Editing IPCC:AR6/WGIII/Chapter-6 (section)

=== Box 6.5 | Methane Mitigation Options for Coal, Oil, and Gas ===

<div id="h2-7-siblings" class="h2-siblings"></div>

Methane emissions mainly from coal, oil, and gas currently represent in 2019 about 18% of energy supply sector greenhouse gas (GHG) emissions and 90% of global energy supply non-CO 2 emissions in 2019 ( [[#Minx--2021|Minx et al. 2021]] b). While approximately 80% of the lifecycle methane emissions in the coal sector occur during underground mining, oil and gas emissions are spread throughout upstream, midstream, and downstream stages ( [[#Alvarez--2018|Alvarez et al. 2018]] ; [[#IPCC--2019|IPCC 2019]] ). For this reason, methane reductions from coal mining can be accomplished through coal mine methane recovery (where methane and coal are recovered simultaneously) and from the ventilation air, which can cumulatively reduce methane emissions by 50–75% ( [[#Zhou--2016|Zhou et al. 2016]] ; [[#Singh--2018|Singh and Hajra 2018]] ). Governments incentivise such operations through a number of emissions trading and offset programmes ( [[#Haya--2020|Haya et al. 2020]] ). Methane emissions in the oil and gas sector can be reduced by leak detection and repair, relevant across varying time scales (hours to decades) and regional scopes (component/facility level to continental) ( [[#Fox--2019|Fox et al. 2019]] ). Around 50% of the methane emitted from oil and gas infrastructure can be mitigated at net-negative costs; that is, the market price of the recovered methane is higher than the mitigation costs ( [[#IEA--2021e|IEA 2021e]] ). As CO 2 emissions are reduced and fossil fuel consumption decreases, methane emissions associated with these supply chains are anticipated to decline ( [[#6.7|Section 6.7]] ). That said, substantial ‘legacy’ methane emissions – methane leaks after abandonment – will remain, even if a complete fossil fuel phase-out takes place. These legacy emissions are estimated to be less than 1–4% of overall methane emissions across all fossil fuel sources ( [[#Kholod--2020|Kholod et al. 2020]] ; [[#Williams--2021b|Williams et al. 2021b]] ). Even without a complete phase-out, 50–80% of methane emissions from coal, oil and gas could be avoided with currently available technologies at less than USD50 tCO 2 -eq –1 ( [[#Harmsen--2019|Harmsen et al. 2019]] ; [[#Höglund-Isaksson--2020|Höglund-Isaksson et al. 2020]] ). Methane recovery from abandoned coal mines could offset most project costs ( [[#Singh--2018|Singh and Sahu 2018]] ). For abandoned oil and gas wells, low plugging costs could be offset through methane recovery, while high plugging costs would likely require some market or policy support ( [[#Kang--2019|Kang et al. 2019]] ).

<div id="6.4.2.7" class="h3-container"></div>

<span id="fossil-energy"></span>
==== 6.4.2.7 Fossil Energy ====

<div id="h3-7-siblings" class="h3-siblings"></div>

Fossil fuels could play a role in climate change mitigation if strategically deployed with CCS ( ''high confidence'' ). On the one hand, the primary mechanism for reducing emissions is to eliminate the unabated fossil fuel use. On the other hand, fossil energy combined with CCS provides a means of producing low-carbon energy while still utilising the available base of fossil energy worldwide and limiting stranded assets. While [[#6.4.2.5|Section 6.4.2.5]] discusses the important aspects of CCS with fossil fuels, this section aims to elucidate the feasibility criteria around these fuels itself.

Fossil fuel reserves have continued to rise because of advanced exploration and utilisation techniques ( ''high confidence'' ). A fraction of these available reserves can be used consistent with mitigation goals when paired with CCS opportunities in close geographical proximity ( ''high confidence'' ). Based on continued exploration, the fossil fuel resource base has increased significantly; for example, a 9% increase in gas reserves and 12% in oil reserves was observed in the USA between 2017 and 2018. This increase is a result of advanced exploration techniques, which are often subsidised ( [[#Lazarus--2018|Lazarus and van Asselt 2018]] ; MA et al. 2018). Fossil reserves are distributed unevenly throughout the globe. Coal represents the largest remaining resource (close to 500 ZJ). Conventional oil and gas resources are an order of magnitude smaller (15–20 ZJ each). Technological advances have increased the reserves of unconventional fossil in the last decade. Discovered ultimate recoverable resources of unconventional oil and gas are comparable to conventional oil and gas (Fizaine et al. 2017).

