Last week, the Pilgrim Nuclear Power Station had to temporarily reduce power output by 15 percent in a summer heat wave when homes and businesses needed the electricity the most in order to keep cool. High temperatures were to blame for the reduction of output. Cooling water drawn from Cape Cod Bay got so warm the power plant couldn’t safely discharge it. On the bright side, the power reduction lasted only 90 minutes. Unfortunately, the Pilgrim Nuclear Power Station produces a huge percentage of the state’s energy needs and they still have to make it through July and August.
Meanwhile in Michigan, a hydropower plant run by the Cloverland Electric Cooperative experienced a 60-80 percent drop in output in 2012 due to falling Great Lakes water levels. Waters far below the long term average reduced the power plant’s water allocation and also let air into the draft tubes. The power plant has built a dam around the discharge area to raise the water levels to moderate the problem.
This is a growing trend around the U.S.: changing conditions from a warming planet are causing disruptions in our power supply. The U.S. Department of Energy this month released a report showing vulnerabilities to our energy sector from climate change. Here are the basics:
Right off the bat, warmer air and water will decrease the efficiency of our thermoelectric power plants (coal, gas, nuke…plants that heat water) by as much as 16 percent. It’s a matter of physics. Steam in the power plant needs to be condensed back into water though a cooling system to efficiently produce power. The warmer the air or water used to cool the steam, the less effective it is. The lower the efficiency as the mercury climbs.
So what happens to the cooling water once it’s been used to cool the steam? It gets hot! And if the power plant has a “once through” cooling system, the hot water needs to be returned back to the source. If the source water is already very warm, as it was in the case of the Pilgrim Nuclear Power Station, discharging even hotter water into it lays waste to ecosystems and fisheries. That might not seem like a big deal unless you’re a commercial fisherman. Or a person who enjoys fish. Or fishing. Or values wildlife in any way.
Dwindling water resources
Out of 410 billion gallons of water drawn in the United States every single day, about half of it goes toward energy production: cooling systems and steam production for thermoelectric power plants, water for hydrofracking, water for oil and gas production. Our energy production is more water intensive even than agriculture. So, what happens when aquifers are running dry and mass bodies of water are strained? The Upper Great Lakes have been below the long term average for the longest time in recorded history and hit a record low in January. Upper Mississippi water levels are so low, there’s a possibility that it may soon be un-navigable.
Lower water levels reduce the water allocations for power plants, hinder barge transport of coal and oil, and can result in costly line extensions for water intakes and discharge. These are all potential interruptions to power supply.
More and stronger storms
After Hurricane Sandy, five nuclear power plants were either shut down or scaled back while over 8 million Americans were without power. As the climate heats up, we’re seeing more extreme weather events. Again, it’s a matter of physics. Warmer air holds more water. For every 1.8 degrees F the water-holding capacity of the air rises by about 7 percent, leading to heavier rains and more flooding. These types of natural disasters directly translate into reduced power production capacity, more maintenance and more idle-time for power plants.
The good news is this, and I return to it over and over again: there is economic opportunity hiding in this national challenge. The United States is looking at an opportunity to upgrade its infrastructure into a durable, resilient one up to the challenges we face. A nationwide upgrade to our infrastructure would inject $1.6 trillion into the U.S. economy and would save us disruptions of electricity and other services far into the future.