely has a CO2 intensity of 1.2 tons per ton, which is also an OK baseline estimate for responsible palm oil producers.

On a global average basis, including land use changes, we think CO2 intensity is around 8 tons per ton, assuming 40% of the land was deforested and 20% peat-degraded. The worst case scenario is a CO2 intensity of 20 tons/ton.

All of this matters for biofuels. Biodiesel sourced from the world’s average palm oil (8 tons/ton) is going to have 2.5x more emissions than burning conventional diesel. Likewise, if renewable diesel is produced from 65% used cooking oil, 35% palm oil, then again, it will have a higher CO2 impact than conventional diesel (model here).

To read more, please see our article here. Our main conclusion is that bio- and renewable diesel expansion plans may be stymied by tighter feedstock constraints and regulations (note here).

CO2 intensity of wood: context by context?

CO2 intensity of wood in the energy transition is calculated in this data-file.

Context matters, and can sway the net climate impacts from -2 tons of emissions reductions per ton of wood through to +2 tons of incremental emissions per ton of wood.

Covered contexts include deforestation, sustainable forestry, commercial thinnings and gathering fallen biomass; which is cross-plotted against wood fuel displacing gas, wood fuel displacing coal, wood material displacing steel/cement, wood products displacing plastics and paper.

Calculations can be stress-tested in the data-file, including all of our carbon accounting and counterfactuals for the fair, apples-to-apples CO2 intensity of wood. For more on our carbon accounting philosophy, please see here.

Recent Commentary: please see our articles here and here. Specifically, this data-file lays out the calculations for our 13-page note. It highlights climate negatives for deforestation, climate positives for using waste wood and wood materials (with some debate around paper), and very strong climate positives for natural gas.

Decarbonization targets: what do the data tell us?

The most comprehensive and useful online resource we have found to track different companies’ net zero commitments is zerotracker.net. The database is freely downloadable under a Creative Commons license. However, we have attempted to clean it up in this data-file, including some additional fields and analytics.

The result is 630 companies that have pledged to reach some definition of ‘net zero’. Although the commitments are somewhat skewed towards easier-to-decarbonize sectors, such as financials (22%), TMT (6%), professional services (5%), retail (5%), healthcare (4%).

The average year to achieve this is 2044, although again, it varies by sector, and easer-to-decarbonize sectors tend to have sooner-dated targets.

A key question is credibility. 20% of the companies are deemed to have unclear decarbonization objectives and 45% are assessed to lack a clear plan to reach their goals (interestingly, energy companies scored above average on both of these metrics, at 16% and 27%, which squares with our own experience that some sectors are working hard to tackle CO2).

Another key question is scope. We were impressed to find that 50% of companies are including Scope 3 emissions in their decarbonization targets.

Finally, the list is substantively composed of large public companies, of which 40% are in Europe, 30% are in the US, 15% in Japan, c5% in both Australia and Canada. Clearly if you are a large public company, operating in these geographies, then investors are increasingly going to start ‘marking you down’ if you do not have clear decarbonization targets. On the other hand, private companies and emerging world companies are vastly under-represented in this data-file, which will re-awaken old fears over industrial leakage, and re-iterates the need for practical and economic decarbonization.

In the spirit of open source data, our clean-up of the database is free to download, in case it is useful for you, or helps inform your own company’s decarbonization targets.

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