Solar Eclipse vs. Solar Power

the solar eclipse will affect solar power

On August 21, 2017, a total solar eclipse is due to sweep across a large swath of the United States. For about 2 minutes, the moon will completely block the Sun across a 70-mile wide path from Oregon to South Carolina, turning day into an ominous, dark twilight. In the ancient world of the Mayans to the Egyptians, a solar eclipse meant one thing: “A disruption of established order.” The solar eclipse is going to be disruptive. As the moon’s shadow passes over North America, experts are predicting huge traffic jams, strained cellphone networks, and insufficient bathrooms for sky enthusiasts descending to the best locations for viewing the Great American Total Solar Eclipse.

Another disruption that will be brought on by the eclipse: Solar Power! Since the last solar eclipse in 1979, solar energy has grown by an average of 68% per year for the past decade.  At least 7 million U.S. homes and businesses are directly powered by the Sun. But, how will the solar eclipse affect your solar PV System? Well, solar panels need the sun to generate electricity and this phenomenon will significantly diminish solar energy production during the times of peak demand for about three hours.

How will the solar eclipse affect solar power?

the solar eclipse will decrease solar production

During the eclipse, we can expect the moon to completely obscure the Sun’s rays, blocking the sunlight that powers the solar panels. Unlike cloudy days, this loss will cause a rapid decline and rebound of solar power. More than 100 million solar panels are expected to be affected, which will drop output by more than 20%. That’s the equivalent of all the energy the city of San Francisco uses in a week!

Even so, experts, like the North American Electric Reliability Corporation (NERC), say that the country will not have any eclipse-related blackouts and it doesn’t expect the eclipse to create reliability issues for the bulk of the power system. Still, the consistency of solar generation on a national scale will be tested, especially in California and North Carolina.

How is California preparing for the solar eclipse?

California relies more on solar energy than any state in the union. And although Californians won’t experience a total eclipse, there is still going to be a significant impact. Solar experts believe solar radiation will be dimmed by 70% when the eclipse rolls across the state.

the solar eclipse will will not affect homeowners solar pv

To maintain grid reliability, solar facilities are going to use a complex combination of other sources of power generation. Utility operators are reserving spare capacity from gas and hydroelectric power plants, as well as coordinating with industrial sources to temporarily curb demand. This process will continue in reverse with gas and hydro plant shutoffs as the sun returns until the eclipse is over shortly before noon.

California Independent System Operator (Cal ISO) said they are working to make sure that the natural gas plants have enough fuel for the day. And the hydro plants at the state’s dams and reservoirs are preparing for strategic water releases to turn turbines as needed. But the greatest challenge will be managing both timing and ramp rates, or changes in energy output.

While solar is ramping down, the other sources of energy generation need to be ramped up. But, once the eclipse is over, the other generation needs to be decreased in order to keep supply balanced with demand. Thankfully, the eclipse is not expected to hit California during times of peak demand production, which typically occurs from 4 to 9PM.

How can you prepare for the solar eclipse?

While there is enough energy supply to make up for lost solar production during the eclipse, homeowners should always use energy wisely. Why turn on carbon-emitting power plants when millions of California homeowners could instead switch to efficient LED light bulbs, unplug televisions and other electric devices, and possibly turn up their thermostat by a few degrees?

The eclipse may be a good time to turn things off and enjoy this rare celestial event. The entire California Public Utilities Commission (CPUC) is collecting pledges from residents to find ways to reduce electricity usage the day of the eclipse. The average homeowner won’t notice the small blip in cost for one day, but the energy industry will. It’s not about the total loss and needing to make up for lost solar power. It’s more about increasing other energy supplies to compensate for solar energy going down. California gas turbines alone, release up to 70 to 90 MW per minute to make up the difference. So, energy efficiency steps taken by homeowners could really do something to offset that gas need.

how to conserve energy during the solar eclipseBased on these finding, here are a few tips we’ve compiled to guide you on conserving energy during the Great American Total Solar Eclipse.

  1. Unplug home electronics – Your cell phone charger, computer or laptop, television, or a radio or sound system, consumes 23% of electricity used to power your home while they are turned off.
  2. Replace light bulbs – If you upgraded to LED bulbs, you could be using 75% less energy than using regular light bulbs. LED’s also last 25 times longer and the state could reduce CO2 emissions equivalent to those produced by a coal-fired power plant in one year.
  3. Time of Use – By using appliances, such as dishwashers, air conditioners, and washing machines after 9PM, you may be able to cut your bills and reduce your use of the most expensive forms of power.
  4. Adjust your thermostat – One of the easiest ways to conserve energy is to turn up the temperature on air conditioning when no one is at home. The recommended thermostat setting is at 78 degrees Fahrenheit only when people are at home and cooling is needed.
  5. Charge your Electric Vehicle the night before – If you own an electric vehicle, you already know that it takes up a lot of electricity to charge it. Start charging it after 9PM so you’ll have a fresh battery in the morning without incurring costly time of use daytime rates.

Ultimately, the eclipse is a reminder of how important solar energy has become to our power generation. However, by reducing electricity consumption, power plants will burn less fossil fuel and fewer greenhouse gasses will be emitted in California when solar energy production dips during the eclipse.

If you’re traveling to see the eclipse while in totality, you’re in for a rare treat. Don’t miss out on this rare opportunity to go outside, save energy, and experience the power of the Sun. Be sure to share your eclipse photos on social media by tagging us @heliopower on Instagram or Facebook.

Happy Solar Eclipse!