Global warming will impact the power grid

pgeweather@pge.comAugust 3, 2013 

The power distribution grid is a remarkable machine that regulates and transports vast amounts of electrical energy that we use in our homes and businesses. It’s there out in the open for all of us to see; in fact, it’s so wide open, most of us don’t even notice the lines and poles any longer. It's only during a power outage when you actually think about it.

Unfortunately, a new report released by the Department of Energy in July, says that our electrical grid will be impacted due to the effects of global warming. Over the last century, air and ocean temperatures have continued to increase and droughts have become more prolonged. Both of these conditions have produced a seemingly never-ending fire season across the Western United States. July 2012 was the hottest month ever recorded in the United States and 2012 was the warmest year overall. 

As ambient air temperatures continue to increase, the demand for electricity will rise as air-conditioners are cranked up. In fact, according to the report, every 1 degree Fahrenheit of temperature rise above 82 degrees leads to an increase in peak demand for electricity of about 700 megawatts — about equal to the combined output of the two large commercial solar projects underway on the Carrizo Plain in San Luis Obispo County.
However, as air temperatures increase, the grid’s ability to transport electricity diminishes.

Increasing temperatures can cause the aluminum transmission lines to begin to sag due to thermal expansion. When this occurs, the amount of power transported through these lines is reduced. 

The greater number and severity of wildfires due to global warming has also escalated the risk of physical damage to electrical transmission towers, which in turn would decrease the available transmission capacity of the grid. According to the report, the probability of exposure to wildfires for some lines in California is projected to increase by 40 percent by the end of the century.  Natural disasters like severe storms and floods made more severe by climate change will also threaten the carrying capacity of the grid.

The good news is that California is leading the fight against climate change through statewide efforts to promote conservation and efficiency. The state’s utilities provide their customers with some of the cleanest energy found anywhere. Currently, nearly 60 percent of the electricity you receive from PG&E is free from greenhouse gas emissions and the mix will continue to get cleaner into the future. 

This coming Saturday, Aug. 10 from 1 to 3 p.m., the San Luis Obispo botanical garden will present a panel discussion on our changing climate. Ecologist Dr. Lou Pitelka, astronomer Dr. Ray Weymann and I will offer an eye-opening presentation and discussion on climate change and how it is affecting our local ecology. To lean more, visit

John Lindsey’s column is special to The Tribune. He is a media relations representative for PG&E and a longtime local meteorologist. He is president of the Point San Luis Lighthouse Keepers. If you have a question, send him an email at

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