It is unlikely that resource constraints will lead to a phase-out of fossil fuels, and instead, such a phase-out would require policy action. Around 80% of coal, 50% of gas, and 20% of oil reserves are likely to remain unextractable under 2°C constraints ( [[#McGlade--2015|McGlade and Ekins 2015]] ; Pellegrini et al. 2020). Reserves are more likely to be utilised in a low-carbon transition if they can be paired with CCS. Availability of CCS technology not only allows continued use of fossil fuels as a capital resource for countries but also paves the way for CDR through BECCS ( [[#Haszeldine--2016|Haszeldine 2016]] ; [[#Pye--2020|Pye et al. 2020]] ). While the theoretical geologic CO 2 sequestration potential is vast, there are limits on how much resource base could be utilised based on geologic, engineering, and source-sink mapping criteria ( [[#Budinis--2017|Budinis et al. 2017]] ).

Technological changes have continued to drive down fossil fuel extraction costs. Significant decarbonisation potential also exists via diversification of the fossil fuel uses beyond combustion (high evidence). The costs of extracting oil and gas globally have gone down by utilising hydraulic fracturing and directional drilling for resources in unconventional reservoirs ( [[#Wachtmeister--2020|Wachtmeister and Höök 2020]] ). Although the extraction of these resources is still more expensive than those derived from conventional reservoirs, the large availability of unconventional resources has significantly reduced global prices. The emergence of liquefied natural gas (LNG) markets has also provided opportunities to export natural gas significant distances from the place of production ( [[#Avraam--2020|Avraam et al. 2020]] ). The increase in availability of natural gas has been accompanied by an increase in the production of natural gas liquids as a co-product to oil and gas. Over the period from 2014 to 2019, exports of natural gas liquids increased by 160%. Natural gas liquids could potentially be a lower-carbon alternative to liquid fuels and hydrocarbons. On the demand side, natural gas can be used to produce hydrogen using steam methane reforming, which is a technologically mature process (Sections 6.4.4 and 6.4.5). When combined with 90% CO 2 capture, the costs of producing hydrogen are around USD1.5–2 kg(H 2 ) –1 ( [[#Collodi--2017|Collodi et al. 2017]] ; [[#Newborough--2020|Newborough and Cooley 2020]] ), considerably less than hydrogen produced via electrolysis.

Significant potential exists for gasifying deep-seated coal deposits ''in situ'' to produce hydrogen. Doing so reduces fugitive methane emissions from underground coal mining. The integration costs of this process with CCS are less than with natural gas reforming. The extent to which coal gasification could be compatible with low-carbon energy would depend on the rate of CO 2 capture and the ultimate use of the gas ( [[#Verma--2015|Verma and Kumar 2015]] ). Similarly, for ongoing underground mining projects, coal mine methane recovery can be economic for major coal producers such as China and India. Coal mine methane and ventilation air methane recovery can reduce the fugitive methane emissions by 50–75% ( [[#Zhou--2016|Zhou et al. 2016]] ; [[#Singh--2018|Singh and Sahu 2018]] ).

The cost of producing electricity from fossil sources has remained roughly the same with some regional exceptions while the costs of producing transport fuels has gone down significantly ( ''high confidence'' ). The cost of producing electricity from fossil fuels has remained largely static, with the exception of some regional changes, for example, a 40% cost reduction in the USA for natural gas ( [[#Rai--2019|Rai et al. 2019]] ), where the gas wellhead price has declined by almost two-thirds due to large reserves. Similarly, the global price of crude oil has declined from almost USD100 bbl –1 to USD55 bbl –1 in the last five years.

The energy return of investment (EROI) is a useful indicator of full fossil lifecycle costs. Fossil fuels create significantly more energy per unit energy invested – or in other words have much larger EROI – than most cleaner fuels such as biomass or electrolysis-derived hydrogen, where intensive processing reduces EROI ( [[#Hall--2014|Hall et al. 2014]] ). That said, recent years have seen a decrease in fossil EROI, especially as underground coal mining still represents a substantial portion of global production. Exploitation of unconventional gas reservoirs is also energy intensive and has led to a reduction in EROI. The primary energy EROI of fossil fuels has converged at about 30, which represents a 20-point decrease from the 1995 value for coal ( [[#Brockway--2019|Brockway et al. 2019]] ). When processing and refining stages are considered, these EROI values further decrease.

