Energy Indicators for Sustainable Development: Guidelines and Methodologies International Atomic Energy Agency United Nations Department of Economic and Social Affairs International Energy Agency Eurostat European Environment Agency

METHODOLOGICAL DESCRIPTION 
(a) Underlying Definitions and Concepts: This indicator is an aggregation of non-
carbon energy sources with respect to TPES and electricity generation and generating 
capacity.
Non-carbon energy sources include combustible and non-combustible renewables and 
nuclear electricity generation. 
(b) Measuring Methods: The share of non-carbon energy sources in TPES is the 
primary supply of non-carbon energy divided by TPES. The share of non-carbon 

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energy in electricity generation is the total electricity generated from non-carbon 
energy sources divided by total electricity generation. 
Energy use is measured in terms of heat content based on specific net calorific values 
(NCVs). 
Electricity from hydropower and other non-combustible renewables (such as wind, 
tide, photovoltaics, etc.) is accounted for by using the factor 1 terawatt hour (TWh) 
equals 0.086 million tonnes of oil equivalent (Mtoe). Electricity from nuclear power is 
accounted based on an average thermal efficiency of 33%; that is, 1 TWh equals 
0.261 Mtoe (see Annex 1). 
For electricity generating capacity, the indicator corresponds to the shares of non-
carbon energy in overall capacity. 
(c) Limitations of the Indicator: For a number of countries, data on non-carbon 
energy sources might be a limitation. 
(d) Alternative Definitions/Indicators: None. 
ASSESSMENT OF DATA 
(a) Data Needed to Compile the Indicator: TPES and total electricity generation 
and generating capacity. Primary energy from non-carbon energy options, and 
electricity generation and generating capacity from renewable and nuclear sources. 
(b) National and International Data Availability: Data on energy supply by fuel are 
available from national statistical offices and country publications, and various 
international sources, such as the International Energy Agency (IEA), the 
International Atomic Energy Agency (IAEA), the World Bank and Eurostat.