Low-carbon power

From Justapedia, unleashing the power of collective wisdom
(Redirected from Low carbon power generation)
Jump to navigation Jump to search

Share of primary energy from low-carbon sources, 2018

Low-carbon power is electricity produced with substantially lower greenhouse gas emissions than conventional fossil fuel power generation. The energy transition to low-carbon power is one of the most important actions required to limit climate change.[1] Power sector emissions may have peaked in 2018.[2] During the first six months of 2020, scientists observed an 8.8% decrease in global CO2 emissions relative to 2019 due to COVID-19 lockdown measures.[3] The two main sources of the decrease in emissions included ground transportation (40%) and the power sector (22%). This event is the largest absolute decrease in CO2 emissions in history, but emphasizes that low-carbon power "must be based on structural and transformational changes in energy-production systems".[3]

Low carbon power generation sources include wind power, solar power, nuclear power and most hydropower.[4][5] The term largely excludes conventional fossil fuel plant sources, and is only used to describe a particular subset of operating fossil fuel power systems, specifically, those that are successfully coupled with a flue gas carbon capture and storage (CCS) system.[6] Globally almost 40% of electricity generation came from low-carbon sources in 2020: about 10% being nuclear power, almost 10% wind and solar, and around 20% hydropower and other renewables.[1]

History

Percentage of electricity generation from low-carbon sources in 2019.

During the late 20th and early 21st century significant findings regarding global warming highlighted the need to curb carbon emissions. From this, the idea for low-carbon power was born. The Intergovernmental Panel on Climate Change (IPCC), established by the World Meteorological Organization (WMO) and the United Nations Environment Program (UNEP) in 1988, set the scientific precedence for the introduction of low-carbon power. The IPCC has continued to provide scientific, technical and socio-economic advice to the world community, through its periodic assessment reports and special reports.[7]

Internationally, the most prominent[according to whom?] early step in the direction of low carbon power was the signing of the Kyoto Protocol, which came into force on 16 February 2005, under which most industrialized countries committed to reduce their carbon emissions. The historical event set the political precedence for introduction of low-carbon power technology.

On a social level, perhaps the biggest factor[according to whom?] contributing to the general public's awareness of climate change and the need for new technologies, including low carbon power, came from the documentary An Inconvenient Truth, which clarified and highlighted the problem of global warming.

Power sources by greenhouse gas emissions

Life-cycle greenhouse gas emissions of electricity supply technologies, median values calculated by IPCC[8]
Life cycle CO2 equivalent (including albedo effect) from selected electricity supply technologies according to IPCC 2014.[8][9] Arranged by decreasing median (gCO2eq/kWh) values.
Technology Min. Median Max.
Currently commercially available technologies
CoalPC 740 820 910
Gascombined cycle 410 490 650
Biomass – Dedicated 130 230 420
Solar PV – Utility scale 18 48 180
Solar PV – rooftop 26 41 60
Geothermal 6.0 38 79
Concentrated solar power 8.8 27 63
Hydropower 1.0 24 22001
Wind Offshore 8.0 12 35
Nuclear 3.7 12 110
Wind Onshore 7.0 11 56
Pre‐commercial technologies
Ocean (Tidal and wave) 5.6 17 28

1 see also environmental impact of reservoirs#Greenhouse gases.

Lifecycle GHG emissions, in g CO2 eq. per kWh, UNECE 2020[10]
Lifecycle CO2 emissions per kWh, EU28 countries, according to UNECE 2020.[10]
Technology gCO2eq/kWh
Hard coal PC, without CCS 1000
IGCC, without CCS 850
SC, without CCS 950
PC, with CCS 370
IGCC, with CCS 280
SC, with CCS 330
Natural gas NGCC, without CCS 430
NGCC, with CCS 130
Hydro 660 MW [11] 150
360 MW 11
Nuclear average 5.1
CSP tower 22
trough 42
PV poly-Si, ground-mounted 37
poly-Si, roof-mounted 37
CdTe, ground-mounted 12
CdTe, roof-mounted 15
CIGS, ground-mounted 11
CIGS, roof-mounted 14
Wind onshore 12
offshore, concrete foundation 14
offshore, steel foundation 13