Several countries have large reserves of fossil fuels. Owing to climate constraints, these may become stranded, causing considerable economic impacts ( ''high confidence'' ) (Sections 6.7.3 and 6.7.4, and Box 6.13). While global fossil energy resources are greater than 600 ZJ, more than half of these resources would likely be unburnable, even in the presence of CCS ( [[#McGlade--2015|McGlade and Ekins 2015]] ; [[#Pye--2020|Pye et al. 2020]] ). This would entail a significant capital loss for the countries with large reserves. The total amount of stranded assets in such a case would amount to USD1–4 trillion at present value (Box 6.13).

Apart from CO 2 emissions and air pollutants from fossil fuel combustion, other environmental impacts include fugitive methane leakages and implications to water systems '''.''' While the rate of methane leakage from unconventional gas systems is uncertain, their overall GHG impact is less than coal ( [[#Tanaka--2019|Tanaka et al. 2019]] ; [[#Deetjen--2020|Deetjen and Azevedo 2020]] ). The stated rate of leakage in such systems ranges from 1–8%, and reconciling different estimates requires a combination of top-down and bottom-up approaches ( [[#Zavala-Araiza--2015|Zavala-Araiza et al. 2015]] ; [[#Grubert--2019|Grubert and Brandt 2019]] ). Similarly, for coal mining, fugitive methane emissions have grown, despite some regulations on the degree to which emission controls must be deployed. Recent IPCC inventory guidance also notes considerable CO 2 emissions resulting from spontaneous combustion of the coal surface, and accounting for these emissions will likely increase the overall lifecycle emissions by 1–5% ( [[#IPCC--2019|IPCC 2019]] ; [[#Singh--2019|Singh 2019]] ; [[#Fiehn--2020|Fiehn et al. 2020]] ).

Another key issue consistently noted with unconventional wells (both oil and gas, and coalbed methane) is the large water requirements ( [[#Qin--2018|Qin et al. 2018]] ). The overall water footprint of unconventional reservoirs is higher than conventional reservoirs because of higher lateral length and fracturing requirements ( [[#Scanlon--2017|Scanlon et al. 2017]] ; [[#Kondash--2018|Kondash et al. 2018]] ). Moreover, produced water from such formations is moderately to highly brackish, and treating such waters has large energy consumption ( [[#Bartholomew--2016|Bartholomew and Mauter 2016]] ; [[#Singh--2019|Singh and Colosi 2019]] ).

Oil and coal consistently rank among the least preferred energy sources in many countries ( ''high confidence'' ). The main perceived advantage of fossil energy is the relatively low costs, and emphasising these costs might increase acceptability somewhat ( [[#Pohjolainen--2018|Pohjolainen et al. 2018]] ; [[#Boyd--2019|Boyd et al. 2019]] ; [[#Hazboun--2020|Hazboun and Boudet 2020]] ). Acceptability of fossil fuels is, on average, similar to acceptability of nuclear energy, although evaluations are less polarised. People evaluate natural gas as somewhat more acceptable than other fossil fuels, although they generally oppose hydraulic fracturing ( [[#Clarke--2016|Clarke et al. 2016]] ). Yet, natural gas is evaluated as less acceptable than renewable energy sources, although evaluations of natural gas and biogas are similar ( [[#Liebe--2019|Liebe and Dobers 2019]] ; [[#Plum--2019|Plum et al. 2019]] ). Acceptability of fossil energy tends to be higher in countries and regions that strongly rely on them for their energy production ( [[#Pohjolainen--2018|Pohjolainen et al. 2018]] ; [[#Boyd--2019|Boyd et al. 2019]] ). Combining fossil fuels with CCS can increase their acceptability ( [[#Van%20Rijnsoever--2015|Van Rijnsoever et al. 2015]] ; [[#Bessette--2018|Bessette and Arvai 2018]] ). Some people seem ambivalent about natural gas, as they perceive both benefits (e.g., affordability, less carbon emissions than coal) and disadvantages (e.g., finite resource, contributing to climate change) ( [[#Blumer--2018|Blumer et al. 2018]] ).

