Petaluma-based Enphase Energy expected first-quarter revenue between $60 million and $65 million but brought in only $54.8 million. The company attributed the weak performance to rain.

“Our revenue for the first quarter was lower than expected due to the extraordinarily wet winter in California, where we have a significant presence,” said Paul Nahi, president and CEO of Enphase.

The company makes micro-inverters that attach to individual solar panels to change direct current into alternating current — the kind used in households and businesses for lighting, computing and manufacturing.

Enphase stock soared 27 percent from $1.50 on Valentine’s Day to $1.90 a share on Feb. 27. Then the stock plunged 40 percent to $1.14 on March 9. In the intervening two months the stock drifted up to $1.40 on March 17 and April 4, and was back down to $1.15 on May 9.

Enphase, which had a peak stock price near $17 a share in Sept. 2014, struggles in a solar-energy market flooded with cheap panels made in Asia. Total revenue for 2016 was $323 million on shipments of 3.1 million micro-inverters.

In its first quarter of 2017, Enphase sold 573,000 microinverters and had operating expenses of $29 million. The company lost $22.1 million in the quarter.

At the end of January, Enphase Energy laid off nearly 18 percent of its workforce, including 75 full-time employees plus another dozen contractors. There were hints of investor confidence, as Enphase reported a $5 million investment by John Doerr, chairman of venture-capital giant Kleiner Perkins Caulfield & Byers, and another $5 million by Thurman John Rodgers, former CEO of Cypress Semiconductor.

“They didn’t make it conditional on the layoff,” said Paul Nahi, CEO of Enphase, of the $10 million from Rodgers and Doerr, who got their shares at a discount — about $1. But “it was very important for them that we achieve profitability as quickly as possible. That was one of the elements,” he told the North Bay Business Journal in February.

In August 2016, Enphase launched measures to survive near-term challenges then reenergize the company long term. It began shipping batteries to solar-array customers in Australia and New Zealand as a new trickle of revenue to augment sales of panels.

Enphase’s new storage units, touted as “AC batteries,” rely on lithium iron phosphate cells, a battery technology with safer chemistry than many. Like other batteries, they store electricity as direct current. The 1.2 kilowatt-hour batteries sell for about $2,200, weigh 53 pounds, and can be discharged up to about 7,300 cycles and down to zero percent of capacity without damage. Modular design allows expansion to optimize energy use in relation to system cost.

“We look forward to the U.S. launch of our integrated AC solar modules, developed with our partners, during the second quarter,” Nahi said in a statement. “These modules, which we believe are the future of rooftop solar, will include our sixth-generation microinverters, creating a simpler and more consolidated solution.”

Enphase expects second-quarter 2017 revenue at $72 million to $80 million.

James Dunn covers technology, biotech, law, the food industry, and banking and finance. Reach him at: or 707-521-4257