List of acronyms:

Differentiating attributes of low-carbon power sources

Low carbon electricity generation percentage worldwide by source

There are many options for lowering current levels of carbon emissions. Some options, such as wind power and solar power, produce low quantities of total life cycle carbon emissions, using entirely renewable sources. Other options, such as nuclear power, produce a comparable amount of carbon dioxide emissions as renewable technologies in total life cycle emissions, but consume non-renewable, but sustainable[12] materials (uranium). The term low-carbon power can also include power that continues to utilize the world's natural resources, such as natural gas and coal, but only when they employ techniques that reduce carbon dioxide emissions from these sources when burning them for fuel, such as the, as of 2012, pilot plants performing Carbon capture and storage.[6][13]

Because the cost of reducing emissions in the electricity sector appears to be lower than in other sectors such as transportation, the electricity sector may deliver the largest proportional carbon reductions under an economically efficient climate policy.[14]

Technologies to produce electric power with low-carbon emissions are in use at various scales. Together, they accounted for almost 40% of global electricity in 2020, with wind and solar almost 10%.[1]

Source:[15]

Technologies

The 2014 Intergovernmental Panel on Climate Change report identifies nuclear, wind, solar and hydroelectricity in suitable locations as technologies that can provide electricity with less than 5% of the lifecycle greenhouse gas emissions of coal power.[16]

Hydroelectric power

The Hoover Dam when completed in 1936 was both the world's largest electric-power generating station and the world's largest concrete structure.

Hydroelectric plants have the advantage of being long-lived and many existing plants have operated for more than 100 years. Hydropower is also an extremely flexible technology from the perspective of power grid operation. Large hydropower provides one of the lowest cost options in today's energy market, even compared to fossil fuels and there are no harmful emissions associated with plant operation.[17] However, there are typically low greenhouse gas emissions with reservoirs, and possibly high emissions in the tropics.

Hydroelectric power is the world's largest low carbon source of electricity, supplying 15.6% of total electricity in 2019.[18] China is by far the world's largest producer of hydroelectricity in the world, followed by Brazil and Canada.

However, there are several significant social and environmental disadvantages of large-scale hydroelectric power systems: dislocation, if people are living where the reservoirs are planned, release of significant amounts of carbon dioxide and methane during construction and flooding of the reservoir, and disruption of aquatic ecosystems and birdlife.[19] There is a strong consensus now that countries should adopt an integrated approach towards managing water resources, which would involve planning hydropower development in co-operation with other water-using sectors.[17]

Nuclear power

Blue Cherenkov radiation light being produced near the core of the Fission powered Advanced Test Reactor

Nuclear power, with a 10.6% share of world electricity production as of 2013, is the second largest low-carbon power source.[20]

Nuclear power, in 2010, also provided two thirds of the twenty seven nation European Union's low-carbon energy,[21] with some EU nations sourcing a large fraction of their electricity from nuclear power; for example France derives 79% of its electricity from nuclear. As of 2020 nuclear power provided 47% low-carbon power in the EU[22] with countries largely based on nuclear power routinely achieving carbon intensity of 30-60 gCO2eq/kWh.[23]

According to the IAEA and the European Nuclear Society, worldwide there were 68 civil nuclear power reactors under construction in 15 countries in 2013.[24][25] China has 29 of these nuclear power reactors under construction, as of 2013, with plans to build many more,[25][26] while in the US the licenses of almost half its reactors have been extended to 60 years,[27] and plans to build another dozen are under serious consideration.[28] There is also a considerable number[clarification needed] of new reactors being built in South Korea, India, and Russia. Nuclear power's capability to add significantly to future low carbon energy growth depends on several factors, including the economics of new reactor designs, such as Generation III reactors, public opinion and national and regional politics.

