Policy ForumEnergy and Environment

Understanding China's non–fossil energy targets

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Science  27 Nov 2015:
Vol. 350, Issue 6264, pp. 1034-1036
DOI: 10.1126/science.aad1084

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Less reliance on coal.

Shizuishan City installed photovoltaic panels in 2014 to augment the power supply and to reduce consumption of coal.

PHOTO: © PENG ZHAOZHI/XINHUA PRESS/CORBIS

More than 130 countries have targets for increasing their share of renewable or nonfossil energy (1). These shares and targets are often reported without clear articulation of which energy accounting method was used to convert nonfossil electricity into units that allow comparison with other energy sources (24). Three commonly used conversion methods are well documented by organizations dealing in energy statistics, but often, the method is not clearly stated when countries translate national targets into international pledges or when organizations track and compare targets across nations. China—the world's largest energy producer, energy consumer, and emitter of energy-related carbon dioxide (CO2)—uses a distinct fourth method that is unique, not well documented in the literature, and not transparent in policy documents. A single, standardized, and transparent methodology for any targets that are pledged as part of an international agreement is essential.

More than 120 national pledges in the form of Intended Nationally Determined Contributions (INDCs) have been submitted in advance of the 21st Conference of the Parties (COP21) to the United Nations Framework Convention on Climate Change (UNFCCC) beginning 30 November. Many of the pledges include targets for increasing the share of renewable or nonfossil electricity in the national energy mix. With this “bottom-up” system of pledges likely to be status quo for the near future, the absence of common methodological guidelines could lead to confusion and inaccuracies as requirements to track and report progress expand.

CONVERSION METHODS. “Primary energy” refers to energy in natural resources, fossil and nonfossil, before conversion into other forms, such as electricity. For nonfossil sources, it is not useful to calculate the primary solar or kinetic energy, for example, before conversion to electricity; thus, these sources are expressed in terms of electricity generated (“primary electricity”). Three methods are used internationally to convert primary electricity into standardized units of primary energy such as joules or British thermal units (Btus) (table S1).

(i) direct equivalent: electricity is considered the primary energy form in all cases, with 1 kWh of noncombustible electricity or heat equal to 3.6 MJ of primary energy [used by the Intergovernmental Panel on Climate Change (IPCC)] (2); (ii) substitution: calculates efficiency for all electricity production as if it had been generated by a fossil fuel power plant with an average electricity conversion factor [used by the U.S. Energy Information Administration (EIA) of the U.S. Department of Energy (DOE), BP, and the World Energy Council] (57); (iii) physical energy content: uses physical energy content of the primary energy source used for electricity production [used by the Organization for Economic Cooperation and Development (OECD), the International Energy Agency (IEA) and Eurostat] (8). For nuclear and geothermal, heat is considered the primary energy form; for other primary electricity production (hydroelectric, solar photovoltaics, or wave or tide), electricity is considered the primary form of energy.

A fourth method, power plant coal consumption (PPCC), in which conversion to standard units is based on the average heat rate of coal-fired power plants in that year, is used only in China. As coal has long been the dominant source of energy in China, it is not surprising that coal power plants are used as the baseline for conversion. However, it is not clear how China calculates the average coal consumption figure, as the derived heat rate matches neither the generation heat rate nor the supply heat rate as published in the China Electric Power Yearbook (9). Because this methodology is not transparently reported, it is difficult to compare China's targets, and progress toward these targets, with those of other countries.

CHINA'S TARGETS. In recent years, China has set a number of domestic energy and climate targets, many of which are reflected in international pledges. In late 2009, China announced a goal to reduce carbon intensity [CO2 per unit of Gross Domestic Product (GDP)] 40 to 45% below 2005 levels by 2020 and to increase the share of nonfossil energy to 15% in 2020. These goals were included in China's UNFCCC Copenhagen Accord pledge in early 2010 (10). In November 2014, as part of the U.S.-China Joint Announcement on Climate Change, China stated its intention to achieve peak CO2 emissions around 2030, making best efforts to peak early, and to increase the share of nonfossil fuels in primary energy consumption to around 20% by 2030 (11). These targets, along with a pledge to lower carbon intensity by 60 to 65% from 2005 levels, were included in China's INDC in June 2015 (12).

