Compared assessment of selected environmental indicators of photovoltaic electricity in OECD cities

Author(s): [s.n.] Compared assessment of selected environmental indicators of photovoltaic electricity in OECD cities

Organization: -

Date of issue: May 2006

Type: Report IEA PVPS Task 10

Reference: IEA PVPS T10-01:2006

Details: 44 pages, graphs, photographs, tables; with annexes

Download: Click here to open or download this report as PDF file (758 kB)

Available from: Task 10 members or the Executive secretary

Abstract: Photovoltaic (PV) based electricity production is pollution-free at the local as well as the global level, it does not emit greenhouse gases, it does not dip into finite fossil fuel resources and it can be easily integrated into the urban environment, close to major consumption needs. However, prior to producing electricity, manufacturing and installing PV systems and later on dismantling and recycling them require spending a certain amount of energy, which must be “reimbursed” before PV can be considered as renewable and clean. The purpose of this report is to provide clear and well-documented answers to politicians, decision-makers and the general public about what PV can and cannot achieve in terms of renewable, clean energy production and environmental protection.

The conclusion of this study is that, depending on the location, rooftop-mounted PV systems produce the amount of energy so as to recover their energy content from manufacturing and recycling in the range of 1,6 to 3,3 years and produce during their energy production period or service life between 17,9 and 8 times their initial energy content. Once they have reimbursed their initial energy input, rooftop-mounted PV systems can avoid, during their lifetime, the emission of up to 40 tons of CO2 depending on their location and on the local electricity mix available.
Results for PV facades are logically slightly worse than for roof-top PV systems since they produce less energy for the same installed power. They produce the amount of energy to recover their energy content from manufacturing and recycling in the range of 2,7 to 4,7 years and produce during their service life between 10,1 and 5,4 times their initial energy content. Their contribution to CO2 emissions mitigation can be up to 23 tons of CO2 per kWp installed.
The first part of this report describes the methodology used for the calculation of two energy indicators, the “Energy Payback Time” (EPBT) and the “Energy Return Factor (ERF) and one environmental indicator, the potential for CO2 emissions mitigation. All factors are dependant on the PV installation location. EPBT and ERF are calculated with the yearly energy production which depends on the amount of sun at a location and the environmental indicator depends on the local electricity mix. The performance of PV systems is therefore assessed on a country-by-country basis and even a city-by-city approach in larger countries where the potential for urban-scale integrated PV is highest, with a view to both better reflect the varying reality and to facilitate the use of the results at national and local levels. The global range for 41 main cities in 26 OECD countries are presented in the second section of the study and detailed results on a country-by-country - and city-by-city when relevant - basis are given in the third part.
Finally, some indications of comparison and ranking between countries are given in annexes for the purpose of comparison of an individual country’s performance amongst the others. These figures clearly demonstrate how beneficial urban-scale PV systems are for reducing the use of highly polluting conventional energy sources and for contributing to improving the general efficiency of large cities wherever they are located worldwide. Country results can be used to raise the awareness of politicians and decision-makers at national level in order to accelerate the development and the deployment of PV technologies in a given country.

Author(s):	[s.n.]
Organization:	-
Date of issue:	May 2006
Type:	Report IEA PVPS Task 10
Reference:	IEA PVPS T10-01:2006
Details:	44 pages, graphs, photographs, tables; with annexes
Download:	Click here to open or download this report as PDF file (758 kB)
Available from:	Task 10 members or the Executive secretary
Abstract:	Photovoltaic (PV) based electricity production is pollution-free at the local as well as the global level, it does not emit greenhouse gases, it does not dip into finite fossil fuel resources and it can be easily integrated into the urban environment, close to major consumption needs. However, prior to producing electricity, manufacturing and installing PV systems and later on dismantling and recycling them require spending a certain amount of energy, which must be “reimbursed” before PV can be considered as renewable and clean. The purpose of this report is to provide clear and well-documented answers to politicians, decision-makers and the general public about what PV can and cannot achieve in terms of renewable, clean energy production and environmental protection.
	The conclusion of this study is that, depending on the location, rooftop-mounted PV systems produce the amount of energy so as to recover their energy content from manufacturing and recycling in the range of 1,6 to 3,3 years and produce during their energy production period or service life between 17,9 and 8 times their initial energy content. Once they have reimbursed their initial energy input, rooftop-mounted PV systems can avoid, during their lifetime, the emission of up to 40 tons of CO2 depending on their location and on the local electricity mix available. Results for PV facades are logically slightly worse than for roof-top PV systems since they produce less energy for the same installed power. They produce the amount of energy to recover their energy content from manufacturing and recycling in the range of 2,7 to 4,7 years and produce during their service life between 10,1 and 5,4 times their initial energy content. Their contribution to CO2 emissions mitigation can be up to 23 tons of CO2 per kWp installed. The first part of this report describes the methodology used for the calculation of two energy indicators, the “Energy Payback Time” (EPBT) and the “Energy Return Factor (ERF) and one environmental indicator, the potential for CO2 emissions mitigation. All factors are dependant on the PV installation location. EPBT and ERF are calculated with the yearly energy production which depends on the amount of sun at a location and the environmental indicator depends on the local electricity mix. The performance of PV systems is therefore assessed on a country-by-country basis and even a city-by-city approach in larger countries where the potential for urban-scale integrated PV is highest, with a view to both better reflect the varying reality and to facilitate the use of the results at national and local levels. The global range for 41 main cities in 26 OECD countries are presented in the second section of the study and detailed results on a country-by-country - and city-by-city when relevant - basis are given in the third part. Finally, some indications of comparison and ranking between countries are given in annexes for the purpose of comparison of an individual country’s performance amongst the others. These figures clearly demonstrate how beneficial urban-scale PV systems are for reducing the use of highly polluting conventional energy sources and for contributing to improving the general efficiency of large cities wherever they are located worldwide. Country results can be used to raise the awareness of politicians and decision-makers at national level in order to accelerate the development and the deployment of PV technologies in a given country.