Investigating the Environmental Impacts of Low-Carbon Energy Technologies
To address the changing environmental concerns that could arise from the increased development of renewable and other low-carbon energy technologies, the United Nations Environment Programme’s International Resource Panel (IRP) commissioned two reports examining the environmental risks, benefits and tradeoffs resulting from the global scaling up of low-carbon electricity generation technologies and technologies that enable energy efficiency.
The report on efficiency technologies, further discussed below, is being managed by Institute for Energy Efficiency and IRP member Sangwon Suh and PhD candidate Joe Bergesen. They are also lead authors for chapters on photovoltaics and energy efficient lighting. The report on electricity generation technologies is led by Professor Edgar Hertwich and PhD candidate Thomas Gibon of NTNU.
These reports will be the first global, comprehensive assessment of the long-term, widespread adoption of low-carbon electricity generation technologies. Both reports quantify the total material demand and potential environmental impacts from following the International Energy Agency’s scenarios for halving global energy-related greenhouse gas emissions by 2050.
Using life-cycle assessment to evaluate scenarios of renewable energy development
To avoid the most dangerous impacts of climate change, it is widely understood that a variety of renewable and low-carbon electricity generation technologies and energy efficient technologies must be deployed across the entire globe. Widespread adoption of these technologies could bring about unforeseen environmental impacts or natural resource constraints.
The report authors use life-cycle assessment (LCA) to examine the environmental impacts and natural resource consumption by the most common low-carbon energy technologies from 2010-2050, focusing on renewables (wind, photovoltaics, hydropower and concentrating solar power) and fossil fuel generation with CO2 capture and sequestration.
LCA allows for a level comparison of low-carbon and conventional energy technologies by accounting for all environmental impacts over the life cycle of a technology — from mining of raw resources to manufacturing, use, combustion of fuels, and end-of-life disposal or recycling.
Findings on the benefits, risks and tradeoffs of low-carbon technologies
The authors found that per unit of generated electricity, most renewable energy technologies lead to lower particulate pollution, ecotoxicity and greenhouse gas emissions compared to fossil fuel-based generation, with emissions just 10% or less compared to those of modern natural gas-fired plants.
Particularly for photovoltaics (PV), the authors find that expected technological advances have the potential to further lower environmental impacts as PV technologies continue to mature.
Results also suggest that carbon capture and sequestration can lead to increased non-CO2 related impacts compared to the same technology without carbon capture.
As a price for lower CO2 emissions, renewable energy technologies generally require larger up-front investment in materials, with photovoltaic generation requiring larger amounts of copper, and wind plants requiring greater amounts of steel compared to fossil fuel-based generation. However, these material requirements do not represent a fundamental obstacle for the scaling up of renewable energy.
Future research on energy efficiency technologies
The report on energy supply technologies will be published in 2014. The authors continue their work in a follow-up report on the environmental implications of technologies that enable energy efficiency, examining technologies used in buildings, mobility and industry.
The graph above shows the life-cycle environmental impacts and materials consumption of renewable and low-carbon electricity production technologies
Author: Joe Bergesen, December 2013
Bren School of Environmental Science & Management, UC Santa Barbara