The 104 U.S. nuclear plants are undergoing a Light Water Reactor Sustainability Program, to sustainably extend the life span of the U.S. nuclear fleet by a further 20 years. With further US power plants under construction in 2013, such as the two AP1000s at Vogtle Electric Generating Plant. However the Economics of new nuclear power plants are still evolving and plans to add to those plants are mostly in flux.[29]

In 2021 United Nations Economic Commission for Europe (UNECE) described nuclear power as important tool to mitigate climate change that has prevented 74 Gt of CO2 emissions over the last half century, providing 20% of energy in Europe and 43% of low-carbon energy.[30]

Wind power

Wind power stations in Xinjiang, China

Wind power or wind energy is mostly the use of wind turbines to generate electricity. Wind power is a popular, sustainable, renewable energy source that has a much smaller impact on the environment than burning fossil fuels. Historically, wind power has been used in sails, windmills and windpumps but today it is mostly used to generate electricity. Wind farms consist of many individual wind turbines, which are connected to the electric power transmission network.

New onshore (on-land) wind farms are cheaper than new coal or gas plants,[31] but expansion of wind power is being hindered by fossil fuel subsidies.[32][33][34] Onshore wind farms have a greater visual impact on the landscape than some other power stations.[35][36] Small onshore wind farms can feed some energy into the grid or provide power to isolated off-grid locations. Offshore wind farms provide a steadier and stronger source of energy and have less visual impact. Although there is less offshore wind power at present and construction and maintenance costs are higher, it is expanding.[37]

Wind power is variable renewable energy, so power-management techniques are used to match supply and demand, such as: wind hybrid power systems, hydroelectric power or other dispatchable power sources, excess capacity, geographically distributed turbines, exporting and importing power to neighboring areas, or grid storage. As the proportion of wind power in a region increases the grid may need to be upgraded.[38][39] Weather forecasting allows the electric-power network to be readied for the predictable variations in production that occur.

In 2021, wind supplied over 1800 TWh of electricity, which was over 6% of world electricity[40] and about 2% of world energy.[41][42] With about 100 GW added during 2021, mostly in China and the United States, global installed wind power capacity exceeded 800 GW.[37][42][43] To help meet the Paris Agreement goals to limit climate change, analysts say it should expand much faster - by over 1% of electricity generation per year.[44]

Solar power

The PS10 concentrates sunlight from a field of heliostats on a central tower.

Solar power is the conversion of sunlight into electricity, either directly using photovoltaics (PV), or indirectly using concentrated solar power (CSP). Concentrated solar power systems use lenses or mirrors and tracking systems to focus a large area of sunlight into a small beam. Photovoltaics convert light into electric current using the photoelectric effect.[45]

Commercial concentrated solar power plants were first developed in the 1980s. The 354 MW SEGS CSP installation is the largest solar power plant in the world, located in the Mojave Desert of California. Other large CSP plants include the Solnova Solar Power Station (150 MW) and the Andasol solar power station (150 MW), both in Spain. The over 200 MW Agua Caliente Solar Project in the United States, and the 214 MW Charanka Solar Park in India, are the world's largest photovoltaic plants. Solar power's share of worldwide electricity usage at the end of 2014 was 1%.[46]

Geothermal power

Geothermal electricity is electricity generated from geothermal energy. Technologies in use include dry steam power plants, flash steam power plants and binary cycle power plants. Geothermal electricity generation is used in 24 countries[47] while geothermal heating is in use in 70 countries.[48]

Current worldwide installed capacity is 10,715 megawatts (MW), with the largest capacity in the United States (3,086 MW),[49] Philippines, and Indonesia. Estimates of the electricity generating potential of geothermal energy vary from 35 to 2000 GW.[48]

Geothermal power is considered to be sustainable because the heat extraction is small compared to the Earth's heat content.[50] The emission intensity of existing geothermal electric plants is on average 122 kg of CO
2
per megawatt-hour (MW·h) of electricity, a small fraction of that of conventional fossil fuel plants.[51]

Tidal power

Tidal power is a form of hydropower that converts the energy of tides into electricity or other useful forms of power. The first large-scale tidal power plant (the Rance Tidal Power Station) started operation in 1966. Although not yet widely used, tidal power has potential for future electricity generation. Tides are more predictable than wind energy and solar power.

