Hans Petersen took a deadly misstep in April while checking his work on a rooftop solar power installation atop a Northern California public housing complex. Petersen, working without a safety harness or a barrier to prevent a fall, tumbled off the pitched roof and landed three stories below on a concrete walkway. He was airlifted to a nearby hospital, where he was pronounced dead.

Following a six-month investigation, California’s Division of Occupational Safety and Health is now seeking $26,500 in fines against SolarCity, Petersen’s employer, in connection with the death of the 30-year-old solar panel installer. The company has been cited by the state agency for one “serious” violation of failing to ensure that employees used fall-protection gear.

SolarCity was also cited last week for two “general” violations. According to agency inspectors, the company failed to train supervisors on the safety and health hazards faced by workers at the site and did not  provide Cal/OSHA with records demonstrating that any fall-protection program was carried out.

Peter Rive, chief operations officer of SolarCity, said the company was waiting to receive Cal/OSHA’s full report on the incident and has not decided whether it will appeal.

The potential safety hazards in installing solar equipment are important because the field is widely touted as a potential boom industry that could produce an abundance of carbon-free energy and well-paying “green jobs.” It also has benefited from billions of dollars in state and federal tax credits and grants, especially through the stimulus plan passed by Congress last year.

While employment in most economic sectors continues to sputter nationwide, the solar industry added 10,000 new jobs last year, according to the trade group Solar Energy Industries Association. SolarCity, based in Foster City, Calif., is one of the nation’s largest solar installation companies, with approximately 780 employees.

But installing solar panels combines three of the most injury-prone jobs — roofing, carpentry and electrical work — making it particularly risky, safety experts say. At the same time, there are no federal or California workplace safety rules — and few, if any, rules in other states — that specifically apply to solar installers. As a result, companies deal with a hodgepodge of regulations.

No one keeps comprehensive figures on injuries or deaths in the the solar installation industry. However, California health authorities have investigated three workplace deaths in the industry in slightly over two years.

In June, 2008, a 34-year-old solar technician was electrocuted when the metal bracket he was hauling touched high voltage power lines. He fell 35 feet from a scaffold to the ground. In the other fatal incident, in April, 2009, a solar installer was carrying panels on a roof when he crashed through a skylight and plunged 40 feet.

According to two SolarCity employees contacted by FairWarning, neglecting to use safety harnesses on installation jobs was common before the accident, even though such gear was available in the warehouse. The employees, who asked not to be identified for fear of losing their jobs, said wearing a safety harness was usually up to the installer.

SolarCity’s Rive, however, disputed those comments. He noted that the company’s safety plan for the job called for workers to use protective gear. He said the reason Petersen wasn’t using the gear was “something that we’re still trying to understand and trying to prevent from happening again.”

Since the accident, company spokesman Jonathan Bass said, Solar City has invested roughly $500,000 to strengthen its safety practices. Company auditors are now doing spot safety checks at 40 percent to 50 percent of job sites, said Bass, compared to a maximum of 10 percent before the accident.

The two employees who spoke with FairWarning said safety gear has been required on all jobs since the accident, and Rive said disciplinary action has been taken against workers not following safety protocols.

Labor, environmental and industry groups all acknowledge that workplace safety needs to be improved in the solar installation field.

Sue Kateley, executive director of the California chapter of the Solar Energy Industries Association, said she is pushing solar companies to look beyond their focus on cost issues and devote more attention to safety. At a July solar industry conference  in San Francisco, Kateley told her audience that she believes that “safety has got to get up there and become the first priority.”

Kateley, in an interview, said workers sometimes fail to wear safety gear because of a pervasive macho attitude in the construction industry. “They’re big and they’re tough and they think they’re invincible,” she said. “They still need to put their tethers on.”

Petersen’s friends and co-workers, however, described him as anything but macho. “He was the kind of person who made me believe there are good people,” one of the co-workers said in an interview.

A passion for alternative energy drove Petersen, a graduate of Oberlin College and a one-time seminary student, to find work as a solar installer. “He cared about his job, he cared about his friends, about the impact he was having, about the craft,” the co-worker said.

Petersen’s father, Glen, a Lutheran pastor, said his son loved to work with his hands and left the seminary to pursue carpentry and then solar work after a stressful summer of pastoral work at a Houston hospital. Petersen had been working for SolarCity for about six months when he died.

The elder Petersen said the family would wait for the full accident report from Cal/OSHA before deciding whether to sue the company, though he said the family was unlikely to take legal action.