Fossil fuel subsidies have been valued in the order of USD0.5–5 trillion annually by various estimates which have the tendency to introduce economic inefficiency within systems ( [[#Jakob--2015|Jakob et al. 2015]] ; [[#Merrill--2015|Merrill et al. 2015]] ) ( ''high confidence'' ). Subsequent reforms have been suggested by different researchers who have estimated reductions in CO 2 emissions may take place if these subsidies are removed ( [[#Mundaca--2017|Mundaca 2017]] ). Such reforms could create the necessary framework for enhanced investments in social welfare – through sanitation, water, clean energy – with differentiating impacts (Edenhofer 2015).

<div id="6.4.2.8" class="h3-container"></div>

<span id="geothermal-energy"></span>
==== 6.4.2.8 Geothermal Energy ====

<div id="h3-8-siblings" class="h3-siblings"></div>

Geothermal energy is heat stored in the Earth’s subsurface and is a renewable resource that can be sustainably exploited. The geophysical potential of geothermal resources is 1.3 to 13 times the global electricity demand in 2019 ( ''medium confidence'' ). Geothermal energy can be used directly for various thermal applications, including space heating and industrial heat input, or converted to electricit '''y''' depending on the source temperature ( [[#Limberger--2018|Limberger et al. 2018]] ; [[#Moya--2018|Moya et al. 2018]] ; [[#REN21--2019|REN21 2019]] ).

Suitable aquifers underlay 16% of the Earth’s land surface and store an estimated 110,000–1,400,000 PWh (400,000–1,450,000 EJ) that could theoretically be used for direct heat applications. For electricity generation, the technical potential of geothermal energy is estimated to be between 30 PWh yr –1 (108 EJ yr –1 ) (to 3 km depth) and 300 PWh yr –1 (1080 EJ yr –1 ) (to 10 km depth). For direct thermal uses, the technical potential is estimated to range from 2.7–86 PWh yr –1 (9.7–310 EJ yr –1 ) ( [[#IPCC--2011|IPCC 2011]] ). Despite the potential, geothermal direct heat supplies only 0.15% of the annual global final energy consumption. The technical potential for electricity generation, depending on the depth, can meet one third to almost three times the global final consumption – based on International Energy Agency (IEA) database for IPCC. The mismatch between potential and developed geothermal resources is caused by high upfront costs, decentralised geothermal heat production, lack of uniformity among geothermal projects, geological uncertainties, and geotechnical risks ( [[#IRENA--2017a|IRENA 2017a]] ; [[#Limberger--2018|Limberger et al. 2018]] ). A limited number of countries have a long history in geothermal. At least in two countries (Iceland and New Zealand), geothermal accounts for 20–25% of electricity generation ( [[#Pan--2019|Pan et al. 2019]] ; [[#Spittler--2020|Spittler et al. 2020]] ). Furthermore, in Iceland approximately 90% of the households are heated with geothermal energy. In Kenya, as of July 2019, geothermal accounted for 734 MW effective capacity spread over 10 power plants and approximately one third of the total installed capacity (Kahlen 2019).

There are two main types of geothermal resources: convective hydrothermal resources, in which the Earth’s heat is carried by natural hot water or steam to the surface; and hot, dry rock resources, in which heat cannot be extracted using water or steam, and other methods must be developed. There are three basic types of geothermal power plants: (i) dry steam plants use steam directly from a geothermal reservoir to turn generator turbines; (ii) flash steam plants take high-pressure hot water from deep inside the Earth and convert it to steam to drive generator turbines; and (iii) binary cycle power plants transfer the heat from geothermal hot water to another liquid. Many of the power plants in operation today are dry steam plants or flash plants (single, double and triple) harnessing temperatures of more than 180°C.

However, medium temperature fields are increasingly used for electricity generation or combined heat and power. The use of medium temperature fields has been enabled through the development of binary cycle technology, in which a geothermal fluid is used via heat exchangers. Increasing binary generation technologies are now being utilised instead of flash steam power plants. This will result in almost 100% injection and essentially zero GHG emissions, although GHG emissions from geothermal power production are generally small compared to traditional baseload thermal energy power generation facilities ( [[#Fridriksson--2016|Fridriksson et al. 2016]] ).