Carbon capture and storage

Carbon capture and storage captures carbon dioxide from the flue gas of power plants or other industry, transporting it to an appropriate location where it can be buried securely in an underground reservoir. While the technologies involved are all in use, and carbon capture and storage is occurring in other industries (e.g., at the Sleipner gas field), no large scale integrated project has yet become operational within the power industry.

Improvements to current carbon capture and storage technologies could reduce CO2 capture costs by at least 20-30% over approximately the next decade, while new technologies under development promise more substantial cost reduction.[52]

Outlook and requirements

Emissions

Greenhouse gas emissions by sector. See World Resources Institute for detailed breakdown

The Intergovernmental Panel on Climate Change stated in its first working group report that “most of the observed increase in globally averaged temperatures since the mid-20th century is very likely due to the observed increase in anthropogenic greenhouse gas concentrations, contribute to climate change.[53]

As a percentage of all anthropogenic greenhouse gas emissions, carbon dioxide (CO2) accounts for 72 percent (see Greenhouse gas), and has increased in concentration in the atmosphere from 315 parts per million (ppm) in 1958 to more than 375 ppm in 2005.[54]

Emissions from energy make up more than 61.4 percent of all greenhouse gas emissions.[55] Power generation from traditional coal fuel sources accounts for 18.8 percent of all world greenhouse gas emissions, nearly double that emitted by road transportation.[55]

Estimates state that by 2020 the world will be producing around twice as much carbon emissions as it was in 2000.[56]

The European Union hopes to sign a law mandating net-zero greenhouse gas emissions in the coming year for all 27 countries in the union.

Electricity usage

World CO2 emissions by region

World energy consumption is predicted to increase from 123,000 TWh (421 quadrillion BTU) in 2003 to 212,000 TWh (722 quadrillion BTU) in 2030.[57] Coal consumption is predicted to nearly double in that same time.[58] The fastest growth is seen in non-OECD Asian countries, especially China and India, where economic growth drives increased energy use.[59] By implementing low-carbon power options, world electricity demand could continue to grow while maintaining stable carbon emission levels.

In the transportation sector there are moves away from fossil fuels and towards electric vehicles, such as mass transit and the electric car. These trends are small, but may eventually add a large demand to the electrical grid.[citation needed]

Domestic and industrial heat and hot water have largely been supplied by burning fossil fuels such as fuel oil or natural gas at the consumers' premises. Some countries have begun heat pump rebates to encourage switching to electricity, potentially adding a large demand to the grid.[60]

Energy infrastructure

Coal-fired power plants are losing market share compared to low carbon power, and any built in the 2020s risk becoming stranded assets[2] or stranded costs, partly because their capacity factors will decline.[61]

Investment

Investment in low-carbon power sources and technologies is increasing at a rapid rate.[clarification needed] Zero-carbon power sources produce about 2% of the world's energy, but account for about 18% of world investment in power generation, attracting $100 billion of investment capital in 2006.[62]

