Minnesota commission tells Xcel to look again at solar load impacts

The Minnesota Public Utilities Commission issued a May 13 order that says that Northern States Power d/b/a Xcel Energy (NYSE: XEL) needs to develop more information about the impacts of solar power on its system.

In November 2011, Xcel Energy filed a stipulation and settlement agreement between it and several parties to its then-pending rate case. Among the terms of the agreement, Xcel agreed to study the load profile of larger solar facilities to determine the applicability of a solar facility’s unique load characteristics to its standby and supplemental rate tariff.

In May 2012, the commission approved the rate case and the settlement. In August 2012, Xcel filed a Solar Load Profile Study, which it re-filed in September 2012 to include previously redacted information after customers consented to the public release of their solar load profile data. Xcel said its Solar Load Profile Study was as an “initial attempt to estimate the contribution of solar photovoltaic (PV) facilities to system reliability and, thus, better understand the value of solar on the [Xcel] electric system.” The study used one year of metering data to approximate the contribution of solar PV facilities to the system.

As a result of the study, Xcel concluded that “solar contributes to capacity requirements during peak periods” but also that “further analysis would be needed to support decision making.”

The commission in the May 13 order accepted Xcel’s Solar Load Profile Study as fulfilling Xcel’s obligation under the commission’s May 2012 order. However, it said Xcel must take further steps to complete its obligation under the November 2011 settlement. More detailed analysis is needed to support a final commission determination of a just and reasonable rate for solar PV facilities, the PUC wrote.

The commission will therefore establish a new docket and a procedural schedule to allow Xcel and interested parties to review Xcel’s Effective Load Carrying Capacity study and to develop and comment on a solar rate proposal for large solar PV customers. The commission establishes this schedule with the intention that it approve a final solar rate by Jan. 1, 2014, and that Xcel will implement the rate within 30 days thereafter.

Among the commission’s findings:

  • Xcel needs to hold a meeting with stakeholders to explain and discuss the preliminary inputs, assumptions, and results of the study, and will encourage stakeholders to file information requests, to which Xcel shall respond.
  • Xcel needs to re-run the ProSym analysis used in the Effective Load Carrying Capacity study in response to stakeholder requests and file the revised results.
  • On or before July 1, 2013, Xcel shall (and stakeholders may) file with the commission a report on progress on the Large Customer Photovoltaic Rate proposal, and agreement or disagreement over results of the Effective Load Carrying Capacity Study.
  • On or before Oct. 1, 2013, Xcel needs to file a large customer photovoltaic rate proposal that appropriately reflects the value of solar resources on Xcel’s system. As part of the company’s proposal, Xcel will also re-evaluate an interim Standby Service tariff capacity credit.
  • Xcel will work with stakeholders to explore and develop the solar rate proposal. The proposal should address concerns raised by interested parties and stakeholders, including responses to the company’s Solar Load Profile Study.
About Barry Cassell 20414 Articles
Barry Cassell is Chief Analyst for GenerationHub covering coal and emission controls issues, projects and policy. He has covered the coal and power generation industry for more than 24 years, beginning in November 2011 at GenerationHub and prior to that as editor of SNL Energy’s Coal Report. He was formerly with Coal Outlook for 15 years as the publication’s editor and contributing writer, and prior to that he was editor of Coal & Synfuels Technology and associate editor of The Energy Report. He has a bachelor’s degree from Central Michigan University.