Additionally, new technologies are being developed like Enhanced Geothermal Systems (EGS), which is in the demonstration stage ( [[#IRENA--2018|IRENA 2018]] ), deep geothermal technology, which may increase the prospects for harnessing the geothermal potential in a large number of countries, or shallow-geothermal energy, which represents a promising supply source for heating and cooling buildings ( [[#Narsilio--2018|Narsilio and Aye 2018]] ). Successful large-scale deployment of shallow geothermal energy will depend not only on site-specific economic performance but also on developing suitable governance frameworks ( [[#Bloemendal--2018|Bloemendal et al. 2018]] ; [[#García-Gil--2020|García-Gil et al. 2020]] ). Technologies for direct uses like district heating, geothermal heat pumps, greenhouses, and other applications, are widely used and considered mature. Given the limited number of plants commissioned, economic indicators (Figure 6.15) vary considerably depending on site characteristics.

<div id="_idContainer045" class="Basic-Text-Frame"></div>

[[File:326f242c673d51a3849ed67058b073a6 IPCC_AR6_WGIII_Figure_6_15.png]]

'''Figure 6.15 | Global weighted averagetotal installed costs, capacity factors and levelised costs of electricity (LCOE) for geothermal power per year (2010–2020).''' The shaded area represents the 5% and 95% percentiles. Source: with permission from [[#IRENA--2021a|IRENA (2021a)]] .

Public awareness and knowledge of geothermal energy is relatively low ( ''high confidence'' ). Geothermal energy is evaluated as less acceptable than other renewable energy sources such as solar and wind, but is preferred over fossil and nuclear energy, and in some studies, over hydroelectric energy ( ''high confidence'' ) ( [[#Pellizzone--2015|Pellizzone et al. 2015]] ; [[#Steel--2015|Steel et al. 2015]] ; [[#Karytsas--2019|Karytsas et al. 2019]] ; [[#Hazboun--2020|Hazboun and Boudet 2020]] ). Some people are concerned about the installation of geothermal facilities close to their homes, similar to solar and wind projects ( [[#Pellizzone--2015|Pellizzone et al. 2015]] ). The main concerns about geothermal energy, particularly for large-scale, high-temperature geothermal power generation plants, involve water usage, water scarcity, and seismic risks of drilling ( [[#Dowd--2011|Dowd et al. 2011]] ). Moreover, noise, smell and damages to the landscape have been reasons for protests against specific projects ( [[#Walker--1995|Walker 1995]] ). However, with the implementation of modern technologies, geothermal presents fewer adverse environmental impacts. At the same time, people perceive geothermal energy as relatively environmentally friendly ( [[#Tampakis--2013|Tampakis et al. 2013]] ).

<div id="6.4.2.9" class="h3-container"></div>

<span id="marine-energy"></span>
==== 6.4.2.9 Marine Energy ====

<div id="h3-9-siblings" class="h3-siblings"></div>

The ocean is a vast source of energy ( [[#Hoegh-Guldberg--2019|Hoegh-Guldberg et al. 2019]] ). Ocean energy can be extracted from tides, waves, ocean thermal energy conversion (OTEC), currents, and salinity gradients ( [[#Bindoff--2019|Bindoff et al. 2019]] ). Their technical potentials, without considering possible exclusion zones, are explored below. Tidal energy, which uses elevation differences between high and low tides, appears in two forms: potential energy (rise and fall of the tide); and current energy (from tidal currents). The global technically harvestable tidal power from areas close to the coast is estimated as about 1.2 PWh yr –1 (4.3 EJ yr –1 ) ( [[#IRENA--2020b|IRENA 2020b]] ). The potential for tidal current energy is estimated to be larger than that for tidal range or barrage ( [[#Melikoglu--2018|Melikoglu 2018]] ). Ocean wave energy is abundant and predictable and can be extracted directly from surface waves or pressure fluctuations below the surface ( [[#Melikoglu--2018|Melikoglu 2018]] ). Its global theoretical potential is 29.5 PWh yr –1 (106 EJ yr –1 ),which means that wave energy alone could meet all global energy demand ( [[#Mørk--2010|Mørk et al. 2010]] ; [[#IRENA--2020b|IRENA 2020b]] ). The temperature gradients in the ocean can be exploited to produce energy, and its total estimated available resource could be up to 44.0 PWh yr –1 (158 EJ yr –1 ) ( [[#Rajagopalan--2013|Rajagopalan and Nihous 2013]] ). Salinity gradient energy, also known as osmotic power, has a global theoretical potential of over 1.6 PWh yr –1 (6.0 EJ yr –1 ) ( [[#IRENA--2020b|IRENA 2020b]] ). The greatest advantage of most marine energy, excluding wave energy, is that their sources are highly regular and predictable, and energy can be furthermore generated both day and night. An additional use of sea water is to develop lower-cost district cooling systems near the sea ( [[#Hunt--2019|Hunt et al. 2019]] ). The greatest barrier to most marine technology advances is the relatively high upfront costs, uncertainty on environmental regulation and impact, need for investments and insufficient infrastructure ( [[#Kempener--2014a|Kempener and Neumann 2014a]] , b). There are also concerns about technology maturity and performance; thus, not all have the potential to become economically viable ( [[#IRENA--2020b|IRENA 2020b]] ).