See also

References

  1. ^ a b c "Global Electricity Review 2021". Ember. 28 March 2021. Retrieved 7 April 2021.
  2. ^ a b Bertram, Christoph; Luderer, Gunnar; Creutzig, Felix; Bauer, Nico; Ueckerdt, Falko; Malik, Aman; Edenhofer, Ottmar (March 2021). "COVID-19-induced low power demand and market forces starkly reduce CO 2 emissions". Nature Climate Change. 11 (3): 193–196. Bibcode:2021NatCC..11..193B. doi:10.1038/s41558-021-00987-x. ISSN 1758-6798.
  3. ^ a b Liu, Zhu; Ciais, Philippe; Deng, Zhu; Lei, Ruixue; Davis, Steven J.; Feng, Sha; Zheng, Bo; Cui, Duo; Dou, Xinyu; Zhu, Biqing; Guo, Rui (14 October 2020). "Near-real-time monitoring of global CO2 emissions reveals the effects of the COVID-19 pandemic". Nature Communications. 11 (1): 5172. Bibcode:2020NatCo..11.5172L. doi:10.1038/s41467-020-18922-7. ISSN 2041-1723. PMC 7560733. PMID 33057164.
  4. ^ Warner, Ethan S. (2012). "Life Cycle Greenhouse Gas Emissions of Nuclear Electricity Generation". Journal of Industrial Ecology. 16: S73–S92. doi:10.1111/j.1530-9290.2012.00472.x. S2CID 153286497.
  5. ^ "The European Strategic Energy Technology Plan SET-Plan Towards a low-carbon future" (PDF). 2010. p. 6. Archived from the original (PDF) on 11 February 2014. ... nuclear plants ... currently provide 1/3 of the EU’s electricity and 2/3 of its low-carbon energy.
  6. ^ a b https://www.gov.uk/innovation-funding-for-low-carbon-technologies-opportunities-for-bidders Innovation funding for low-carbon technologies: opportunities for bidders. "Meeting the energy challenge and government programme names nuclear power in the future energy mix, alongside other low-carbon sources, renewables and carbon capture and storage (CCS)."
  7. ^ "Intergovernmental Panel on Climate Change Web site". IPCC.ch. Archived from the original on 25 August 2006. Retrieved 1 October 2017.
  8. ^ a b "IPCC Working Group III – Mitigation of Climate Change, Annex III: Technology - specific cost and performance parameters - Table A.III.2 (Emissions of selected electricity supply technologies (gCO 2eq/kWh))" (PDF). IPCC. 2014. p. 1335. Archived (PDF) from the original on 14 December 2018. Retrieved 14 December 2018.
  9. ^ "IPCC Working Group III – Mitigation of Climate Change, Annex II Metrics and Methodology - A.II.9.3 (Lifecycle greenhouse gas emissions)" (PDF). pp. 1306–1308. Archived (PDF) from the original on 23 April 2021. Retrieved 14 December 2018.
  10. ^ a b "Life Cycle Assessment of Electricity Generation Options | UNECE". unece.org. Retrieved 26 November 2021.
  11. ^ "The 660 MW plant should be considered as an outlier, as transportation for the dam construction elements is assumed to occur over thousands of kilometers (which is only representative of a very small share of hydropower projects globally). The 360 MW plant should be considered as the most representative, with fossil greenhouse gas emissions ranging from 6.1 to 11 g CO2eq/kWh" (UNECE 2020 section 4.4.1)
  12. ^ "Is Nuclear Energy Renewable Energy?". large.Stanford.edu. Retrieved 1 October 2017.
  13. ^ "Amid Economic Concerns, Carbon Capture Faces a Hazy Future". NationalGeographic.com. 23 May 2012. Retrieved 1 October 2017.
  14. ^ "Promoting Low-Carbon Electricity Production - Issues in Science and Technology". www.Issues.org. Archived from the original on 27 September 2013. Retrieved 1 October 2017.
  15. ^ Weißbach, D. (2013). "Energy intensities, EROIs (energy returned on invested), and energy payback times of electricity generating power plants". Energy. 52: 210–221. doi:10.1016/j.energy.2013.01.029.
