A recent Asian Development Bank report is shedding light on a little-known peril of rising greenhouse gas emissions, as evidence that climate change continues to mount.
Titled Climate Risk and Adaptation in the Electric Power Sector, the July 2012 report highlights the vulnerability of the sector by detailing the effects that shifting weather patterns can have on the generation, transmission and distribution of electrical power. It is an issue that merits attention: Investment decisions in the electric power sector involve long lead times and long-lasting effects, with power plants and grids often lasting for 40 years or more.
In addition, a recent assessment of 193 countries found that 30 of them--many of which are in the Asia-Pacific region--are extremely vulnerable to climate change. Some countries are already addressing this risk, by integrating climate change considerations into their planning and policymaking for the electric power sector. However, details on risk evaluation methods and practical action plans remain scant.
The vulnerability of the power sector can be broadly manifested in several ways:
- Increases in water temperature are likely to reduce generation efficiency
- Increases in air temperature also reduce generation efficiency, but also lead to increases in customers' cooling demands which stress generation capacity and grid networks
- Changes in precipitation patterns and surface water discharges, as well as a higher frequency or intensity of droughts, may adversely impact hydropower generation and reduce the availability of water for cooling thermal and nuclear power plants.
- Rapid changes in cloud cover or wind speed can affect the stability of grids with a sizeable input of renewable energy. These changes may go on to affect the viability of a range of renewable energy systems in the long term
- Rising sea levels can reduce the number of options for the siting of power plants and grids
- Extreme weather events such as stronger or more frequent storms can damage generation and grid infrastructure, reduce the supply and quality of fossil fuels, and reduce the input of energy such as wind, sun and biomass
Some of these impacts, such as rising air temperature, cover a wide geographic area. Others, such as changes in wind speed, are highly site-specific. Drilling down further, we see a more complex set of dynamics influencing the various effects of climate change on various power sector technologies. Some of these are:
- Flooding generally has the biggest impact for a wide range of generation technologies
- Higher water temperatures generally exert a more severe impact than higher air temperatures, especially in areas where water is used for cooling purposes
- Biomass generation is highly susceptible to climate change, as the energy density of biomass can vary with photosynthetic and plant physiological interactions, which are in turn driven by changes in CO2 concentration.
- Ocean power technologies have varying sensitivities to climate change, with some technologies sensitive to changes in water temperature or sea level
- T&D grids can be highly-sensitive to storm damage and high ambient temperatures, which increase electrical resistance
- Geothermal power has a relatively lower sensitivity to climate change. When disruption does occur, flooding is usually the main cause
- Like geothermal power, solar photovoltaic technologies have a relatively lower sensitivity to climate change, but the output changes with changing cloud movements, and the infrastructure can be damaged by high winds and hail
- Finally, electricity end-use demand is sensitive to temperature changes, particularly heat waves
The complex effects of climate change phenomena on the electric power sector, coupled with the long lead times and effects of power infrastructure investment decisions, necessitates the need to assess adaptation options. This includes their technical and economic viability. These can generally be divided into engineering and non-engineering options. The former comprises measures such as building new storage reservoirs for hydropower facilities, designing more robust feedstock for biomass generation that are tolerant to heat, salt or water, and designing multiple or underground T&D routes to safeguard grids against wind and floods.
On the other hand, non-engineering adaptation measures include putting in place more robust operational and maintenance procedures, improved and better coordinated land use planning, and the integration of climate change and disaster management planning. Yet, despite the number of adaptation measures that can be considered, a "do nothing" approach can occasionally be most appropriate and cost-effective.
BY: Asian Development Bank