The Electrical Safety Foundation was recently featured in an article about the growth of solar photovoltaic installations and the safety precautions needed to be taken to safely install them. Here is an excerpt from the article from Electrical Contractor Magazine.
During May, National Electrical Safety Month, the Electrical Safety Foundation International (ESFI) is spreading awareness of hazards associated with solar photovoltaic (PV) installations, bidirectional current flow to and from the grid and electrical energy storage.
These risks include fires, power loss and lethal ground faults that can injure installers, property occupants and first responders. As on-site energy storage gains popularity, challenges similar to those for electric vehicle batteries have begun, including:
- Thermal runaway, which occurs when overheated battery cells cause a chain reaction with other cells that results in an explosion
- Stranded energy caused by damaged terminals that can reignite fires days later
- Toxic and flammable gases
- Fires that are difficult to extinguish
- Additional electrical shock hazards that come with pooling water
Foundational to solar safety are safe installation practices, said Brett Brenner, president of ESFI.
“For properly installing solar, you need to be able to understand how solar systems connect and interact with energy storage and the grid,” he said. “It’s one thing if you’ve been trained to do the same thing over and over in a sterile environment. It’s another to be able to do it properly out in the field where each location is different.”
Skilled workers are a necessity
Compounding this circumstance, the solar industry’s demand for labor continues to outstrip the supply of skilled workers. The industry remains on track to continue the Department of Labor’s predicted 50% expansion from 2019–2029, he said.
Trained labor better supports solar safety, but even the work of trained electricians can vary widely depending on state adoption of related codes. In home-rule states such as Illinois, consistency becomes even more challenging, because code adoption varies widely among county and municipal governments.
“Because electricians are more likely to fully understand how electrical systems interact, they have the best chance overall of doing installations correctly,” Brenner said.
ESFI’s website features a downloadable PDF that can be a resource for installers. The promotional flyer states that connector issues are the leading cause of fire hazards and performance issues in solar installations. It also suggests installers need to abide by NEC 690.33/UL6703, which requires that two parts of connector pairs must be tested together and certified for intermatability when made by different manufacturers.
The best way to assure intermatability and workability is to use only connector parts from the same manufacturer, Brenner said. ESFI also recommends using tools specified by each manufacturer, carefully following their instructions, and ensuring parts are kept clean and dry before installation.
Echoing that advice is Jonathan Stewart, managing director of utility systems at the National Electrical Manufacturers Association, which is working to bring about more universal standards among connector manufacturers to enhance intermatability.
“For a large project, like 100 MW, there might be upwards of 200,000 connections,” Stewart said. “It only takes one bad one to cause a real problem, which equates to a very slim margin for error.”
With many manufacturers and new products coming on the market, problems arise with incompatible connector pairings.
“Very few connectors have been tested for intermatability with different brands,” he said. “For now, the safest approach is to stick with the same manufacturer and pay close attention when working with connectors.”
ESFI’s solar safety resource materials also warn electricians to watch out for loose or disconnected connectors, high temperature and discolored or cracked casings while monitoring systems that sound alarms under fault conditions. For diagnosing and preventing system failure, ESFI recommends using thermal imaging and close visual inspection.
Safety for first responders
Solar safety goes beyond installation, which is why ESFI also provides solar safety information for first responders. It is key for them to understand the properties of a PV system. The information should be available through permitting records or consulting with building department staff, but that is not always the case.