  16. ^ http://www.ipcc.ch/pdf/assessment-report/ar5/wg3/ipcc_wg3_ar5_chapter7.pdf[bare URL PDF]
  17. ^ a b International Energy Agency (2007). Renewables in global energy supply: An IEA facts sheet (PDF), OECD, p. 3.
  18. ^ "Understand Hydropower energy through Data | Low-Carbon Power".
  19. ^ Duncan Graham-Rowe. Hydroelectric power's dirty secret revealed New Scientist, 24 February 2005.
  20. ^ http://www.iea.org/publications/freepublications/publication/KeyWorld_Statistics_2015.pdf pg25
  21. ^ "Archived copy" (PDF). Archived from the original (PDF) on 11 February 2014. Retrieved 17 August 2015.{{cite web}}: CS1 maint: archived copy as title (link) The European Strategic Energy Technology Plan SET-Plan Towards a low-carbon future 2010. Nuclear power provides "2/3 of the EU's low carbon energy" pg 6.
  22. ^ "Assuring the Backbone of a Carbon-free Power System by 2050 -Call for a Timely and Just Assessment of Nuclear Energy" (PDF).
  23. ^ "Live CO₂ emissions of electricity consumption". electricitymap.tmrow.co. Retrieved 14 May 2020.
  24. ^ "PRIS - Home". www.IAEA.org. Retrieved 1 October 2017.
  25. ^ a b Bruenglinghaus, Marion. "Nuclear power plants, world-wide". ENS, European Nuclear Society. Archived from the original on 19 May 2013. Retrieved 1 October 2017.
  26. ^ "China Nuclear Power - Chinese Nuclear Energy - World Nuclear Association". www.World-Nuclear.org. Retrieved 1 October 2017.
  27. ^ "Nuclear Power in the USA". World Nuclear Association. June 2008. Retrieved 25 July 2008.
  28. ^ Matthew L. Wald (7 December 2010). Nuclear ‘Renaissance’ Is Short on Largess The New York Times.
  29. ^ Location of Projected New Nuclear Power Reactors
  30. ^ "Global climate objectives fall short without nuclear power in the mix: UNECE". UN News. 11 August 2021. Retrieved 2 September 2021.
  31. ^ "Levelized Cost Of Energy, Levelized Cost Of Storage, and Levelized Cost Of Hydrogen". Lazard.com. Retrieved 24 November 2021.
  32. ^ "UNDP: More spent on fossil fuel subsidies than fighting poverty". Africa Renewal. 29 October 2021. Retrieved 24 November 2021.
  33. ^ "Fossil fuel subsidies and renewable energies in MENA: An oxymoron?". Middle East Institute. Retrieved 24 November 2021.
  34. ^ "COP26: How much is spent supporting fossil fuels and green energy?". BBC News. 15 November 2021. Retrieved 24 November 2021.
  35. ^ What are the pros and cons of onshore wind energy? Archived 22 June 2019 at the Wayback Machine. Grantham Research Institute on Climate Change and the Environment. January 2018.
  36. ^ Nathan F. Jones, Liba Pejchar, Joseph M. Kiesecker. "The Energy Footprint: How Oil, Natural Gas, and Wind Energy Affect Land for Biodiversity and the Flow of Ecosystem Services". BioScience, Volume 65, Issue 3, March 2015. pp.290–301
  37. ^ a b "Wind Power – Analysis". IEA. Archived from the original on 23 November 2021. Retrieved 23 November 2021.
  38. ^ Holttinen, Hannele; et al. (September 2006). "Design and Operation of Power Systems with Large Amounts of Wind Power" (PDF). IEA Wind Summary Paper, Global Wind Power Conference 18–21 September 2006, Adelaide, Australia. Archived from the original (PDF) on 26 July 2011.
  39. ^ Abbess, Jo (28 August 2009). "Wind Energy Variability and Intermittency in the UK". Claverton-energy.com. Archived from the original on 12 January 2011.
