- Weather extremes, particular heat-waves, cause higher peak demands, and larger swings in power demand. For example, p1 refers to challenges in the Texas interconnect (ERCOT) as follows: "The Anticipated Reserve Margin for ERCOT is 12.88 percent for summer 2013. This is below the 13.75 percent target for ERCOT. Sustained extreme weather could be a threat to supply adequacy this summer. ERCOT may need to declare Energy Emergency Alerts (EEA) if there are higher‐than‐normal forced generation outages or if record‐breaking weather conditions similar to the summer of 2011 lead to higher‐than‐expected peak demands."
- Drought (expected to increase under climate change) can affect the operation of thermal generation plants (both nuclear and fossil-fuel powered). Eg p4 says: "When water levels fall significantly, water intake structures may be exposed above the water surface, causing the plant to become nonoperational. Additionally, generators are less efficient as the temperature of cooling water increases and results in a reduction of the power capability of the plant. Along some bodies of water, regulatory limits are placed on the temperature of the cooling water system discharges, and power plants are not allowed to raise water temperatures above levels deemed safe for species of fish and other aquatic life. Again, no major system impacts are expected; however, in certain extreme cases, waivers may be needed to keep critical generation online."
- Drought more obviously reduces available hydro-electric generation, eg in the midwest this year (p5): "For the upcoming summer season, the Missouri River main‐stem water levels are being monitored closely, as impacts to this water source may affect significant hydro generation. The U.S. Army Corps of Engineers predicts that 2013 will be a drought year, and electric energy produced from the Missouri River will be approximately 80 percent of the historical average."
- Major storms appear to be worsening, and these can cause unpredictable damage to the grid, or the fuel sources required to run the grid. For example, hurricane Sandy caused substantial outages in the northeast last year, and hurricanes in the Gulf of Mexico can cause loss of natural gas production required for electricity generation (p6).
- Finally, the increase in solar and wind production (which is being undertaken to reduce the causes of climate change) itself is a grid-stressor as these sources are intermittent and mostly not under the control of the grid operators. The larger the mix of these sources becomes, the more we will demand of the transmission grid.
Thursday, June 6, 2013
It's interesting reading the NERC 2013 Summer Reliability Assessment. Although it's not a focus of the report, reading between the lines you can see that climate change is going to have complex effects on the grid, and all of them increase the stress on it: