NREL study finds US solar interconnection delays a common problem

The U.S. Department of Energy’s (DOE) National Renewable Energy Laboratory (NREL) has taken the first in-depth look of its kind at solar completion timelines in the U.S. with a view to understanding how to streamline the process to benefit solar end-users.

NREL gathered and analyzed data from more than 30,000 PV installations across the U.S. and assessed the correlation between interconnection regulations and actual project completion timelines.

Initial findings revealed that interconnection process delays were a common occurrence, ranging from several days to – in some cases – many months.

Data was gathered from PV projects in 87 utility territories and 16 states. For the average residential or small commercial-scale installation (typically less than 50 kW), it took an average of 63 business days from the date the PV installer submitted the interconnection application to when permission to operate was granted from the utility.

The median timescale was 53 days, yet within that average completion rates varied dramatically, ranging from less than one week to more than six months, NREL reveals. The fastest part of the process was system construction (averaging four business days), while the interconnection application review and approval was the stage of the process that took the most time, average 27 business days for completion.

Statewide variation

As expected, there were slight variables between states, largely dictated by how stringent interconnection timeframe regulations were. NREL’s findings – based on analysis of Arizona, California, Colorado, New Jersey and New York – suggest that robust policy guidance does actually help reduce overall project length, which indicates that more states should introduce binding timeframe regulations.

However, NREL stressed that "such regulations do not necessarily limit timeframes to the targets specified by interconnection standards", which means that there are other delaying factors at play.

"We now have a clearer understanding of the different process elements associated with connecting a PV system to the grid, such as how long it takes to review and approve an application for interconnection, how long it takes to construct and inspect a system, and how long it takes to get final authorization from the utility," said Kristen Ardani, policy analyst at NREL and lead author of the report, which is titled Understanding Processes and Timelines for Distributed Photovoltaic Interconnection in the United States.