<div id="6.4.2.10" class="h3-container"></div>

<span id="waste-to-energy"></span>
==== 6.4.2.10 Waste-to-Energy ====

<div id="h3-10-siblings" class="h3-siblings"></div>

Waste-to-energy (WTE) is a strategy to recoverenergy from waste in a form of consumable heat, electricity, or fuel ( [[#Zhao--2016|Zhao et al. 2016]] ). Thermal (incineration, gasification, and pyrolysis) and biological (anaerobic digestion and landfill gas to energy) technologies are commonly used ( [[#Ahmad--2020|Ahmad et al. 2020]] ). When WTE technologies are equipped with proper air pollution reduction facilities they can contribute to clean electricity production and reduction of GHG emissions. However, if not properly operated, they can exacerbate air quality issues.

In 2019, there were more than 1,200 WTE incineration facilities worldwide, with estimated capacity of 310 million tonnes per year ( [[#UNECE--2020|UNECE 2020]] ). It is estimated that treatment of a minimum of 261 million tonnes/year of waste could produce 283 TWh (1 EJ) of power and heat by 2022 ( [[#Awasthi--2019|Awasthi et al. 2019]] ). Incineration plants can reduce the mass of waste by 70–80% and the volume of waste by 80–90% ( [[#Haraguchi--2019|Haraguchi et al. 2019]] ). Incineration technology can reduce water and soil pollution ( [[#Gu--2019|Gu et al. 2019]] ). However, if not properly handled, dust, and gases such as SO 2 , HCL, HF, NO 2 , and dioxins in the flue gases can harm the environment ( [[#Mutz--2017|Mutz et al. 2017]] ). Anaerobic digestion technology has a positive environmental impact and the ability to reduce GHG emissions ( [[#Ayodele--2018|Ayodele et al. 2018]] ; [[#Cudjoe--2020|Cudjoe et al. 2020]] ). The by-product of the anaerobic digestion process could be used as a nutrient-rich fertiliser for enhancing soil richness for agricultural purposes ( [[#Wainaina--2020|Wainaina et al. 2020]] ). Due to the potential negative impacts on domestic environment and residents’ health, WTE projects such as incineration encounter substantial opposition from the local communities in which they are located ( [[#Baxter--2016|Baxter et al. 2016]] ; [[#Ren--2016|Ren et al. 2016]] ). Therefore, for WTE to be deployed more widely, policies would need to be tailored with specific guidelines focused on mitigating emissions, which may have an adverse effect on the environment.

Depending on the origin of the waste used, the integration of WTE and carbon capture and storage (CCS) could enable waste to be a net-zero or even net negative emissions energy source ( [[#Kearns--2019|Kearns 2019]] ; [[#Wienchol--2020|Wienchol et al. 2020]] ). For example, in Europe only, the integration of CCS with WTE facilities has the potential to capture about 60 to 70 million tonnes of carbon dioxide annually ( [[#Tota--2021|Tota et al. 2021]] ).

Waste-to-energy is an expensive process compared to other energy sources such as fossil fuels and natural gas ( [[#Mohammadi--2020|Mohammadi and Harjunkoski 2020]] ). However, the environmental and economic benefits make its high financial costs justifiable. In 2019, the global WTE market size was valued at USD31 billion, and it is predicted to experience 7.4% annual growth until 2027 ( [[#UNECE--2020|UNECE 2020]] ).

<div id="6.4.3" class="h2-container"></div>

<span id="energy-system-integration"></span>