Energy traders who had hoped to make an easy profit by betting that spot electricity prices would climb around midday on Monday – an idea they may have found on this website - were bitterly disappointed when, instead of spiking, prices tumbled because of an unexpectedly large drop in demand.

Utilities and grid operators had contingency plans ready to compensate for the expected drop in solar. But even with utilities’ backup grids humming, supplies were still widely expected to drop. Instead, energy providers encountered something that they hadn’t anticipated – what one trader called “an irregular human behavior pattern.”

Basically, more Americans than anticipated were outdoors during the middle of the day Monday, around the time when electricity demand typically peaks, than grid operators had expected. Therefore, while supplies took a slight dip, it was amplified by a dramatic pullback in demand, which exhibited a weird U-shaped dip over a two-hour period across the country,” according to Bloomberg. Ironically, if traders hadn’t been so distracted by the eclipse, maybe they would’ve realized that millions of Americans standing outside together staring up at the sun for an hour would have a marked impact on demand, and adjusted their positions accordingly.

“This was a bummer for traders who’d bet prices would jump as a whole load of solar-produced megawatts faded to black. “If anything, it was bearish from a trading perspective because people were more busy looking at the eclipse and talking about the eclipse,” said Tom Hahn, vice president of U.S. power derivatives at brokerage ICAP Energy LLC in Durham, North Carolina.

Spot power in California fell to negative levels as the eclipse wiped out and restarted thousands of megawatts of solar power, and they also dipped from Texas to New York. While natural gas demand rose to a one-month high on Monday, spot prices at several hubs weakened versus the U.S. benchmark.”

The dip in Northern California was particularly vicious.

“Spot electricity at Northern California’s NP15 hub averaged $21.50 a megawatt-hour at 10 a.m. to 11 a.m., less than half the price for supply secured in advance for the hour in the day-ahead market, according to grid data compiled by Bloomberg. Then at 11:50 a.m. local time - as the sun started to reappear from behind the moon -- the ramp-up in solar power sent prices to a low of minus $15.97.”

Tech firms like Alphabet Inc. helped conserve energy usage during the eclipse, part of a partnership with the state utility commission that helped it cut consumption by about 1,500 megawatts.

“Alphabet Inc.’s Nest Labs unit, which deploys thermostats and other smart home technologies, drew more than 750,000 customers into its Solar Eclipse Rush Hour experiment to cut consumption. They reduced power use by about 700 megawatts nationwide, helping to offset a 10,000-megawatt drop in solar power. In California, Nest and other partners worked with the state utility commission to cut consumption by about 1,500 megawatts.

In hubs from Texas to New Jersey, spot electricity prices slumped. Though in several cases, unexpected cloud cover helped mitigate the drop.

“While that was the most dramatic case of a power-price retreat, there were noticeable dips elsewhere. Cloud coverage in places like North Carolina, Texas and New Jersey had reduced solar output before the eclipse anyway, limiting the magnitude of the loss. The moon’s shadow also reduced temperatures a bit. And then there were all those people playing hooky from work and school.”

There were also “very evident” dips in New England, New York and the nearby 13-state grid managed by PJM Interconnection LLC, said Tom DiCapua, managing director at Con Edison Energy in Valhalla, New York, according to Bloomberg. Con Edison, which manages the largest grid in the US with 65 million people, said demand fell by 5,000 megawatts, or as much as 3.8%, during the event.

“People drove up the day-ahead price thinking that prices would settle higher in real time,” DiCapua said. That was the wrong way to go. “The people who tended to be short tended to make money. You wanted to be short.”

Luckily for traders on the east coast, they will get another shot to clinch the eclipse trade in seven years, when the eclipse's path of totality is expected to stretch from Texas to Maine.