In order to compare China's PPCC method–derived values to others used internationally, we reproduced China's methodology using published China energy balances expressed both in physical units [tonnes (metric tons), m3, terawatt-hours (TWh)] and in standard energy terms [metric tons of coal equivalent (tce)]. [For full details of the analysis, see the supplementary materials (SM).] By using the same energy and electricity data from China's 2010 National Energy Balance Table (13) but applying different methods of calculating the standard energy equivalent of primary electricity, the share of nonfossil electricity in China varies from a low of 3.4% (direct equivalent) to a high of 9.2% (substitution method). Using China's PPCC method results in an 8.4% share, whereas using the physical energy content method results in a 4.2% share.

China's INDC goal of a 20% share of non-fossil energy in total energy by 2030 was calculated using the PPCC method. If the direct-equivalent method had been used, the share would have been different. Using the forecast electricity generation composition of the “continued-effort” scenario of a recent modeling forecast (14), if one assumes an average China coal power plant heat rate of 0.3098 kgce/kWh in 2030, the share of nonfossil energy in total energy in 2030, when using the direct-equivalent method, is 9% compared with 20% when using the PPCC method (details in SM).

Although the PPCC method that China uses calculates a higher share of primary electricity in total energy than the direct-equivalent method, its use increases the difficulty of reaching China's stated energy intensity (energy per unit of GDP) reduction goal. For example, since China's 12th Five-Year Plan target (2011–2015) to reduce energy intensity by 16% is calculated as total energy consumption (in tce) divided by GDP, use of the PPCC method increases the amount of primary electricity in the numerator energy total by a multiple defined by the ratio of the PPCC method coefficient to the direct-equivalent method coefficient (see SM). In 2010, this ratio was 2.6, and China's total primary energy supply calculated by using the PPCC method was 5% larger than if calculated using the direct-equivalent method. As the proportion of primary electricity increases over time, this gap will widen and increase the difficulty of reducing overall energy intensity.

TRANSPARENCY IN INTERNATIONAL NEGOTIATIONS. Because of the prevalence of countries adopting non–fossil energy targets, consistency in the reporting of methodologies for calculating energy-related mitigation targets will be increasingly important. The issue of comparability is complex and can include not just technical comparisons, but also procedural and political ones. Recognizing these complications, and the diversity of nationally determined rationales for setting a target in a specific format, translating these targets by using a standardized international convention when pledged or committed internationally would serve as an important first step.

China has been consistent in its use of the PPCC method for many years, but since it is not publicly documented and not simple to derive, China's non–fossil energy targets are not easily comparable with those of other countries. China does now report the direct-equivalent number in its national energy balance but has not used it for formulating energy and climate targets. Since China's national non–fossil energy target was pledged within the context of the UNFCCC, it would be easier to understand if China followed UN and IPCC convention and reported on the basis of the direct-equivalent method (2). The same is true for any other countries submitting non–fossil share pledges to the UNFCCC to allow for comparability across all of the other UNFCCC parties.

An alternative, more-transparent, and comparable metric for understanding a country's share of nonfossil electricity generation is to report directly in electricity units. This avoids the need to convert from electricity to energy and, instead, clarifies exactly how much new nonfossil electricity will be generated to meet the target. For example, China's share of nonfossil electricity generation in total generation was 21% (842 TWh nonfossil of a total generation of 3937 TWh) in 2010. The continued-effort scenario referenced above results in a 39% share (4071 TWh nonfossil of a total generation of 10,490 TWh) of nonfossil electricity generation in 2030. So this near-doubling in the share of nonfossil generation between 2010 and 2030 represents an absolute increase of 3229 TWh between 2010 and 2030. Achieving such a level of nonfossil generation would require ∼900 GW of new nonfossil power capacity to be installed in China between 2015 and 2030 (15), the actual amount dependent on the capacity factors of the mix of generation technologies. For context, the entire fossil and non–fossil electricity–generating capacity of the United States in 2015 is 1009 GW (16).

If reaching an agreement on guidelines for use of a standard methodology in the reporting of INDCs is not possible, then promulgating requirements for increased transparency to facilitate comparison and analysis would greatly improve understanding of different targets. Transparency has long been on the agenda in the UNFCCC negotiations, but it remains a complex and often politically sensitive topic. The issue raised in this paper is a tangible illustration of the need for methodological clarity, one aspect of the broader transparency discussion that is more technical than political. Addressing methodological transparency in the UNFCCC negotiations would have a positive impact on our ability to understand national pledges made at COP21 and beyond.

Correction (15 January 2016): The Chinese had a target to reduce carbon intensity 60 to 65% from 2005 levels by 2030. Now, the energy intensity is now correctly described as targeted for 16% reduction in that time frame.

References and Notes

  1. Acknowledgments: This work was supported by the Energy Foundation China through the Department of Energy under contract DE-AC02-05CH11231, NSF award 1262452, and Georgetown University.

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