How Will The Eclipse Affect Electricity Generation? Posted on Aug 16, 2017

As the majority of the country prepares to experience darkness mid-day for the first time in nearly a century, the approaching total solar eclipse offers an opportunity for reflection, lessons and unification. On August 21, 2017, when the total solar eclipse occurs, our cleantech and renewable energy industry can pause to realize just how far we have come in transforming our nation’s electric supply and technological innovations. In the months leading up to this event, grid operators have prepared to navigate the rapid loss of large amounts of solar energy and the whiplash of solar energy coming back as the sun appears again higher in the sky than when it disappeared. As viewers travel in mass to watch from coast to coast, our relative size to the universe will be underscored.

The path of totality of the eclipse will start in Oregon and move eastward to South Carolina over the course of approximately 90 minutes. Since the last total solar eclipse, our country’s electric grid has undergone drastic changes that will be affected. In March and April of this year, U.S. monthly electricity generation from utility-scale renewable sources, including solar and wind, exceeded nuclear generation for the first time since hydro and nuclear were at the same level in July of 1984. Total PV power installed across the U.S. is estimated to be over 44 GW today with most large scale solar plants built within the past five years. More than 60% of all utility-scale electricity generating capacity that came online in 2016 was from wind and solar technologies. 

The path of totality where the sun is completely blocked during the eclipse will affect 17 utility-scale solar systems, and hundreds of plants, mostly in North Carolina and Georgia, will be at least 90% obscured. More than 6 GW of capacity will be affected in areas that are at least 70% obscured. Northern California is expected to be 76% obscured and Southern California 62% obscured. The rolling effects of the eclipse are expected to have the biggest impact at approximately 10:30 a.m., when PV output is projected to drop 5 GW below typical generation levels. This represents the amount of energy needed to power approximately 1 million homes.

Despite the moon obscuring the sun during a peak time for solar-power production, no reliability issues are expected in the U.S.. Grid operators are lining up extra capacity primarily from natural gas powered turbines. In California, home to 40% of the country’s total PV capacity, the California Independent System Operator plans to replace solar generation from natural gas and hydropower. 

To help offset solar-power loss during the eclipse, CleanTech Docs became a Do Your Thing for the Sun Partner with the California Public Utilities Commission. We have pledged to implement an energy-savings plan that will be deployed during the eclipse, and we are encouraging our customers to join us by taking specific actions to conserve energy during the eclipse. A few reminders about ways to reduce energy use during the eclipse, and thus, reduce greenhouse gas emissions are below:

  1. Visit CalEclipse.org or your local/state organization and take an eclipse energy saver pledge.
  2. Replace light bulbs with LEDs.
  3. Turn off lights in areas that are not being used.
  4. Don't charge electronics during the eclipse (9 a.m. to noon).
  5. Unplug all appliances not in use.
  6. For labs with fume hoods, shut the sash.
  7. Turn up the thermostat by 2-5 degrees.
  8. Take lunch an hour earlier and turn off lighting and equipment in your office while you’re out.
  9. If you regularly do laundry or run the dishwasher during the eclipse period, do so another time of day.
  10. Turn off computer monitors if out of the office.
  11. Avoid using microwaves during the event.
  12. Power down – shut off your computer. Powering down your computer completely uses 50% less energy than sleep mode.
  13. Power to the strip – use an electronic power strip. This will help reduce phantom loads. Turn the strip off when not using it.
  14. Retrofit old equipment with Energy Star products

We can all do better to reduce our carbon footprint, even those who work at companies or organizations dedicated to growing the cleantech and renewable energy industries. The eclipse is a chance to be reminded not only that we exist in a vast universe, but also that our life is supported by natural systems dependent on the sun. Our success is dependent on working together to solve climate change, one of the greatest threats facing humanity in the 21st century.

The California Independent System Operator has a webpage dedicated to the eclipse and its grid where viewers will be able to track solar production, current and net energy demand in real time.