  40. ^ "Global Electricity Review 2022". Ember. 29 March 2022. Retrieved 2 April 2022.
  41. ^ "bp Statistical Review of World Energy 2020" (PDF). BP p.l.c. pp. 55, 59. Archived (PDF) from the original on 19 September 2020. Retrieved 23 October 2020.
  42. ^ a b "Wind energy generation vs. installed capacity". Our World in Data. Archived from the original on 19 October 2021. Retrieved 23 November 2021.
  43. ^ "Global wind industry breezes into new record". Energy Live News. 25 March 2022. Retrieved 2 April 2022.
  44. ^ "Expansion of wind and solar power too slow to stop climate change". ScienceDaily. Retrieved 24 November 2021.
  45. ^ "Energy Sources: Solar". Department of Energy. Retrieved 19 April 2011.
  46. ^ http://www.ren21.net/wp-content/uploads/2015/07/REN12-GSR2015_Onlinebook_low1.pdf pg31
  47. ^ Geothermal Energy Association. Geothermal Energy: International Market Update May 2010, p. 4-6.
  48. ^ a b Fridleifsson, Ingvar B.; Bertani, Ruggero; Huenges, Ernst; Lund, John W.; Ragnarsson, Arni; Rybach, Ladislaus (11 February 2008). O. Hohmeyer and T. Trittin (ed.). The possible role and contribution of geothermal energy to the mitigation of climate change (PDF). IPCC Scoping Meeting on Renewable Energy Sources. Luebeck, Germany. pp. 59–80. Retrieved 6 April 2009.[dead link]
  49. ^ Geothermal Energy Association. Geothermal Energy: International Market Update May 2010, p. 7.
  50. ^ Rybach, Ladislaus (September 2007), "Geothermal Sustainability" (PDF), Geo-Heat Centre Quarterly Bulletin, Klamath Falls, Oregon: Oregon Institute of Technology, vol. 28, no. 3, pp. 2–7, ISSN 0276-1084, retrieved 9 May 2009
  51. ^ Bertani, Ruggero; Thain, Ian (July 2002), "Geothermal Power Generating Plant CO2 Emission Survey" (PDF), IGA News, International Geothermal Association (49): 1–3, retrieved 13 May 2009[permanent dead link]
  52. ^ The National Energy Technology Laboratory Web site “Tracking New Coal Fired Power Plants”
  53. ^ Climate Change 2007: The Physical Science Basis. Contribution of Working Group I to the Fourth Assessment Report of the Intergovernmental Panel on Climate Change. Intergovernmental Panel on Climate Change (2007-02-05). Retrieved on 2007-02-02. Archived 14 November 2007 at the Wayback Machine
  54. ^ "Carbon Dioxide Information Analysis Center (CDIAC), the primary climate-change data and information analysis center of the U.S. Department of Energy (DOE)" (PDF). ORNL.gov. Retrieved 1 October 2017.
  55. ^ a b "World Resources Institute; "Greenhouse Gases and Where They Come From"". WRI.org. Archived from the original on 14 July 2007. Retrieved 1 October 2017.
  56. ^ "Energy Information Administration; "World Carbon Emissions by Region"". DOE.gov. Archived from the original on 14 March 2009. Retrieved 1 October 2017.
  57. ^ "EIA - International Energy Outlook 2017". www.eia.DOE.gov. Retrieved 1 October 2017.
  58. ^ "Prediction of energy consumption world-wide - Time for change". TimeForChange.org. 18 January 2007. Retrieved 1 October 2017.
  59. ^ "Energy Information Administration; "World Market Energy Consumption by Region"". DOE.gov. Retrieved 1 October 2017.
  60. ^ "Air source heat pumps". EnergySavingTrust.org.uk. Retrieved 1 October 2017.
  61. ^ "Analysts' inaccurate cost estimates are creating a trillion-dollar bubble in conventional energy assets". Utility Dive. Retrieved 7 April 2021.
  62. ^ "United Nations Environment Program Global Trends in Sustainable Energy Investment 2007". UNEP.org. Retrieved 1 October 2017.