Conflicts continue over Duke’s interconnection rules

Last week saw a number of conflicts over Duke Energy‘s interconnection rules as the North Carolina Utilities Commission (NCUC) issued an orders on the interconnection restrictions it wants to impose on solar developers, but also served notice to Duke on three other projects.

The utility is trying to institute what Duke has labelled a “stiffness test” — a requirement that new solar installations don’t overly burden distribution lines.

On Nov. 1, the NCUC approved a settlement agreement between Duke and seven solar developers, including the state’s largest developer Strata Solar. “The Commission is satisfied that Duke is taking appropriate steps to ensure electric service to retail customers is not degraded due to the operations of newly interconnected generation facilities,” noted North Carolina Utilities Commission. “Therefore, the Commission finds there is no need for additional action at this time.”

However, the conflict over the application of interconnection rules continues. On Nov. 3, the commission issued orders serving complaints by developer O2 emc about its Wadesboro Solar, Bear Poplar Solar and Salisbury Solar projects, requiring a response by Duke Energy by December 5. O2 has alleged in these complaints that Duke “is in violation of the commission’s interconnection procedures”.

Duke will also be required to keep these projects in the interconnection queue, at least until such time as the matter is resolved.

O2 has additionally asked that Duke be required “to immediately complete the system-impact study for each project and comply with all other deadlines, enforces the maximum of $1,000 per day in penalties for non-compliance with the interconnection procedures from the date of the complaint.”

Duke Energy spokesman Randy Wheeless said the utility had not responded to the O2 emc complaints at press time. But he dismissed the idea that Duke is trying to slow solar’s growth in North Carolina.

“[Duke has] 900 MW of solar that has worked its way through the queue and will be connected as soon as it is built,” Wheeless said. “With more than 500 pending projects in North Carolina, I’m sure there are examples where developers feel the process is going too slow — but our track record of bringing on new solar is impressive.”

While Wheeless’ contention about the amount of solar Duke has installed and the number of projects it has in the pipeline are undoubtedly true, it should be noted that those numbers are not mutually exclusive with a strategy to make it more difficult for individual installers to interconnect with the grid Duke maintains.

The utility argues burdens on distribution lines can cause power to other customers to fluctuate wildly and, in some cases, go out completely. An assessment of these technical claims is beyond the scope of this article, however pv magazine has reported on the ability of solar projects to provide various grid services including reactive power to stabilize voltage, contingent on cooperation between grid operators and PV plant operators.

Correction: This article was corrected at 12:30 pm EST on Nov. 7. The article implied that Duke Energy was playing favorites in North Carolina because of its significant investment in solar installer REC Solar. But REC Solar does not do business in North Carolina, which means there’s no conflict of interest for Duke in the state. The story has been edited to remove the REC Solar reference.

Correction: This article was corrected at 12:00 PM EST on Nov. 8. The article had previously mischaracterized language in a complaint by developer O2 emc as an order by the NCUC. NCUC issued no such orders but did serve Duke with the complaint and require a response, as indicated in the current text of this article. We regret the error and any confusion that this may have caused.