The total eclipse of the sun Monday is expected to prompt fossil fuel generators to ramp up quickly to fill in the gaps as solar power goes dark from Oregon to the Carolinas.
Grid operators and watchdogs say the biggest effects from the loss of solar-generated electricity will occur in California, which represents 40 percent of the nation’s solar capacity. Other states expected to be especially hit by the loss of solar include North Carolina, Utah, and New Jersey.
PJM Interconnection, the federally-overseen grid operator that ensures the lights stay on in 13 states and the District of Columbia, said it doesn’t expect any major impact on electric grid reliability, such as brownouts or blackouts, although it is keeping a close eye on New Jersey and North Carolina.
“Certainly, this is an unusual solar event, but as far as potential impacts to the grid, PJM and its members are prepared,” said PJM President and CEO Andrew Ott. “While this is an anticipated event, we routinely plan and prepare for unpredictable events or things that can’t be forecast far in advance, such as severe storms and heat waves.”
PJM said solar power produces less than 1 percent of its 13-state grid, with a mix of rooftop and utility-scale solar arrays that make up 2,000 megawatts and 500 megawatts, respectively, across its territory. But even with a small “reduction in power from the rooftop panels” the result still means “an increase in electric demand on the grid,” PJM said in a statement on the eclipse.
That increase in demand needs to be filled by something, which can get dicey especially when demand for electricity is high because Monday will be a hot summer day and people need electricity to run their air conditioners.
The North American Electric Reliability Corporation, the congressionally-chartered reliability watchdog, pointed out in an eclipse white paper it sent out to grid operators the concerns it wants to address during the event to stave off problems that could arise as more solar is added to the grid.
The watchdog organization said it hopes to use the event to prepare for the next eclipse in 2024 when solar energy will represent even more of the grid’s total generation. The last total eclipse in the U.S. was 38 years ago on Feb. 26, 1979, when solar energy generation barely existed, if at all.
It wants to use the eclipse to examine what happens when a state loses all its solar capacity. NERC, which enforces mandatory grid standards for keeping the lights on, says one of the issues with solar energy is that not all of it is under the control of the operator or a regulated utility. So, when the sun goes dark when electricity demand is at its peak, say in the middle of a hot summer day, it is not completely known how big of a drop in power will be experienced.
In the nine states with the most solar energy generating capacity, the eclipse does pose real problems if another resource, such as natural gas power plants, cannot ramp up fast enough to fill in the gaps, NERC said.
The need to meet any sudden increase in demand “would indicate a great vulnerability to the eclipse and ramping concerns,” according to the white paper. Ramping refers to the ability of a power plant to throttle up and down with changing electricity demands to stave off a loss in power. Natural gas and some oil-fired power plants are able to do this. And a renewable power plant with the ability to store and inject power into the grid would be able to generate when the sun wasn’t shining. But few renewable energy resources have storage capabilities.
The nine states are Texas, California, Nevada, New York, North Carolina, New Jersey, Arizona, Massachusetts, and Utah. NERC tracks Canada and also includes Ontario as an area of concern. In some states, such as Utah, where solar can generate up to 39 percent of electricity at peak times, the grid watchdog says solar energy may need to be disconnected from the grid to avoid the huge anticipated drop in power from the eclipse at peak times. In the summer, peak demand for electricity can typically occur from noon until 8 p.m.
Read more at Washington Examiner